gs (2020 edition) · gs (2020 edition) 2 . general specification for civil engineering works (gs),...

GS (2020 Edition)

2

General Specification for Civil Engineering Works (GS), 2020 Edition Volume 1 of 2

(This Version is Continuously Updated to include Amendments issued)

This Electronic File has incorporated the following Amendments:-

Rev Issue Date Amendment Incorporated

First Issue 31 December 2020 -

GS (2020 Edition)

3

FOREWORD

The General Specification for Civil Engineering Works lays down the quality of materials, the standards of workmanship, the testing methods and the acceptance criteria for civil engineering works undertaken for the Government of the Hong Kong Special Administrative Region. Where necessary, this General Specification should be supplemented by a particular specification. The 2020 Edition of the General Specification comprises mainly the latest update on the review of obsolete standards with the updated text printed in green colour for easy reference. It was produced under the guidance of a Steering Committee comprising members from the main Government departments involved in civil engineering works. The Quality Management & Standards Unit of the Civil Engineering and Development Department (CEDD) was responsible for the overall co-ordination of comments received from departmental circulation, editing and production of the document. The 2020 Edition comprises 26 sections and is posted on CEDD Homepage on the Internet.

The General Specification will be updated continuously. The electronic files of the sections affected by any amendment issued will be kept up-to-date on CEDD Homepage.

December 2020

GS (2020 Edition)

4

GENERAL SPECIFICATION FOR CIVIL ENGINEERING WORKS

CONTENTS

VOLUME 1

SECTION 1 GENERAL

2 SITE CLEARANCE

3 LANDSCAPE SOFTWORKS AND ESTABLISHMENT WORKS

4 FENCING

5 DRAINAGE WORKS

6 EARTHWORKS

7 GEOTECHNICAL WORKS

8 PILING WORKS 9 CARRIAGEWAYS: SUB-BASE MATERIAL AND BITUMINOUS MATERIALS

10 CONCRETE CARRIAGEWAYS

11 MISCELLANEOUS ROADWORKS

12 TRAFFIC SIGNS, ROAD MARKINGS AND ROAD STUDS

VOLUME 2

SECTION 13 WORK FOR ELECTRICAL AND MECHANICAL INSTALLATIONS

14 FORMWORK AND FINISHES TO CONCRETE

15 STEEL REINFORCEMENT

16 CONCRETE AND JOINTS IN CONCRETE

17 PRESTRESSING

18 STEELWORK

19 HANDRAILING, LADDERS, STAIRS AND FLOORING

20 BRIDGEWORKS

21 MARINE WORKS

22 WATER SUPPLY PIPEWORKS

23 WATER RETAINING STRUCTURES

24 BUILDING WORKS

25 ENVIRONMENTAL PROTECTION

26 PRESERVATION AND PROTECTION OF TREES

GS (2020 Edition)

5

CONTENT OF VOLUME 1

SECTION 1

GENERAL

INTERPRETATION OF DOCUMENTS 1.01 Application of the General Specification for Civil Engineering Works ....................................... 1.3 1.02 Abbreviations ................................................................................................................................ 1.3 1.03 Glossary of terms .......................................................................................................................... 1.5 1.04 Trials and approval ....................................................................................................................... 1.5 1.05 British Standards, European Standards adopted as British Standards, Codes of Practice

and other standards ....................................................................................................................... 1.6 1.06 Specifications in metric and imperial units................................................................................... 1.6 1.07 Dimensions from Drawings .......................................................................................................... 1.6

PROGRAMME 1.08 Programme.................................................................................................................................... 1.6

CONTRACTOR'S SUPERINTENDENCE 1.09 Surveyor........................................................................................................................................ 1.7 1.10 Foreman for concrete works ......................................................................................................... 1.7 1.11 Supervision of piling works .......................................................................................................... 1.7 1.12 Particulars of Agent and employees ............................................................................................. 1.8

CONSTRUCTION SAFETY AND SAFETY OF THE PUBLIC 1.13 Construction safety and safety of the public ................................................................................. 1.9

WORK ON ROADS 1.14 Approval for temporary traffic arrangements and control .......................................................... 1.10 1.15 Temporary traffic arrangements and control............................................................................... 1.10 1.16 Particulars of temporary traffic arrangements and control ......................................................... 1.11 1.17 Use of roads and footways .......................................................................................................... 1.11 1.18 Work on roads and footways ...................................................................................................... 1.11 1.19 Reinstatement of roads and footways ......................................................................................... 1.12

CARE OF THE WORKS 1.20 Protection from water ................................................................................................................. 1.12 1.21 Protection from weather ............................................................................................................. 1.13 1.22 Protection of works ..................................................................................................................... 1.13

DAMAGE AND INTERFERENCE 1.23 Damage and interference ............................................................................................................ 1.13 1.24 Watercourses and drainage systems ............................................................................................ 1.13

GS (2020 Edition)

6

1.25 Utilities ....................................................................................................................................... 1.14 1.26 Structures, roads and other property ........................................................................................... 1.16 1.27 Access ......................................................................................................................................... 1.16

RECORDS 1.28 Records of wage rates ................................................................................................................. 1.16 1.29 Records of correspondence ......................................................................................................... 1.16 1.30 Records and reports .................................................................................................................... 1.16

LIAISON WITH OTHERS 1.31 Liaison with others ..................................................................................................................... 1.17

SITE CLEANLINESS 1.32 Site cleanliness ........................................................................................................................... 1.17 1.33 Prevention of mosquito breeding ................................................................................................ 1.18 1.34 Prevention of dust ....................................................................................................................... 1.18 1.34A Control of Dogs on Construction Sites ....................................................................................... 1.18

MATERIALS AND EQUIPMENT 1.35 Materials and equipment provided by the Employer .................................................................. 1.20 1.36 Materials ..................................................................................................................................... 1.20

