基于MINDLIN解的土钉墙变形计算方法

 土钉墙变形是影响其安全的关键指标，已有的研究没有给出其变形的合理理论计算方法。提出基于MINDLIN解的土钉墙变形理论计算方法，该方法通过虚拟开挖应力模拟土钉墙开挖状态，基于实测资料假定钉土剪力在潜在滑动面两侧沿土钉方向呈双三角形分布，利用MIDLIN应变解计算虚拟应力和钉土剪力在钉尾和潜在滑动面位置产生的侧向变形，根据钉土剪力在潜在滑动面位置等于0的特点得到钉土相对位移在潜在滑动面位置为0的结论，并利用该结论及土钉力学平衡条件得到钉土剪力计算模型的2个相关参数，最后通过钉尾变形和土钉自身拉伸变形的叠加得到土钉墙任意位置的侧向变形。通过与法国CEBTP大型试验1#墙实测数据的对比分析，初步验证该计算方法的合理性和可行性。

CALCULATION METHOD OF LATERAL DISPLACEMENT OF SOIL NAILING BASED ON MINDLIN SOLUTION

Lateral displacement of soil nail is a key parameter affecting its safety，however，the existed studies have not provided any reasonable theorical calculation method. A theorical calculation approach based on the MIDNLIN solution，in which virtual excavation stress is used to simulate the excavation status of soil nailing，is applied to obtain the lateral displacement of soil at potential failure surface and the end of nail caused by the virtual excavation stress and soil and nail shear stress. The approach has a hypothesis on the base of the in-situ measured data that the distribution of between soil and nail is double-triangle including two unknown coefficients，which can be worked out by two equations from the zero relative displacement and the equivalent axial force of soil nail at both sides of potential failure surface. Then the lateral displacement at the surface of soil nailing is the sum of the tension deformation of nail and the lateral deformation of soil at the end of nail. The measured data from French research test on soil nailing are used to illustrate the validity of the proposed calculation model.