Key Construction Technology for Super Large Diameter Shield Tunneling in Extremely Soft Shallow Buried Soil Layer in Zhuhai Tunnel
There are some key and difficult problems in the construction of a super-large-diameter shield in a shallow,buried,extremely soft stratum,such as roof collapse and slurry leakage,segment up-floating,segment leakage and difficult control of shield attitude.Based on the Zhuhai Tunnel Project,aiming at the characteristics of the shallow buried depth and extremely weak surrounding stratum on the side of shield launching,systematic measures such as stratum pre-reinforcement treatment,targeted design of shield machine,transformation and optimization of synchronous double liquid grouting system and grouting method,and improvement of segment waterproof system were formulated and adopted,and the key and difficult problems in shallow buried extremely soft stratum were effectively controlled.A single stratum pre-reinforcement measure has limited effect on the floating control of shallow buried segments.The partition grouting method combined with thick slurry and double slurry can shorten the initial setting time and early strength of the top slurry,and effectively solve the floating and leakage of the segment.The problems of segment leakage and crack leakage can be avoided by controlling the uneven floating of the segment.
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NSTL
万方数据
维普
