Backfilling
After the pipeline is installed and passed the inspection and acceptance, backfilling work is carried out.
. When the fixed wall support needs to be removed during backfilling, it should be removed by first lowering and then raising.
Backfill both sides of the pipe pit with medium-coarse sand to m above the top of the pipe. When backfilling, do both at the same time to prevent the pipe from shifting, and flush it with water. Backfill soil above m from the top of the pipe and compact it in layers. The density must be Meet the roadbed design requirements.
When backfilling, there should be no accumulated water in the tank, and no backfilling of silt, humus and organic matter is allowed. The backfill soil shall not contain large pieces of masonry, and the large pieces of soil must be crushed to a size of less than 3 m before being used for backfilling.
The sequence of trench backfilling should be from high to low according to the trench drainage direction, and the virtual paving layer should be m thick.
When replacing various fillers, they should still be compacted layer by layer with a flat vibrator or handheld light roller according to regulations. The thickness of each layer of empty paving must not exceed mm.
The construction method of sewage pipes is basically the same as that of rainwater pipes. The difference is that the sewage pipes must undergo a closed water test before backfilling the trench.
Beijing municipal sewage pipeline construction pipeline backfill Beijing Pipe Network Construction Company