TESTING 1.37 Not used ...................................................................................................................................... 1.20 1.38 Batches, samples and specimens ................................................................................................ 1.20 1.39 Samples for testing ..................................................................................................................... 1.20 1.40 Testing ........................................................................................................................................ 1.22 1.41 Compliance of a batch ................................................................................................................ 1.23 1.42 Raw records of tests and test reports .......................................................................................... 1.23

WORKMANSHIP AND TOLERANCES 1.43 Workmanship .............................................................................................................................. 1.24 1.44 Tolerances ................................................................................................................................... 1.24

SITE ESTABLISHMENT 1.45 Use of the Site ............................................................................................................................. 1.25 1.45A Occupancy and Rental of Private Land of Ecological Values .................................................... 1.25 1.46 Submission of particulars ........................................................................................................... 1.25 1.47 Survey of the Site ....................................................................................................................... 1.26 1.48 Fences and signs on the Site ....................................................................................................... 1.26 1.49 The Engineer's Site accommodation ........................................................................................... 1.26 1.50 The Contractor's Site accommodation ........................................................................................ 1.27 1.51 Site utilities and access ............................................................................................................... 1.27 1.52 Transport for the Engineer .......................................................................................................... 1.27 1.53 Clearance of the Site ................................................................................................................... 1.28

GS (2020 Edition)

7

MEETINGS

1.54 Meetings ..................................................................................................................................... 1.28

PHOTOGRAPHS 1.55 Progress photographs and record photographs ........................................................................... 1.29

APPENDIX 1.1 STANDARDS

1.1.1 BRITISH STANDARDS ............................................................................................................ 1.30 1.1.2 AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) STANDARDS ........... 1.37 1.1.3 AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION

OFFICIALS (AASHTO) STANDARD ...................................................................................... 1.38 1.1.4 AMERICAN WATER WORKS ASSOCIATION (AWWA) STANDARDS/ AMERICAN

NATIONAL STANDARDS INSTITUTE (ANSI) ..................................................................... 1.39 1.1.5 CONSTRUCTION STANDARDS OF THE GOVERNMENT OF THE HKSAR .................... 1.39 1.1.6 AMERICAN PUBLIC HEALTH ASSOCIATION (APHA) STANDARDS ............................. 1.39 1.1.7 EUROPEAN STANDARDS ADOPTED AS BRITISH STANDARDS (BS EN) ..................... 1.39 1.1.8 EUROPEAN STANDARDS (EN) and/or INTERNATIONAL ORGANIZATION FOR

STANDARDIZATION (ISO) STANDARDS ADOPTED AS BRITISH STANDARDS (BS EN ISO) ............................................................................................................................... 1.51

1.1.9 JAPANESE INDUSTRIAL STANDARDS (JIS) ....................................................................... 1.58 1.1.10 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO)

STANDARDS............................................................................................................................. 1.58 1.1.11 WATER INDUSTRY SPECIFICATION, WATER RESEARCH CENTRE ............................... 1.58 1.1.12 NATIONAL WATER COUNCIL, UK ....................................................................................... 1.58 1.1.13 AUSTRALIAN/NEW ZEALAND STANDARDS (AS/NZS) ................................................... 1.59 1.1.14 中華人民共和國行業標準 ........................................................................................................ 1.59 1.1.15 CANADIAN STANDARD ........................................................................................................ 1.59 1.1.16 PUBLICLY AVAILABLE SPECIFICATION ............................................................................. 1.59 1.1.17 GEO PUBLICATION ................................................................................................................. 1.59 1.1.18 DESIGN MANUAL PUBLISHED BY HIGHWAYS DEPARTMENT ..................................... 1.59 1.1.19 IEC SYSTEM OF CONFORMITY ASSESSMENT SCHEMES FOR

ELECTROTECHNICAL EQUIPMENT AND COMPONENTS (IECEE) ............................... 1.59

APPENDIX 1.2 REQUIREMENTS FOR STEEL CONTAINER ROOM

1.2.1 General........................................................................................................................................ 1.60 1.2.2 Equipment ................................................................................................................................... 1.60

APPENDIX 1.3 REQUIREMENTS FOR CURING TANK

1.3.1 General........................................................................................................................................ 1.61 1.3.2 Equipment ................................................................................................................................... 1.61 1.3.3 Maintenance ................................................................................................................................ 1.61

GS (2020 Edition)

8

SECTION 2 SITE CLEARANCE

GENERAL

2.01 General requirements .................................................................................................................... 2.3 2.02 Pipes and manholes to be abandoned ........................................................................................... 2.3 2.03 Earthworks .................................................................................................................................... 2.3

SITE CLEARANCE 2.04 Demolition .................................................................................................................................... 2.3 2.05 Pipes and cables ............................................................................................................................ 2.3 2.06 Trees ............................................................................................................................................. 2.3 2.07 Reinstatement ............................................................................................................................... 2.3 2.08 Materials and equipment for re-use and storage ........................................................................... 2.4

SECTION 3 LANDSCAPE SOFTWORKS AND ESTABLISHMENT WORKS

GENERAL

3.01 General requirements .................................................................................................................... 3.3 3.02 Site clearance ................................................................................................................................ 3.3 3.03 Earthworks .................................................................................................................................... 3.3 3.04 Landscape hardworks ................................................................................................................... 3.3 3.05 Geotechnical works ...................................................................................................................... 3.3 3.06 Weather and ground conditions .................................................................................................... 3.3 3.07 Use of chemicals ........................................................................................................................... 3.3

GLOSSARY OF TERMS 3.08 Landscape softworks .................................................................................................................... 3.3 3.09 Landscape hardworks ................................................................................................................... 3.3 3.10 Establishment works ..................................................................................................................... 3.3

MATERIALS 3.11 Seedling trees ................................................................................................................................ 3.4 3.12 Whip trees ..................................................................................................................................... 3.4 3.13 Light standard trees ...................................................................................................................... 3.4 3.14 Standard trees................................................................................................................................ 3.5 3.15 Heavy standard trees ..................................................................................................................... 3.5 3.16 Semi-mature trees ......................................................................................................................... 3.5 3.17 Small shrubs ................................................................................................................................. 3.6 3.18 Large shrubs.................................................................................................................................. 3.6 3.19 Conifers ........................................................................................................................................ 3.6

