05- Site Preparation Earthworks DEP Amend _A_-Rev-3

AMENDMENTS / SUPPLEMENTS TO DEP No.

: 34.11.00.11 - Gen

DEP Date

: April 2003

DEP Title

: Site Preparation and Earthworks Including Tank Foundations and Tank Farms

THIS DOCUMENT IS INTENDED FOR USE BY ADCO AND ITS NOMINATED CONSULTANTS, CONTRACTORS, MANUFACTURERS AND SUPPLIERS

ORIGINATOR:

ENGINEERING SUPPORT DEPARTMENT ADCO DOCUMENT No. 34.11.00.11 A DOCUMENT CLASSIFICATION

Rev. 3

GENERAL

Date of Issue: November 2011

REVISION RECORD

REV

DATE

ORIGINATOR

REVIEWED (Custodian)

APPROVED (Forum Facilitator)

DESCRIPTION

1.

15-01-04

SCiE(YK)

SCiE(MT)

SCiE(MT)

Issued for Tie-in Contract

2.

16-05-06

SCiE(YK)

SCiE(MT)

SCiE(MT)

In line with DEP version 22

SCiE(DH)

SSpE(civil)

SSpE(civil)

3. 11-11-2011

In line with DEP version 30 and filling materials types are revised.

DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 2 OF11

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DATE :30-11-2011

TABLE OF CONTENTS 1.0

INTRODUCTION

2.0

GENERAL

3.0

SITE PREPARATION

4.0

EARTHWORKS

5.0

BUNDED AREAS AND FOUNDATIONS FOR TANKS

6.0

TANK MAINTENANCE

7.0

DRAINAGE OF BUNDED AREAS

8.0

REFERENCES

9.0

APPENDICES APPENDIX 1: FIELD COMPACTION TRIALS – SUGGESTED PROCEDURE APPENDIX 2: INDICATIVE COMPACTION VALUES APPENDIX 3: MIXTURES OF SAND AND BITUMEN FOR TANK FOUNDATIONS APPENDIX 4: WET SAND MIX FOR TANK FOUNDATION SHOULDERS AND BUND WALLS APPENDIX 5: TYPICAL CPT VALUES TO VERIFY COMPACTION AND QUALITY OF TANK FOUNDATIONS APPENDIX 6: HYDROSTATIC TESTING PROCEDURE APPENDIX 7: TYPICAL TANK FARM LAYOUTS WITH SAFETY DISTANCES APPENDIX 8: TYPICAL EXAMPLES OF RETAINING WALLS APPENDIX 9: EFFECT OF TANK DIMENSIONS ON SOIL SETTLEMENT APPENDIX 10: TYPICAL RING FOUNDATION WITH CONCRETE SLAB APPENDIX 11: SOIL IMPROVEMENT BY GROUND REPLACEMENT APPENDIX 12: EXAMPLES OF TANK FOUNDATION CONSTRUCTION APPENDIX 13: MATERIALS APPENDIX 14: NUMBER OF VERIFICATION CPTs FOR COMPLETED TANK FOUNDATION APPENDIX 15: TYPICAL MINIMUM CONE RESISTANCES FOR SOIL COMPACTION

DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 3 OF11

DEP NO : 34.11.00.11

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DATE :30-11-2011

1.0

INTRODUCTION

1.1

SCOPE

1.2

DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS Add: This DEP and its amendment is intended for use in all ADCO areas including Production facilities, Accommodation, BAB-13, Industrial and Tank farm areas.

1.3

DEFINITIONS Add: The Principal shall mean ADCO in this DEP and its amendment.

