深基坑疏排桩锚与土钉墙水平联合支护数值模拟

Numerical simulation of scattered row pile-anchor and soil-nailed wall level composite support in deep foundation pit

为了验证疏排桩锚—土钉墙水平联合支护结构的稳定、安全及可行性,得出桩、锚等结构构件的受力及变形规律,以北京京温市场二期地下车库基坑工程为例,分别构建了桩锚支护和疏排桩锚—土钉墙水平联合支护两种方案,然后对两种方案进行了数值模拟,并将以下方面的模拟结果进行了对比分析:基坑开挖面水平位移、地面沉降、各道锚杆的轴向受力规律及支护桩的受弯规律。模拟结果表明:当基坑土层适合土钉支护但开挖深度超过土钉支护深度时,采用疏排桩锚—土钉墙水平联合支护结构替代桩锚支护结构是稳定的、安全的、可行的。

In order to verify the stability,safety and feasibility of scattered row pile-anchor and soil-nailed wall level composite support structure,obtain force and deformation law of piles,anchor and other structural elements,taking underground garage foundation pit of Beijing Jingwen Market as an example,two kinds of supporting programs are constructed,one is scattered row pile-anchor and soil-nailed wall level composite support program,and the other is pile-anchor support program,then the two programs are simulated.The following simulation results are compared such as excavation surface horizontal displacement,ground subsidence,the law of axial force of different anchor and the bending moment of support pile.The results show that when soil nailing is suitable for the soil,but excavation depth is deeper than what soil nailing can do,scattered row pile-anchor and the soil-nailed wall level composite support structure used as a alternative of pile-anchor support structure is safe and feasible.