RVS 09.02.31

1. ------IND- 2008 0360 A-- EN- ------ 20080905 --- --- PROJET Tunnel Tunnelausrüstung Belüftung

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GRUNDLAGEN

RVS 09.02.31

Tunnels Tunnel equipment Ventilation Basic principles

TABLE OF CONTENTS 0 Preliminary remarks................................................................................................................. 1 Area of application................................................................................................................... 2 Basic principles of planning................................................................................................... 3 Determining the air requirement............................................................................................. 3.1 Traffic data................................................................................................................................. 3.1.1 Traffic flow.................................................................................................................................. 3.1.2 Traffic composition..................................................................................................................... 3.1.3 Condition of the traffic................................................................................................................ 3.2 Design limit values..................................................................................................................... 3.2.1 CO concentration....................................................................................................................... 3.2.2 NOx [oxides of nitrogen] concentration...................................................................................... 3.2.3 Turbidity...................................................................................................................................... 3.2.4 Maximum longitudinal speed...................................................................................................... 4 Choice of system...................................................................................................................... 4.1 Decision-making criteria............................................................................................................. 4.1.1 Criterion of traffic type/structural conditions............................................................................... 4.1.2 Criterion of the situation in the surroundings............................................................................. 4.1.3 Reviewing the choice of ventilation system............................................................................... 4.2 Ventilation systems.................................................................................................................... 4.2.1 Longitudinal ventilation............................................................................................................... 4.2.2 Semi-transversal ventilation....................................................................................................... 4.2.3 Transverse ventilation................................................................................................................ 5 5.1 5.2 5.2.1 5.2.2 5.3 5.3.1 5.3.2 5.3.3 5.3.4 5.3.5 5.3.6 5.3.7 5.4 5.5

Technical specifications.......................................................................................................... General....................................................................................................................................... Fans and ventilators................................................................................................................... Jet fans....................................................................................................................................... Air intake ventilators and exhaust fans...................................................................................... Manoeuvrable smoke dampers.................................................................................................. Operating condition.................................................................................................................... Case of fire................................................................................................................................. Design parameters..................................................................................................................... Specifications............................................................................................................................. Operation.................................................................................................................................... Testing smoke dampers............................................................................................................. Checks, servicing and tests following commissioning............................................................... Auxiliary equipment.................................................................................................................... Air ducts and structure...............................................................................................................

“Tunnel construction” working group

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AUSTRIAN RESEARCH

“Works and safety equipment” working committee ASSOCIATION FOR Issued 1 August 2008 ROADS, RAIL AND TRANSPORT We are finding new ways This RVS was subject to a notification procedure. Further details can be found on the FSV's homepage (www.fsv.at). This document is protected by copyright. All rights, in particular, in respect of translation, reproduction, the extraction of figures, radio transmission, reproduction by photomechanical or similar means, and storage on data processing equipment, including extracts thereof, are reserved exclusively for the FSV. Where the electronic form is acquired, storage on data carriers within the meaning of the licence agreement is permitted.

Tunnels

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BASIC PRINCIPLES

RVS 09.02.31

6 Aerodynamic dimensioning........................................................................................... 6.1 General............................................................................................................................. 6.2 Longitudinal ventilation...................................................................................................... 6.3 Semi-transversal and transverse ventilation...................................................................... 7 Controlling and operating the ventilation system........................................................ 7.1 Requirements relating to control........................................................................................ 7.1.1 Measured values and data................................................................................................ 7.1.2 Limit values for barricading the tunnel............................................................................... 7.1.3 Theoretical values for standard operation......................................................................... 7.1.4 Limit values for servicing operation................................................................................... 7.2 Control procedures depending on traffic numbers............................................................. 7.2.1 Input values....................................................................................................................... 7.2.2 Determining the differential air requirement (qdiff)............................................................... 7.2.3 Variance analysis of the quantities of air required............................................................. 7.3 Control procedures according to the measured air quality values..................................... 7.3.1 Description of the control procedure.................................................................................. 7.3.2 Control parameters........................................................................................................... 7.4 Special operation-related requirements............................................................................. 7.4.1 Automatic operation........................................................................................................... 7.4.1.1 Automatic control during standard operation..................................................................... 7.4.1.2 Semi-automatic operation.................................................................................................. 7.4.1.3 Automatic control during emergency operation.................................................................. 7.4.2 Manual operation............................................................................................................... 7.4.3 Servicing operation............................................................................................................ 7.4.4 Inspection operation.......................................................................................................... 7.5 Special system-related requirements................................................................................ 7.5.1 Longitudinal ventilation with unidirectional traffic............................................................... 7.5.2 Longitudinal ventilation with bi-directional traffic................................................................ 7.5.3 Semi-transversal ventilation.............................................................................................. 7.5.4 Transverse ventilation....................................................................................................... 7.5.5 Combined ventilation systems........................................................................................... 7.6 Cross cuts and exits.......................................................................................................... 7.7 Portal designs.................................................................................................................... 8 Smoke and fire behaviour tests..................................................................................... 8.1 General............................................................................................................................. 8.2 Fire behaviour tests........................................................................................................... 8.3 Parameter studies using 3D computer programmes.......................................................... 9 Simplified risk assessment procedure.......................................................................... 9.1 Frequency equivalent........................................................................................................ 9.2 Equivalent extent of damage S.......................................................................................... 9.2.1 Equivalent extent of damage for unidirectional tunnels...................................................... 9.2.2 Equivalent extent of damage for bi-directional tunnels...................................................... 9.2.3 Coefficients of correction for other influencing factors....................................................... 9.3 Risk equivalent value R and hazard classes..................................................................... 9.4 Area of application for the simplified method and notes relating to more in-depth risk analyses............................................................................................................................ 9.5 Model principles................................................................................................................ 10 Cited Acts, guidelines and standards............................................................................ 11 Annex............................................................................................................................... 11.1 Application example for unidirectional tunnels................................................................... 11.2 Application example for bi-directional tunnels....................................................................

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Preliminary remarks RVS 01.01.11 applies with regard to the provisions for the EEA [European Economic Area]

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and Turkey.

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1

RVS 09.02.31

Area of application These Guidelines and Regulations for Highway Construction [German designation: RVS] shall be applied as a basis for the replanning and operation of ventilation systems in road tunnels and housings. They apply, mutatis mutandis, to reconstructions, taking national laws and acts into account.

2

Basic principles of planning In principle, a check shall be carried out in relation to every tunnel and housing as to whether mechanical ventilation is required. Tunnels, which are temporarily used by bidirectional traffic, for instance as a result of blocking the second tube, are regarded as unidirectional tunnels. The following principles must be observed in relation to the ventilation system: • In the operating condition - tunnel users and operational staff should not suffer any injuries, taking into account the length of stay which is required in all traffic situations which arise during operation, and - the field of vision which is required when stopping must be maintained. • In case of fire - escape routes must be kept free of smoke when escaping, - the emergency services must be able to benefit from favourable conditions for a sufficient period of time, - a reduction in the extent of the damage (incurred by individuals, vehicles and the tunnel structure) must be achieved. If mechanical ventilation is needed based on the data contained in Table 1, the size of this ventilation must also take the fire scenario into consideration.

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Determining the air requirement

3.1

Traffic data

3.1.1

Traffic flow The definitive hourly traffic flow as the Q30 value which forms the basis when calculating the air requirement, i.e. that value which is achieved or exceeded for 30 hours per annum, as well as the composition of the traffic, shall be taken from a traffic forecast study for the section of road in question in which the tunnel is located. The correlation between the hourly traffic flow and the annual average daily traffic flow shall be taken from RVS 03.01.11. The forecast is designed to estimate the anticipated traffic conditions for the year when the tunnel is commissioned, and for a period of ten years thereafter. In addition to this, by way of comparison, the maximum traffic flow shall also be examined since the more flexible ventilation system shall be preferred in the borderline case with regard to the service life of the structural works. The traffic flow calculated in accordance with RVS 03.01.11 shall be established as the maximum traffic flow for the tunnel. In every case, it shall be reviewed whether a deduction must be made from this figure in connection with the road network.

3.1.2

Traffic composition Emission calculations shall be broken down according to • the proportion of passenger cars, and • the proportion of lorries (HGVs) (see RVS 09.02.32) and the emissions relative to these proportions determined separately.

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RVS 09.02.31

In principle, the proportion of HGVs shall be forecast which should also include HGVs of average weight. In the case of tunnels with low traffic levels (annual average daily traffic flow ≤ 5 000 vehicles/day) and gradients of less than 2%, an HGV proportion of 10% may be assumed unless the proportion given in the most recent traffic census is above this figure. Otherwise, detailed freight traffic analyses shall be taken as a basis. 3.1.3

Condition of the traffic As a rule, only the condition of “moving traffic” (≥ 30 km/h) shall be taken as a basis. Stop–and-go traffic (< 30 km/h) shall be taken into consideration if, at the very least, a mean congestion frequency (see point 4.1.1) must be envisaged. Preferably, however, this traffic condition shall be minimised or limited to certain sections by corresponding traffic control measures. These sections shall be laid down on the basis of the transport engineering project. The mean vehicle speed on inclines is specified by the maximum speed per lane which can be achieved by lorries (see RVS 09.02.32).

3.2

Design limit values The quantity of fresh air which is required shall be determined for the traffic condition as per point 3.1.3, as well as in relation to the predicted traffic data, in which connection the limit values given below shall be taken as a basis.

3.2.1

CO concentration 100 ppm shall be accepted as the design limit value for CO concentration.

3.2.2

NOx [oxides of nitrogen] concentration If NOx-controlled tunnel ventilation is required, the design limit value for NO x, depending on the total amount of immissions introduced in the portal area, shall be stipulated pursuant to RVS 09.02.33.

3.2.3

Turbidity The extinction coefficient of 7 ⋅ 10-3 ⋅ m-1 shall be assumed as the design limit for turbidity.

3.2.4

Maximum longitudinal speed The longitudinal speed occurring in the tunnel, supported by meteorological influences and the thrust of the vehicle, may not exceed a value of 10 m/s.

4

Choice of system The key factors when deciding on the ventilation system are cost effectiveness and the safety analysis during operation and in the event of fire. As regards economic considerations, 20 years is anticipated as the service life of electrical machine parts and fittings. As regards the structural works in a tunnel, service life shall generally be set at 80 years.

