第一卷 开槽埋管（PVC-U管）
1.开挖沟槽
1.1槽底宽度应为管外径+0.4m。
1.2沟槽开挖时，应严格控制基底高程，不得超挖或扰动基面。挖掘机挖至距基底20cm时，采用人工继续开挖直至标高。
1.3槽底不得受水浸泡。
1.4、开挖沟槽质量标准：
1.4.1槽底松散土、淤泥、大块石等杂物必须清除，保持槽底不浸水。
1.4.2沟槽允许偏差见表：
Vol slot buried (PVC-U tube)
1. Excavation trench
1.1 The bottom width of the pipe diameter should be +0.4 m.
1.2 The trench excavation should be strictly controlled basement elevation, excavation or disturbance shall not exceed the base plane. Excavator dug to 20cm from the base, the use of artificial continue excavation until the elevation.
1.3 shall be subjected to water immersion bottom.
1.4, trench excavation quality standards:
1.4.1 bottom loose soil, silt, large stones and other debris must be removed to maintain bottom is not flooded.
Table 1.4.2 Tolerance groove: