Concrete Pipes Reference Manual

Concrete Pipes Reference Manual January 2009 *

Build Build on our on our

expertise

http://www.humes.com .au/fileadmin/template s/HUMES/doc/Brochur es/Humes_ConcretePi peManual.pdf

contents 1. Introduction...................................................... 2 2. Test Load Data ................................................. 8 3. Pipes for Culvert Applications ......................... 9 Flush Joint Pipes.......................................... 15 4. Pipes for Drainage Applications ................... 16 Rubber Ring Joint (Belled Socket) Pipes...... 17 Rubber Ring Joint (In-wall ) Pipes............... 18 5. Pipes for Sewerage Applications .................... 21 6. Pipes for Pressure Applications ..................... 27 Standard Pressure Pipe Class Range ........... 29 7. Pipes for Irrigation Applications .................... 35 8. Jacking Pipes ................................................. 38 9. Handling and Installation .............................. 43 10. Reference Material...........................................51 10.1. Approx. Critical Depth Relationships for Circular Pipe . 51 10.2. Relative Discharge & velocity for part-full pipe flow ...

51

10.3. Flow relationships for Inlet Control in Culverts ...........

52

10.4. Energy Head relationships for pipes flowing full .........

53

10.5. Colebrook White Nomograph, ks = 0.06 .................... (applicable to concrete culverts carrying stormwater)

54

10.6. Colebrook White Nomograph, ks = 0.15 .................... 55 (applicable to concrete rising mains carrying clean water) 10.7. Colebrook White Nomograph, ks = 0.6 ...................... (applicable to concrete pipes carrying stormwater)

56

10.8. Colebrook White Nomograph, ks = 1.5 ...................... (applicable to concrete pipes carrying sewerage)

57

10.9. Minimum pipe cover required for various compactors . 58 10.10. Metric and Empirical Equivalency Table ....................

60

Index ...................................................................61 Pipe Quotation Request Sheet ............................. 62

*

The information in this publication is for guidance only. Expert advice must be obtained on the suitability of any product and on its installation in the particular circumstances in which it is proposed to be used. Further, a check should be made, at www.humes.com.au, for the current version of this document, and also as to the availability of any particular product. 1

1. Introduction General 1. Introduction

Humes is the leading manufacturer of steel reinforced concrete pipes (SRCP) and associated precast products in Australia. Available in a wide range of diameters, lengths and with varying strengths, Humes concrete pipes have a proven track record and are custom designed for user applications including drainage, sewage, water supply and irrigation. This publication provides the information necessary to specify Humes concrete pipes for all of these applications. Specification of Humes concrete pipes has also been simplified with the inclusion of a Pipe Design Request Sheet on page 62 of Concrete Pipes. Please copy the sheet and complete the necessary information, then fax or mail to your nearest Humes office for the fastest possible service.

Manufacturing Humes steel reinforced concrete pipes are made from coarse and fine aggregates, cement and hard drawn deformed steel reinforcement. They are manufactured and factory tested for quality to AS/NZS 4058: 2007 "Precast concrete pipes (pressure and non-pressure)". Pipes can also be custom made and tested to meet specific customer requirements. Generally Humes concrete pipes up to 2100mm nominal diameter (DN2100) are centrifugally cast using the Humespun process invented in 1910 in Australia by Walter Hume. In use throughout the world, the Humespun process of centrifugal casting produces strong and durable concrete pipes. Humes concrete pipes larger than DN2100 are vertically cast in steel moulds using high frequency vibration which produces concrete pipes with characteristics compatible with those of centrifugally spun pipes. High abrasion resistance and impermeability of spun concrete makes SRCP the most appropriate selection for handling peak flows. A range of natural characteristics further enhance performance, including an indefinite increase in strength in the presence of moisture and autogenous healing of cracks.

Joint Types Humes concrete pipes are manufactured with two basic joint types - Flush Joint and Rubber Ring Joint. Flush Joint pipes provide an interlocking joint which allows for a small degree of flexibility in the pipeline alignment. Rubber Ring Joint pipes, either belled-socket or in-wall joint depending on the diameter of the pipe and its application, are designed to accommodate change in pipeline alignment and settlement in a pipeline whilst still maintaining a watertight joint. Further information on the joints specific to the pipe application types is provided in sections 3,4,5,6,7 and 8 of this manual.

Durability For most common installations, the service life of concrete pipe is virtually unlimited. The longevity of steel reinforced concrete pipe provides Asset Managers with a resource requiring low in-service maintenance and the ability to be recycled into other projects if exhumed. Some of the Roman aqueducts are still in use after 2000 years and samples from the first known concrete pipes in the US, laid in 1842, were in excellent condition after more than 140 years service. Of the 350 million kilometres plus of reinforced concrete pipe that has been laid in Australia, the number of pipelines which have suffered from durability problems has been extremely small and confined mainly to unprotected pipe in highly aggressive conditions. Advances in concrete, process and product technologies such as the use of Humes Plastiline™ for sewer pipe lines together with our stringent quality control and assurance programs ensures that our pipes and associated products will be fit for their purpose.

80 year old Humes pipes reused for new culvert!

Pipes manufactured in 1920 at Loveday S.A. have been exhumed and reused in a culvert at the Gurra Road Project in S.A. in 2000. The manufacture of centrifugally spun pipes.

2

consulting the "Australian/New Zealand Standard AS/NZS 3725: 2007 Design for Installation of buried concrete pipes" which provides methods for determining the installed load on concrete pipes from the earth fill over the pipes as well as any induced live (vehicle) load effects.

Size Class (DN) Humes standard range of concrete pipes are available in sizes DN300 - DN2100. (DN = nominal diameter) Diameters outside the standard range and up to DN3600 are also available. Special project pipes are also available for all sizes when required or specified. Humes concrete pipes are typically manufactured in nominal 2.44m lengths to optimise transport and handling. Other lengths, longer or shorter can be manufactured on request.

1. Introduction

The standard also provides a range of recommended Bedding Support Type options. The range varies from no support, to haunch support, to haunch and side support. For the majority of pipe installations, Humes Standard-Strength (Class 2-4) concrete pipes, used in conjunction with type H2 or type HS2 Bedding Support, are suitable (see Figure 1.1).

Comprehensive tables listing the availability of Size Classes (DN) are provided in each section.

The letter 'H' in the terminology indicates haunch support only. 'HS' indicates both haunch and side support. The numerals after 'H' and 'HS' indicate the level of support in the material used.

Load Class Humes steel reinforced concrete pipes are available in StandardStrength (Class 2-4) and Super-Strength (Class 6-10) Load Classes.

Design Tables 1.1 & 1.2 (page 5) for Bedding Type H2 and HS2 are provided for ease of specifying concrete pipes within a limited range of stated conditions. Figure 1.2 (page 4) compares the results for a sample pipe installation using both Type H and Type HS Bedding Supports. Similarly, for embankment installation, Table 1.5 (page 7) is provided.

The numeric classification system adopted to identify the load carrying capacity of concrete pipes is based on the rationale that any particular pipe class is able to carry approximately the same proportionate height of fill. For example, a Class 10 pipe can carry five times the height of fill of a Class 2 pipe, under the same installation conditions.

Hydraulics To establish the flow rates for the various types of concrete pipes, Manning's formula should be used for short run culvert and drainage applications, while the Colebrook-White formula should be used for long run drainage, gravity sewer lines and all pressure pipe applications.

See Section 2: Test Load Data, for further information on test loads for each size class. The required strength of a concrete pipe depends on both the load to be carried by the installed pipe, and the supporting ground installation conditions. The load transmitted onto the pipe depends on the height and type of fill material. Also, when installed in a trench, the width of the trench at the top of the pipe is important. Generally the wider the trench, the greater the load for any height of fill over the pipe.

The Concrete Pipe Association of Australasia (CPAA) publication "Hydraulics of Precast Concrete Conduits" is recommended as a reference. Comprehensive details on the hydraulics for the different pipe types are provided in each section.

The load class for concrete pipes can be determined by Finished surface lc ≥ D/6 or 150mm, whichever is greater*

lc ≥ D/6 or 150mm, whichever is greater*

Natural ground surface or compacted fill

Backfill

Embankment fill

150mm min. overlay

150mm min. overlay

150mm min.

Compacted ordinary fill

Haunch Bed

Compacted

D/3 Compacted

Compacted select fill

D Compacted select fill

D

Haunch Bed

Compacted

Trench

D/3 Compacted

Embankment * Refer AS/NZS 3725: 2007 for cement stabilised soil

Figure 1.1 - Type H1 and Type H2 Supports

3

Finished surface

1. Introduction

lc ≥ D/6 or 150mm, whichever is greater *

lc ≥ D/6 or 150mm, whichever is greater *

Natural ground surface or compacted fill

Backfill

Embankment fill

150mm min. overlay

150mm min. overlay

150mm (min. width)

Compacted ordinary fill

Bed

Compacted

Side

≥ 0.5 D

≥ 0.5 D

Haunch

Compacted select fill

D Compacted select fill

D Side

D/3 Compacted

Haunch Bed

Compacted

Trench

Embankment * Refer AS/NZS 3725: 2007 for cement stabilised fill

Figure 1.2 - Type HS Support

Indicative depth of fill

Ground surface

Note: Economies may be achieved by modifying bedding type as opposed to increasing pipe class

Figure 1.3 Indicative depth of fill for various bedding installation types

4

D/3 Compacted

Table 1.1 Material Quantities - H1 & HS1 Support Types Material Quantities (m3/lin.m) Bedding Zone

Haunch Zone

H1 Overlay Zone

HS1 Side Zone

HS1 Overlay Zone

Trench

Embank

Trench

Embank

225

600

0.066

0.015

0.201

0.161

0.044

0.157

0.117

300

650

0.072

0.020

0.234

0.197

0.053

0.181

0.144

375

750

0.083

0.028

0.292

0.237

0.070

0.222

0.167

450

850

0.094

0.037

0.356

0.281

0.089

0.267

0.192

525

900

0.099

0.044

0.386

0.316

0.097

0.289

0.219

600

1000

0.110

0.055

0.457

0.362

0.118

0.338

0.243

675

1100

0.121

0.067

0.532

0.408

0.142

0.390

0.267

750

1150

0.127

0.076

0.562

0.444

0.148

0.414

0.296

825

1250

0.138

0.090

0.644

0.503

0.174

0.470

0.329

900

1400

0.154

0.112

0.786

0.594

0.221

0.564

0.372

1050

1650

0.182

0.155

1.046

0.771

0.309

0.736

0.461

1200

1850

0.204

0.195

1.276

0.935

0.388

0.888

0.547

1350

2050

0.338

0.239

1.528

1.080

0.475

1.053

0.605

1500

2300

0.380

0.302

1.875

1.296

0.597

1.278

0.699

1650

2500

0.413

0.357

2.178

1.482

0.704

1.474

0.778

1800

2700

0.446

0.418

2.494

1.658

0.815

1.679

0.843

1950

2900

0.479

0.483

2.836

1.856

0.973

1.959

0.949

2100

3200

0.528

0.584

3.421

2.242

1.154

2.267

1.088

1. Introduction

Min Trench Size Class Width (DN) (m)

Note: Volume quantities are approximate & based on an assumed 10% bulking See figures 1.1 (page 3) and 1.2 (page 4) for zone descriptions

Table 1.2 Material Quantities - H2, HS2 & HS3 Support Types Min Trench Size Class Width (DN) (mm)

Material Quantities (m3/lin.m) Bedding Zone

Haunch Zone

H2 & HS3 Overlay Zone Trench

Embank

HS2 & HS3 Side Zone

HS2 & HS3 Overlay Zone Trench

Embank

225

600

0.066

0.042

0.174

0.134

0.017

0.157

0.117

300

650

0.072

0.053

0.200

0.164

0.020

0.181

0.144

375

750

0.083

0.072

0.247

0.192

0.026

0.222

0.167

450

850

0.094

0.095

0.299

0.224

0.032

0.267

0.192

525

900

0.099

0.108

0.323

0.253

0.033

0.289

0.219

600

1000

0.110

0.133

0.379

0.283

0.040

0.338

0.243

675

1100

0.121

0.161

0.438

0.314

0.048

0.390

0.267

750

1150

0.127

0.176

0.461

0.344

0.048

0.414

0.296

825

1250

0.138

0.208

0.526

0.384

0.056

0.470

0.329

900

1400

0.154

0.261

0.636

0.444

0.072

0.564

0.372

1050

1650

0.182

0.363

0.837

0.563

0.101

0.736

0.461

1200

1850

0.204

0.456

1.014

0.674

0.126

0.888

0.547

1350

2050

0.338

0.560

1.207

0.759

0.155

1.053

0.605

1500

2300

0.380

0.705

1.472

0.893

0.194

1.278

0.699

1650

2500

0.413

0.833

1.702

1.006

0.228

1.474

0.778

1800

2700

0.446

0.971

1.941

1.105

0.262

1.679

0.843

1950

2900

0.479

1.120

2.200

1.219

0.313

1.959

0.949

2100

3200

0.528

1.364

2.641

1.462

0.374

2.267

1.088

Note: Volume quantities based on assumed 10% bulking See figures 1.1 (page 3) and 1.2 (page 4) for zone descriptions

5

Table 1.3 Max. Fill Heights - Trench Installation, H2 Bedding Fill height Max. (m)

1. Introduction

Size Class (DN)

Pipe Load Class 2

3

4

6

8

10

225 300 >25 metre height

375

5.8

450

4.9

525

4.8

600

4.4

675

4.5

750

4.2

12.1

825

4.4

12.7

900

3.9

8.7

1050

3.7

7.3

19.7

1200

3.5

6.1

10.7

1350

3.4

6.1

10.7

1500

3.1

5.4

8.7

1650

3

5.2

8

21.9

1800

2.9

4.8

7.2

15.7

1950

2.3

3.9

5.9

11.7

2100

2.2

3.7

5.6

10.9

Table 1.4 Max. Fill Heights - Trench Installation, HS2 Bedding Fill height Max. (m) 21.7

Notes: Assumed minimum trench width & Clayey Sand Soil Internal weight of water is considered for > DN180 In onerous fill situations, a combination of StandardStrength concrete pipes and Type HS3 Bedding Support* can provide the most appropriate solution. Table 1.6 provides details for such an installation. *Type HS3 Bedding Support is similar to that required for a flexible pipe installation.