4.1

Decision-making criteria The following criteria shall be taken into consideration as regards the operating condition: • the type of traffic (unidirectional traffic, bi-directional traffic, periodic bi-directional traffic, maximum traffic flow, stop–and-go traffic and suchlike)

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• structural conditions (length, gradient, cross section, escape routes and suchlike) • the situation in the surroundings (immissions, protective measures and suchlike) 4.1.1

Criterion of traffic type/structural conditions Longitudinal ventilation systems are permitted, depending on the length of the tunnel and the traffic load as per Table 1. With longer tunnels, provision shall be made for transverse ventilation systems or combined systems. Table 1: Area of application for ventilation systems

Type of traffic Annual average daily traffic Tunnel length [m] flow/lane [motor vehicles/day]

Unidirectional traffic

Bi-directional traffic

-

≤ 500

Natural ventilation

< 5 000 and low congestion frequency

≤ 700

Natural ventilation

≥ 5 000 to < 10 000 and mean congestion frequency

500 to ≤ 3 000

Longitudinal ventilation

≥ 5 000 and high congestion frequency

500 to ≤ 1500

Longitudinal ventilation

≥ 5 000 and high congestion frequency

1 500 to ≤ 3 000

Longitudinal ventilation and point exhaust suction (max. gap 750 m)

-

> 3 000

Exhaust air suction with suspended ceiling

-

≤ 500

Natural ventilation

< 2 000

≤ 700 m

Natural ventilation

< 5 000 with low congestion frequency

500 to 2 000 m

Longitudinal ventilation

< 5 000 and mean congestion frequency

500 to 1 500

Longitudinal ventilation

≥ 5 000

1 500 to 3 000

Longitudinal ventilation with point exhaust suction (max. gap 750 m)

-

> 3 000

Exhaust air suction with suspended ceiling

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Type of ventilation

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Low congestion frequency: Standard value: ≤ 25 hours/annum Definition: tunnels and adjoining outdoor road sections are sufficiently efficient; no references to specific causes of congestion If no external influences on the flow of traffic in the tunnel are indicated (e.g. points of convergence, slip roads with adjoining intersections), generally speaking, a low congestion frequency of 0.29% of the operating time is assumed. This value takes account of tailbacks forming in the area of the tunnel as a result of breakdowns and accidents. If external influences impact on the traffic flow, resulting in jams in the tunnel, a check shall be carried out as to the extent to which congestion frequency is raised as a result. Mean congestion frequency: Standard value: 25 to 75 hours/annum Definition: occasional congestion as a result of intermittent traffic peaks, tunnels and adjoining road sections are sufficiently efficient in the standard scenario and only occasionally overloaded (e.g. as a result of seasonal traffic peaks on individual days during holiday traffic) High congestion frequency: Standard value: > 75 hours/annum Definition: frequent (e.g. daily) congestion as a result of regularly occurring traffic peaks (for instance, owing to the capacity of the tunnel or the adjoining road sections being exceeded on a regular basis, or owing to tailback effects from the secondary network in the case of departure ramps or before crossroads after the tunnel) The occurrence of a jam with a duration in excess of 20 min/hour is regarded as a congestion hour. 4.1.2

Criterion of the situation in the surroundings If tunnel portals are situated in areas which have more stringent requirements in terms of protection against immissions, mechanical ventilation may also be necessary in the case of tunnel systems for which no ventilation would otherwise be necessary as per point 4.1.1. The decision on the need for ventilation must be clarified in the preliminary draft relating to the tunnel within the framework of the environmental analysis. To this end, the methods as per RVS 09.02.33 shall be applied.

4.1.3

Reviewing the choice of ventilation system The following iterative process shall be implemented when choosing the system: Choice of ventilation system Determining the hazard class based on a risk analysis (see point 9) Stipulating the works and safety equipment High tunnel cross sections generally have a positive impact on safety in the event of fire. Structural measures, including cross girders or similar, considerably impede the expulsion of smoke.

4.2

Ventilation systems

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A distinction must be drawn between the following principal types of ventilation system regarding their mode of action and possible applications. 4.2.1

Longitudinal ventilation In the case of longitudinal ventilation, longitudinal air flow in the tunnel area is generated naturally or by means of fans and ventilators. The following requirements must be observed in this regard: • The maximum longitudinal speed in the clear tunnel cross section as per point 3.2.4 must be observed. • The fans and ventilators shall be constructed in such a way that they are reversible and able to achieve a flow velocity of 2 m/s or an air flow volume of 120 m3/s in case of fire under the marginal conditions specified in point 6.1. The more critical of the two values is decisive with regard to the ventilation construction. • To raise operational safety under the effects of fire and minimise turbulence, the fans and ventilators shall be deployed over the length of the tunnel. The jet fans shall be arranged in various fire alarm sections (numbering at least two). • With point exhaust suction, the capacity of the exhaust fan must be at least 200 m3/s in the event of fire.

4.2.2

Semi-transversal ventilation With semi-transversal ventilation, the air supply is introduced via the tunnel portals while the exhaust air is extracted over the length of the tunnel and flows to the outside via ducts. Exhaust air semi-transversal ventilation, or exhaust air semi-transversal ventilation in combination with longitudinal ventilation or transverse ventilation, is permitted. The following requirements must be observed in this regard: • The maximum longitudinal speed as per point 3.2.4 must be observed. • In the event of fire, at any random point of the exhaust air duct, the ventilation system must extract at least 120 m³/s of the air in the tunnel over a 150 m section (based on 20°C and 1 013 bar). • The exhaust ports shall be opened fully in the area of the scene of the fire. All other exhaust ports must be closed. • Generally speaking, the gap between the exhaust ports may not exceed 110 m. • To optimise the operating costs, a longitudinal air flow shall be generated by jet fans or suitable smoke damper control.

4.2.3

Transverse ventilation With transverse ventilation, supply air is introduced, distributed over the length of the tunnel, and exhaust air extracted. The following requirements must be observed in this regard: • The maximum longitudinal speed as per point 3.2.4 must be observed. • In the event of fire, at any random point of an air duct, the ventilation system must be able to extract at least 120 m³/s of the air in the tunnel over a 150 m section (based on 20 °C and 1 013 bar). • Provision shall be made for adjustable air intake outlets as regards the supply of air from the air intake duct. Provision shall be made for manoeuvrable smoke dampers as regards the extraction of exhaust air from the carriageway. The air intake outlets and smoke dampers must be adjusted in such a way that air is distributed in a uniform manner along the tunnel in relation to the design scenario. • The exhaust air ports above the scene of the fire shall be opened fully, while all other exhaust ports must be closed. • Generally speaking, the gap between the exhaust ports may not exceed 110 m, while the gap between air intake openings may not exceed 55 m.

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5

Technical specifications

5.1

General

RVS 09.02.31

The following technical specifications must be observed by fans and ventilators, their auxiliary equipment and any ventilation ducts: If provision is made for fans and ventilators, their auxiliary equipment and cabling to operate in flue gas situations (fire scenarios), they must continue to operate at a temperature of 400°C over a two-hour period (e.g. using temperature-controlled forced cooling). The failure of a fan or ventilator should not affect the functionality of other fans or ventilators. This provision applies, mutatis mutandis, to all components in the exhaust air duct. As regards jet fans, including cabling in tunnels with longitudinal ventilation and hazard classes I to III, and a minimum distance between the jet fans ≥ 200 m, a temperature stability of 250 °C over a 60-minute period is sufficient. 5.2

Fans and ventilators

5.2.1

Jet fans The housings of jet fans, including their mountings and sound absorbers, shall be constructed from corrosion-resistant material (at least material quality 1.4571 or higher-value steels in the V5A group). The drive motor and terminal boxes shall be realised with at least degree of protection IP 65 in accordance with the Austrian Electrotechnical Association [German designation: ÖVE]. The jet fan shall be mounted in a way which limits vibrations. The fan or ventilator shall be protected against falling by means of an additional safeguard (e.g. a steel cable).

5.2.2

Air intake ventilators and exhaust fans Axial fans are envisaged as ventilators. The air intake ventilators and exhaust fans comprise the fan or ventilator with a wheel, guide wheel and electric motor [fan motor unit], as well as the nozzle, diffuser, shut-off valve and, if applicable, the front and rear reducer [total unit ventilator]. As regards the dimensioning of the ventilation system, the efficiency of the fan motor unit where ηVME = 0.9 and the efficiency of the total unit ventilator where η VGE = 0.7 may be set as the standard values. In accordance with the structural conditions, the ventilators for controlling air quantities shall be fitted with a rotor blade adjustment, a speed control, or a combination of the two. Provision shall be made to monitor the vibrations in the fan motor unit and the temperature of the coil and bearings. The quantity of air which is discharged and the change in pressure in the fans or ventilators must be documented. Proof of the air tightness of both the flaps and the air duct shall be furnished in the form of a measurement. The drive motor shall generally be constructed as a three-phase asynchronous motor with maintenance-free rolling bearings. The insulation class as per ÖVE-M Part 10 must be two classes higher than the maximum thermal load during continuous operation. The fan or ventilator shall be designed in such a way that at all times, safe start-up (even with a 10% undervoltage, fluctuations in the supply voltage) is guaranteed. The maximum permitted starting current shall be set in accordance with the requirements of the respective public utility, but may not exceed six times the rated current. The fans or ventilators are generally installed in portal stations or in caverns. At the same time, every effort shall be made to ensure that maintenance work can always be performed outside the traffic area, including, where possible, replacing the fans or ventilators. If necessary, appropriate access and installation openings shall be incorporated and provision made for a lifting gear.

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Any maintenance and repair work performed on a total unit ventilator should not adversely affect the rest of the ventilation system. 5.3

Manoeuvrable smoke dampers Manoeuvrable smoke dampers assist in the targeted regulation of the exchange of air between the carriageway and the exhaust air ducts. They shall fulfil a variety of purposes in transverse-ventilated tunnels during operation and in the event of fire.

