长江小直径浅覆土盾构隧道上覆土增厚技术

Overburden Thickening Technology of Small Diameter Shallow Overburden Shield Tunnel in Yangtze River

上覆土对盾构施工的影响十分突出。以常熟电厂取水隧道盾构施工为研究背景,针对长江下游水域小直径盾构隧道上方覆土较薄的情况,通过对江底浅覆土中盾构机推进时的受力状态进行分析,利用理论计算的方法得出覆土的最小安全厚度,然后阐述了利用充填砂袋的方式分层对盾构机上方的土层进行增厚施工,最终使得盾构机顺利通过江低浅覆土区域。

The influence of overlying soil on shield construction is very prominent.This paper takes the shield construction of intake tunnel in Changshu Power Plant as the research background.Firstly,the force state of the riverbed shield machine during propulsion is analyzed.Then the minimum safe thickness of overlying soil is obtained by theoretical calculation method.Finally,the soil layer above the shield machine is thickened by filling sand bags,which makes the shield machine pass through the shallow overlying area of the river bottom smoothly.