土钉支护工作性能参数分析

采用三维分离式有限元模型 ,考虑土钉的加固作用及土钉与土体的相互作用 ,模拟土钉支护施工过程。选择能够反映开挖特点的土的本构关系 ,从而建立有限元分析方法 ,并通过编程计算研究土钉支护的工作机理、变形和受力性能 ,分析支护参数的影响。通过对一个大型足尺模型试验实例的分析计算 ,与实测结果和现有有限元分析结果进行比较分析 ,说明对二维有限元分析结果的改进。研究结论对土钉支护的设计和施工具有较高的应用价值。

Parametric studies on behaviors of soil nailing

A discrete three dimensional(3 D) finite element model(FEM) has been developed for the analysis of soil nailed structures.The soil constitutive law is chosen to analogize the behaviors of soil during excavation.The tensions of nails and their adhere slip behaviors are simulated by bar elements and two note double spring elements,respectively.The staged excavation and retaining can also be simulated in this model.The working principle and strain stress performances of soil nailing are researched.Parametric studies are applied to examine the effects of several factors on the deformation.An engineering case is,as an example,analyzed and the predicted soil deflections are compared with those measured in situ and computed by the existing 2 D FEM.The 3 D FEM obtains better results than the 2 D FEM.Conclusions may be of very high practical value in design and construction of soil nailing.