We have few projects that boundary wall is included. The boundary wall we installed was precast, the advantage is it is easy and fast to erect.
Here is the method statement for precast boundary wall works.
Method Statement for Precast Boundary Wall Works
2. Purpose and scope
The aim of this method statement is to describe the process and sequence of erection of precast elements for the boundary wall in this project.
3. Work procedure
- Erection process shall conform to the requirements of project specification and or relevant standard.
- Precast concrete element will be transported to site after the approval by in-house QA/QC staff.
- On site survey shall be carried out for all site dimensions, axes locations, and to meet project requirements.
- Preparation of Civil Works
- Earthwork shall be carried out as per required level.
- Compaction, testing and blinding shall be done before starting erection.
- Main grid line and benchmark will be marked by surveyor.
- Site access road for the movement and parking of mobile cranes and trailers will be ensured at site before starting of erection.
- Backfilling after completion of erection of boundary wall shall be made after installation of precast elements.
- Stage 1 – After erecting of footing and columns.
- Stage 2 – After erecting of first boundary wall panel.
- Erection of Footing
- Footings for columns shall be transported on the bed trailers where they are properly tied with chains and latches.
- Lifting anchors and sleeves openings are provided in the footings in proper locations as per design requirements for safe and easy handling and erecting purposes.
- Footing shall be received at site painted with one primer coat of water proofing bitumen followed by two finishing coats of water proofing bitumen.
- Footing shall either be installed in its location at site using mobile crane of adequate capacity.
- Individual markings for footings shall be made by the surveyor.
- Blinding shall be cleaned and the water proofing bitumen shall be applied before erecting any precast footing.
- Footing shall be leveled prior to receive column and four line (axis of column) to be marked on the foundation to specify the locations of the column face.
- Backfilling around the footing shall be done as per approved method statement of backfilling works.
- Erection of Precast Column
- Column shall be provided with 1 anchor on hole on top for handling and for erection purposes.
- Column shall be transported on flat-bed trailers secured to the trailer with the help of latching chains or belt.
- Precast column shall be unloaded by mobile crane of adequate capacity.
- Then column shall be tilted with crane and lifted vertically in order to bring it to its exact location onto the footing.
- Column shall be aligned at tail end to match the axis.
- Wooden wedges shall be fixed at the sides between the face of the neck column and the inner face of the footing to keep the column in place without tilting or displacing.
- Verticality of the column shall be checked with the help of line and other instruments and any deviation shall be adjusted prior to grouting.
- The bottom of the column shall be grouted in the footing with approved grouting material.
- Erection of Precast Wall
- Precast walls shall be transported on flat-bed trailers with double “A” frame secured with bed of trailer by chain and latches. The precast elements shall be secured with frame by the help of latching belts.
- Precast wall shall be provided with lifting anchor or hook as per drawing for easy and safe handling and erecting purposes.
- Precast wall is unloaded from the trailer by mobile crane of adequate capacity.
- Precast wall then shall be placed on proper storage racks or taken directly for erection.
- Precast shall be installed in its exact location between two columns and shall ensure the stability of the wall and prevent it from tilting or displacing.
- Inspection Request would then be submitted for checking and approval of the Engineer.
- All works shall comply with safety procedure or instruction set out in project safety plan and Municipality rules and regulations.
- Know the safe working load of the hoisting equipment and hardware before use. Never exceed the Safe Working Load (SWL).
- Know the height and size of the precast element before rigging for lifting.
- Always inspect the rigging element prior to every use.
- Never wrap the hoist line around the load.
- Always use taglines with the precast element while lifting to keep the load steady.
- Always check the stability of the load before lifting.
- Check for any over head power lines.
- Make sure that the rigging elements are correct and safe to use for the intended load.
- Never use damaged slings, blocks, hooks for lifting, all damaged lifting gears to be returned to the store for repair or replacement.
- Basic PPE to worn by all staff and laborers.
- Trained operator and banks man will be engaged to control or operate heavy equipment machine.
5. Equipments and tools
- Mobile crane
- Flat trailers
- Shovel and JCB for excavation
- Plate compactors
- Web sling
- Grinders and drill machines
- Plastic chem for leveling
- Total Station for survey
6. Materials and references
- Hollow core panels
- Grouting material
- Approved drawing