GS (2020 Edition)

9

3.20 Palms ............................................................................................................................................ 3.7 3.21 Bamboos ....................................................................................................................................... 3.7 3.22 Herbaceous plants ......................................................................................................................... 3.7 3.23 Ground covers ............................................................................................................................... 3.8 3.24 Climbers........................................................................................................................................ 3.8 3.25 Containerised plants ..................................................................................................................... 3.8 3.26 Grass seed ..................................................................................................................................... 3.8 3.27 Turf ............................................................................................................................................... 3.9 3.28 Sprigs ............................................................................................................................................ 3.9 3.29 Plant name .................................................................................................................................... 3.9 3.30 Soil-mix ........................................................................................................................................ 3.9 3.31 Soil conditioner ........................................................................................................................... 3.10 3.32 Mulch .......................................................................................................................................... 3.10 3.33 Mulch for hydroseeding .............................................................................................................. 3.10 3.34 Fertilizer...................................................................................................................................... 3.10 3.35 Soil binder................................................................................................................................... 3.11 3.36 Stakes, ties and guys ................................................................................................................... 3.11 3.37 Protective fabric material ............................................................................................................ 3.11

SUBMISSIONS 3.38 Particulars of seed mixture, turf, sprigs, soil conditioner, soil-mix and water ........................... 3.12 3.39 Particulars of hydroseeding ........................................................................................................ 3.12 3.40 Samples of materials ................................................................................................................... 3.13

HANDLING, STORAGE AND TRANSPORT 3.41 Handling and storage of rootballed stock ................................................................................... 3.13 3.42 Handling and storage of container grown and containerised stock ............................................ 3.13 3.43 Transport of plants ...................................................................................................................... 3.13 3.44 Storage of plants ......................................................................................................................... 3.14 3.45 Storage of trees and shrubs ......................................................................................................... 3.14 3.46 Handling and storage of turf and sprigs ...................................................................................... 3.14 3.47 Storage of grass seed .................................................................................................................. 3.14 3.48 Storage of fertilizer ..................................................................................................................... 3.14

PRE-PLANTING WORKS 3.49 Preparatory works ....................................................................................................................... 3.14 3.50 Cleaning ground ......................................................................................................................... 3.14 3.51 Ripping ....................................................................................................................................... 3.14 3.52 Contaminated ground ................................................................................................................. 3.14 3.53 Soiling ......................................................................................................................................... 3.14 3.54 Cultivation .................................................................................................................................. 3.15 3.55 Scarifying.................................................................................................................................... 3.15 3.56 Protection of prepared ground .................................................................................................... 3.15 3.57 Removal of material ................................................................................................................... 3.15

PLANTING 3.58 General........................................................................................................................................ 3.15 3.59 Use of excavated material ........................................................................................................... 3.16 3.60 Planting ....................................................................................................................................... 3.16 3.61 Staking, tying and guying ........................................................................................................... 3.16 3.62 Mulching ..................................................................................................................................... 3.16 3.63 Notch planting of seedlings ........................................................................................................ 3.16

GS (2020 Edition)

10

3.64 Pit planting of seedlings, shrubs, whips, climbers, ground covers and herbaceous plants ......... 3.16 3.65 Pit planting of light standard trees and standard trees ............................................................. 3.17 3.66 Pit planting of heavy standard tree and semi-mature trees ......................................................... 3.17 3.67 Pit planting of bamboo, conifers and palms ............................................................................... 3.18 3.68 Pit planting on slopes .................................................................................................................. 3.18

GRASSING 3.69 Hydroseeding .............................................................................................................................. 3.18 3.70 Hydroseeding cover .................................................................................................................... 3.18 3.71 Surface conditions for hydroseeding .......................................................................................... 3.18 3.72 Application of hydroseeding....................................................................................................... 3.18 3.73 Protective material ...................................................................................................................... 3.19 3.74 Patching up ................................................................................................................................. 3.19 3.75 Post-planting fertilizer ................................................................................................................ 3.19 3.76 Turfing ........................................................................................................................................ 3.19 3.77 Sprigging .................................................................................................................................... 3.19 3.78 Completion of turfing and sprigging .......................................................................................... 3.20

ESTABLISHMENT WORKS 3.79 Establishment works ................................................................................................................... 3.20 3.80 Inspection of establishment works .............................................................................................. 3.20 3.81 Replacement of plants and grass ................................................................................................. 3.20 3.82 Security of stakes, ties and guys ................................................................................................. 3.20 3.83 Firming up plants ........................................................................................................................ 3.21 3.84 Watering ...................................................................................................................................... 3.21 3.85 Weeding ...................................................................................................................................... 3.21 3.86 Pruning........................................................................................................................................ 3.21 3.87 Grass cutting ............................................................................................................................... 3.22 3.88 Litter collection ........................................................................................................................... 3.22 3.89 Post-planting fertilizer ................................................................................................................ 3.22 3.90 Control of pests, fungi and disease ............................................................................................. 3.23 3.91 Forking over ............................................................................................................................... 3.23 3.92 Mulching ..................................................................................................................................... 3.23 3.93 Completion of work .................................................................................................................... 3.23

TESTING: GRASS COVER 3.94 Testing: grass cover .................................................................................................................... 3.24 3.95 Compliance criteria: grass cover ................................................................................................ 3.24 3.96 Non-compliance: grass cover ..................................................................................................... 3.24

TREE TRANSPLANTING 3.97 Transplanting of existing trees .................................................................................................... 3.24

SECTION 4 FENCING

GENERAL

4.01 General requirements .................................................................................................................... 4.3

GS (2020 Edition)

11

4.02 Handrailing ................................................................................................................................... 4.3 4.03 Earthworks .................................................................................................................................... 4.3 4.04 Pedestrian guardrailing ................................................................................................................. 4.3 4.05 Formwork and finishes to concrete ............................................................................................... 4.3 4.06 Reinforcement .............................................................................................................................. 4.3 4.07 Concrete ........................................................................................................................................ 4.3 4.08 Steelwork ...................................................................................................................................... 4.3 4.09 Vehicular parapets ......................................................................................................................... 4.3

MATERIALS 4.10 Wire .............................................................................................................................................. 4.3 4.11 Chain link fence ............................................................................................................................ 4.3 4.12 Timber........................................................................................................................................... 4.3 4.13 Steel .............................................................................................................................................. 4.3 4.14 Bolts, nuts, washers and fittings ................................................................................................... 4.4

FABRICATION OF FENCING 4.15 Fabrication of steelwork ............................................................................................................... 4.4 4.16 Galvanizing to steel ...................................................................................................................... 4.4 4.17 Welding steel ................................................................................................................................ 4.4

POSTS AND GATES FOR FENCING 4.18 Concrete posts ............................................................................................................................... 4.4 4.19 Gates ............................................................................................................................................. 4.5

SUBMISSIONS 4.20 Particulars of fencing .................................................................................................................... 4.5 4.21 Samples of materials ..................................................................................................................... 4.5

STORAGE OF MATERIALS 4.22 Storage of fencing ......................................................................................................................... 4.5

ERECTING FENCING 4.23 Alignment of fencing .................................................................................................................... 4.5 4.24 Posts for fencing ........................................................................................................................... 4.6 4.25 Erecting posts for fencing ............................................................................................................. 4.6 4.26 Fixing wire for fencing ................................................................................................................. 4.6 4.27 Fixing gates................................................................................................................................... 4.7

TOLERANCES 4.28 Tolerances: fencing ....................................................................................................................... 4.7

SECTION 5 DRAINAGE WORKS

GS (2020 Edition)

12

GENERAL

5.01 General requirements .................................................................................................................... 5.3 5.02 Metalwork ..................................................................................................................................... 5.3 5.03 Earthworks .................................................................................................................................... 5.3 5.04 Formwork ..................................................................................................................................... 5.3 5.05 Concrete ........................................................................................................................................ 5.3 5.06 Materials for grout ........................................................................................................................ 5.3 5.07 Water supply pipeworks ............................................................................................................... 5.3 5.08 Cable duct systems ....................................................................................................................... 5.3 5.09 Recycled Aggregates .................................................................................................................... 5.3

GLOSSARY OF TERMS

5.10 Pipes ............................................................................................................................................. 5.3

MATERIALS

5.11 Precast concrete pipes and fittings ................................................................................................ 5.3 5.12 Vitrified clay pipes and fittings ..................................................................................................... 5.3 5.13 DI pipes and fittings ..................................................................................................................... 5.4 5.14 Grey iron pipes and fittings .......................................................................................................... 5.4 5.15 uPVC pipes and fittings ................................................................................................................ 5.4 5.16 GI pipes and fittings ..................................................................................................................... 5.4 5.16A PE pipes and fittings ..................................................................................................................... 5.5 5.17 Bolts, nuts and washers ................................................................................................................ 5.6 5.18 Elastomeric joint rings .................................................................................................................. 5.6 5.19 Detachable couplings and flange adapters .................................................................................... 5.6 5.20 Anticorrosion tape ........................................................................................................................ 5.7 5.21 Bituminous coatings ..................................................................................................................... 5.8 5.22 Aggregates for granular bed and granular fill ............................................................................... 5.9 5.23 Joint filler and compressible padding ........................................................................................... 5.9 5.24 Polyethylene sheeting ................................................................................................................... 5.9 5.25 Precast concrete manholes ............................................................................................................ 5.9 5.26 Chambers and gullies .................................................................................................................. 5.10 5.27 Step irons .................................................................................................................................... 5.10 5.28 Manhole covers, gully gratings and kerb overflow weirs made of cast iron .............................. 5.10 5.28A Gully gratings and channel gratings made of compound material ............................................. 5.10 5.29 Penstocks .................................................................................................................................... 5.12 5.30 Gate valves ................................................................................................................................. 5.13 5.31 Flap valves .................................................................................................................................. 5.13 5.32 Sludge valves .............................................................................................................................. 5.13 5.33 Air valves .................................................................................................................................... 5.14 5.34 Fittings for penstocks and valves ................................................................................................ 5.14 5.35 Filling abandoned pipes and manholes ....................................................................................... 5.15

SUBMISSIONS

5.36 Particulars of pipes, joints and fittings ....................................................................................... 5.15 5.37 Particulars of anticorrosion tape and joint filler ......................................................................... 5.15 5.38 Particulars of aggregates for granular bed .................................................................................. 5.16 5.39 Particulars of manholes, chambers and gullies ........................................................................... 5.16 5.40 Particulars of penstocks and valves ............................................................................................ 5.16 5.41 Particulars of foam concrete and PC/PFA grout ......................................................................... 5.17 5.42 Particulars of tests ....................................................................................................................... 5.17 5.43 Particulars of CCTV inspections ................................................................................................ 5.17

GS (2020 Edition)

13

5.44 Particulars of diversions of flow ................................................................................................. 5.17

TRANSPORT, HANDLING AND STORAGE OF MATERIALS 5.45 Transport, handling and storage of pipes, joints and fittings ...................................................... 5.18 5.46 Handling of pipes and fittings..................................................................................................... 5.18 5.47 Storage of pipes .......................................................................................................................... 5.18 5.48 Storage of anticorrosion tape and joint filler .............................................................................. 5.18 5.49 Handling and storage of aggregates for granular bed ................................................................. 5.19 5.50 Handling and storage of units for manholes, chambers and gullies ........................................... 5.19 5.51 Storage of covers, gratings, weirs penstocks and valves ............................................................ 5.19

