CONTENTS
- Scope of Work
- Definitions
- References
- Subcontractors
- Materials
- Plant & Equipment
- Safety
- Prior Activities
- Procedure
- Responsibilities
- Attachments
1. Scope:
| 1.1 | This Method Statement covers the construction of ducts for fire and water supply network under taxiways, roads and wherever needed. |
2. Definitions:
| 2.1 | MS: STM Method Statement : Ducts for fire and water supply networks. |
| 2.2 | ITP Inspection and Testing Plan |
| 2.3 | PS-GCMI Project Specifications-General, Civil and Mechanical Infrastructure |
| 2.5 | UG Underground |
3. References:
| 3.1 | PS-GCMI : Section 901 Pipework |
| Section 901 : clause 901.3.10 Concrete surround | |
| 3.2 | PS-GCMI : Section 401: Clause 401.7 and 401.9, Concrete grade and Quality Control |
| Clauses 401.12, 401.13 Placing of concrete and Formwork | |
| 3.3 | PS-GCMI : Section 401: Clause 401.20.2: Application of protective coatings |
| 3.4 | MS – 1005 Surveying |
| 3.5 | MS -1004 Dewatering |
| 3.6 | MS -1008 Earthworks |
| 3.7 | Inspection Testing plan to be submitted for approval |
4. Subcontractors:
| 4.1 | N/A. |
5. Products:
| 5.1 | GRP Pipes, dia 450mm and fittings as sleeves. |
| 5.2 | Concrete class 40/20/S |
| 5.3 | Brush-applied tanking membrane and Protection Board: Bitutex FBR and Bituboard Refer to Material submittal 1008-OAJ-FM-MSF-RO / STR 002 or similar approved. |
| 5.4 | Lubrication soap for rubber rings |
| 5.5 | 20 mm thickness fiber board. |
| 5.6 | Teflon Spacers |
6. Plant & Equipment:
| 6.1 | Dewatering Equipment (If required) |
| 6.2 | Excavators, JCB |
| 6.5 | Crane (if required). |
| 6.7 | Concrete Mix Trucks |
| 6.8 | Light Vehicles |
| 6.9 | Concrete vibrators |
| 6.10 | Surveying Instruments |
| 6.12 | Ladders |
| 6.13 | Concrete Barricades |
| 6.15 | Flagging Tape/Warning Tape |
| 6.16 | Concrete Formwork |
| 6.17 | Concrete Temp. Gauge |
| 6.18 | Slump cone, cube moulds |
7. Safety
| 7.1 | PS-GCMI Section 102: Clause 102.11, 102.12 and 102.14 General and Preliminary |
| 7.2 | PS-GCMI Section 901 Clause 901.3: Trench Excavation and Backfill. |
| 7.3 | PS-GCMI Section 100: Clause 100.2 Airport Emergency And Safety |
| 7.4 | OAJ JV Safety Manual |
| 7.5 | Activity Hazard Analysis to be submitted for approval |
| 7.6 | Safety Hazards and Precautions |
| a)- Strike UG Services: Use Locator and/or hand excavation (trial holes) | |
| b)-Excavation Collapse: Batter sides to safe slope or provide shoring (as directed by Geotechnical Consultant) and subject to the Engineer’s approval. Keep vehicles/equipment safely away from excavation edge Keep spoil at least 2.0 meter away from edge c)- Fall into excavation: Provide fencing, guardrails or flagging tape around edges and night lights. Provide safely fixed ladders (every 50m) Provide banks man when operating equipment near excavation. d)-Crane Accidents: All cranes checked and certified Operators professional and well experienced Provide banks man when operating near excavation Check load indicator, slings and wire ropes daily e)- Falling Objects: Stand clear during lifting operations Wear hard hats f)- Equipment & Vehicles: Use Safety belts Slow down and obey speed limits Provide “back-ups” alarms Provide banks man when operating equipment near excavation. g)- Confined Space: Check excavations for snakes and scorpions before entering trenches. Take precautions against flooding Develop rescue procedures |
8. Prior Activities:
| 8.1 | Calibrate Surveying Instruments. |
| 8.2 | Check for Existing Utilities before excavation (Trial Holes). |
| 8.3 | Check all pipes free of cracks and chips or damage to liner. |
| 8.4 | Prepare and get approval of Shop Drawings. |
| 8.5 | Pipes transportation, handling and storage will strictly comply with the manufacturer’s instructions |
| 8.6 | In case of dewatering, proper water discharge away from work area will be provided. Permits will be obtained where needed. |
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9. Procedure:
All activities carried out will comply with the OAJ-JV Inspection Test Plan (1008-OAJ-ITP-1020) which reflects the testing requirements of the Contract and which will be submitted for approval.
