1, polyethylene pipe laying under the ditch, should immediately cover with fine soil or sand pipe, the thickness of not less than 30cm, to ensure that the polyethylene tube from external damage.
2, trench backfill, should first fill the bottom of the tube, and then backfill both sides of the pipeline, and then back to the top of the tube to the top 50 cm, such as ditch water, must line up after the backfill.
3, the support of the groove should ensure that the construction of the security situation, according to the progress of the backfill demolition, removal of vertical pile, the sand should be filled with cracks.
4, the top of the tube and the top of the tube 50 cm above the backfill, shall not contain gravel, bricks, garbage and other debris, shall not use frozen soil backfill, from the top of the tube 50 cm above the backfill allowed a small diameter More than 10cm of stones and permafrost, the number of which can not exceed the total volume of 15% of the filling. The backfill should be tamped with each layer, the thickness of each layer should be 20-30cm, both sides of the pipe and 50cm within the pipe backfill must be manually compacted, when the backfill beyond the tube 50cm, you can use a small mechanical compaction, Should be 25-40cm.
The density of each part of the groove should meet the following requirements:
(Ⅱ) 85%; C, tube top 50cm above the ground (Ⅲ) in the urban area 95%, —- 90% of cultivated land.
5, tracing warning belt. In order to protect the pipeline in the mouth after the operation from the accidental damage, in the pipeline above the vertical, 50cm away from the top of the tube radiation laying a warning band, warning to remind the third party construction, dug this warning, It should be noted that there are polyethylene pipes below, be careful to open the cavity, to avoid damage to the polyethylene gas pipeline.
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