5.3.1

Operating condition The contaminated air shall be extracted into the exhaust air duct in a uniform manner over the length of a ventilation section. This shall be ensured by adjusting the angle of opening of the smoke dampers accordingly. As regards semi-transversal ventilation, in order to minimise operating costs, longitudinal air flow can be bolstered by jet fans (see point 4.2.2).

5.3.2

Case of fire In the event of an accident involving smoke formation, the smoke in the immediate vicinity of the source is to be extracted. In this regard, depending on the ventilation design in the ventilation section in question, one or more smoke dampers (see points 4.2.2 or 4.2.3) are open, with the remainder closed. The effects of this are as follows: • the concentrated extraction of smoke with the highest possible level of efficiency • preservation of the natural stratification of smoke with a smoke-free zone in the lower area • concentration of the smoke in that area where the fire originates, inter alia, by also generating excess pressure in areas still not affected by the fire

5.3.3

Design parameters

5.3.3.1 Volume of exhaust air The smoke dampers shall be dimensioned in such a way that a minimum quantity of exhaust air of 120 m³/s flows through the dampers which are opened in the event of fire (measured in the exhaust air duct based on 20 °C and 1 013 bar). 5.3.3.2 The velocity of air through the smoke dampers The mean longitudinal speed through the open smoke damper may not exceed 25 m/s. Speeds above this result in significant pressure losses. Moreover, the danger exists that air is extracted from the lower zones, which may still be free from smoke, on account of the large vertical impulse, thereby reducing the efficiency of flue gas extraction. 5.3.3.3 The shape and position of smoke dampers The dampers shall be as wide as possible. The desired width shall be 3.0 m. When fully open, the sum of the area of the clear damper openings through which air flows must at least equal the area of the exhaust air duct over a length of 150 m. The following possibilities exist as regards installation: • Installation in the suspended ceiling: if a suspended ceiling forms the floor of the exhaust air duct, the smoke dampers are installed directly in the latter. If possible, the smoke dampers shall be rectangular in shape. As far as possible, these dampers shall be positioned concentrically in the tunnel cross section, in which connection the aim is to achieve a hydraulically optimum design for the smoke damper. • Lateral ducts: if provison is made for lateral ducts for dissipating exhaust air in cut-andcover tunnels, the smoke dampers must be situated such that they are as close as possible to the tunnel crown. The vertical dimensions may not be too large such that they prevent the absorption of fresh air from the area beneath the smoke layer. With large tunnel cross sections, care must be taken that smoke is extracted from the upper carriageway area in an efficient manner. 5.3.3.4 Distance between the smoke dampers Can be obtained from the Austrian Research Association for Roads, Rail and Transport Issued 1 August 2008 This document is protected by copyright. finding new ways.

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As a rule, the distance between the smoke dampers may not exceed the values indicated in points 4.2.2 or 4.2.3. 5.3.4

Specifications

5.3.4.1 Static pressure The smoke dampers shall be dimensioned such that they satisfy the maximum pressure differentials relative to the installation without suffering losses in terms of air tightness or functionality. 5.3.4.2 The impact of temperature on damper operation In a fire situation, smoke dampers can be exposed to very high temperatures. For this reason, the dampers, operating units and all of the associated equipment, as well as the supply and control lines, must be fully operational for at least two hours at a temperature of 400 °C. Proof of this temperature stability shall be furnished by means of a test conducted by an accredited inspection body and corroborated in the form of a test report. In this regard, during the first 30 minutes, complete opening (90° or 120°) and closing by the corresponding actuation shall be effected every five minutes, and every ten minutes for the remainder of the time thereafter. 5.3.4.3 Leakage quantities Smoke dampers must be as airtight as possible since leakages reduce the effective quantities extracted. The following leakage quantities may not be exceeded: Table 2: Permitted leakage quantities depending on the test pressure Temperature [°C]

Pressure [N/m2]

Volume flow [m3/s/m2]

20

4 000

0.10

20

3 500

0.09

20

3 000

0.08

20

2 500

0.07

20

2 000

0.06

20

1 500

0.055

20

1 000

0.05

Proof of air tightness shall be furnished in the form of a measurement (see point 5.3.6.1). 5.3.4.4 Operating times The time taken to change the operating condition from “closed” to “open” (a maximum of 120°) and vice versa may not exceed 25 s. 5.3.5

Operation

5.3.5.1 Operating principle The following types of smoke dampers are currently used internationally: • Smoke dampers with plates • Sliding smoke dampers Can be obtained from the Austrian Research Association for Roads, Rail and Transport Issued 1 August 2008 This document is protected by copyright. finding new ways.

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In terms of design, compared with smoke dampers with plates, sliding smoke dampers generally exhibit higher pressure losses and lower exhaust air volumes with the same crosssectional area. 5.3.5.2 Requirements in the event of fire The following points must be taken into consideration in relation to the optimum working of smoke dampers in the event of fire: • The equipment as a whole in the exhaust air duct (including control and monitoring) must be resistant to a temperature of 400 °C over an exposure time of 120 minutes (see point 5.3.4.2) or be protected accordingly to ensure that it continues to function. The mechanics of the construction must be preserved for a 60-minute period up to a temperature of 750°C. • Where fresh air and exhaust air ducts are present, the controls must be installed in the fresh air duct, in which connection effective thermal insulation must be present in the driveshaft in order to prevent the transmission of heat to the electrical actuator. • In the event of fire, air flow shall be generated in the carriageway from both sides of the open damper(s), in which connection the zero point of the air flow must occur in the carriageway in the area of the open damper(s). 5.3.6

Testing smoke dampers

5.3.6.1 Test conducted by the manufacturer and/or the inspection body (acceptance inspection) The procedure for accepting the damper is as follows: • At the time of acceptance, the damper must be constructed such that it is fully functional and appropriate to the system. The envisaged actuator shall be mounted, connected electrically and the end positions adjusted and started up. • During the acceptance inspection, the pressure ratios at the damper must be reproduced in keeping with the system. • Prior to acceptance of the leakage test, the damper shall first be operated with the actuator in the “open” position and then in the “closed" position. In both positions, the actuator shall be deactivated using the end switches. Once the damper is closed, its position may no longer be altered prior to the acceptance inspection (e.g. turning the handwheel). • Subsequent waterproofing measures (e.g. the use of silicone) are not permitted. • The smoke dampers are pressurised to varying degrees (1 000 Pa, 1 500 Pa, 2 000 Pa, 2 500 Pa, 3 000 Pa, 3 500 Pa, 4 000 Pa). Every pressure stage is maintained for five minutes and the final one for 30 minutes. At the end of the test, the pressure difference is returned to the value 0 and the smoke dampers fully opened and closed at least ten times. Following each pressure stage, the amount of deformation at characteristic points of the damper is measured. In this regard, any deformation which adversely affects air tightness should not be present. • Operating conditions under pressure: the damper is tested under pressure. At maximum pressure (4 000 Pa), five opening and closing cycles are effected using the mounted electrical driving mechanism. All the tests mentioned are performed using a prototype and, with a lot in excess of ten units, one smoke damper freely selected by the Client from those manufactured is subjected to mechanical tests and leakage tests under low temperatures and pressure. 5.3.6.2 On-site tests The following functional tests shall be performed on site prior to commissioning: • Every smoke damper shall be opened and closed using the local and/or remote operating systems installed and, in this way, tested in terms of their functionality. Can be obtained from the Austrian Research Association for Roads, Rail and Transport Issued 1 August 2008 This document is protected by copyright. finding new ways.

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• Suction tests shall be performed using routine fans and ventilators and by measuring the

volume flow under different configurations. The minimum required exhaust air volume flow must particularly be observed at the smoke damper which is furthest away from the exhaust fan. • An examination shall be carried out with regard to the functionality of the sealing elements in the exhaust air duct and at the dampers. • The smoke dampers must be tested as a system in connection with the fire programmes. 5.3.7

Checks, servicing and tests following commissioning Preventative servicing and tests constitute the basis for the smooth functioning of all the components in an emergency system. Preventative servicing procedures must be specified and their implementation supervised. The inspections, servicing and tests carried out shall be recorded and these records archived.

5.3.7.1 Visual inspection of the smoke dampers Smoke dampers shall be serviced and inspected in accordance with the recommendations from the manufacturer. At least on an annual basis, provision shall be made for a visual inspection of the exhaust air duct along the following lines: 1. Checking the surfaces of the dampers (exhaust air-side and traffic-side) for corrosion. Obvious browning discolouration must be removed promptly so as to prevent progressive corrosion damage. 2. Checking for sedimentation and foreign bodies on the damper plates and gaskets. 3. Checking the fastening elements of the dampers and their fittings. 4. Checking the seals of the dampers in relation to the concrete. 5. Checking the plates and driveshaft for possible deformation (plastic deformation). 6. Checking the open and closed positions, along with the operating position, in which connection it must be ensured that the plates run synchronously. 5.3.7.2 Functional testing of the ventilation system 1. Monthly functional testing: all fans and ventilators and smoke dampers shall be inspected monthly as regards their functionality under all volume flows and damper positions involving automated control in terms of their planned design. The dampers are to be moved through their individual operating positions (open, normal operation and closed) and the operating positions checked based on the feedback received in the control room. 2. Annual functional testing: This shall be carried out together with the annual visual inspection with the aim of inspecting and, if necessary, readjusting the correct position and functioning of every damper on site and reporting this back to the central control system. 3. Every six years, suction tests involving volume flow measurements shall be performed in order to examine the minimum exhaust air volume flow required at every smoke damper. 5.4

Auxiliary equipment In order to prevent uncontrolled flows into the exhaust air and air intake ducts when the fans and ventilators are deactivated, dampers are required in front of and also behind the fans and ventilators. It shall be examined with regard to the incidence of cold air and ice formation whether an additional damper is required close to the fresh air inlet which is closed when the fan or ventilator has stopped. In addition to the requirements as per point 5.1, attention must be paid to the fact that the auxiliary equipment is resistant to corrosion.