Size Class (DN)

Pipe Load Class 2

3

4

6

8

225 300

>25 metre height

375 450 525

10.7

600

7.5

675

7.7

750

6.6

825

6.8

900

5.7

1050

5.2

1200

4.8

10

1350

4.6

9.3

1500

4.2

7.7

14.5

1650

4

7

12.3

1800

3.8

6.5

10.5

1950

3

5.3

8.4

20.8

2100

2.9

5.1

7.9

17.8

13.5

Notes: Assumed minimum trench width & Clayey Sand Soil. Internal weight of water is considered for > DN1800.

6

Table 1.5 Max. Fill Heights - Embankment Installation, H2 (& HS2) Fill height Max. (m) Pipe Load Class

225

2

3

4

6

8

10

H2

HS2

H2

HS2

H2

HS2

H2

HS2

H2

HS2

H2

HS2

3.2

4.6

4.9

6.8

6.5

9.2

-

-

-

-

-

-

300

2.7

3.9

4.2

5.9

5.5

7.7

8.1 11.6

10.9 15.4

13.6

19.3

375

2.5

3.5

3.8

5.4

5.0

7.0

7.5 10.6

10.0 14.0

12.5

17.5

450

2.4

3.4

3.7

5.2

4.9

6.9

7.3 10.3

9.7

13.8

12.2

17.2

525

2.5

3.5

3.8

5.4

5.0

7.1

7.5 10.6

10.1 14.2

12.6

17.7

600

2.5

3.5

3.7

5.3

5.0

7.0

7.5 10.5

9.9

14.0

12.4

17.4

675

2.6

3.6

3.9

5.5

5.2

7.3

7.7 10.9

10.3 14.5

12.9

18.2

750

2.6

3.6

3.8

5.4

5.1

7.2

7.7 10.8

10.2 14.4

12.8

18.0

825

2.6

3.6

3.9

5.5

5.2

7.2

7.7 10.9

10.3 14.5

12.9

18.2

900

2.5

3.5

3.8

5.3

5.0

7.0

7.4 10.6

9.9

13.9

12.3

17.3

1050

2.6

3.5

3.7

5.2

5.0

7.0

7.4 10.0

9.9

13.9

12.3

17.3

1200

2.6

3.4

3.6

5.0

4.8

6.7

7.1 10.4

9.5

13.6

11.8

16.7

1350

2.7

3.4

3.7

5.1

4.8

6.8

7.2 10.1

9.6

13.5

12.0

16.9

1500

2.7

3.3

3.7

4.9

4.7

6.5

7.0

9.7

9.2

13.0

11.5

16.5

1650

2.7

3.2

3.7

4.8

4.6

6.4

6.9

9.6

9.1

12.8

11.4

16.0

1800

2.7

3.2

3.7

4.8

4.6

6.3

6.8

9.5

9.0

12.6

11.2

15.7

1950

2.3

2.9

3.4

4.2

4.4

5.8

6.3

8.8

8.4

11.9

10.6

14.9

2100

2.2

2.8

3.4

4.2

4.4

5.6

6.2

8.7

8.3

11.7

10.4

14.7

Notes: Assumed Clayey Sand Soil (p=0.7 for H2 & p=0.3 for HS2). Internal weight of water is considered for > DN1800

1. Introduction

Size Class (DN)

Table 1.6 Max. Fill Heights - Embankment Installation, HS3 Fill height Max. (m) Size Class (DN)

Pipe Load Class 2

3

4

6

225

7.4

11.0

14.7

-

300

6.2

9.4

12.3

18.5

375

5.6

8.6

11.3

16.9

450

5.5

8.3

11.0

16.5

525

5.6

8.6

11.4

17.1

600

5.6

8.4

11.2

16.9

675

5.8

8.7

11.6

17.4

750

5.8

8.6

11.5

17.3

825

5.8

8.7

11.6

17.4

900

5.6

8.4

11.2

16.7

1050

5.6

8.3

11.1

16.7

1200

5.3

8.0

10.7

16.0

1350

5.4

8.1

10.8

16.2

1500

5.2

7.8

10.4

15.6

1650

5.2

7.7

10.3

15.4

1800

5.1

7.6

10.1

15.1

1950

4.5

7.0

9.4

14.3

2100

4.4

6.8

9.3

14.1

Notes: Assumed Clayey Sand Soil with p=0.3. Internal weight of water is considered for > DN1800

7

2. Test Load Data Commonly supplied size classes: DN300 - DN2100 Note: Intermediate strength classes are specified by linear interpolation between values and Humes can advise on individual applications.

Steel Reinforced Concrete Pipes are manufactured and proof tested to Australian Standards requirements. The Australian/NewZealand Standard, AS/NZS 4058: 2007 - Precast concrete pipes (pressure and non-pressure) provides levels of proof test loads for concrete pipes and sample pipes taken for routine quality assurance during normal production which ensures the pipes' strength. Test load requirements for all Humes concrete pipes are given below.

Table 2.1 - Test Loads in kilonewtons/metre length Test Loads KN/m (length)

2. Test Load Data

Load Class

8

Standard Strength Class 2

Class 3

Super Strength Class 4

Class 6

Class 8

Size Class (DN)

Crack

225

14

21

21

32

28

42

-

-

-

300

15

23

23

34

30

45

45

56

375

17

26

26

39

34

51

51

450

20

30

30

45

40

60

525

23

35

35

52

46

600

26

39

39

59

675

29

44

44

750

32

48

825

35

900

Class 10

Ultimate Crack Ultimate Crack Ultimate Crack Ultimate Crack Ultimate

Crack

Ultimate

-

-

-

60

75

75

94

64

68

85

85

106

60

75

80

100

100

125

69

69

86

92

115

115

144

52

78

78

98

104

130

130

163

66

58

87

87

109

116

145

145

182

48

72

64

96

96

120

128

160

160

200

52

52

78

69

104

104

130

138

173

173

217

37

56

56

84

74

111

111

139

148

185

185

231

1050

42

63

63

95

84

126

126

158

168

210

210

263

1200

46

69

69

104

92

138

138

173

184

230

230

288

1350

50

75

75

113

100

150

150

188

200

250

250

313

1500

54

81

81

122

108

162

162

203

216

270

270

338

1650

58

87

87

131

116

174

174

218

232

290

290

363

1800

62

93

93

139

124

186

186

233

248

310

310

388

1950

66

99

99

149

132

198

198

248

264

330

330

413

2100

70

105

105

158

140

210

210

263

280

350

350

438

2250

74

111

111

167

148

222

222

278

296

370

370

463

2400

78

117

117

176

156

234

234

293

312

390

390

488

2700

86

129

129

194

172

258

258

323

344

430

430

538

3000

94

141

141

212

188

282

282

353

376

470

470

588

3300

102

153

153

230

204

306

-

-

-

-

-

-

3600

110

165

165

248

220

330

-

-

-

-

-

-

3. Pipes for culvert applications Rubber Ring Joint (RRJ) RRJ pipes are also suitable for culvert applications and are most effective when differential ground settlement is anticipated or if a pipeline is expected to flow full under outlet control conditions with a significant hydraulic pressure head. See Section 4, Concrete Stormwater Pipes for further details.

