August 21, 2023
Before backfilling, the buried pipeline system requires students to conduct a complete and thorough inspection and pressure test, and the backfill soil can only cover the pipeline section during the test method inspection process, while the connection needs to be kept bare. The steel wire mesh pipe has the strength, rigidity and impact resistance that exceed ordinary pure plastic pipes, and is similar to the low linear expansion coefficient and creep resistance of steel pipes. PE steel wire mesh skeleton composite pipe is a new type of steel skeleton plastic composite pipe that has been improved. This kind of pipe is also called SRTP pipe. The PE steel mesh skeleton pipe composite pipe also has plastic components, and has the same water supply function as most plastic pipes.
Ideally, backfilling in summer should be done in the morning as much as possible, when the pipeline is fully contracted and the shrinkage stress on the nozzle is small.
Pipes should be laid in deep soil. The soil must not only be strong, but also protect the pipes from damage. To guide the laying of buried pipelines, experience in the installation of buried pipelines should be used for reference.
Backfilling shall be carried out after acceptance of concealed works. The backfill soil within 100mm around the pipeline shall not contain hard rocks (bricks) with a particle size greater than 100mm. The backfill should be compacted in layers to ensure that the outward lateral driving force is evenly generated. If conditions permit, it is recommended to maintain the pipeline water pressure at 103-172Kpa during backfilling.
In the process of research and compaction of sand, gravel and other materials, the effect of backfilling with vibration control method is the best, and the thickness of backfill soil should be as saturated as possible. If analytical injection of backfill is required, ensure that the pipe is completely uncovered. Do not add some other backfill materials to the backfill soil after water injection before pedestrians can step on it. At the same time, it is necessary to avoid that the pipeline enterprise is in a floating state when injecting water.
When the gravel contains a high proportion of fine-grained materials, such as clay, mud, etc., manual compaction should be used. If mechanical compaction is used, the effect will be better.
When backfilling the remaining backfill soil, it should be filled evenly to ensure that the trench is completely filled. There shall be no unfilled gaps around or at the bottom of large rocks or soil clods, and sharp large stones, soil clods and gravels with a diameter greater than 100mm shall be cleaned up. Heavy equipment such as road rollers can only be used to compact the outer backfill soil, and it is strictly forbidden for compactors to stop and walk directly above the buried pipeline.