EXCAVATION 5.52 Excavation .................................................................................................................................. 5.19

LAYING AND BEDDING PIPES 5.53 Laying pipes ............................................................................................................................... 5.20 5.54 Bedding pipes ............................................................................................................................. 5.21

CUTTING PIPES 5.55 Cutting pipes ............................................................................................................................... 5.21

JOINTING PIPES 5.56 Jointing pipes .............................................................................................................................. 5.22 5.57 Flanged joints ............................................................................................................................. 5.22 5.58 Flexible collar joints ................................................................................................................... 5.22 5.59 Push-in joints .............................................................................................................................. 5.23 5.60 Detachable joints ........................................................................................................................ 5.23 5.61 Flange adapters ........................................................................................................................... 5.23 5.62 Solvent welded joints .................................................................................................................. 5.23 5.63 Screw joints ................................................................................................................................ 5.23

PROTECTION OF JOINTS 5.64 Protection of joints ...................................................................................................................... 5.24

REPAIRS TO COATINGS AND LININGS 5.65 Repairs to coatings and linings ................................................................................................... 5.24

THRUST AND ANCHOR BLOCKS 5.66 Thrust and anchor blocks ............................................................................................................ 5.24

BED, HAUNCH AND SURROUND 5.67 Granular bed ............................................................................................................................... 5.25 5.68 Concrete bed, haunch and surround ............................................................................................ 5.25 5.69 Fill material surround ................................................................................................................. 5.26

GS (2020 Edition)

14

TOLERANCES

5.70 Tolerances: pipelines for drainage works ................................................................................... 5.26

CONNECTIONS 5.71 Connections to structures ............................................................................................................ 5.27 5.72 Connections to pipes ................................................................................................................... 5.27

MANHOLES, CHAMBERS, GULLIES AND CHANNELS 5.73 Manholes, chambers and gullies ................................................................................................. 5.28 5.74 Concrete open channels .............................................................................................................. 5.29

MARKER BLOCKS 5.75 Marker blocks ............................................................................................................................. 5.29

INSTALLATION OF PENSTOCKS AND VALVES 5.76 Installation of penstocks and valves ........................................................................................... 5.29

PIPES AND MANHOLES TO BE ABANDONED 5.77 Pipes and manholes to be abandoned ......................................................................................... 5.29

CLEANING OF PIPELINES 5.78 Cleaning of pipelines .................................................................................................................. 5.30

INSPECTION OF PIPELINES 5.79 Inspection of pipelines ................................................................................................................ 5.31 5.80 Inspection of pipelines by CCTV ............................................................................................... 5.31

TESTING: PIPES FOR DRAINAGE WORKS 5.81 Batch: pipes for drainage works ................................................................................................. 5.31 5.82 Samples: pipes for drainage works ............................................................................................. 5.31 5.83 Testing: pipes for drainage works ............................................................................................... 5.31 5.84 Non-compliance: pipes for drainage works ................................................................................ 5.32

TESTING: AGGREGATES FOR GRANULAR BED 5.85 Batch: aggregates for granular bed ............................................................................................. 5.32 5.86 Samples: aggregates for granular bed ......................................................................................... 5.32 5.87 Testing: aggregates for granular bed ........................................................................................... 5.32 5.88 Compliance criteria: compaction fraction value ......................................................................... 5.32

TESTING: PRECAST CONCRETE UNITS FOR MANHOLES, CHAMBERS AND GULLIES

5.89 Batch: manholes, chambers and gullies ...................................................................................... 5.33

GS (2020 Edition)

15

5.90 Samples: manholes, chambers and gullies .................................................................................. 5.33 5.91 Testing: manholes, chambers and gullies ................................................................................... 5.33 5.92 Non-compliance: manholes, chambers and gullies..................................................................... 5.33

TESTING: MANHOLE COVERS, GULLY GRATINGS AND KERB OVERFLOW WEIRS MADE OF CAST IRON

5.93 Batch: covers, gratings and weirs ............................................................................................... 5.33 5.94 Samples: covers, gratings and weirs ........................................................................................... 5.33 5.95 Testing: covers, gratings and weirs ............................................................................................. 5.33 5.96 Compliance criterion: resistance to fracture of covers and gratings ........................................... 5.34 5.97 Non-compliance: mass of covers, gratings and weirs................................................................. 5.34 5.98 Non-compliance: resistance to fracture of covers and gratings .................................................. 5.34

TESTING: GULLY GRATINGS AND CHANNEL GRATINGS MADE OF COMPOUND MATERIAL

5.98A Batch ........................................................................................................................................... 5.34 5.98B Samples ....................................................................................................................................... 5.34 5.98C Testing and compliance critieria ................................................................................................. 5.34

TESTING: WATERTIGHTNESS OF PENSTOCKS 5.99 Testing: watertightness of penstocks .......................................................................................... 5.37 5.100 Compliance criteria: watertightness of penstocks ...................................................................... 5.37 5.101 Non-compliance: watertightness of penstocks ........................................................................... 5.37

TESTING: GRAVITY PIPELINES FOR DRAINAGE WORKS 5.102 Testing: gravity pipelines for drainage works ............................................................................. 5.37 5.103 Compliance criteria: gravity pipelines for drainage works ......................................................... 5.38 5.104 Non-compliance: gravity pipelines for drainage works .............................................................. 5.39

TESTING: PRESSURE PIPELINES FOR DRAINAGE WORKS 5.105 Testing: pressure pipelines for drainage works ........................................................................... 5.38 5.106 Compliance criteria: pressure pipelines for drainage works ....................................................... 5.39 5.107 Non-compliance: pressure pipelines for drainage works ............................................................ 5.39

REPAIR OF PIPELINES AND CULVERTS BY INTERNAL LINING 5.108 General........................................................................................................................................ 5.40 5.109 Materials ..................................................................................................................................... 5.40 5.110 Design of lining .......................................................................................................................... 5.40 5.111 Submissions ................................................................................................................................ 5.40 5.112 Installation of lining .................................................................................................................... 5.40 5.113 Performance tests on internal lining materials ............................................................................ 5.41

