National Building Standard Design Atlas: 20S515 - Reinforced Concrete and Brick Drainage Inspection Wells

National Building Standard Design Atlas: 20S515 - Reinforced Concrete and Brick Drainage Inspection Shaft - Real Estate

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Trough. If the foundation soil is disturbed or over-excavated, the corresponding foundation treatment is required. 8.7 When the excavation depth of the foundation pit is large, effective measures should be taken to ensure the stability and safety of the foundation pit.

8.8 When there is groundwater in the range above the bottom surface of the design foundation, effective construction and drainage measures should be taken to ensure the construction of dry grooves

8.9 If the text, thousands of pipe foundation is located in the well chamber foundation pit, below the base can be graded sand and gravel, low-strength grade concrete filling.

8.10 After the excavation of the foundation pit reaches the design elevation, it should be inspected in conjunction with the relevant departments.

8.11 Foundation pit backfill requirements:

8.11.1 foundation pit backfill must be implemented after the launder and inspection manhole cover plate travel is completed and the design strength is reached.

8.11.2 foundation pit around the backfill should be synchronized, the height difference shall not be greater than 300m, heavy machinery shall not be used when backfilling, backfill compaction coefficient should not be less than 0.94. The foundation pit in the frost depth range should be backfilled with non-frost heave village material.

8.11.3 When the inspection well is located in the subgrade, the square range, the compaction coefficient required by the subgrade is greater than 0.94, according to the compaction coefficient required by the subgrade; The compaction of the backfill of the inspection well foundation pit located in the green space or farmland can be appropriately reduced, but it should not be less than 0.85.