Culvert

Size Class (DN) See Table 3.2 (page 15) for details of Flush Joint Pipes.

They are available with two basic joint types - Flush Joint (FJ) and Rubber Ring Joint (RRJ).

Load Class

Flush Joint (FJ)

The most appropriate culvert installation can be obtained by matching both pipe Load Class and the Bedding Support Type. For the majority of installations, Standard-Strength concrete culvert pipes used in conjunction with type H2 or type HS2 Bedding Support, are suitable.

FJ pipes with External Bands (EB) are recommended for normal culvert conditions. They provide an interlocking joint between pipes, as shown in Figure 3.1, and give a true and positive alignment along the length of the pipeline. When EB bands are used in conjunction with FJ culvert pipes, they provide a soil-tight joint along the pipeline and prevent loss of bedding material into the pipe. Groundwater infiltration may occur however, when the groundwater level is significantly above the pipeline obvert (approx. 3m). FJ pipes fitted with EB bands allow a small degree of flexibility for the bedding-in/movement of the pipeline during natural processes of consolidation.

Humes concrete culvert pipes are available in Standard-Strength (Class 2-4) and Super-Strength (Class 6-10) Load Classes.

For large fill situations, a combination of Super-Strength pipes and type HS3 Bedding Support can provide the most appropriate and economical solution.

3. Culvert Applications

Humes can provide a comprehensive range of steel reinforced concrete culvert pipes in sizes DN225 - DN3600. (commonly supplied size classes: DN300 - DN2100).

Further information on the Load Class of concrete pipes can be obtained by referring to Section 1: Introduction (page 3).

Hydrology The maximum flow to be considered in storm water culverts and pipes is a function of: • the hydrological data pertaining to tributary overland flows, as experienced throughout the service life of the drainage system The most commonly used formula to determine the quantity of water generated by a storm event is known as the rational formula: Q = 0.278 C I A where Q = discharge (m3/s) C = coefficient of runoff (dimensionless) I = intensity (mm/hour) A = catchment area (km2), ‘C’ will most commonly vary between 0.7 and 0.9 say, for grassed surfaces and paved (sealed) areas. The magnitude of I, the intensity is a function of geographical area. By example a Brisbane storm may have an intensity of two times that of a Melbourne storm.

Figure 3.1 - Flush Joint Profile

Australian Rainfall and Runoff (ARR) is a guide to flood estimation produced by (and the subject of continuing review by) the Institution of Engineers, Australia. In addition to ARR, local and state authorities may have specific or alternative data/design requirements, such the Queensland Urban Drainage manual (QUDM).

9

Inlet control

Outlet control

Inlet control conditions shown in Figure 3.2 exist in a pipeline where the capacity of the pipeline is limited by the ability of upstream flow to easily enter the pipeline, a common situation in coastal Australia where short culvert lengths on steep grades are used. The flow under inlet control conditions can be either inlet submerged or unsubmerged.

Where culverts are laid on flat grades and empty below the downstream water level, the culvert typically operates with outlet control conditions as shown in Figure 3.3.

H HW > D D

TW >D

Unsubmerged HW ≤ 1.2D

D

H

HW > D D

Submerged HW > 1.2D

TW = D

D

HW ≥ 1.2D

H D

TW < D

Figure 3.2 - Inlet Control Legend for Figure 3.2 and 3.3

3. Culvert Applications

HW = Head Water TW = Tail Water D = Diameter

HW< 1.2D

D

Figure 3.3 - Outlet Control When operating under outlet control conditions, the culvert pipe may flow full or part-full depending on the tailwater depth. Where the tailwater depth is greater than the pipe diameter, the pipe will typically flow full. Where the tailwater depth is less than the pipe diameter, the design tailwater depth should be taken as the greater of the actual tailwater depth or (dc + D)/2, where dc is the critical depth for the actual flow discharge (see Figure 3.4).

10

H TW < D

Installation

The design charts Figures 10.3 & 10.4 (pages 52, 53) for pipe culvert inlet and outlet conditions allow the designer to evaluate maximum discharge conditions at maximum headwater. For a lesser discharge, Figure 3.4 can be used to determine flow characteristics.

Humes culvert pipes above DN525 are normally supplied with elliptical grid reinforcement, unless a circular grid is specifically requested. Elliptical grid reinforced pipes must be laid with the word "TOP" at the crown (or invert) of the pipe, and within 10° each side of the vertical centreline. To simplify handling, lifting holes are generally provided in the top of all FJ pipes and FJ splays above DN 525.

Where inlet flow conditions exist in a culvert, the flow capacity of the pipeline is independent of the pipe surface roughness (Manning's 'n').

See Section 9 (page 43) : Handling and Installation for further details.

Figure 3.4 - Relative discharge and velocity in part-full pipe flow

y

D

1.0 .9

.7

Qf

Q/

.6 .5

3. Culvert Applications

Proportional Depth y/D

.8

.4

Vf

.3

V/

.2 .1

0

.1

.2

.3

.4

.5

.6

.7

.8

.9

1.0

1.1

1.2

Proportional Discharge Q/Qf and Proportional Velocity V/Vf Q = Part-full Velocity Qf = Full Flow Discharge

Installing flush joint pipes

V = Part-full Velocity Vf = Full Flow Discharge

The pipeline flow capacity for inlet control conditions is dependent on the ratio of headwater depth to culvert diameter and the inlet geometry type. Outlet control conditions operating in a culvert determine the pipeline flow capacity by the effects of pipe surface roughness (Manning's ‘n'), pipeline length and slope, and inlet geometry type.

Installing 3600mm diameter pipes.

11

Other Culvert Products Humes manufactures a wide range of associated components to provide the complete culvert pipeline solution. These include: • Headwalls - These are used where the hydraulic design requires improved inlet and outlet flow conditions. • FJ Splay pipes - These permit curves in pipeline alignment without the usual problems of hydraulic head loss (turbulence) that can result from a rapid change in the direction of the flow at a sharp bend. Details are given for the minimum radius of curved alignment. See Table 3.1 and Figure 3.5 for minimum radius using double ended splays and recommended radius using single ended splays. EB bands can also be used with FJ Splays. For lesser radii, FJ bend pipes may be supplied.