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RVS 09.02.31

Examples of other auxiliary equipment include: • • • •

Fire and flue gas dampers Sound absorbers Deflection vanes Access covers for the installation openings

Regarding the impact of noise from ventilation systems on the area surrounding the tunnel, an examination shall be conducted in connection with the relevant guidelines and provisions. 5.5

Air ducts and structure The following technical requirements pertaining to air ducts and the structure must be observed: • The air ducts and all appurtenant fixtures must be designed in an aerodynamically favourable manner. • Adequate air tightness of the air ducts must be ensured for efficient flue gas extraction and proof of this furnished by means of an air tightness test. • During the acceptance inspection, the quantity leaking from the exhaust air duct as a whole (excluding leakages from the smoke dampers) may not exceed 5 m³/s/km. • Provision shall be made for a corresponding snow precipitation area in the case of the fresh air inlet. • As regards the design of portals, cross cuts, ventilation structures and appurtenant plant and equipment, measures must be taken to avoid air short circuits. • The penetration of atmospheric pollutants and dirt from the traffic area into the cavern station shall be prevented (e.g. by means of excess pressure). • The number of natural vibrations in the supporting structure and the vibrations in the fan motor unit shall be analysed and attention paid to the fact that adequate frequency spacing is maintained.

6

Aerodynamic dimensioning

6.1

General Aerodynamic calculations shall be performed, taking the quantity of air required as a basis. The aerodynamic parameters determined in this regard assist in the dimensioning of the ventilation system and the optimum coordination of structural conditions and the ventilation design. The basic principles governing aerodynamic dimensioning are as follows: • Meteorological influences, such as barometric pressure differentials and the effects of the wind Where possible, several years of measurement results relating to pressure differentials and wind speeds at the site of the planned portals and lift shafts shall be consulted. As regards hazard classes I to III, those barometric pressures and wind speeds which correspond to the 95th percentile and, as regards hazard class IV, those which correspond to the 98th percentile, of the half-hour averages, shall be taken as a basis. The wind speed shall be converted to a height of 4 m above the ground using the function  4 u = u mess ⋅   zmess

P

  [ m / s ] 

The wind direction shall be limited to the components which are relevant to the portal. Portal designs which raise dynamic pressure (e.g. as a result of noise barriers) shall be considered accordingly. where: u is the speed 4 m above the ground [m/s] Can be obtained from the Austrian Research Association for Roads, Rail and Transport Issued 1 August 2008 This document is protected by copyright. finding new ways.

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umess zmess p

RVS 09.02.31

is the speed at the measured height [m/s] is the measured height (generally 10 m above the ground) [m] is the exponent pursuant to ÖNORM [Austrian Standard] M 9440 regarding neutral propagation conditions (0.25) [-]

If such measurement results are not available, the decisive meteorological influence shall be determined by a meteorological report. • Thermal influences as a result of differences in temperature Differences in temperature between the portals and shafts, converted to the same height, and the air in the tunnel shall be included. Aerodynamic calculations must also take the fire scenario into account. For all tunnels with a longitudinal gradient < 3%, two lanes and a standard tunnel cross section, a fire involving one HGV and two passenger cars is stipulated as a design fire for ventilation purposes, resulting in a flue gas quantity of 120 m3/s. In the case of structural conditions which deviate from this, separate investigations shall be carried out as regards calculation formulations. In the standard scenario as well as in the event of fire, the effect of the pressure of the air in the tunnel as a result of warming up shall be taken into consideration in the calculation based on the following formulations: Δρnat = (ρa ± ρi) ·g · LTunnel · s/100 [Pa] ΔρBrand = (ρi – ρBrand) ·g · LBrand · sBrand · ηBrand /100 [Pa]

ρ=

p [kg/m 3 ) RLT

where: Δpnat is the pressure effect as a result of natural buoyancy [Pa] ΔpBrand is the pressure effect as a result of the heated air (fire) [Pa] ρ is the density dependent on the temperature and external pressure [kg/m3] LBrand is the length of the fire compartment [m] s is the longitudinal gradient [%] sBrand is the longitudinal gradient in the fire compartment (LBrand) [%] ηBrand is the extent of the effect of the fire (ratio of actual to theoretical heat released) Index a is outside the tunnel Index i is inside the tunnel with no fire present ΔTnat is Ta - Ti [K] ΔTBrand is Ti - TBrand [K] In the case of tunnels with a mixture of passenger cars and HGVs, the design fire shall be set at 30 MW. Where the traffic consists solely of passenger cars, this figure shall be 5 MW. As regards tunnels with a higher proportion of HGVs (> 15%), the impact on tunnel safety shall be presented on the basis of a tunnel risk analysis or a risk assessment and an increase in the fire load reviewed as a measure. The following characteristic values apply to design fires: 5 MW ΔTBrand without extraction 25 K ΔTBrand with smoke extraction 20 K ΔTnat 10 K LBrand 400 m ηBrand 0.85

Design fire 30 MW 65 K 40 K 10 K 800 m 0.75

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The above values represent mean empirical values. Deviations must be considered with special structural conditions. 6.2

Longitudinal ventilation In the case of mechanical longitudinal ventilation, the thrust needed to achieve the requirements determined by the system (see points 4.2.1 and 7.5) shall be determined, taking into account • meteorological influences • the quantity of air which needs to be supplied • building-related structural conditions and fixtures which are relevant in terms of ventilation • traffic data • the pumping action of the vehicles, and • economic aspects (e.g. electrical energy requirement). Jet fans shall be arranged in such a way that optimum realisation of the thrust in the tunnel cross section is possible (no influence from structural works, road signs and the like). With large tunnel cross sections (clear width upwards of 12.00 m), the aim shall be to position the fans at uniform intervals across the width of the tunnel. Appreciable changes in the cross section as a result of road signs, traffic control systems and the like must be taken into consideration when designing the capacity of the fans. In addition to the stipulations in the preceding section, the aerodynamic calculations relating to longitudinal ventilation comprise a calculation of the flow losses in the tunnel, taking account of the characteristic features and fittings (road signs, alcoves, portal design, surface unevenness, etc.). Furthermore, consideration must be given to the fact that jet fans located in the flue gas exhibit a low thrust on account of the increase in temperature. The jet fans shall be arranged such that they do not exert a mutual influence on one another. If this cannot be avoided given the requirements of the installation, the anticipated loss of thrust must be taken into account. Fans and ventilators in the area of the fire may not be operated (destruction of the flue gas stratification, etc.). The design shall give consideration to this (i.e. at least one fan/ventilator or a row thereof). The fire area shall be laid down specific to the installation.

6.3

Semi-transversal and transverse ventilation As regards semi-transversal or transverse ventilation, the flow conditions and pressure losses in the area of the ventilation structures, the air intake and exhaust air ducts and in the tunnel area must be taken into consideration. As a result of the aerodynamic calculations, the design-related data concerning the size of the fans and ventilators and the data concerning the adjustment of the air intake outlets and the smoke dampers is laid down. Therefore, as regards these ventilation systems, the aerodynamic dimensioning shall be augmented as follows: • determining the pressure losses in the area of the ventilation buildings, the air intake and exhaust air ducts and shafts, as well as the air inlet distribution ducts and the exhaust air collection flues • determining the pressure losses in the traffic area • determining the pressure losses at the air intake outlets and exhaust air devices • new installations must be designed and dimensioned in such a way that the maximum pressure differential between the exhaust air duct and the carriageway does not exceed 3 000 Pa • as a rule, the length of the ventilations sections (exhaust air) should not exceed 2 500 m • since, over the course of operation, leakage quantities increase compared with the

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condition which prevailed at the time of initial testing, as regards the safe operation of the flue gas extraction device in the event of fire, the permitted leakage quantity (see Table 2 and point 5.5) shall be increased by 100% with regard to ventilator design

7.

Controlling and operating the ventilation system

7.1

Requirements relating to control The ventilation system shall be controlled on the basis of economic criteria, taking account of safety during operation and in the event of fire. Generally, fans and ventilators operate automatically, although manual intervention must be possible in every operating condition. Adaptation by the operator of the parameters and the programme procedures in line with operating conditions must be possible at all times. Deviations from the stipulations in this chapter are only permitted in instances requiring special justification.

7.1.1

Measured values and data In addition to the measurable variables relating to CO, turbidity, longitudinal speed and traffic indicated in RVS 09.02.22, the following data must be recorded and taken into consideration when designing the control: • the volume flow and pressure increase at the ventilator in the case of semi-transversal and transverse ventilation • regarding traffic data, the following data is recorded in relation to optimisation of the ventilation depending on the structural conditions for every ventilation section, lane and direction: the number of vehicles in the tunnel (separated according to HGVs and passenger cars, vehicle speed, congestion) • data specific to the total unit ventilator (temperature, vibration, etc.) • maximum monitoring (electrical power)

7.1.2

Limit values for barricading the tunnel The tunnel shall be barricaded automatically if one of the following conditions applies: ● CO levels ≥ 100 ppm for a period exceeding ten minutes ● CO levels ≥ 150 ppm ● an extinction coefficient ≥ 12 ⋅ 10-3 ⋅ m-1 for a period exceeding one minute The tunnel blockade shall be automatically lifted again if ● CO levels of 90 ppm, or ● an extinction coefficient of 7 ⋅ 10-3 ⋅ m-1 are fallen short of for a period exceeding one minute and this trend is downwards.

7.1.3

Theoretical values for standard operation a theoretical CO value of 30 ppm a theoretical value for turbidity of 4 ⋅ 10-3 ⋅ m-1 These values shall be adapted in line with an economic modus operandi during operation.