1.4

CROSS-REFERENCES

1.5

CHANGES FROM THE PREVIOUS EDITION

1.6

COMMENTS ON THIS DEP

2.0

GENERAL Add: Contractor shall carry out all the required testing at his expense by a laboratory that will be approved by ADCO. Work Permits The Contractor shall be responsible for obtaining all permits relating to Earthworks (excavation in particular) and shall bear all costs involved. The Contractor shall abide by all conditions, etc. specified in the permits. Setting-Out The Contractor shall carry out the necessary setting out / stake-out of the work as shown on the Drawings and secure ADCO's approval of his stake-out before proceeding with construction. 2.1

EXISTING SERVICES AND FACILITIES

2.2

SITE LEVELS DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 4 OF11

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DATE :30-11-2011

Delete the item “Cut and fill should be economically ……… unsuitable materials.” 2.3

SITE INVESTIGATIONS

Add: The Contractor shall be deemed to have carried out his own investigation in the Site of Works and verified the information provided by ADCO. The Contractor should satisfy himself as to the nature of the ground quality and distribution of materials to be excavated, filled, spoiled and borrowed and made himself conversant with the local conditions to be encountered during the execution of the Work. 2.4

CLASSIFICATION OF SOILS AND ROCKS

2.5

SEISMIC ASPECTS 2.5.1

Replace the first paragrah with the following “The design and eventual execution of site preparation and earthworks shall consider the relevant seismic conditions and the relevant consequences and per Structural Design Basis specification - ADCO document no. 30-99-77-0067.”

3.0

SITE PREPARATION

3.1

General “River works” are not applicable to ADCO areas and to be deleted.

3.2

DEMOLITION AND SITE CLEARANCE Second paragraph is not applicable and to be deleted

3.3

STRIPPING OF TOP SOIL

3.4

REROUTING OF EXISTING DITCHES AND WATER COURSES

3.5

TREATMENT OF UNDERGROUND CAVITIES

3.6

TREATMENT OF SUBSOILS

3.7

PROVISION OF SITE DRAINAGE

3.8

PROVISION OF TEMORARY ACCESS

3.9

LAYDOWN AND STOCKPILE AREAS

3.10 SCOUR PROTECTION, COASTAL DEFENSE AND RIVER WORKS DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 5 OF11

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“River Works” are not applicable to ADCO areas and to be deleted. 4.0

EARTHWORKS

4.1

GENERAL

4.2

CONTROL OF EARTHWORKS Add: 4.2.1 General 4.2.2 Planking and Strutting The terms "Planking and Strutting" will be deemed to cover whatever methods the Contractor elects to adapt for shoring the sides of excavation and also for planking and strutting the excavations against the sides of adjoining buildings, public roadways, etc.. The Contractor will be held responsible for shoring the sides of all excavations, adjoining building and the like and no claim for additional excavation, concrete or other material and workmanship will be considered. In the event of any collapse occurring during the excavations, the Contractor shall re-excavate and reinstate such excavations at his own expense. No additional excavations shall be paid if the Contractor batters the sides of the excavations to provide safe excavations slopes. 4.2.3 Excavation The Contractor shall perform all excavations true to lines, widths and depths shown on the drawings within a tolerance of +75 mm to the true lines and +25mm to the true depth and as may be directed by ADCO to reach a suitable bearing strata. All excavations shall be kept clear of water arising from any cause. During excavation for foundations, the bottom layer of excavation of minimum 150 mm in thickness, shall be left undisturbed and subsequently removed manually only when the concrete blinding is about to be placed in order to avoid softening or deterioration of the surfaces of the excavation. Bottom of all excavations shall be formed to correct levels as shown on the drawings or as directed in writing by ADCO and shall be trimmed, leveled and well cleaned before pouring any concrete. The Contractor shall provide adequate marking and temporary barricades and take all necessary steps to prevent any entry of public or others to the vicinity of open excavations. DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 6 OF11

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DATE :30-11-2011

After each excavation is complete, the Contractor shall notify ADCO and no concrete shall be placed until ADCO has approved the excavation and the character of the foundation material. 4.2.4 Filling The contractor shall submit to ADCO proposals regarding the materials, their source and the plant for spreading and compacting, filling and backfilling. Imported filling material shall only be used if excavated materials are not in full compliance with the required relevant fill type as described in clause 4.2.4.1 of this specification. In general all different fill materials (imported/excavated) shall be free from clay, rock/gravel larger than 75 mm and shall comprise non-plastic granular matter, well graded and free from organic or other perishable items and shall not contain an excess of fines. Unsuitable material and excess material of that required for construction works arising from site works shall be disposed / removed to a disposal area approved by local authorities and ADCO. Sample loads of the imported material shall be delivered to the site for inspection, testing (including sieve analysis) and compaction trials. This will be advised where applicable by construction. The contractor shall carry out compaction trials generally as described in Appendix (1), using the proposed methods and plant and shall satisfy ADCO that all the specified requirements regarding compaction can be achieved. All the specified compaction tests shall be carried out during these trials. 4.2.4.1 Filling Material The contractor shall use the filling/backfilling materials per the following classifications: a. General Fill Material General fill material shall be used as fill only at locations where installation of structures or equipment is not planned and in open areas where only grading is required to reach elevations noted on the drawings such as flare areas. The extent of use of general fill shall be subject to prior COMPANY approval. Properties and characteristics for general fill shall meet or exceed the following criteria:  Type of soil – Inorganic granular or silty soil  Gradation BS Sieve Size 75 mm 0.075 mm

Percent Passing 100 0.0 – 35.0

DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 7 OF11

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DATE :30-11-2011



Liquid limit = 40 max.

Fill shall be placed in layers not exceeding 500mm loose measurement. A capping layer, as stipulated afterwards, shall be used every three layers. Also, the final layer shall be a capping layer. General fill shall be compacted to at least 80% MDD of the maximum modified Proctor density in accordance with ASTM D1557, or 85% MDD of the maximum Standard Proctor density in accordance with ASTM D698. b. Engineering Fill Material Engineering fill material shall be used as fill in the following locations unless noted otherwise in the Project Documents: a. Roadway and paving sub-grades b. Embankments and dikes c. Grading of general area to be used by construction or plant operation such as warehouse and open storage area Properties and characteristics for engineering fill shall meet or exceed the following criteria:  Type of soil – Inorganic granular or silty soil.  Gradation BS Sieve Size 75 mm 37.5 mm 5 mm 0.6 mm 0.075 mm

Percent Passing 100 80 -100 20 -90 10-50 0-35

 Liquid limit = 40 max.  Plastic index minimum of 4 and maximum of 15. Field testing for each layer at each location shall be conducted to determine compacted density at a minimum frequency of two (2) tests per 1200 m2 of fill placed, with a minimum of two tests per layer. Fill shall be placed in layers not exceeding 300mm loose measurement. Engineering fill shall be compacted to at least 85% MDD of the maximum modified Proctor density in accordance with ASTM D1557, or 90% MDD of the maximum Standard Proctor density in accordance with ASTM D698. c. Structural Fill Material DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 8 OF11

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Structural fill shall be used as per the following criteria with 1:1 slope for axial load dissipation in the soil:   

Beneath or immediately surrounding foundations. Beneath slabs. Where otherwise indicted on the drawings.

Properties and characteristics for structural fill shall meet or exceed the following criteria:  Type of soil – Inorganic granular and free-draining soil.  Gradation – Uniformly graded BS Sieve Size 50 mm 37.5 mm 10 mm 5 mm 0.6 mm 0.075 mm  

Percent Passing 100 85-100 45-90 30-80 8-45 0-15

Liquid limit = 25 max Plastic index minimum of 4 and maximum of 12

Field testing for each layer at each location shall be conducted to determine compacted density at a minimum frequency of two (2) tests per 800 m2 of fill placed, with a minimum of two tests per layer. Fill shall be placed in layers not exceeding 300mm loose measurement. Structural fill shall be compacted to at least 90% MDD of the maximum modified Proctor density in accordance with ASTM D1557, or 95% MDD of the maximum Standard Proctor density in accordance with ASTM D698. No imported fill shall be used in the works until it has been approved by ADCO. No -fill material used overlying or within 500 mm of concrete structures or cement bound materials shall have a soluble sulfate content exceeding 2.5g/litre when tested in accordance with Test 10 of BS 1377. The amount of soluble chlorides within fill material shall be limited to less than 10,000 ppm. ADCO will require seeing sample test results for the fill material indicating the soluble sulfate and chloride content. d. Gatch, Where specified on drawings as fill material, shall be borrowed from areas predominantly consisting of cemented particles (wide range of soft rock DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 9 OF11

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DATE :30-11-2011

characteristics, silty sand, sandy silt and clayey sand). The combined content of gypsum and soluble salts shall be not more than 8%. The maximum content of gypsum shall be limited to 5% and of salts shall be limited to 3%. The particle composition when delivered at work site shall meet the following requirements: Sieve Size 3 in (75 mm) 1 / 2 in (38.1 mm) 3 / 8 in (9.52 mm) No. 4 (4.76 mm) No. 40 (0.425 mm) No. 200 ( 0.075 mm) Liquid Limit (BS 1377, Test 2) Plasticity Index (BS 1377, Test 2) Max. dry density 4 day soaked CBR at 95% MDD Max. Acid Soluble Chloride Content Max. Soluble Sulfate Content Max. Carbonate Content

Percentage Passing 100 85 to 100 40 to 90 25 to 85 30 to 50 10 to 30 Not greater than 40% Not greater than 10% Not less than 1.6 g/cm3. Not less than 30% 10000 ppm 2.5 g/liter 50% by weight

e. Capping layer Capping layer can be either engineering fill or Gatch. For embankments/bund walls capping material shall be only Gatch. f. Concrete stabilized sand Should any excavation be made below the required levels as shown on the drawings, Contractor shall fill up such excavation to the proper level with cement-sand mix (1:10) with sufficient potable water content to hydrate the cement. The cement, sand and water shall be mixed in a pugmill type mixer, which meets the approval of the Principal. Cement shall be type I Portland cement conforming to ASTM C150 and sand shall be clean durable sand, free from organic matter, and plasticity index shall be 6 or less when tested in accordance with ASTM D4318. The sand cement mix shall be placed in 200 mm maximum thick lifts, loose measure, and thoroughly rodded and tamped in a manner that shall fill all voids. Materials not placed and compacted within four (4) hours after mixing shall be rejected. Sand-cement mixtures shall not be placed in standing or free water. A minimum of one sample shall be taken at random for testing to represent the production. However, the Principal shall have the option to ask for more samples to be tested on the contractor’s expense. DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 10 OF11

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4.2.4.2 Programming of Filling Operations Filling operations shall be programmed so as to ensure that the specified compaction is attained throughout and that reasonable time is allowed for all tests that are required for verification. 4.2.4.3 Backfill of Pipe Trenches Following the completion of pipeline bedding, laying, jointing and testing (not covered by this specification) the trench shall be backfilled with material as specified above and as shown on the drawings. 4.2.4.4 Filling Around and Over Substructures and Foundations To prevent movement or damage, fill around structures and over substructures and foundations shall be brought up evenly on each side and shall not be placed over the foundation until the latter has attained 75% of its specified strength and protective coating been applied and that great care shall be taken with the first layers of fill over the top of the structure. Heavy compaction plant shall not be employed to a distance of 1.25 m or greater beyond the sides of the structure and over foundations until the fill is at least 1 meter deep having been compacted in layers by light plant or mechanical rammers. 4.2.4.5 Backfilling around Manholes The space around the manhole walls and the faces of the excavation and the spaces above the chamber roofs and around shafts shall be backfilled with the selected excavated material in layers of 200 mm loose depth and fully compacted with mechanical rammers. 4.2.5 Compaction Frequency of compaction tests, unless specified earlier, shall be minimum one in situ test per 1000 square meter per layer. Materials used as fill in embankments and elsewhere shall be compacted as soon as practicable after placing. Water used for compaction for structural fill shall be clean potable water as specified in ADCO’s Specifications of Concrete Document number 3099-75-0066. Only brackish water with 0.50-30 ppt. can be used for compaction of other types of fill material. Earth moving plant shall not be used as compaction equipment. The moisture content of the material being compacted shall be within plus or minus 3 percent of optimum moisture content prior to compaction in accordance with the applicable ASTM D1557 or ASTM D698. DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 11 OF11

