地下连续墙黏性土夹砂层槽壁稳定性分析?

为了探讨地下连续墙黏性土夹砂层泥浆槽壁局部稳定性问题，建立稳定性分析力学模型，对槽壁夹砂层土体单元应力状态进行分析。基于朗肯极限平衡原理，提出泥浆槽壁局部稳定性系数计算方法。通过算例分析可知：（1）开挖将导致槽壁夹砂层土体单元产生负孔隙水压力，局部稳定性系数将会随负孔隙水压力的消散逐渐降低。（2）局部稳定性系数随相关因素的变化规律：地面超载每增大10 kPa，稳定性系数降低7%左右；泥浆重度每增大0.5 kN/m³，稳定性系数提高13%左右；有效内摩擦角每增大3°，稳定性系数提高11.5%左右；局部稳定性系数随地下水位埋深的增大而增大，但增幅逐渐减小；随泥浆液面深度的增大而减小，且降幅逐渐增大。

Trench Stability Analysis of Diaphragm Wall in Cohesive Soil Sandwiched Sand

In order to study the local stability of slurry trench of diaphragm wall in cohesive soil sandwiched sand, mechanical model was established to analyze the stress state of the sand layer. Based on Rankine limit equilibrium principle, calculating method for local stability coefficient of slurry trench was proposed. The main conclusions through the analysis of example are as follows: (1) excavation will lead to negative pore water pressure in the soil element with sand layer, and the local stability coefficient will gradually decrease with the dissipation of negative pore water pressure. (2) the variation of local stability coefficient with relevant factors was obtained: the stability coefficient decreases about 7% for each 10 kPa increase of ground overload and increases about 13% for each 0.5 kN/m³ increase of mud gravity. It increases about 11.5% for every 3 degree increase of effective internal friction angle. Local stability coefficient increases with the depth of the groundwater level at a decelerated growth rate, while decreases with the increase of slurry liquid level depth at an accelerated growth rate.