APPENDIX 5.1 CCTV INSPECTION OF PIPELINES

5.1.1 Scope .......................................................................................................................................... 5.44 5.1.2 Equipment ................................................................................................................................... 5.44 5.1.3 Procedure .................................................................................................................................... 5.44

GS (2020 Edition)

16

5.1.4 Recording of results .................................................................................................................... 5.45

APPENDIX 5.2 DETERMINATION OF THE COMPACTION FRACTION VALUE OF AGGREGATES FOR GRANULAR BED

5.2.1 Scope .......................................................................................................................................... 5.46 5.2.2 Apparatus .................................................................................................................................... 5.46 5.2.3 Procedure .................................................................................................................................... 5.46 5.2.4 Calculation .................................................................................................................................. 5.46 5.2.5 Reporting of results .................................................................................................................... 5.47

APPENDIX 5.3 DETERMINATION OF THE RESISTANCE TO FRACTURE OF MANHOLE COVERS AND GULLY GRATINGS

5.3.1 Scope .......................................................................................................................................... 5.48 5.3.2 Equipment ................................................................................................................................... 5.48 5.3.3 Procedure .................................................................................................................................... 5.48 5.3.4 Reporting of results .................................................................................................................... 5.48

APPENDIX 5.4 TESTS ON GRAVITY PIPELINES FOR DRAINAGE WORKS

5.4.1 Scope .......................................................................................................................................... 5.49 5.4.2 Equipment ................................................................................................................................... 5.49 5.4.3 Procedure: before tests and inspections ...................................................................................... 5.49 5.4.4 Procedure: water test .................................................................................................................. 5.49 5.4.5 Procedure: air test ....................................................................................................................... 5.50 5.4.6 Procedure: visual inspection ....................................................................................................... 5.50 5.4.7 Procedure: infiltration test .......................................................................................................... 5.50 5.4.8 Calculation .................................................................................................................................. 5.50 5.4.9 Reporting of results .................................................................................................................... 5.50

APPENDIX 5.5 TESTS ON PRESSURE PIPELINES FOR DRAINAGE WORKS

5.5.1 Scope .......................................................................................................................................... 5.52 5.5.2 Equipment ................................................................................................................................... 5.52 5.5.3 Procedure .................................................................................................................................... 5.52 5.5.4 Calculation .................................................................................................................................. 5.53 5.5.5 Reporting of results .................................................................................................................... 5.53

SECTION 6 EARTHWORKS

GENERAL

6.01 Reclamation .................................................................................................................................. 6.3 6.02 Trip-ticket System ........................................................................................................................ 6.3

GS (2020 Edition)

17

GLOSSARY OF TERMS 6.03 Areas of fill ................................................................................................................................... 6.3 6.04 Earthworks final surface ............................................................................................................... 6.3 6.05 Inert construction and demolition material ................................................................................... 6.3 6.06 Earthworks material ...................................................................................................................... 6.3 6.07 Formation...................................................................................................................................... 6.3 6.08 Intermediate areas of fill ............................................................................................................... 6.3

MATERIALS 6.09 Fill material................................................................................................................................... 6.3

SUBMISSIONS 6.10 Particulars of earthworks .............................................................................................................. 6.5 6.11 Particulars of blasting ................................................................................................................... 6.6

GENERAL EARTHWORKS REQUIREMENTS 6.12 Ownership of earthworks material ................................................................................................ 6.6 6.13 Temporary Works for earthworks ................................................................................................. 6.7 6.14 Handling and storage of earthworks material ............................................................................... 6.7 6.15 Protection from water and weather ............................................................................................... 6.7 6.16 Earthworks material allowed to become unsuitable or to deteriorate ........................................... 6.7 6.17 Additional excavation and stabilisation ........................................................................................ 6.8 6.18 Removal of earthworks material ................................................................................................... 6.8

EXCAVATION 6.19 Disposal of excavated material ..................................................................................................... 6.8 6.20 Use of excavated material ............................................................................................................. 6.8 6.21 Obstructions in excavations .......................................................................................................... 6.9 6.22 Excavation .................................................................................................................................... 6.9 6.23 Excavations adjacent to structures and utilities ............................................................................ 6.9 6.24 Excavations for structures, pits and trenches ................................................................................ 6.9

NOT USED 6.25 Not used ........................................................................................................................................ 6.9 6.26 Not used ........................................................................................................................................ 6.9 6.27 Not used ........................................................................................................................................ 6.9 6.28 Not used ........................................................................................................................................ 6.9 6.29 Not used ........................................................................................................................................ 6.9

BLASTING 6.30 Statutory requirements for blasting............................................................................................. 6.10 6.31 Recording vibrations and air-overpressures due to blasting ....................................................... 6.10 6.32 Preparatory work for surface blasting ......................................................................................... 6.11 6.33 Notification of blasting ............................................................................................................... 6.11 6.34 Storage of explosives .................................................................................................................. 6.11 6.35 Restrictions on blasting times ..................................................................................................... 6.11 6.36 Blasting ....................................................................................................................................... 6.11 6.37 Controlled blasting ..................................................................................................................... 6.12

GS (2020 Edition)

18

DEPOSITION OF FILL MATERIAL

6.38 Types of fill material ................................................................................................................... 6.13 6.39 Sources of fill material ............................................................................................................... 6.13 6.40 Surface preparation for fill material ........................................................................................... 6.13 6.41 Commencement of deposition of fill material ............................................................................ 6.13 6.42 Haulage of fill material ............................................................................................................... 6.14 6.43 Deposition of fill material ........................................................................................................... 6.14 6.44 Overfilling .................................................................................................................................. 6.14 6.45 Deposition of fill material adjacent to structures and utilities .................................................... 6.14 6.46 Deposition of rock fill material ................................................................................................... 6.15 6.47 Deposition of fill material in excavations for structures, pits and trenches ................................ 6.15