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Compaction by water jetting or flooding shall not be permitted. The Contractor shall be responsible for making good all settlement of filling that may occur until the end of the maintenance period of the Contract. 4.2.6 Dewatering Excavations shall be kept free from water at all times. The responsibility for removing water shall rest with the contractor and no claim for expense shall be entertained. All dewatering methods and disposal of water shall be approved by the COMPANY. The method statement for dewatering system shall include the following:  Number, location, sizes and capabilities of pumping station.  Location and number of well points and pump sumps.  Locations, depth and arrangements of cofferdams and sheet piling, if sheet piles are necessary.  Type of materials for shoring, strutting, bracing and/or sheet piling.  Method and routing of water discharge.  Calculation for the stability and slopes.  Proposed precautions for emergency. If required for construction, before excavation, an approved dewatering system shall be installed and approved when necessary to lower groundwater. Unless otherwise specified in the contract documents, the design of the dewatering system shall be the responsibility of the contractor. Contractor shall be responsible for the effects of dewatering on adjacent facilities. Any damage occurring during the above mentioned period shall then be made good by the Contractor. Surface water shall be prevented from flowing into excavations by installing ditches, trenches, protective swales or other purchaser approved measures. Excavations for foundations and other underground installations shall not be used as temporary ditches. At all times during construction, ample means with which to remove and properly dispose of all water from every natural source entering the excavation shall be provided and maintained. Any water to be discharged that is potentially suspect of quality shall be tested for water quality to determine whether the water can be disposed of through the natural waterways or whether it shall be contained for treatment. The Contractor has to consider the possibility of a temporary failure of any pump, diesel engine and/or the electrical power service and shall install emergency DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 12 OF11

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power units with sufficient capacity to feed the necessary power to the installed unit at the moment of failure. 4.3

PREPARATION OF SOIL BEARING FOUNDATIONS

4.4

MOUNDS FOR BURIED VESSELS

5

BUNDED AREAS AND FOUNDATIONS FOR TANKS

5.1

Bunded Areas for Tanks

5.2

Impounding Basin

5.3

Bunds And Bundwalls

5.3.1

Design of Bunds

5.3.2

Bund Materials

Delete the statement "A bund constructed entirely with clay is normally preferred” Add: Bund wall construction can also consist of compacted sand body with a cover of impermeable compacted gatch layer 300 mm thick. 5.3.3

Construction of Bunds

5.3.4

Bund covering (erosion protection)

Delete the third paragraph Add: Bund wall finish can be by pre-cast concrete tiles with all necessary layers, proper joints and filter membrane underneath. 5.3.5

Structural elements

Delete “or sheet piles” and the last paragraph “A walling ................the joints” 5.4

Surface Finishes of Bunded Areas

5.5

Tank Foundations

5.5.1 General Delete the paragraph " Atmospheric ................sometimes used as foundation" Delete part of the statement in the next paragraph "In earthquake, hurricane or typhoon areas, or" DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 13 OF11

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Delete the last paragraph 5.5.2 Tank foundation functions and requirements 5.5.3 Design of tank foundations 5.5.4 Materials 5.5.5 Construction 5.5.6 Tank foundation finishes 5.5.7 Tank bottom settlements th

Delete part of the statement in the 4 paragraph “Freeze /thaw effects in cold climates” 5.5.8 Hydrostatic settlement of tanks 5.5.9 5.6 Tank Foundation with Leak and Detection of Leak Management System 5.7

Special Tank Foundations

6

TANK MAINTENANCE

7

DRAINAGE OF BUNDED AREAS

8

REFERENCES Add: Reinforced Concrete Foundations and Structures

DEP 34.19.20.31-Gen.

BRITISH STANDARDS BS 6031 BS 1377 9

Code of Practice for Earthworks Methods of Test for Soils for Civil Engineering Purposes

APPENDICES

DOCUMENT TITLE :

Site Preparation and Earthworks Including Tank Foundations and Tank Farms

ADCO DOCUMENT No. 34.11.00.11A PAGE 14 OF11

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DATE :30-11-2011