苏通GIL电力综合管廊大直径泥水盾构泥浆成膜特性试验研究

Experimental Study on Filter Cake Formation of Large Diameter Slurry GIL Utility Tunnel at Sutong

针对苏通GIL电力综合管廊盾构隧道在砂土地层泥浆成膜和泥膜特性的问题,考虑实际施工中在刀盘转动影响下泥浆成膜空间分布不均、成膜过程波动较大,研制一套泥水盾构动态成膜及渗透特性试验装置,在砂土地层开展6组4工况泥浆渗透模型试验,研究盾构典型掘进环境中的泥浆渗滤量、入渗地层电导率及泥膜成膜形态。结果表明,考虑刀盘周期性切削、泥浆反复渗透下的分级加载渗滤曲线存在明显的"渗滤滞后区",泥浆渗透后土体电导率变化过程可分为不稳定、稳定下降、平稳3个阶段,泥膜在砂土地层成膜厚度随刀盘转速增大而减小。研究结果可为今后大直径泥水盾构泥浆成膜特性分析提供参考。

Aiming at the problem of the filter cake formation and characteristics of Sutong GIL electric power utility tunnel in sand stratum,a new test device for dynamic filter cake formation and permeability of slurry shield was developed.A model test of filter cake formation characteristics was carried out in sand formation.As the cutter head rotates,the distribution of filter cake fluctuates in actual tunnelling process,slurry penetration,stratum conductivity and distribution shape of filter cake in four operating modes were analyzed.The results show that there is a"filtration hysteresis zone"in the graded loading filtration curve with the influence of the cutter head rotation.The change process of soil conductivity is divided into three stages:unstable,stable descending and stable.The thickness of filter cake formation decreases with the increase of rotary speed.The research result offers a reference for evaluating the filter cake forming quality of large diameter slurry shield tunnel.