COMPACTION OF FILL MATERIAL 6.48 Compaction of fill material ......................................................................................................... 6.15 6.49 Moisture content of fill material ................................................................................................. 6.15 6.50 Compaction of fill material adjacent to structures and utilities .................................................. 6.15 6.51 Compaction of rock fill material ................................................................................................. 6.15 6.52 Compaction of general fill material with a large portion of coarse material .............................. 6.16

COMPLETION OF EARTHWORK SURFACES 6.53 Completion of earthwork final surfaces ..................................................................................... 6.17 6.54 Completion of formations ........................................................................................................... 6.17 6.55 Protection of earthwork final surfaces and formations ............................................................... 6.18

INTERMEDIATE AREAS OF FILL 6.56 Deposition of fill material in intermediate areas of fill .............................................................. 6.18 6.57 Compaction of fill material in intermediate areas of fill ............................................................ 6.18

EARTHWORKS IN PUBLIC FILLING AREA 6.58 Public filling area ........................................................................................................................ 6.18 6.59 Public fill .................................................................................................................................... 6.18 6.60 Combined reception and exit offices .......................................................................................... 6.18 6.61 Reception areas, queuing areas and access roads ....................................................................... 6.20 6.62 Management of dump truck movements .................................................................................... 6.20 6.63 Temporary haul roads and drains ................................................................................................ 6.21 6.64 Handling and storage of wet soil ................................................................................................ 6.21 6.65 Deposition of public fill .............................................................................................................. 6.21 6.66 Compaction of public fill ............................................................................................................ 6.21 6.67 Use of fill material adjacent to structures and utilities in public filling area .............................. 6.24

TOLERANCES 6.68 Tolerances: earthworks final surfaces and formations ................................................................ 6.25

TESTING: FILL MATERIAL - GENERAL REQUIREMENTS 6.69 Batch: fill material ...................................................................................................................... 6.26 6.70 Samples: fill material .................................................................................................................. 6.26

GS (2020 Edition)

19

TESTING: FILL MATERIAL - PARTICLE SIZE DISTRIBUTION, LIQUID LIMIT, PLASTICITY INDEX, COEFFICIENT OF UNIFORMITY AND SULPHATE CONTENT

6.71 Samples: particle size distribution, liquid limit, plasticity index, coefficient of uniformity,

sulphate content .......................................................................................................................... 6.26 6.72 Testing: particle size distribution, liquid limit, plasticity index, coefficient of uniformity,

sulphate content .......................................................................................................................... 6.27 6.73 Non-compliance: particle size distribution, liquid limit, plasticity index, coefficient of

uniformity, sulphate content ....................................................................................................... 6.27

TESTING: FILL MATERIAL - OPTIMUM MOISTURE CONTENT AND MAXIMUM DRY DENSITY

6.74 Samples: optimum moisture content, maximum dry density ..................................................... 6.28 6.75 Testing: optimum moisture content, maximum dry density ....................................................... 6.28 6.76 Consistency: optimum moisture content, maximum dry density ............................................... 6.28

TESTING: FILL MATERIAL - MOISTURE CONTENT 6.77 Samples: moisture content .......................................................................................................... 6.29 6.78 Testing: moisture content ............................................................................................................ 6.29 6.79 Compliance criteria: moisture content ........................................................................................ 6.29 6.80 Non-compliance: moisture content ............................................................................................. 6.29

TESTING: FILL MATERIAL - RELATIVE COMPACTION 6.81 Testing: relative compaction ....................................................................................................... 6.30 6.82 Compliance criterion: relative compaction ................................................................................. 6.31 6.83 Non-compliance: relative compaction ........................................................................................ 6.31

APPENDIX 6.1 TEST METHODS FOR FILL MATERIAL

6.1.1 General........................................................................................................................................ 6.32 6.1.2 Terms and symbols ..................................................................................................................... 6.32 6.1.3 Grouping of material .................................................................................................................. 6.32

APPENDIX 6.2 DETERMINATION OF THE MOISTURE CONTENT OF FINE GRAINED AND MEDIUM GRAINED MATERIAL BY THE MICROWAVE OVEN DRYING METHOD


GS (2020 Edition)

20

APPENDIX 6.3 DETERMINATION OF THE MAXIMUM CONVERTED BULK DENSITY BY THE HILF METHOD


APPENDIX 6.4 ADJUSTMENT OF THE MAXIMUM CONVERTED BULK DENSITY FOR THE DETERMINATION OF THE RELATIVE COMPACTION


APPENDIX 6.5 DETERMINATION OF THE MOISTURE CONTENT OF SOIL BY THE INFRARED OVEN DRYING METHOD AT 105 ± 5 °C


SECTION 7 GEOTECHNICAL WORKS

PART 1: GENERAL REQUIREMENTS

GENERAL

7.01 General requirements .................................................................................................................... 7.3 7.02 Site clearance ................................................................................................................................ 7.3 7.03 Drainage works ............................................................................................................................. 7.3 7.04 Earthworks .................................................................................................................................... 7.3 7.05 Concrete ........................................................................................................................................ 7.3 7.06 Prestressed ground anchors........................................................................................................... 7.3 7.07 Reinforced fill structures .............................................................................................................. 7.3

GS (2020 Edition)

21

TRIALS

7.08 Trials for geotechnical works ....................................................................................................... 7.3

PART 2: GROUND INVESTIGATION

GLOSSARY OF TERMS 7.09 Block Sample ................................................................................................................................ 7.4 7.10 Bulk Sample ................................................................................................................................. 7.4 7.11 Inspection Pit ................................................................................................................................ 7.4 7.12 Jar Sample..................................................................................................................................... 7.4 7.13 Sample .......................................................................................................................................... 7.4 7.14 Slope Surface Stripping ................................................................................................................ 7.4 7.15 Trial Pit ......................................................................................................................................... 7.4 7.16 Trial Trench .................................................................................................................................. 7.4 7.17 U76/U100 Sample ........................................................................................................................ 7.4 7.18 Undisturbed Soil Sample .............................................................................................................. 7.4 7.19 Ground Investigation .................................................................................................................... 7.4 7.20 Ground Investigation Site ............................................................................................................. 7.4 7.21 Investigation Station ..................................................................................................................... 7.4 7.22 Common Ground .......................................................................................................................... 7.4 7.23 Rock .............................................................................................................................................. 7.4 7.24 Boulders ........................................................................................................................................ 7.4 7.25 Cobbles ......................................................................................................................................... 7.4 7.26 Gravel / Sand ................................................................................................................................ 7.5 7.27 Hard Strata .................................................................................................................................... 7.5 7.28 AGS Digital Format ...................................................................................................................... 7.5

SUBMISSIONS 7.29 Particulars of ground investigation ............................................................................................... 7.5

INSPECTION PITS, TRIAL PITS AND SLOPE SURFACE STRIPPING

7.30 Inspection pits ............................................................................................................................... 7.5 7.31 Trial pits and trial trenches ........................................................................................................... 7.5 7.32 Pumping from trial pits and trial trenches .................................................................................... 7.6 7.33 Backfilling of inspection pits, trial pits or trial trenches ............................................................... 7.6 7.34 Slope surface protection stripping ................................................................................................ 7.7 7.35 Access ........................................................................................................................................... 7.7 7.36 Protection of stripped surface ....................................................................................................... 7.7 7.37 Reinstatement of stripped surface ................................................................................................. 7.7 7.38 Disturbed samples from trial pits, trial trenches or slope stripping .............................................. 7.8 7.39 Records of inspection pits ............................................................................................................. 7.8 7.40 Records of trial pits and trial trenches .......................................................................................... 7.8 7.41 Photographs of trial pits or trial trenches ...................................................................................... 7.9 7.42 Slope stripping records ................................................................................................................. 7.9

DRILLING FOR GROUND INVESTIGATION 7.43 Drilling rigs for ground investigation ......................................................................................... 7.10 7.44 Drilling equipment for ground investigation .............................................................................. 7.10

GS (2020 Edition)

22

7.45 Drilling for ground investigation ................................................................................................ 7.11 7.46 Categories of core drilling .......................................................................................................... 7.12 7.47 Rotary open hole drilling ............................................................................................................ 7.12 7.48 Air-Foam Drilling ....................................................................................................................... 7.12 7.49 Disposal of flush returns ............................................................................................................. 7.12 7.50 Backfilling of drillholes and rotary open holes .......................................................................... 7.12 7.51 Sampling from drillholes ............................................................................................................ 7.13 7.52 Records of drillholes ................................................................................................................... 7.13

SAMPLING FOR GROUND INVESTIGATION 7.53 Supply of sampling equipment and containers ........................................................................... 7.14 7.54 General sampling requirements .................................................................................................. 7.14 7.55 Numbering and labelling of samples .......................................................................................... 7.15 7.56 Sealing of common ground tube samples ................................................................................... 7.15 7.57 Core boxes .................................................................................................................................. 7.16 7.58 Delivery and storage of samples ................................................................................................. 7.16 7.59 Undisturbed tube sampling of common ground in drillholes ..................................................... 7.16 7.60 Retractable triple tube core sampling ......................................................................................... 7.16 7.61 Piston sampling ........................................................................................................................... 7.18 7.62 U100 and U76 sampling ............................................................................................................. 7.18 7.63 Block samples ............................................................................................................................. 7.20 7.64 Recovery of cores ....................................................................................................................... 7.20 7.65 Extrusion and handling of cores ................................................................................................. 7.21 7.66 Photographs of core boxes .......................................................................................................... 7.21 7.67 Groundwater samples ................................................................................................................. 7.22

IN-SITU TESTING 7.68 Standard penetration tests ........................................................................................................... 7.22 7.69 Dynamic probe tests ................................................................................................................... 7.24 7.70 Vane shear tests ........................................................................................................................... 7.24 7.71 In situ density tests ..................................................................................................................... 7.25 7.72 Falling or rising head permeability test ...................................................................................... 7.25 7.73 Response test .............................................................................................................................. 7.26 7.74 Constant head permeability test .................................................................................................. 7.26 7.75 Packer (water absorption) test .................................................................................................... 7.27 7.76 Impression packer tests ............................................................................................................... 7.28 7.77 Inclination and bearing measurements ....................................................................................... 7.28

REPORTS FOR GROUND INVESTIGATION 7.78 General........................................................................................................................................ 7.28 7.79 Site log book ............................................................................................................................... 7.28 7.80 Daily site records ........................................................................................................................ 7.29 7.81 Preliminary records ..................................................................................................................... 7.29 7.82 Submission of Final Field Work Report ..................................................................................... 7.29 7.83 Submission of digital image of Final Field Work Report ........................................................... 7.30

PART 3: SLOPE TREATMENT WORKS

MATERIALS 7.84 Cement mortar ............................................................................................................................ 7.31 7.85 Rock for masonry infilling.......................................................................................................... 7.31 7.86 Soil-cement ................................................................................................................................. 7.31

GS (2020 Edition)

23

7.87 Aggregates for sprayed concrete ................................................................................................ 7.31 7.88 Reinforcement for sprayed concrete ........................................................................................... 7.31 7.89 Protective mesh and fixings ........................................................................................................ 7.31 7.90 Rock bolts ................................................................................................................................... 7.32 7.91 Grout for rock bolts .................................................................................................................... 7.32 7.92 Rock dowels ............................................................................................................................... 7.32 7.93 Grout for rock dowels ................................................................................................................. 7.32 7.94 Soil nails .........................................................................................................

gs (2020 edition) · gs (2020 edition) 2 . general specification for civil engineering works (gs),...

Documents