海陆交互相不同地层盾构掘进影响对比分析

Comparative Analysis for Impact of Shield Tunneling on Different Strata in Marine-terrestrial Interaction Zone

为确保天津海陆交互相地层盾构掘进施工安全,本文根据海陆交互相典型地层(富水软土地层、饱和液化土地层和双层承压水地层)的物理力学特性与渣土改良试验结果,采用MIDAS-GTS软件对不同地层盾构掘进施工进行模拟,得到适用于各地层的合理盾构掘进参数,结果表明:(1)海陆交互相地层土样具有渗透性差、易于压缩、亲水性强和强度较低等特性;(2)当黏质粉土与淤泥质粉质黏土分别选用泡沫剂与膨润土的组合、单一泡沫剂作为改良剂时,可以满足渣土改良要求;(3)海陆交互相3种典型地层存在不同的盾构掘进建议值,且富水软土地层掘进参数建议值最小,双层承压水地层掘进参数建议值最大。

To ensure the safety of shield tunneling in the marine-terrestrial interaction strata in Tianjin,this paper analyzed the physical and mechanical properties of typical marine-terrestrial interaction strata(water-rich soft soil stratum,saturated liquefied soil stratum,and double confined water stratum)and the results of spoil improvement experiments.The MIDAS-GTS software was used to simulate the shield tunneling in different strata,thereby deriving reasonable shield tunneling parameters suitable for each stratum.The results show:(1)The soil samples in the marineterrestrial interaction strata have characteristics such as poor permeability,a high propensity to compress,strong hydrophilicity,and low strength.(2)When a combination of foaming agents and bentonite is selected for clay and silt clay respectively,and single foaming agents as modifying agents respectively,muck improvement requirements could be met.(3)The three typical strata found in marine-terrestrial interaction zones each have different recommended shield tunneling values.The suggested tunneling parameter value is lowest for the water-rich soft soil stratum,and highest for double confined water stratum.