7.1.4

Limit values for servicing operation As regards servicing operations which continue over a longer period, the following limit values must be observed in the ventilation section in question: CO Turbidity

20 ppm 3 ⋅ 10-3 ⋅ m-1

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7.2

Control procedures depending on traffic numbers

7.2.1

Input values

RVS 09.02.31

The following input values shall be stipulated in relation to the use of ventilation, irrespective of the parameters determined: • Traffic composition The traffic shall be broken down as follows: - passenger cars - HGVs • Predicted emission value - CO On the basis of the emission tables as per RVS 09.02.32, the current traffic flow and the composition of the traffic, the anticipated CO value can be calculated. Depending on the CO emissions from vehicles, the predicted emission value shall be used as a parameter for the air requirement which is determined mathematically (CO air requirement qco). • Predicted emission value - turbidity On the basis of the emission tables as per RVS 09.02.32, the current traffic flow and the composition of the traffic, the anticipated turbidity value can be calculated. Depending on the turbidity emissions from vehicles and the dust which is whirled up, the predicted emission value shall be used as a parameter for the air requirement which is determined mathematically (air requirement relating to turbidity (qTr)). • The maximum permitted deviation from the predicted emission values (range of tolerance) • The theoretical concentration values which are required for calculating the air requirement shall be stipulated for the time being as 30 ppm for CO and 4 ⋅ 10–3 ⋅ m–1 in relation to turbidity, and then adjusted over time in the course of operating experience. • As regards both CO and turbidity, a traffic-dependent (temporary) range of tolerance shall be laid down within which no direct change is made to the method of regulation. However, the maximum range of tolerance may not exceed the design limit values. • Critical time constant tkrit for regulation In the case of the system, a period shall be laid down for which the predicted emission value may be exceeded or fallen short of without altering the method of regulation. In the case of longitudinal ventilation with simple structural conditions (e.g. unidirectional traffic, short tunnel), stipulation of the maximum tolerance ranges for maximum permissible operating values suffices. If no traffic data is available for regulation purposes (e.g. when traffic is at a standstill), a switch to control procedures according to the measured air quality values (see point 7.3) must be effected automatically. In this instance, any reduction in the quantity of supply air qsoll available at the time of the malfunction may only take place following a 20-minute delay. 7.2.2

Determining the differential air requirement (qdiff) Determination of the differential air requirement is required for automatic ventilation control. This shall be done separately for every ventilation section. To this end, the following criteria are decisive: • Air requirement in relation to CO (qco) (air requirement which is determined mathematically, depending on CO emissions from vehicles) The air requirement for each lane and direction of travel shall be calculated in relation to CO from the predicted emission values which have been determined. The air requirement qco results from the sum of the air requirement for all lanes. • Air requirement in relation to turbidity (qTr) (air requirement which is determined mathematically, depending on particle emissions from vehicles) The air requirement qTr shall be determined in the same way as the air requirement qco.

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• Air requirement (qsoll) (decisive air requirement) The higher of the two calculated values qco or qTr is the value qsoll and is authoritative in terms of the total air requirement. • Total air requirement (qges) (necessary air requirement) The total air requirement is the air requirement qsoll, adjusted to the forecast value which is derived from the variance analysis as per point 7.2.3 using the coefficient of correction Kf. • Quantity of supply air (qvorh) (actual quantity of supply air present in the tunnel area) The value qvorh shall be measured directly at the fan motor unit with semi-transversal and transverse ventilation. As regards longitudinal ventilation, the approximate determination of qvorh is possible using the mean longitudinal speed and the cross-sectional area. The differential air requirement qdiff is the difference between the total air requirement q ges and the quantity of supply air qvorh which is already present as a result of natural or mechanical ventilation. The definitive value is determined from calculations performed every minute over six-minute intervals, taking into account the conditions below: - With a rising qdiff, the newly calculated value applies (final minute value) - Where the qdiff figure remains constant or is falling, the calculated six-minute value applies If the adjusted total air requirement q ges exceeds the maximum range of tolerance laid down pursuant to point 7.2.1 for longer than tkrit, qvorh shall be adjusted in line with qsoll. If the measured emission values exceed the maximum stipulated ranges of tolerance on a permanent basis (e.g. when the control mechanism is faulty), control shall be effected using manually specified air quantities. This condition shall be notified by means of an announcement. 7.2.3

Variance analysis of the quantities of air required The variance analysis of the quantities of air required is necessary for adjusting the control cams. For the purposes of this comparison, the CO concentration and the turbidity concentration in the ventilation section shall each be measured twice. The higher of each of the CO and turbidity values shall be used for calculating the air requirement. The higher of these two air requirement values shall be compared with the authoritative total air requirement q soll. This comparison shall take place under the following conditions: • The values shall only be compared if the ventilation system is operational for a period of at least six minutes. Over a period of at least 24 hours, the measured and calculated CO and turbidity values and quantities of air shall be assimilated with regard to the comparable periods (considering system inactivity) and calculated from the difference between the corresponding coefficient of correction and the forecast value. Physically, this coefficient of correction represents an adaptation of the emission tables as per RVS 09.02.32 in line with the actual emission behaviour exhibited by the traffic under the given tunnel conditions (e.g. as a result of gradients, contamination, traffic composition). 24 h

∫Q

MESS

Kf =

dt

0

24 h

∫Q

PROGNOSE

dt

0

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Q

PROGNOSE

RVS 09.02.31

= Max │q ,q │ co

Tr

QMESS

is the volume flow measured in the ventilation section [m3/s]

Kf

is the coefficient of correction [-]

qco,qTr

pursuant to RVS 09.02.32 points 4.1 and 4.2 in [m³/s] per ventilation section, although control values for CO and turbidity as per point 7.3.2

• Adaptation may automatically extend to ± 10% from the respective forecast value. Should more extensive adaptation requirements (in excess of ± 10%) emerge over a longer period, this must be reported accordingly. On this basis, the emission tables as per RVS 09.02.32 and, where applicable, the traffic composition, shall be examined. 7.3

Control procedures according to the measured air quality values The aim of operational ventilation control is the observance of air quality values which facilitate safe passage through a tunnel. Since these air quality values (CO content and visual turbidity as standard) are measured continually, these measured values and parameters shall also be used for managing ventilation control. The measured values pertaining to air quality inherently include all traffic-related and environmental influences, such as traffic frequency, the varying emission levels of all vehicles, the variations in loads as a result of gradients or inclines, tunnel contamination, and also meteorological influences. They are the result of all the influences as a whole. In the case of large tunnels, especially those with bi-directional traffic and, consequently, those which mostly have consistently controllable ventilation and aeration, this procedure is particularly recommended because it takes account of the continually changing load and environmental influences. What is important as far as economic operation is concerned, is the optimum adjustment of the control elements, on the one hand, and the professional servicing of the air quality measuring instrument on the other.

7.3.1

Description of the control procedure: Irrespective of the amount of traffic, observance of the theoretical values for CO and turbidity must be guaranteed. This shall be achieved by using corresponding control elements (e.g. a proportional-integral-differential regulator [PID]). For every air quality parameter and every ventilation section, provision shall be made for a separate regulator. The control parameters (e.g. time constant) shall be adjusted in view of the ventilation section’s inactivity. A theoretical value relating to air quality is set on the respective regulator. The regulator receives measured values relating to air quality from the ventilation section on a continual basis. These values are actual values (the maximum figures of all the measured values taken from a ventilation section/CO or turbidity). The regulator compares the actual value with the theoretical value. The difference is the control deviation. If this deviation is positive, i.e. the actual value exceeds the corresponding theoretical value, an optional two-minute delay in terms of activation may begin. Once the delay in terms of activating the ventilation has lapsed, the section is ventilated at 20% of the discharge. Irrespective of the development in the control deviation, the regulator alters the discharge from the ventilator unit. As long as the deviation is positive, the regulator increases the discharge. If the deviation is regressive, falling to zero, the adjusted discharge remains the same (balance between contaminant entry and discharge). If the control deviation is negative, the regulator again scales back the level of discharge to a level below the minimum discharge quantity which deactivates the ventilator. Positive control deviation therefore brings about an increase, negative deviation a decrease, in the discharge quantity. The absolute amount of control deviation determines the running speed of the regulator. The regulator’s differential term takes account of an abrupt change in the control deviation.

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7.3.2

RVS 09.02.31

Control parameters The following parameters shall be adjusted for operation: Activation delay: two minutes Switching off point, minimum discharge quantity, axial ventilators: e.g. 20% Proportional share: control amplification Integral share: time constant Differential share: differential time constant (factor) It must be possible for authorised personnel to adjust these parameters at the control system of the central monitoring station and for these parameters to then be transferred to the respective regulators on site.

7.4

Special operation-related requirements Every operating mode must be clearly indicated at all monitoring devices. Likewise, the respective command must be clearly indicated at every control level.

7.4.1

Automatic operation

7.4.1.1 Automatic control during standard operation In principle, automatic operation of the ventilation system, taking into account the parameters and control conditions cited under point 7.1, in which connection the ventilator is operated in accordance with economic principles at constant levels of comfort, constitutes standard operation. All the interlocks, installation and machine protection devices are active. 7.4.1.2 Semi-automatic operation Essentially, all the conditions as under point 7.4.1 apply, although the possibility exists of specifying a certain theoretical value for individual ventilation sections without interrupting automatic operation in the other sections. 7.4.1.3 Automatic control during emergency operation In the event of fire, on the basis of the parameters and measured values from the tunnel section in question which are available, the control system must be able to conduct all the flue gases away the tunnel tube in the most concentrated manner possible. In this regard, attention must be paid to the fact that the flue gases remain stratified for as long as possible and are not intermingled by fans or ventilators. In the control state which applies in the event of fire, all the machine protection devices, with the exception of vibration monitoring and flow measurement devices (if present), become inoperative. This also applies to any maximum energy level observations. In addition, when a fire breaks out, the control system must allow manual correction control interventions (e.g. opening another smoke damper) without deactivating the automated control system. In case of fire, the control system must also ensure that the escape galleries are kept free from smoke, in which connection interruptions to flow must be controllable at all times by means of open cross-cut doors, for instance. Ventilation in case of fire takes priority over all other ventilation operating modes, with the exception of inspection operation. 7.4.2

Manual operation In the “manual” operating mode, the most recent automatic operation control settings are frozen until altered by manually inputting ventilation condition values. To protect the machines and installation, however, all the locking conditions remain active. Manual operation is automatically terminated by a fire alarm, however. As regards the various manual control levels, the hierarchy and locking conditions below apply, beginning with the topmost hierarchy:

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• on site • operating station • superordinate central offices and others 7.4.3

Servicing operation During servicing operation, all the measurement and control parameters from the tunnel tube or ventilation section in question are set to constant values which enable corresponding servicing and inspection work (e.g. fire alarm system) to be performed in the tunnel with good air quality. The limit values which apply in this regard shall be harmonised with provisions concerned with the protection of workers

7.4.4

Inspection operation This operating mode renders inoperative all the automatic supervision and control conditions in relation to all relevant parts of the ventilation system and is only permitted when repair and inspection work is carried out on mechanical parts of the ventilation system. This operating mode has the highest priority and cannot be deactivated by a fire alarm either.