Precast Concrete Headwall

Table 3.1 - Minimum Radius for curved pipe alignment: Flush Joint Splays

Notes: 1. The number of splay pipes required is determined from the deflection angle and the centreline radius. This information should be given when ordering splay pipes. Humes Engineers will calculate the optimum number of splay pipes required.

Size Class (DN)

3. Culvert Applications

2. The curve "hand" is described as when looking downstream in the direction of the flow.

Stan (nom dard P ipe inal leng th) L/2

Multiple Barrel Splay Pipes (EB Joint).

CL

Min CL Radius* (m) Economical (single ended)

Absolute Min. (double ended)

600

11.5

4

675

11.8

4.3

750

12.2

4.6

825

12.4

4.9

900

12.6

5.2

1050

13

5.8

1200

13.4

6.4

1350

13.7

7

1500

14

7.7

1650

14.4

1800

15

1950

15.9

2100

16.7

Not typically supplied

* Minimum radius is measured to the pipe centre line at joint

Radiu

Pipeline deflection angle (Ø)

12

Splay pipes

Right hand curve looking down stream

Direction of flow

s (R)

Figure 3.5 - Minimum single-ended splay radius achieved with flush joint splays in curved pipeline alignment

Example 3 - Culvert Pipe A culvert is to be laid under a proposed road embankment. From the catchment physical data and hydraulic information, the designer has determined a peak flow of 5.5 cumecs (5500 litres/sec) passing through the culvert pipeline. The roadway alignment requires an embankment height of 2.0m above existing ground surface, and the culvert is to be laid at natural ground level. To avoid flooding the roadway pavement the maximum upstream flood level is to be 300mm below roadway level. Due to downstream flow restrictions, the estimated tailwater level is 1.0m above the natural ground surface. The width of the roadway formation including embankment slope is to be 50m, over which the natural ground surface falls 500mm. The culvert is to be constructed with headwalls.

Step 1.3 Q = 2 x 3.1 = 6.2 m3/s

Step 1.1 Q = 4.1 m3/s

Step 1.2 Q = 2 x 2.4 = 4.8 m3/s

Step 1.4 HW/D = 1.23

• Calculate appropriate culvert pipe diameter/s for these conditions. • Calculate outlet velocity and check if erosion requires consideration. From the information provided: Q required = 5.5 cumecs (5500 litres/sec) Max Headwater HW = 1.70m (embankment height minus min. freeboard), Max Tailwater TW = 1.00m Pipe culvert length = 50m, Pipe culvert slope = 1 in 100 (500mm fall over 50m length) Assume square edge inlet

Figure 10.3 - Flow Relationships for Inlet Control in Culverts

Step 2 — Check for outlet control conditions:

from Figure 10.1 — Approx. Critical Depth Relationships for Circular Pipe (Page 51), dc/D = 0.75, therefore dc = 0.90m

Step 1 — Assume inlet Control Conditions: 1.1 Try 1500mm diameter FJ pipe (as max headwater is 1.7m):

1.2 Try twin 1050mm FJ pipe: HW/D = 1.7/1.05 = 1.62 From Figure 10.3 — Flow Relationships for Inlet Control in Culverts (page 52), using scale (1) Square edge with headwall: Q = 2 x 2.4 = 4.8 cumecs < Q required, therefore try larger pipe diameter/culvert area.

Figure 10.1 - Approximate Critical Depth Relationships for Circular Pipe 1.0 .8 .6 .4

.2

Step 2.1 dc/D = 0.75

dc/ D

HW/D = 1.7/1.5 = 1.13 From Figure 10.3 — Flow Relationships for Inlet Control in Culverts (page 52), using scale (1) Square edge with headwall: Q = 4.1 cumecs < Q required, therefore try larger pipe diameter/culvert area.

.1 .08 .06

dc

.04

HW/D = 1.7/1.2 = 1.42 From Figure 10.3 — Flow Relationships for Inlet Control in Culverts (page 52), using scale (1) Square edge with headwall: Q = 2 x 3.1 = 6.2 cumecs > Q required. 1.4 Establish head water height with twin 1200mm diameter FJ pipe and max. flow: Qmax. = Q required = 5.5 cumecs (5500 litres/sec) Q per pipe = 2.75 cumecs From Figure 10.3 — Flow Relationships for Inlet Control in Culverts (page 52), using scale (1) Square edge with headwall: HW/D = 1.23; therefore HW (inlet control) = 1.23 x 1.2 = 1.48m (TW, then approx. HW can be established by using (dc+D) in Figure 10.4 — Energy Head relationship for Pipes Flowing Full (page 53). 2.2 Establish HW level for outlet control conditions — HW = [TW or (dc + D) / 2] + H - fall (dc + D) / 2 = (0.9 + 1.2) / 2 = 1.05m (> TW =1.0m) therefore adopt (dc + D)/2 = 1.05m in Fig. 10.4 (page 53) (in lieu of TW): From Figure 10.4 — Energy Head relationship for Pipes Flowing Full (page 53): for Q = 2.75 cumecs, L =50m & ke = 0.5 (square edge head wall) then H = 0.65m HW (outlet control) = 1.05 + 0.65 – 0.5 = 1.20m

13

Step 3 — Determine Flow Velocity:

Step 2.2 H = 0.65m

For inlet control conditions, the outlet velocity can be determined via the Colebrook-White formula (adopt k = 0.60mm) Hydraulic gradient = (HW -TW + fall)/Length = (1.51.0+0.5)/50 = 0.02 from Figure 10.7 — Full Flow Conditions Colebrook-White Formula (ks = 0.6) (Page 56) with Qf = 6.2/2 = 3.1 cumecs: Vf = 4.52 m/s,

Step 2.2 Q = 5.5/2 = 2.75 m3/s

.0400

7.5 m/ s 7.0 m/ s m/ s 6.0 m/ s 5.5 m/ s 5.0 m/ s

.0300

DN

30 0

6.5

45 0

4.5

52 5

m/

4.0

67 5

2.5

200

300

500

700

1000

2000

3000

19 50 21 00 DN 22 50 DN 24 00 DN 2 DN 550 2 DN 700 28 50

DN

18 00

4000 5000

DN

DN

16 50

s

DN

15 00

m/

m 1.9 /s m 1.8 /s m 1.7 /s m/ s 1.6 m 1.5 /s m/ s 1.4 m/ s 1.3 m/ s 1.2 m/ s 1.1 m/ s 1.0 m/ s

.0010

s

DN

DN 10 50 DN 1 DN 125 12 00 DN 12 75 DN 13 50

82 5

90 0

DN

DN

2.0

.0020

s

m/

97 5

75 0 DN

3.0

.0030

100

s

m/

DN

Hydraulic Gradient (m/m)

3.5

.0050

.0005

s

m/

DN

DN

.0100

60 0

DN

DN

DN

37 5

.0200

7000

10000

Discharge in litres per second ks = 0.6mm

Figure 10.4 - Energy head relationships for pipes flowing full (n = 0.011)

