This civil Method Statement defines the procedure to carry out the pond work as per requirements in project specifications to ensure the safety and quality of the work.
Method statement covers excavation activity, rebar installation, formworks, concrete pouring, curing of concrete, formwork dismantling, finishing, and other civil work base on civil work item list.
Subcontractor will follow Project Health & Safety Plan.
Relevant health and safety concerns during the excavation and pond construction work are as a mentioned below:
- Ensure Permit To Work and JSA is ready before starting the work.
- Assign a safety supervisor frequently on site to ensure work is being conducted in accordance with the Permit to Work and job safety and environmental analysis JSEA
- Conduct inspection of mixer truck when loading & unloading.
- Provide all mandatory PPE to all operatives on the pond construction site.
- Conduct toolbox talk before commencement of works on daily basis.
- Make sure that all personnel are aware of all safety signs, barricades and other type of safety controls as per hazard identification.
- All personnel should maintain awareness of potential hazards before beginning each shift.
- Establish effective communication system between operators, supervisors and other parties.
Necessary Materials Tools & Equipment’s
Below is list of materials that shall be used for pond work installation and construction:
- Rebar D 13 for dowel
- Wire mesh M10 for reinforcement
- Anchor bolt with template setting
- Polyethylene sheet & geomembrane HDPE 2mm for waterproofing
- Embedded steel
- Waterstop & Bitumen for construction joint: SIKA WATERBAR FLEXIBLE PVC WATER STOP SIKA BITUSEAL
- Plywood 12 mm & support for formwork
- Lean concrete 150 Kg/cm2 and structure concrete 250 Kg/cm2
- BRC for fence
- Embedded parts & pipe
List of equipment’s
- Excavation machinery
- Truck mixer and concrete pump
- Crane and truck
- Scaffoldings and accessories,
- Formwork and accessories
- Lighting in situational (If needed)
- Hand tools
- Hand Cutter
- HDPE Weld machine
Manpower List
Direct manpower shall be allocated as per the following list:
- Foreman
- Concrete worker
- Carpenter
- Batching plant Operator & Crew
- Truck mixer operator
- Concrete pump operator
- General Labor
- Masson
- Rebar men
- Surveyor
- Mechanic & electrician
- HDPE Welder
Sequence of Work
General Flow chart to Construct Pond
Joint Survey to check original ground level
Excavation: monitored by surveyor team to avoid over cut, done by layer per layer
Polyethylene Installation
Rebar, Embedded Items Installation
Request for Inspection
Pouring / Casting Concrete
HDPE Geomembrane Installation
Cleaning / Housekeeping
Excavation:
The surveyor will perform joint survey to get the original ground level; afterwards will mark the area to allow the excavation.
Excavation will start after subcontractor receives approved drawings for pond construction.
Excavation will be performed as per layer (not designed depth layer). Excavation work is finished when the bottom of the excavation has reached as per the elevations shown in the drawings.
Temporary sum pit will be constructed to collect the water (if rainy season), and the sum pit with temporary drainage shall be provided.
Polyethylene & Rebar Installation
Polyethylene will be installed after excavation has reached design elevation.
Lifting loading and mobilization will be performed by using suitable crane (if needed).
Rebar and or wire-mesh will be mobilized to designated area from stockpile area/ bar bending area and it will be installed by workers (tightened by hand tool).
The formwork will be replaced by chicken mesh to perform rough surface to next joint pouring and or to next joint construction.
Forms shall be constructed from sound materials of plywood with supporting accessories (Wood, Steel hollow, tie rod etc.).
The formwork shall be fixed in perfect alignment and securely braced to withstand displacements and deflections due to construction loads, such as vertical, horizontal and impact construction loads.
Formwork shall be done in such a way as to produce a smooth surface free from irregularities.
All formwork surfaces shall be cleaned before re use.
The formwork shall be of sufficient strength, properly rigid throughout the placing and compacting of the concrete without visible deflection.
Forms shall be so constructed that they can be removed without shock or vibration to the concrete.
Before concreting is commenced the forms shall be thoroughly cleaned and free from dust, dirt and other debris.
Temporary openings shall be provided where necessary to drain away water and rubbish.
Wooden formwork (plywood), thickness shall not be less than 12 mm.
Forms shall be removed in such manner as to ensure the complete safety of the structure, and similar sort vertical forms may be removed after a lapse of 3 days.
Concrete Pouring for Pond Work
Concrete shall be sprayed to the pouring area by equipment (concrete pump or other) ensuring its requirements.
Concrete shall be deposited directly in it, final position/elevation and shall not be allowed to flow in a manner to permit or cause segregation.
Fresh concrete will be smoothed by using temporary rail as guidance, the support of guidance/rail shall be on the top of concrete, and during the pouring time the guidance/rail will be removed and all the top concrete will be smoothed by hand trowel.
When pouring of concrete has started, it shall be carried out as a continuous operation until the placing of the complete block is complete.
Concrete pouring in the pond shall be done phase to phase (area by area), refer to joint construction details.
Where joints are to be made, the surface of the hard concrete shall be cleaned thoroughly, roughened, and all laitance shall be removed by chipping and treated with a thin layer of neat cement before additional fresh concrete is placed.
Curing & Concrete Protection
All concrete surfaces shall be kept wet at least 7 days after placing the concrete, except the high early strength concrete shall be so maintained for at least 3 days as per the method statement approved by the client.
The covering material shall remain in place during the full curing period, and the covering material may be removed when the concrete has hardened sufficiently.
Surface Treatment of Structural Concrete
Top surfaces of structural concrete slabs shall be levelled unless otherwise indicated.
Hand tool trowel finish shall be achieved.
Same requirements apply as for monolithic finish, except that the consistency of concrete shall be maintained for which steel troweled finish is specified.
Geo membrane Installation
Geo membrane materials shall be stocked and prepared near the pond area, it will be sprayed/installed as per the marked area, installation will be conducted by general workers in supervision of experienced supervisors.
Some of them will be cut to make smooth connections (as drawing below), the geo membrane will be connected with fusion welding, before installation of the geomembrane the pond will be emptied from water by using water pump.
Fence installation and concrete paving work
The foundation of fence and concrete paving will be performed with precast, and then it will be installed by using excavator and guided by surveyor for alignment and excavation will be performed manually by general workers.
