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 laying and installation of GRP and u-PVC Pipes with Concrete encasement. |
2. Definitions:
| 2.1 | MS: STM Method Statement : Storm Water Drainage Work |
| 2.2 | ITR Inspection and Test Request |
| 2.3 | PPS Particular Project Specification |
| 2.4 | GPS General Project Specification |
| 2.5 | UG Underground |
| 2.6 | TPS Technical Project Specification |
3. References:
| 3.1 | Drawing PGAD 745/1008/CD/927 (REV (A) Section A-A |
| 3.2 | TPS Section 901 : clause 901.3.10 Concrete surround |
| 3.4 | MS – 1005 Surveying |
| 3.5 | MS -1004 Dewatering |
| 3.6 | MS -1008 Earthworks |
4. Subcontractors:
| 4.1 | N/A. |
5. Products:
| 5.1 | GRP and/or u-PVC Pipes, dia (160mm to 1500mm). |
| 5.2 | Rubber gasket rings of approved source |
| 5.3 | Warning tapes of approved source |
| 5.4 | Lubrication soap for rubber rings |
| 5.5 | Concrete class 40/20/S |
| 5.6 | 20 mm thickness fiber board. |
6. Tools & Equipments:
| 6.1 | Dewatering Equipments (If required) |
| 6.2 | Excavators, JCB |
| 6.3 | Front End Loader (Shovel) |
| 6.4 | Tipper Trucks |
| 6.5 | Crane (if required). |
| 6.6 | Flat-bed truck and trailer |
| 6.7 | Concrete Mix Trucks |
| 6.8 | Small Vehicles |
| 6.9 | Compactor (Plat or Roller) |
| 6.10 | Concrete vibrators |
| 6.11 | Surveying Instruments |
| 6.12 | Nylon lifting slings |
| 6.13 | Cable pullers (come-along) |
| 6.14 | Ladders |
| 6.15 | Concrete Barricades |
| 6.16 | Flagging Tape/Warning Tape |
| 6.17 | Concrete Formwork |
| 6.18 | Concrete Temp. Gauge |
| 6.19 | Slump cone, cube moulds |
7. Safety
| 7.1 | GPS Section 102: Clause 102.11, 102.12 and 102.14 General and Preliminary |
| 7.2 | TPS Technical Project Specification Section 901 Clause 901.3: Trench Excavation and Backfill. |
| 7.3 | PPS Section 100: Clause 100.2 Airport Emergency And Safety |
| 7.4 | OAJ JV Safety Manual |
| 7.5 | 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 |
.
9. Procedure:
All activities carried out will comply with the OAJ-JV Inspection Test Plan which reflects the testing requirements of the Contract.
| 9.1 | Prepare the Shop Drawings and submit to the Engineer for approval prior to starting any excavation works. |
| 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 Consultants 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, or bearing value. |
| 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 Consultants Inspector before proceeding with blinding concrete. |
| 9.7 | Excess excavation will be replaced with blinding concrete or selected excavated materials or as instructed by the engineer. |
| 9.8 | Blinding concrete and pipe installation will be undertaken after the compaction and the Engineer’s approval. |
| Note: | The pipe installation is a hold point and lines and levels must be checked and approved by the Consultant’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. |
| 9.9 | Concrete cradles are then placed to support the pipe and allow easy adjustment to mentioned correct lines and levels. |
| 9.10 | Hooks will be anchored to the blinding. |
| 9.11 | 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. 20mm thickness comprisable board at each joint will be applied. |
| 9.12 | Levels will be checked to confirm accuracy as per approved shop drawings followed by the fixing of an approved shutter. |
| 9.13 | Class 40/20/S mass concrete will be poured (refer to attached shop drawings). |
| 9.14 | Pipeline will then be visually checked by torch and mirror |
Backfilling:
| 9.15 | 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 | It is the Contractor’s Site Manager’s duty to ensure that all necessary safety and protective equipment are provided along with properly trained and qualified personnel. |
| 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 Site Engineer will ensure that the site preparation activities are conducted according to the approved method statement. |
| 10.5 | The Material Engineer will ensure that the materials being used are in accordance to the project specifications and the approved method statement. |