2.3 Compare HW level for inlet control and outlet control conditions: HWinlet =1.50m > HWoutlet = 1.20m, therefore inlet control governs. Use twin 1200mm diameter FJ pipes

from Figure 10.2 — Relative Discharge & Velocity in Part-Full Pipe Flow (page 51), Q/Qf = 2.75/3.1 = 0.88, gives V/ Vf = 1.12 and y/D = 0.72 Therefore V = 5.1 m/s, and y = 0.86m (< dc = 0.90m) As actual flow depth (y) is less than the critical depth (dc), a hydraulic jump may occur at the culvert outlet if the downstream channel flow is not supercritical. Erosion protection at the culvert outlet may be necessary. Figure 10.2 - Relative discharge and velocity in part-full pipe flow

y

D

1.0 .9 .8

y/D Proportional Depth y/D

.7

Qf

.6

Q/

.5 .4

Vf

V/

.3 .2 .1

0

.1

.2

.3

.4

.5

.6

.7

.8

V/Vf

Q/Qf

3. Culvert Applications

Figure 10.7 - Full Flow Conditions Colebrook-White Formula ks=0.6mm

.9

1.0

1.1

1.2

Proportional Discharge Q/Qf and Proportional Velocity V/Vf

Summary • Use twin 1200mm diameter FJ Pipes • Erosion protection at the culvert outlet may be necessary

14

Pipe length

Flush Joint Pipes for culvert applications Commonly Supplied Size Classes: DN300 - DN2100 Nominal Length: 2.44m except where denotes. Other lengths may be available on request.

ID

*

OD

Note: Pipe mass based on product density of 2600kg/m3 for spun pipe and 2500kg/m3 for vertically cast pipe. Flush Joint Pipe

Table 3.2 - Flush Joint Pipes Actual Internal Diameter D (mm), Pipe Class, Mass (kg) and Outside Diameter (OD) Standard Strength Load Classes Class 2

Class 3

Super Strength Load Classes Class 4

Class 6

ID (mm)

Mass (kg)

ID (mm)

Mass (kg)

225

229

125

229

125

229

130

300

300

205

300

205

300

210

290

235

280

260

268

295

362

375

375

280

375

285

375

290

363

330

355

360

343

395

445

450

450

400

450

405

450

415

444

445

438

465

418

545

534

525

534

465

518

545

502

625

502

625

502

630

486

705

616

600

610

565

600

625

586

705

586

710

570

800

554

885

698

675

685

690

679

735

661

850

661

860

637

1005

615

1135

781

750

762

815

756

865

730

1045

730

1055

714

1170

682

1385

864

825

838

945

832

1000

806

1205

806

1215

782

1400

754

1605

946

900

915

1090

903

1200

883

1370

883

1390

851

1655

795

2085

1029

1050

1066

1420

1054

1550

1026

1830

1026

1855

966

2430

926

2775

1194

1200

1219

1775

1207

1925

1179

2245

1171

2355

1109

3045

1059

3580

1359

1350

1372

2165

1360

2340

1332

2700

1292

3230

1242

3830

1202

4335

1524

1500

1524

2405

1504

2710

1468

3245

1424

3860

1374

4590

1324

5230

1676

1650

1676

2885

1656

3220

1620

3820

1576

4495

1516

5450

1476

6065

1842

1800

1828

3375

1808

3745

1772

4400

1718

5295

1668

6200

1628

6855

2006

1950

1994

4200

1982

4515

1944

5225

1904

5980

1834

7340

1794

8040

2198

2100

2160

5215

2136

5655

2110

6205

2050

7535

1990

8715

1960

9335

2388

2250*

2250

8140 2250

8775

2250

9165

ID (mm)

279

2718 15050

2742 2250

2742 10850

2768 2438

11460

2700

2438

20715

2438

20855

3060 3030

13115

3060 2700

3060

20620

11585 2700

3000*

2850 2718

9640 2438

2700

18640

8795 2438

2700*

2550

14195 2250

2438

2530

Typically project specific production only 2250

2400*

Mass (kg)

OD (mm)

Mass (kg)

ID (mm)

Mass (kg)

Class 10

ID (mm)

ID (mm)

Mass (kg)

Class 8

3. Culvert Applications

Size Class (DN)

21250

2700

21340

2700

21490

13750

3410 3410

3060

15835

3060

16510

3460 3060

32700

3060

32800

3060

32950

4010

3300

3300

21110

3300

21240

3300

21350

3900

3600

3600

24535

3600

24700

3600

24820

4240

Note: Internal diameters (ID) subject to change without notice

15

Rubber ring

4. Pipes for drainage applications Humes provide a comprehensive range of steel reinforced concrete stormwater pipes from DN225 to DN3600 (Common Size Classes: DN300 to DN2100). Rubber Ring Joint (RRJ) pipes are recommended for stormwater drainage systems, although Flush Joint (FJ) pipes can also be used dependant on requirements of the client / asset owner. RRJ pipes up to DN1800 are supplied with a belled-socket joint, while those larger than DN1800 are supplied with an in-wall joint (see Figures 4.1 & 4.2).

Max. joint draw Socket

Witness marks Spigot

Nominal laying gap

Inside surface

Figure 4.1 - RRJ Pipe with Belled Socket Joint

Rubber ring

Rubber Ring Joint (RRJ) Rubber Ring Joints provide concrete pipes with a high degree of flexibility to accommodate ground settlement or alignment adjustments. The RRJ profile is designed for ease of installation, and allows curved alignment adjustments while maintaining a watertight joint capable of withstanding the common levels of hydraulic head occurring in a storm water pipeline. Table 4.1 presents the minimum radius for curves in the pipeline for the standard range of pipes. Details on other sizes can be obtained by contacting Humes.

Socket

Spigot

Max. joint draw Inside surface

Nominal laying gap

Figure 4.2 - RRJ Pipe with In-wall (Skid) Joint

Size Class (DN)

Table 4.1 - Maximum Joint Deflection: RRJ - Drainage Applications

See Tables 4.2 & 4.3 (pages 17, 18) for details.

4. Drainage Applications

Size Class (DN)

R =

L 2 (tan 1/2 ∆/N)

where:

Figure 4.3 - Curved Alignment using Deflected Straight Pipe

16

R = Radius of curvature, feet L = Average laid length of pipe sections measured along the centerline, feet ∆ = Total deflection angle of curve, degrees N = Number of pipes with pulled joints ∆/N = Total deflection of each pipe, degrees

Max Max CL deflection Min CL Deviation angle at joint Radius* per pipe /N (m) (mm) (degrees)

300

81

1.9

45

375

81

1.9

50

450

55

1.3

55

525

43

1.0

60

600

38

0.9

70

675

34

0.8

70

750

26

0.6

80

825

21

0.5

85

900

34

0.8

90

1050

26

0.6

95

1200

21

0.5

95

1350

21

0.5

100

1500

26

0.6

125

1650

21

0.5

130

1800

68

1.6

80

1950

26

0.6

80

2100

34

0.8

80

* Minimum radius is measured to the pipe mid point

Nominal Pipe length

Rubber Ring Joint (Belled Socket) Pipes for culvert, drainage and sewerage applications

A

ID OD

Commonly Supplied Size Classes: DN300 - DN1800 Pipe Length (nom): 2.44m Pipes available in most areas indicated by bold type. Other lengths may be available on request. Additional sizes have restricted availability and designers should consult Humes to confirm their supply status.