| 9.1 | Prepare the Shop Drawings and submit to the Engineer for approval prior to starting any excavation works. The actual location of ducts will then be determined and checked on Site. Any obstruction encountered will be reported to the Engineer and will be indicated in a revised shop drawing. A shop drawing will be issued for each section of line and will be subject to the Engineer’s approval. |
| Note: | Only the drawings marked as approved “Issued for Construction” are allowed to be used by the Site Staff. |
| 9.2 | Survey will be conducted according to MS-1005 |
| 9.3 | Dewatering (If required) will be conducted according to MS-1004. |
| 9.4 | Excavation will be conducted to the proper formation level according to MS-1008. |
| Note: | The Engineer’s Inspector will be notified if any areas are over excavated or unsuitable materials are encountered, in which case replacement material will be used. |
| 9.5 | The trench formation shall be compacted to 98% MDD. |
| 9.6 | The formation level will be to the required lines and grades as detailed in the approved Shop Drawings. |
| Note: | Formation compaction is a Hold Point and will be confirmed by the Engineer’s Inspector before proceeding with blinding concrete. |
| 9.7 | Blinding concrete class 30/20/S and pipe installation will be undertaken after the compaction and the Engineer’s approval is given. |
| Note: | The pipe installation is a hold point and lines and levels must be checked and approved by the Engineer’s Inspector before other work proceeds. Any adjustment in the line and grade shall be made by scrapping away or filling and tampering in under the Barrel of the pipe. |
| 9.8 | Concrete cradles are then placed to support the pipe and allow easy adjustment to mentioned correct lines and levels. |
| 9.9 | The pipes will be fixed over the cradles as per the required levels and tightened to the fixed hooks to prevent any movement or uplifts during concrete casting according to Manufacturer’s recommendation. 20mm thickness compressible filler board will be installed at each joint. |
| 9.12 | Levels will be checked to confirm accuracy as per approved shop drawings followed by the fixing of an approved shutter as per clause 401.13 “Formwork”. |
| 9.13 | Once all pre-pour aspects are checked and found acceptable by the Engineer’s Inspectors, concrete grade 40/20/S mass concrete will be poured according to clause 401.12 “Placing of concrete” to the levels shown on the shop drawings. |
| 9.14 | Pipeline will then be visually checked by torch and mirror. |
| 9.15 | As soon as is practicable, all concrete shall be cured by the application of approved concrete curing membrane or materials. |
| 9.16 | All foreign materials shall be thoroughly cleaned after striking the formwork (Clause 401.13.5). Brush-applied tanking membrane will be applied according to specifications and protection board installed as per clause 401.20.2 and as per manufacturer’s recommendations. |
Backfilling:
| 9.17 | Backfilling will proceed in layers in accordance with MS-1008 only after striking the formwork and after the concrete has gained enough strength to sustain the filling material load and compaction. |
10. Responsibilities:
| 10.1 | The CM will coordinate with SE and ensure that the necessary resources to implement the approved method statement and ITP have been allocated to the task. |
| 10.2 | It is the Site Supervisor’s duty to organize the work in a safe manner to ensure that safety and protective equipment are being properly utilized. He must also assure the method statement procedure is followed and must observe the Hold-points and notify the Engineer for inspection. |
| 10.3 | It is the worker’s duty to properly wear the protective equipment provided and obey all safety rules. They must also perform the work as described in the method statement procedure. |
| 10.4 | The SE will ensure that the site preparation activities are conducted according to the approved method statement and all in-situ tests according to the ITP are implemented. |
| 10.5 | The ME will ensure that the materials being used are in accordance to the project specifications, the approved method statement and the ITP. |