7.5

Special system-related requirements As regards the automatic operational check, provision shall be made for special control systems so as to guarantee the functionality of moving parts in an emergency (e.g. dampers, fans and ventilators). In the event of an incident, from the time fire breaks out, the theoretical values for longitudinal airspeed in the tunnel must be achieved and kept stable for five minutes in the case of longitudinal ventilation and ten minutes in the case of transverse ventilation. Special consideration shall be given to the position of passable cross-cuts (open doors) in the fire programmes and when stipulating the measurement locations. The same applies to the requirements in the action plans.

7.5.1

Longitudinal ventilation with unidirectional traffic Under standard operation, the envisaged direction of blow of the jet fans is the direction of travel. In a fire situation, the theoretical value for longitudinal speed is 1.5 to 2 m/s. The measurement values specified are valid without measuring tolerances. For the time being, the jet fans shall be activated starting with the exit portal (suction operation). Depending on the location of the fire, a pressure mode may also be employed. Fumigation of the escape routes must be prevented (fire in the direction of travel after the last escape route). The flow shall be reversed in the adjacent tube and an excess pressure generated in relation to the fire tube by means of suitable ventilation control.

7.5.2

Longitudinal ventilation with bi-directional traffic Under standard operation, the following criteria must be taken into consideration: • • • • •

environmental requirements (control structures, other restrictions), the principal direction of the traffic (pronounced), pronounced existing natural air flow, the preferential direction of the jet fans (efficiency), minor changes in the principal direction of traffic flow or in the natural air flow may not result in any change in the direction of discharge of the jet fans.

In a fire situation, the ventilation shall be operated as follows: • The aim is to achieve an air speed of 1.0 to 1.5 m/s in the tunnel area in order to keep escape routes free from smoke for as long as possible. The measurement values specified are valid without measuring tolerances.

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• The existing direction of flow must be maintained. • A reversal in the direction of flow is permitted if, as a result, the risk for tunnel users can be minimised. Structural conditions and longitudinal speed shall be used as a basis for optimisation. • Fans and ventilators shall primarily be operated from that side which is located upstream of the fire. The following criteria must be taken into consideration: • • • • 7.5.3

The location of the source of the fire. The number of vehicles, their speed and direction. The existing direction of flow at the time fire breaks out. The location and principal direction of discharge of the fans and ventilators.

Semi-transversal ventilation Under normal operation, consideration must be given to • environmental requirements, and • structural conditions. In the case of semi-transversal ventilation, the air supplied shall be drawn off via portals and the exhaust air extracted via the air duct. In the event of fire, the semi-transversal ventilation shall be controlled in such a way that it can extract flue gases in the area of the source of the fire. In this connection, the exhaust fan shall be operated at maximum suction capacity. At the same time, the manoeuvrable smoke dampers as per point 5.3 shall be adjusted. If there are several ventilation sections, the adjacent ones shall be controlled in such a way that air flow is generated from both sides in relation to the area of the fire. As regards unidirectional tunnels, the quantities of air are to be distributed in such a way that more air flows from the scene of the fire and the speed of flow does not fall below a value of 1.2 m/s in the direction of traffic (in front of the fire smoke damper). As regards bi-directional traffic, the aim shall be to achieve uniform flow from both sides. If necessary, bolstering by jet fans is required. Dividing walls between ventilation sections shall be constructed in such a way that they can be opened as required for support purposes (largest possible opening cross section). As regards inspection work carried out in the ventilation ducts, special precautions which guarantee safe operation and protection of the inspection staff shall be taken for the fire scenario.

7.5.4

Transverse ventilation Under normal operation, consideration must be given to • environmental requirements, and • structural conditions. In case of fire, the manoeuvrable smoke dampers as per point 5.3 shall be adjusted. The exhaust air in the ventilation section in question shall be switched to full suction capacity, irrespective of the respective longitudinal flows in the tunnel. If several ventilation sections are present, they shall be regulated in such a way that in the case of bi-directional traffic operation, an equally high longitudinal air speed is generated in the carriageway from both sides of the scene of the fire (in order to clear the tunnel of flue gases as quickly as possible). With unidirectional traffic, the speed of air flow in the direction of travel (in front of the fire smoke damper) may not exceed 1.2 m/s and, if possible, should be higher than the counterflow behind the fire smoke damper (so as to protect individuals staying in the area of the vehicle congestion in front of the fire against back layering).

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BASIC PRINCIPLES

RVS 09.02.31

Dividing walls between ventilation sections shall be constructed in such a way that they can be opened as required (largest possible opening cross section), on the one hand, as support and, on the other, as assistance for the ventilation section in the adjacent section. As regards inspection work carried out in the ventilation ducts, special precautions which guarantee safe operation and protection of the inspection staff shall be taken for the fire scenario. 7.5.5

Combined ventilation systems If ventilation systems are combined, special programmes shall be developed which take account, mutatis mutandis, of the control conditions listed above.

7.6

Cross cuts and exits The ventilation system shall be designed such that in the open escape doors of the cross cuts and escape routes, a longitudinal air speed of at least 2.5 m/s is achieved in the direction of the fire tubes in the event of a fire. The maximum permitted opening pressures as per RVS 09.01.24 must be heeded, however.

7.7

Portal designs In the case of portals situated close to one another, short circuiting of the ventilation must be avoided. Depending on the geographical or meteorological situation, provision shall be made for portal drifts or dividing walls approximately 30 m long and whose height is adjusted in line with the height of the portal.

8

Smoke and fire behaviour tests

8.1

General Fire behaviour tests shall be carried out in tunnel installations with mechanical ventilation. Where mechanical ventilation is not present, the need for these tests shall be reviewed in consultation with the State fire brigade federation.

8.2

Fire behaviour tests In order to obtain a representative declaration relating to smoke extraction (semi-transversal and transverse ventilation) or to the dispersal of flue gas (longitudinal ventilation), a fire behaviour test is necessary. Prior to clearance for traffic, this test shall be performed in coordination with the competent State fire brigade federation, taking account of local conditions. The purpose of fire behaviour tests is • to test the operational efficiency of the safety equipment in case of fire, • to review the functions of the fire programme and, if necessary, adjust it in line with current knowledge, and • to familiarise the fire brigade and the operating personnel with the fire situation. The parameters of the fire behaviour test are as follows: • two steel cones, each 1 m2 in area, 50 to 80 cm high, filled with 20 l of diesel and 5 l of petrol respectively • location of the fire cones: adjacent to one another • location of the fire: the location of the fire shall be laid down in consultation with the persons responsible for assisting public authorities in planning new ventilation projects. The test should be conducted at an unfavourable spot in terms of ventilation. A record shall be submitted of the result of the fire behaviour test. Provision shall be made for corresponding barriers to protect the facilities in the environment (carriageway, surfacing).

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RVS 09.02.31

So as to ensure the functionality of the ventilation system in the event of fire, even after the initial commissioning of the tunnel, and to obtain a better insight into the opportunities for ventilation control in the event of fire and fire-fighting measures, it is recommended to conduct fire practices at regular intervals. The results of these practices, and also any actual fire scenarios in the tunnel, shall be recorded. 8.3

Parameter studies using 3D computer programmes In the case of tunnels with complex structural conditions (approach roads and exits within the tunnel, appreciable changes in the cross section, etc.), or for considering large fire loads, numerical calculations can be performed as back-up to the fire behaviour tests. The programmes used must be validated for such investigations.

9

Simplified risk assessment procedure The aim of the risk assessment based on the simplified method is to gauge the risk posed by a tunnel and to assign the tunnel to one of four hazard classes in respect of which minimum technical standards are defined in RVS 09.02.22. For evaluating standard tunnels, a simplified calculation method for calculating a risk equivalent value is defined on the basis of the analyses of the results of the tunnel risk analysis (in accordance with RVS 09.03.11). This risk equivalent value takes into account the principal factors influencing the risk posed by a road tunnel as regards the frequency of incidents and the extent of damage and represents an equivalent of the total expectation value of the annual risk posed by a road tunnel.

9.1

Frequency equivalent The frequency equivalent H represents the anticipated frequency of accidents involving personal injury/annum and is calculated according to the following formula: H = JDTV ⋅ 3.65 ⋅ 10–4 ⋅ LTU ⋅ UR ⋅ fVK ⋅ fTL ⋅ fVF JDTV is the annual average daily traffic flow at the cross section as a whole (i.e. both directions in the case of unidirectional tunnels), forecast value (time of traffic clearance + ten years) [motor vehicles/day] LTU is the length of the tunnel + portal area [km] UR is the specific accident rate [accidents involving personal injury/1 million motor vehicle km] UPS means accidents involving personal injury fVK is the coefficient of correction “traffic capacity” fTL is the coefficient of correction “tunnel length” fVF is the coefficient of correction “point of convergence” Tunnel length LTU The length of the tunnel structure shall be set as the length of the tunnel itself (as regards unidirectional tunnels with two tubes, the mean structural lengths of the two individual tubes), in which connection, on both sides, an additional 50 m section in the open shall be added on for considering the portal area. Any gallery or well which adjoins the tunnel structure is disregarded when calculating tunnel lengths. If the difference in the lengths of the two tubes exceeds 10%, a separate consideration is necessary (assessment of the risk expectation value involving both lengths).

