考虑承压水地连墙穿越粉砂层槽壁稳定性分析

Trench Stability Analysis of Artesian Water Underground Diaphragm Wall Passing Through Silty Sand Layer

地下连续墙在成槽施工中粉砂层特别容易发生局部失稳现象,针对粉砂层在承压水作用的出现失稳破坏问题,通过建立粉砂层三维滑动体稳定性分析模型,基于极限平衡原理,提出槽壁稳定性安全系数计算公式,并结合实际工程案例进行理论验证分析以及槽壁稳定性影响因素分析。研究结果表明:提出的粉砂层槽壁稳定性安全系数计算公式基本是可靠的,可为后续粉砂层地连墙施工提供一些理论参考;通过槽壁稳定性影响因素分析,承压水和地下水位是造成粉土夹砂层槽壁失稳破坏的最主要原因,泥浆液面深度和泥浆重度对槽壁稳定性影响较大,相比之下,地面附加荷载对槽壁稳定性影响较小。

The silt layer is particularly prone to local instability in the construction of underground diaphragm wall.Aiming at the instability and failure of silt layer under the action of artesian water,a three-dimensional sliding body stability analysis model of silt layer is established.Based on the principle of limit equilibrium,a formula for calculating the safety factor of trench wall stability is proposed,and the theoretical verification analysis and analysis of the influencing factors of trench wall stability are carried out combining with actual engineering cases.The research results show that the proposed formula for calculating the safety factor of the stability of the trench wall of the silty sand layer is basically reliable,which can provide some theoretical references for the subsequent construction of the silty sand layer diaphragm wall;based on the analysis of the influencing factors of the trench well stability,it is found that artesian water and groundwater level are the main reasons for the instability and failure of the trench well in silty sand layer.The slurry depth and mud weight have a greater impact on the stability of the trench well,while the additional load on the ground has a smaller impact on the stability of the trench well.