土钉支护深基坑的二次加固数值模拟与加固效果

Numerical simulation and reinforcing effect of secondary reinforcement of deep foundation pit supported with soil nails

以西北某深基坑工程为例,通过采用有限元软件PLAXIS对该深基坑的初次支护及二次加固进行二维有限元数值模拟分析,得到加固前后的位移场变化规律,结合现场的实时监测数据对模拟分析进行验证.通过对比分析模拟结果和实测数据可知:加固后的基坑变形均控制在允许范围内;模拟结果和监测数据的良好吻合关系表明所采用的强化土模型非常合理;钢管桩加预应力锚杆的支护方式对于基坑加固具有明显的优势和适用性;实践证明该基坑二次加固方案合理,加固效果良好.

Taking aproject of deep foundation pit in northwest as an example,2-D finite element numerical simulation analysis is conducted for primary supporting structure and secondary reinforcement of this foundation pit by using finite element software PLAXIS,variation pattern of its displacement field before and after its reinforcement is obtained,and the simulation analysis is verified according to real-time site monitoring data.It can be known from comparison and analysis of the simulation results and monitoring data that the deformation of the foundation pit after its reinforcement are controlled within allowable region,and the fine agreement of simulation result with monitoring data will show that the adopted reinforced soil model is very reasonable and the supporting mode of steel pipe piles with prestressed anchor has obvious superiority and applicability for the reinforcement of deep foundation pit.Practice proves that the secondary reinforcement scheme is reasonable and its reinforcement effect is fine.