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RVS 09.02.31

Specific accident rate - base value UR As regards unidirectional and bi-directional tunnels, a separate base value (accidents involving personal injury) shall be set each time in relation to the specific accident rate. The accident rate base value is as follows: • as regards unidirectional tunnels: Specific accident rate, unidirectional traffic = 0.112/1 million motor vehicle km • as regards bi-directional tunnels: Specific accident rate, bi-directional traffic = 0.077/1 million motor vehicle km This accident rate base value shall be adapted in line with the respective structure using the coefficient of corrections for traffic capacity or tunnel length. Coefficient of correction for traffic capacity fVK The coefficient of correction for traffic capacity is calculated according to the following formulae: • as regards unidirectional tunnels: fVK ,RV =

7,934 ⋅ 10 −2 ⋅ ln( x ) − 0,6935 0,112

x.........annual average daily traffic flow (for both directions) ln(x) ...Logarithmus naturalis The formula for the coefficient of correction for traffic capacity applies in the case of unidirectional tunnels in the region from 15 000 to 40 000 motor vehicles/day; above or below this, the values for 15 000 or 40 000 motor vehicles/day shall be used. • as regards bi-directional tunnels: fVK ,GV =

3,217 ⋅ 10 -14 ⋅ x 3 − 2,209 ⋅ 10 −9 ⋅ x 2 + 5,021 ⋅ 10 -5 ⋅ x - 0,2781 0,077

x......annual average daily traffic flow The formula for the coefficient of correction for traffic capacity applies in the case of bi-directional tunnels in the region from 10 000 to 20 000 motor vehicles/day; above or below this, the values for 10 000 or 20 000 motor vehicles/day shall be used. Coefficient of correction for tunnel length fTL The coefficient of correction for tunnel length where this ranges from 0.5 km to 3.0 km is determined in accordance with the following formula: fTL =

0,1081 ⋅ x −0,3543 0,112

x ….LTU [km] As regards tunnels more than 3.0 km long, the value for L TU = 3.0 km is used. This coefficient of correction only applies to unidirectional tunnels. As regards bi-directional tunnels, the value f TL shall be set at 1.0, irrespective of the length of the tunnel. Factors influencing points of convergence in or before the tunnel fVF If points of convergence and their sphere of influence (stretch of road which can be travelled in ten seconds at maximum speed) are to be found in the tunnel or in the portal area, the accident rate over the length of this point of convergence shall be increased by a factor of 2: Can be obtained from the Austrian Research Association for Roads, Rail and Transport Issued 1 August 2008 This document is protected by copyright. finding new ways.

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RVS 09.02.31

fVF ,GV =

(LTU − ∑LV ) + 2∑LV

fVF ,GV =

(2 ⋅ LTU − ∑ LV ) + 2 ⋅ ∑ LV

Bi-directional traffic:

LTU

Unidirectional traffic:

2 ⋅ LTU

where Σ V is the sum of the points of convergence and their sphere of influence. If the respective points of convergence and their sphere of influence exceed 200 m, for every point of convergence, a maximum length of 200 m shall be taken into consideration in the calculation. If points of convergence and their sphere of influence are to be found in the portal area, these shall be considered up to a length of 50 m in front of the portal and the corresponding length in the tunnel. 9.2

Equivalent extent of damage S The equivalent extent of damage S corresponds to a specific risk (statistically anticipated deaths/1 million motor vehicle km per annum) in the tunnel. The specific risk was stipulated in relation to defined tunnel classes on the basis of the results of the tunnel risk analysis and is indicated in the following tables depending on the • • • • •

tunnel system ventilation system traffic load distance to the emergency exit (only in the case of bi-directional tunnels) and congestion frequency.

The simplified method can only be used for tunnels with low to average congestion frequency (see point 4.1.1). Tunnels with high congestion frequency require a more in-depth analysis. 9.2.1

Equivalent extent of damage for unidirectional tunnels The values relating to the equivalent extent of damage for unidirectional tunnels shall be taken from Table 3. Table 3: Equivalent extent of damage for unidirectional tunnels Equivalent extent of damage S

Longitudinal area

Ventilation

Low congestion frequency

Mean congestion frequency

0.5 to 0.7 km

No mechanical ventilation

0.13407

0.13420

0.5 to 1.0 km

Longitudinal ventilation

0.09547

0.09580

1.0 to 2.0 km

Longitudinal ventilation

0.09570

0.09649

2.0 to 3.0 km

Longitudinal ventilation

0.09582

0.09684

> 3.0 km

Transverse ventilation

0.09539

0.09557

On account of the modest share of the overall risk which is accounted for by the fire risk in the case of unidirectional tunnels (the exception being tunnels with high congestion frequency), emergency exits only have an insignificant impact on the specific risk and are not therefore indicated separately.

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9.2.2

RVS 09.02.31

Equivalent extent of damage for bi-directional tunnels In the case of bi-directional tunnels, different values relating to the specific risk apply to tunnels with and without emergency exits (see Tables 4 and 5): Table 4: Equivalent extent of damage for bi-directional tunnels, low congestion frequency Equivalent extent of damage S Traffic load in terms of annual average daily traffic flow < 10 000 motor vehicles/day

Traffic load in terms of annual average daily traffic flow > 10 000 motor vehicles/day

without an emergency exit

without an emergency exit

Longitudinal area

Ventilation

0.5 to 0.7 km

no mechanical ventilation

0.30491 0.28700 0.26910 0.33094 0.31304 0.29513

0.5 to 1.5 km

Longitudinal ventilation

0.32711 0.29199 0.25687 0.38950 0.34075 0.29186

1.5 to 3.0 km

Longitudinal ventilation with point exhaust suction

0.33847 0.30047 0.26272 0.37692 0.32806 0.28004

> 3.0 km

Transverse ventilation

0.24372 0.23926 0.23482 0.27834 0.26106 0.24355

Distance to Distance to the the emergency emergency exit 500 m exit 250 m

Distance to the emergency exit 500 m

Distance to the emergency exit 250 m

Table 5: Equivalent extent of damage for bi-directional tunnels, mean congestion frequency Equivalent extent of damage S Traffic load in terms of annual average daily traffic flow < 10 000 motor vehicles/day

Traffic load in terms of annual average daily traffic flow > 10 000 motor vehicles/day

without an emergency exit

without an emergency exit

Longitudinal area

Ventilation

0.5 to 0.7 km

no mechanical ventilation

0.30517 0.28720 0.26930 0.33114 0.31323 0.29533

0.5 to 1.5 km

Longitudinal ventilation

0.32798 0.29255 0.25712 0.39037 0.34131 0.29211

1.5 to 3.0 km

Longitudinal ventilation with point exhaust suction

0.33926 0.30098 0.26294 0.37771 0.32857 0.28027

> 3.0 km

Transverse ventilation

0.24386 0.23933 0.23487 0.27849 0.26114 0.24360

Distance to the emergency exit 500 m

Distance to the emergency exit 250 m

Distance to the emergency exit 500 m

Distance to the emergency exit 250 m

With other distances to emergency exits, the values in the above tables shall be interpolated in a linear manner (as regards the category “No emergency exit”, the maximum tunnel length for this category shall be accepted as the distance to the emergency exit). If the tunnel structure has somewhat different distances to emergency exits, the mean of these distances shall be used.

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9.2.3

RVS 09.02.31

Coefficients of correction for other influencing factors Coefficient of correction for the proportion of lorries A proportion of heavy traffic in the region of 20% forms the basis for the values specified in relation to the equivalent extent of damage. Where proportions of heavy traffic deviate from this, the values relating to the equivalent extent of damage as per Tables 4 and 5 shall be adapted using the factors in Table 6, with interim values interpolated in a linear manner: Table 6: Coefficients of correction in the case of deviating proportions of heavy traffic Proportion of HGVs Tunnel type

Unidirectional tunnel

5%

20%

30%

Natural ventilation

- 8.5%

0%

+ 5.1%

Longitudinal ventilation

- 5.5%

0%

+ 3.1%

Transverse ventilation

- 5.2%

0%

+ 2.9%

- 44.7%

0%

+ 26.9%

- 44.4%

0%

+ 27.2%

- 39.4%

0%

+ 24.4%

- 42.1%

0%

+ 26.1%

- 41.9%

0%

+ 25.6%

- 39.8%

0%

+ 24.6%

- 39.7%

0%

+ 26.5%

- 38.9%

0%

+ 23.7%

- 40.3%

0%

+ 24.9%

- 41.5%

0%

+ 25.7%

- 43.6%

0%

+ 26.5%

- 36.7%

0%

+ 22.7%

-40.1%

0%

+ 24.8%

- 31.3%

0%

+ 25.4%

- 38.0%

0%

+ 23.5%

- 38.4%

0%

+ 23.8%

- 38.3%

0%

+ 23.5%

- 39.5%

0%

+ 24.4%

Natural ventilation without emergency exits

Bi-directional tunnel Emergency Annual average daily exits every 500 traffic flow < 10 000 motor m vehicles/day

Longitudinal ventilation Transverse ventilation Natural ventilation Longitudinal ventilation Transverse ventilation Natural ventilation

Emergency exits every 250 m

Longitudinal ventilation Transverse ventilation Natural ventilation

without emergency exits

Bi-directional tunnel Emergency Annual average daily exits every 500 traffic flow > 10 000 motor m vehicles/day

Emergency exits every 250 m

Longitudinal ventilation Transverse ventilation Natural ventilation Longitudinal ventilation Transverse ventilation Natural ventilation Longitudinal ventilation Transverse ventilation

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BASIC PRINCIPLES

9.3

RVS 09.02.31

Risk equivalent value R and hazard classes The risk equivalent value R is calculated by multiplying the frequency equivalent H by the equivalent extent of damage S: R=H⋅S The risk equivalent value R corresponds to the risk expectation value (statistically anticipated deaths per annum) of the tunnel under investigation over a one-year period. On the basis of the risk equivalent value, the tunnels to be assessed can be divided into hazard classes. Table 7: Hazard class arrangement Risk equivalent value

9.4

Hazard class

lower limit

upper limit

-

2 ⋅ 10-2

I

> 2 ⋅ 10-2

1 ⋅ 10-1

II

> 1 ⋅ 10-1

5 ⋅ 10-1

III

> 5 ⋅ 10--1

-

IV

Area of application for the simplified method and notes relating to more in-depth risk analyses The simplified method shall be applied to all tunnels more than 500 m long. In the case of tunnels less than 500 m long, no separate considerations of the risk are necessary as a rule. The simplified method for evaluating risk can only be applied in the context of the limits cited below. As regards tunnels for which the conditions cited below apply, only a rough estimate of the risk is possible using the simplified method. As regards a calculation of the risk and an assessment of the effectiveness of safety measures, more in-depth analyses, for instance, in the form of a tunnel risk analysis as per RVS 09.03.11, are necessary. • • • • • • • • • •

tunnels more than 7.5 km long unidirectional tunnels with annual average daily traffic flows > 60 000 motor vehicles/day bi-directional tunnels with annual average daily traffic flows > 40 000 motor vehicles/day tunnels with uneven surfaces (e.g. cross girders) tunnels with combined ventilation systems tunnel tubes with more than two lanes throughout tunnels with a high probability of congestion tunnels with a maximum longitudinal gradient ≥ 3% tunnels with a maximum fire detection time ≥ 150 seconds (see RVS 09.02.22) tunnels with cross-sectional changes (e.g. widening based on additional lanes or hard shoulders)

Even when applying the simplified method, additionally, the obligation exists to examine every tunnel in terms of special characteristics which may impact on the safety of tunnel users and to take these characteristics into account when assessing the risk (refer to the Road Tunnel Safety Act). 9.5

Model principles

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The following assumptions formed the basis of the calculations: • a horse shoe cross section 53 m2 in area, with two continuous lanes per tunnel tube • fire detection and the start of smoke extraction after 150 seconds • individuals only leave their vehicles if the smoke spreads as far as the vehicle in question; 3% of individuals remain in their vehicles • source rates for 5 or 30 MW fires: • CO2 production: 0.65 or 2.8 kg/s • CO production: 0.018 or 0.1089 kg/s • HCN [hydrogen cyanide] production: 0.0045 or 0.027 kg/s • flue gas release in the tunnel with 5 or 30 MW fires: in three or five minutes • achieving the maximum fire load with 5 or 30 MW fires: in three or five minutes • reaction time until full suction capacity is achieved: with unidirectional traffic - four minutes in the case of longitudinal ventilation and five minutes in the case of transverse ventilation; with bi-directional traffic - two minutes in the case of longitudinal ventilation and three minutes in the case of transverse ventilation.