Rubber Ring Joint (Belled Socket) Pipe

G H

Note: Pipe mass based on product density of 2600kg/m3 for spun pipe and 2500kg/m3 for vertically cast pipe.

Table 4.2 - Rubber Ring Joints (Belled Socket) Actual Internal Diameter (ID), Socket Dimensions (A,G & H), Outside Diameter (OD) and Pipe Mass. Load Class

Class 2

Class 3

Super Strength Load Classes

Class 4

Class 6

Class 8

Class 10

Socket Dimensions Socket Dimensions (A,G & H) Load Class

Size Class ID (mm) Mass (kg) ID (mm) Mass (kg) ID (mm) Mass (kg) ID (mm) Mass (kg) ID (mm) Mass (kg) ID (mm) Mass (kg) A (mm) (DN) 225 225 300 375 450 525 600 675 750 825 900 1050 1200 1350 1500 1650 1800

229 229 229 229 300 304 300 375 381 380 450 450 457 534 534 530 610 610 610 685 680 680 760 750 762 762 838 830 838 910 900 915 1070 1050 1066 1220 1200 1200 1370 1350 1524 1676 1828

110 135 220 240 220 280 370 305 340 545 435 605 800 515 650 880 625 815 1130 760 845 1175 940 955 1145 1380 1050 1200 1410 1415 1425 2030 1895 1790 2335 2175 2190 3275 2460 2690 3550 3890 4450

229 229 229 229 300 304 300 375 381 380 50 450 457 518 534 530 598 610 610 673 680 680 744 750 762 762 818 830 838 910 900 915 1070 1050 1066 1220 1200 1200 1370 1350 1524 1676 1828

110 140 220 240 220 280 375 310 345 545 440 610 805 595 650 880 685 820 1135 805 855 1180 985 1000 1150 1385 1105 1210 1420 1425 1435 2035 1910 1800 2345 2195 2210 3290 2610 2715 3575 3925 4495

229 229 229 229 300 304 300 375 381 380 450 450 457 518 534 530 598 610 610 673 680 680 744 750 762 762 818 830 838 910 900 915 1058 1050 1066 1200 1194 1200 1330 1344 1504 1636 1788

110 140 Not typically supplied 220 240 240 288 250 280 280 268 310 280 304 285 298 305 284 340 375 300 375 300 380 300 380 315 355 345 351 395 343 420 345 375 370 361 425 357 430 545 380 545 380 545 380 550 450 438 480 438 500 418 580 615 450 615 450 615 444 640 805 457 805 457 810 457 810 675 502 680 502 685 486 755 655 534 665 524 715 510 785 880 530 890 530 895 530 895 765 586 770 570 860 554 945 820 610 830 600 895 578 1015 1135 610 1140 610 1145 610 1150 920 653 930 645 1030 615 1205 860 670 930 648 1070 616 1255 1185 680 1190 680 1200 656 1350 1170 728 1125 712 1290 680 1500 1010 734 1125 710 1295 680 1485 1160 762 1170 738 1340 706 1560 1390 762 1395 762 1405 762 1630 1305 798 1320 782 1500 748 1745 1215 814 1350 782 1590 750 1825 1425 838 1445 814 1635 782 1875 1535 878 1555 862 1850 800 2335 1445 884 1595 852 1855 790 2335 2040 915 2055 915 2075 851 2600 2115 1022 2250 990 2725 950 3075 1820 1018 2140 960 2695 920 3035 2355 1066 2380 1010 2930 966 3340 2555 1156 2695 1120 3360 1070 3905 2300 1160 2685 1090 3435 1040 3970 3300 1200 3325 1160 3775 1110 4345 2995 1294 3400 1240 4115 1200 4630 2810 1286 3555 1230 4210 1190 4720 3905 1460 4515 1404 5335 1354 5990 4470 1596 5065 1546 6045 1486 6915 5085 1744 5900 1668 7285 1608 8220

362 368 394 406 451 470 508 540 546 622 622 694 749 711 762 822 797 851 932 886 915 988 997 996 1033 1084 1064 1098 1149 1197 1190 1302 1391 1364 1454 1543 1540 1670 1695 1710 1937 2089 2267

G (mm)

H (mm)

Pipe OD (mm)

89 108 114 114 76 114 114 80 114 121 114 147 133 133 133 140 133 133 143 133 176 196 143 196 143 143 146 196 171 152 215 178 171 215 178 171 215 210 171 230 194 194 194

83 95 114 114 89 114 114 95 114 133 114 116 190 133 133 133 133 133 152 133 113 146 152 118 152 152 146 128 149 152 138 259 149 151 259 149 165 215 149 170 292 292 203

279 293 305 311 362 381 400 445 457 496 534 560 597 616 636 666 698 724 762 781 784 820 864 860 890 914 946 950 978 1042 1040 1093 1220 1190 1244 1372 1350 1420 1524 1514 1714 1866 2032

4. Drainage Applications

Standard Strength Load Classes

Note: Internal diameters (ID) subject to change without notice

17

Rubber Ring Joint (In-wall) Pipes

Effective Pipe length

for culvert, drainage and sewerage applications Commonly Supplied Size Classes: DN1200 - DN3600 Nominal Pipe Length: 3.0m (*denotes 2.44m) Other lengths are available.

ID

OD

Rubber Ring In-wall Joint Pipe Note: Pipe mass based on product density of 2600kg/m3 for spun pipe and 2500kg/m3 for vertically cast pipe.

Table 4.3 - Rubber Ring Joints (In-wall) Actual Internal Diameter (ID), Outside Diameter (OD) and Pipe Mass. Standard Strength Load Classes Size Class (DN) 1200*

Class 2

Class 3

Super Strength Load Classes Class 4

Class 6

Class 8

Class 10

ID (mm)

Mass (kg)

ID (mm)

Mass (kg)

ID (mm)

Mass (kg)

ID (mm)

Mass (kg)

ID (mm)

Mass (kg)

ID (mm)

Mass (kg)

1280

2985

1280

3005

1280

3025

1260

3285

1240

3545

1200

4015

1950*

1950

5515

1950

5540

1950

5580

1894

6715

1830

7850

1780

8760

2220

2100

6340

2100

6370

2100

6415

2068

7265

2000

8585

1920

10055

2388

2250

2250

8795

2250

8880

2250

12120

2550

11925

2650 2250

15050

2742 2250

2400

2438

9575

2438

2700

11505

2700

10895

2768

13795

3060

2438

20715

2438

20855

3060 3030

13175

3060 2700

3060

20620

11590 2700

3000

2850 2742

2438 2700

18640

9660 2438

4. Drainage Applications

1500

2100*

2250

21250

2700

21340

2700

21490

15875

3410 3410

3060

16585

3460 3060

32700

3060

32800

3060

32950

4010

3300*

3300

21110

3300

21240

3300

21350

3900

3600*

3600

20165

3600

20220

3600

20320

4130

= Not typically supplied

18

OD (mm)

Hydraulics

Installation

Generally, a stormwater pipeline system is designed so that the hydraulic gradeline is at or below the level of the line joining the upstream and downstream manhole surface levels as shown in Figure 4.3 (page16).

