Safe work method statement for back filling of the excavation area is provided in steps as below.
Ensure all clearances from the concerned Government Department obtained. Selected working area should be barricaded to avoid accidents.
Ensure suitable access / safe ramps provided for safety of all site personnel’s proper safety PPE to be followed.
Place signage such as Keep Out, Excavation/Backfilling is going on and Exclusion Zone & physical barrier to be erected around the excavation/backfill area where it is appropriate
Water proofing works to be completed prior to start backfilling.
Ensure that the area to be backfilled is clean from any debris wooden or other materials.
MEP clearance to be approved prior to start backfilling works.
Ensure that the approved selected excavated material /Dune Sand is clean from any roots, rubbish and other deleterious materials.
Proceed promptly with backfilling work, area to be backfilled has been inspected and approved by Engineer.
Place backfill in 200mm thick maximum layers. Compact each layer before placing next. Maintain optimum moisture content to achieve required densities.
Backfill evenly on both sides of foundation walls to avoid unequal fill pressures on walls, Fill over-excavations under bearing surfaces and footings, or within pyramid enclosed by 7 in 10 slope from bearing surface with concrete of same strength as specified for footings.
Fill over-excavation under all other areas with backfilling material in accordance with the specification and compact as directed.
Compaction equipment shall be of size and type to permit required compaction without causing lateral forces resulting in displacement of foundation walls and with extra care to avoid damage on other underground installations.
The permission of the Engineer shall be obtained before deposition of fill material starts in any area of fill.
Haulage of fill material to an area of fill shall proceed only when the compaction plant operating at the area to be filled is sufficient to achieve the specified requirements for relative compaction of the fill material.
Fill material shall be deposited in layers of a thickness appropriate to the compaction method to be used. Unless otherwise permitted by the Engineer, layers to fill material shall be horizontal, except for any gradient required for drainage, and the thickness of each layer shall be uniform over the area to be filled.
Trenches shall be backfilled only after all required tests are performed and verified that the pipes and cables have been installed in accordance with the specifications and drawings.
Fill material in areas of fill shall be compacted in layers to a stable condition as soon as practicable after deposition and in a manner appropriate to the location and to the material to be compacted.
Except as stated fill material shall be compacted to obtain a relative compaction of at least 95% throughout.
Fill material shall be compacted in such a manner that structures or utilities shall not be disturbed or damaged.
Maintain optimum moisture content during backfill and fill compaction to achieve required density. Deposit in layers of such thickness that equipment being used for compacting can produce specified density.
During and immediately after leveling, thoroughly compact each layer of fill by use of compaction equipment of size and type to permit required compaction without causing lateral forces resulting in displacement of foundation walls. Exercise caution in this regard to avoid movement of foundations.
After a period adequate to reveal settlement has passed, place additional fill and compact in all depressions. Make good any subsequent settlement.
The profile of the excavation for all exterior work, such as roads and footways, and for all structural work, shall be treated as though it were the uncompact profile of a layer of fillPE/SE8.0Any irregularities in the excavation profile may be made up to an approximately level grade only after this initial compaction of the existing subgrade.
Withdraw shoring material during backfill, & backfill material shall be compacted such a manner that structures or utilities shall not disturbed or damaged.
Creation and dispersion of dust shall be minimized during backfilling by suitable means.
Inspection request to be submitted for completion of work and ensure its approval from consultant.