10

Cited Acts, guidelines and standards STSG

Road Tunnel Safety Act, Federal Law Gazette 54/2006, as amended RVS 03.01.11 Road planning, principles, examining the structural conditions of roads RVS 09.01.24 Tunnel construction, structural design, structural works RVS 09.03.11 Tunnels, safety, risk analysis model RVS 09.02.32 Tunnel equipment, calculating the air requirement RVS 09.02.33 Tunnel equipment; immissions burden at tunnel portals ÖVE/ÖNORM + A1 EN 60529 Degrees of protection provided by enclosures, issued 1 October 2000 ÖVE-M 10 Electrical machines DIN ISO 2533 Standard atmosphere

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11

Annex

11.1

Application example for unidirectional tunnels Data pertaining to the tunnel: Two tubes (unidirectional traffic), for every two lanes per direction of travel Ventilation system: longitudinal ventilation Average tunnel length: 2.85 km => LTU = 2.95 km Annual average daily traffic flow: 24 500 motor vehicles/day; proportion of HGVs: 23% Low congestion frequency Distance to the emergency exits: 300 m North tube: the interweaving lane extends 80 m into the tunnel South tube: the interweaving lane extends 220 m into the tunnel With a permitted maximum speed of 100 km/h, the sphere of influence (see point 9.1) of points of convergence in the unidirectional tunnel is 278 m long. a) Frequency equivalent H = annual average daily traffic flow [motor vehicles/day] · 3.65 · 10–4 · LTU [km] · UR · fVK · fTL · fVF where the annual average daily traffic flow = 24 500 motor vehicles/day LTU = 2.95 km UR = 0.112 fVK = (7.934 · 10-2 · ln(24 500) - 0.6935) / 0.112 = 0.9674 fTL = (0.1081 · 2.95–0.3543) / 0.112 = 0.6579 fVF = 1.0678 (see the Points of convergence) H = 2.0080 - Points of convergence A point of convergence + its sphere of influence up to 200 m is considered (per tube). System sketch:

Key to diagram: Portalbereich Tunnelbereich Ausfahrtsstreifen Verflechtungsbereich Einflussbereich Einfahrtsstreifen

Portal area Tunnel area Exit road Weaving area Sphere of influence Entry road

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f vf = =

RVS 09.02.31

( 2 ⋅ LTU − ∑Verflechtungsstrecken ) + ∑Verflechtungsstrecken

( 2 ⋅ 2,95 − 0,40) + 0,40 ⋅ 2 = 1,0678

⋅2

2 ⋅ LTU

5,90

[Key to equation: Verflechtungsstrecken = points of convergence] b) Equivalent extent of damage S = 0.09582 (as per Table 3) Coefficient of correction as a result of an increased proportion of HGVs of 23%: Increase in the equivalent extent of damage by 3.1% (as per Table 6) with a proportion of HGVs of 30%; as regards a proportion of HGVs of 23%, linear interpolation results in an increase in S of 0.93% => S = 0.09671 The distance to the emergency exits has a negligible impact in the case of unidirectional tunnels. c) Risk equivalent R = H · S = 2.0080 · 0.09671 = 0.19419 Hazard class assignment pursuant to Table 7: => hazard class III 11.2

Application example for bi-directional tunnels Data pertaining to the tunnel: One tube (bi-directional traffic), for every lane per direction of travel Ventilation system: longitudinal ventilation with point exhaust suction Average tunnel length: 2.85 km => LTU = 2.95 km Annual average daily traffic flow: 16 700 motor vehicles/day; proportion of HGVs: 16% Mean congestion frequency Distance to the emergency exits: 500 m The interweaving lane extends 50 m into the tunnel With a maximum permitted speed of 80 km/h, the sphere of influence (see point 9.1) of points of convergence in the bi-directional tunnel is 222 m long. a) Frequency equivalent H = annual average daily traffic flow [motor vehicles/day] · 3.65 · 10–4 · LTU [km] · UR · fVK · fTL · fVF where the annual average daily traffic flow = 16 700 motor vehicles/day LTU = 2.95 km UR = 0.077 (3,217 ⋅ 10 −14 ⋅ 16.7003 − 2,209 ⋅ 10 −9 ⋅ 16.7002 + 5,021 ⋅ 10 −5 ⋅ 16.700 − 0,2781) fVK = 0,077 fTL= 1.00 fVF = 1.0678 (see the Points of convergence) H = 1.8082 - Points of convergence System sketch:

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fVF = =

RVS 09.02.31

(LTU − ∑ Verflechtu ngsstrecke n ) + ∑ Verflechtu ngsstrecke n ⋅ 2) LTU

(2,95 0,20) + 0,20 · 2 = 1,0678 2,95

A point of convergence up to 200 m is taken into consideration b) Equivalent extent of damage S = 0.32857 (as per Table 5) Coefficient of correction as a result of a low proportion of HGVs of 16%: Reduction in the equivalent extent of damage by 31.3% (as per Table 6) with a proportion of HGVs of 5%; as regards a proportion of HGVs of 16%, linear interpolation results in a reduction in S of 8.35% => S = 0.30113 c) Risk equivalent R = H ∙ S = 1.8082 ∙ 0.30113 = 0.5445 Hazard class assignment pursuant to Table 7: => hazard class IV

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Drawn up by the “Tunnel construction” working group, and the “Works and safety equipment, ventilation working party” working committee in collaboration with Dipl.-Ing. Rudolf Hörhan, Federal Ministry of Transport, Innovation and Technology (Head) Dipl.-Ing. Katharina Hoyer, ILF Beratende Ingenieure ZT GmbH Dipl.-Ing. Bernhard Kohl, ILF Beratende Ingenieure ZT GmbH Dipl.-Ing. Dr. Guntram Lechner, ZT Univ.Prof. Dr. Karl Pucher Ing. Günter Rattei, Asfinag [Autobahn- und Schnellstraßen Finanzierungs AG] Dipl.-Ing. Josef Santner, Asfinag Margareta Schludermann, Federal Ministry of Transport, Innovation and Technology Dipl.-Ing. Michael Steiner, Asfinag Dipl.-Ing. Wolfgang Stroppa, Tiwag-Tiroler Wasserkraft AG ao. Univ.Prof. Dr. Peter-Johann Sturm, Institute for Internal Combustion Engines and Thermodynamics at the Graz University of Technology Ing. Anton Waltl, Office of the Styrian Provincial Government Dipl.-HTL-Ing. Mag. (FH) Alexander Wierer, Asfinag

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Explanatory report of 2 August 2007 relating to drawing up X publication RVS 09.02.31 Title [German]: Tunnelausrüstung, Belüftung, Grundlagen Title [English]: Tunnel equipment, ventilation, basic principles These Guidelines and Regulations for Highway Construction are to be published in the form of X an RVS guideline (binding) an RVS consultative document. Working group: Tunnel construction Working committee: Works and safety equipment Consent of the executive committee to draft the guideline on 20 April 2004 > Need for the guideline Adaptation in line with the current safety technology used in road tunnels and technical facilities, as well as in line with the requirements of the Road Tunnel Safety Act [German designation: STSG] and the EU Directive on minimum safety requirements for tunnels in the Trans-European Road Network > Effects on existing RVS, standards, instructions (replacement, in whole or in part; changes on account of new RVS, ...): Replacement of the existing RVS 9.261 and 09.02.31 of 18 February 1997 and the addendum of 25 January 2001 > Consideration given to European and international standards (CEN) Yes > Expected savings or additional costs: These Guidelines and Regulations are already taken into account in current replanning. Additional costs are to be anticipated in part. > Environmental effects: No > Legal consequences: No > Other effects: RVS 09.02.31 only deals with the simplified risk assessment procedure. The risk analysis model to be drafted in accordance with the requirements of the EU Directive is dealt with in detail in RVS 09.03.11 and published as a consultative document

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> Contributors: (if already known, name and organisation) Dipl.-Ing. Katharina Botschek, ILF Dipl.-Ing. Rudolf Hörhan, Federal Ministry of Transport, Innovation and Technology (Head) Dipl.-Ing. Bernhard Kohl, ILF Dipl.-Ing. Dr. Guntram Lechner, ZT Univ.Prof. Dr. techn. Karl Pucher Ing. Günter Rattei, Asfinag Dipl.-Ing. Josef Santner, Asfinag Margareta Schludermann, Federal Ministry of Transport, Innovation and Technology Dipl.-Ing. Michael Steiner, Asfinag Dipl.-Ing. Wolfgang Stroppa, Tiwag-Tiroler Wasserkraft AG A. Univ.Prof. Dr. Peter Sturm, Graz University of Technology Ing. Anton Waltl, Office of the Styrian Provincial Government Dipl.-Ing. FH Alexander Wierer, Asfinag