All Humes RRJ belled socket pipes are supplied with laying witness marks indicated in the RRJ profile for easy control of the deflected joint. (See Fig. 4.1, pg 16 or Fig. 9.8, pg 45)

1

2 Horizontal Reference

V2/2g

Total Energ y Line Free Water Surface

2 Hfriction V2/2g

Flow

H1

Pipe Invert Slope

H2

Base Level

Note: Humes concrete stormwater pipes are normally supplied with elliptical grid reinforcement, unless a circular grid is specifically requested. Elliptical grid reinforced pipes must be laid with the word "TOP" at the crown (or invert) of the pipe and within 10° each side of the vertical centreline. To simplify handling, lifting anchors can be provided if requested in heavy large size RRJ pipes, and for RRJ pipes DN1800 and over, Humes provides a special rubber ring lubricant to assist joining. See Section 9: Handling and Installation for further details.

H1 + V2/2g = H2 V2/2g + Hfriction

Figure 4.4 - Uniform Flow Conditions The loss of energy head in the pipeline is the aggregate of elevation, exit velocity and friction head losses. Of these, normally only elevation and friction head losses are major considerations. The flow of water in a stormwater pipeline operating full or with minor energy head is determined from the hydraulic gradient in the pipeline. For determining head loss in a stormwater pipeline, the Colebrook-White formula is recommended as is a roughness height (ks) of 0.6mm.

Figure 3.4 - Relative discharge and velocity in part-full pipe flow (page 11), can be used to determine part-flow depth, velocity and discharge in a pipeline. Although a value of ks = 0.6mm is recommended, where the stormwater system is located in a fully developed urban environment, this reasonably conservative value, which is determined from the combined effects of pipe surface and solid material carried in the flow, may be reduced to 0.15mm, considerably increasing the flow capacity where appropriate (see Figure 10.5, page 54).

Load Class Humes concrete stormwater pipes are available in StandardStrength (Class 2-4) and Super-Strength (Class 6-10) Load Classes. The most appropriate stormwater pipe installation can be obtained by matching both pipe Load Class and the Bedding Support Type. For the majority of installations, StandardStrength concrete stormwater pipes used in conjunction with Type H2 or Type HS2 Bedding Support, are suitable. For large fill situations, a combination of Super-Strength pipes and Type HS3 Bedding Support can provide the most appropriate and economical solution. Further information on the Load Class of concrete pipes can be obtained by referring to Section 1. Introduction (page 3).

Large diameter Rubber Ring Joint (In-wall)Pipe installation

Other Stormwater Products Humes supplies a wide range of associated components to provide the complete stormwater drainage system. These include precast access chambers and maintenance shafts, drop inlets, side entry pits, bends, tees and junctions, as well as stormwater pits. With the ever increasing need to responsibly manage a healthy environment, Humes have developed a technically advanced portfolio of stormwater quality management products. Humeceptor™ non-scouring sediment and oil interceptor targets priority fine sediments, which transport nutrients and toxicants, close to where they are generated, protecting local creeks, wetland habitats and wildlife as well as downstream rivers, bays and oceans. Humeceptor™ is proven to capture as much as 90% of ALL sediment (including the material less than 100 microns which is of most concern), 97.8% of free oils and significant quantities of other materials lighter than water (eg. cigarette butts, polyester beads, plastic food wrappers etc) Humegard™ in-line gross pollutant traps are designed to trap a range of gross pollutants including plastics, aluminum, waxed packaging, drink containers, cigarette buttts, syringes, polystyrene, paper and coarser-grained sediment (150 microns+). Laboratory and field testing has proven capture rates up to 100% for gross pollutants prior to by-pass and up to 85% on an annualised basis, allowing for periods of high flow by-pass.

19

4. Drainage Applications

Figure 4.4 gives the capacity and flow velocity of a pipeline flowing with an established hydraulic grade. Alternatively, available energy head can be used to determine the required pipe size for a given flow discharge.

Example 4 — Stormwater Pipe

• Calculate the peak flow rate • Check suitability of DN600 pipe with respect to maximum velocity & energy head:

.0400

7.5 m/ s 7.0 m/ s m/ s 6.0 m/ s 5.5 m/ s 5.0 m/ s

.0300

DN

30

0

6.5

4.5 52

5

m/

4.0

60 5 75

0

0 97

2.5

m/

500

700

1000

2000

3000

00

00 50 19

DN 2 DN 250 2 DN 400 2 DN 550 2 DN 700 28 50

21

DN

00

18

4000 5000

DN

DN

15

50 16

DN

300

s

DN

DN 1 DN 125 12 00 DN 1 DN 275 13 50

10 DN

DN

.0010

s

50

5

90

m/

2.0 m 1.9 /s m 1.8 /s m 1.7 /s m 1.6 /s m 1.5 /s m/ s 1.4 m/ s 1.3 m/ s 1.2 m/ s 1.1 m/ s 1.0 m/ s

.0020

200

s

5 82 DN

3.0

.0030

100

s

m/

DN

DN

DN

DN

3.5

.0050

.0005

s

m/

67

.0100

0

DN

DN

45

0

DN

37

5

.0200

Hydraulic Gradient (m/m)

A stormwater drainage pipeline is proposed to service a new industrial development in Sydney. The new line is to connect into an existing system at an existing downstream manhole. The total catchment area of 4 hectares (0.04km2) is to be paved/sealed, resulting in an estimated coefficient of run = 0.9. The estimated time for the total catchment to be contributing to the outflow discharge is 30 minutes. The 1:50 year rain fall intensity has been calculated as 100mm/hr (for the 30 minute duration), and the new line length is 80 metres. A minimum 600mm dia pipe is specified for maintenance purposes, and the asset owner requires a maximum velocity of 8 m/s and design life of 100 years. An estimation of the system confirms the total energy head at the downstream (Hd/s) pit to be 0.5m.

7000

10000

Discharge in litres per second ks = 0.6mm

Step 1 — Calculate Peak Flow: Peak flow rate formula: Q = 0.278 CIA Therefore Q = 0.278 x 0.9 x 100 x 0.04 = 1.0 cumec (m3/s) Step 2 — Check suitability of DN600 From Figure 10.7 — Full Flow Conditions Colebrook-White Formula (ks=0.6mm) (page 56), with 600mm dia pipe: Hydraulic Gradient = 0.21 m/m and v = 3.55m/sec (