土钉支护计算模型及其优化方法探讨

针对目前土钉支护优化设计方法中存在的一些缺陷和不足,深入研究了土钉支护的工作机理,尤其是土钉的受力情况,提出了以钉土间抗剪强度为土钉最大拉力分配刚度的原则,并给出了土钉最大拉力分配系数的计算公式;结合土钉支护整体稳定性的极限平衡分析,推导了土钉最大拉力的计算方法,将计算结果与现场测试进行对比分析证明了该方法的合理性;在深入分析土钉长度计算模型的基础上,建立了以单位支护面积的土钉长度为目标函数的土钉支护优化设计模型;通过引入改进的模拟退火算法和几何控制参数法,探讨了土钉支护优化设计方法的具体实施步骤,并开发出相应的计算程序。工程实例分析表明:所建立的优化设计方法在能保证支护安全的同时兼具有较明显的经济性,其研究成果有一定的理论与工程实用价值。

Discussion on Optimum Design Model and Method of Soil Nailing

Aiming at the irrationality and limitation of design method in soil nailing,firstly,a concept of distribution coefficient of soil nail's tense is advanced in this paper by analyzing its mechanism.Then,based on researching the computing model of soil nail's length,and combined with the limit equilibrium analysis method for the globe stability of soil nailing,a optimum design model is established.Finally,the improved simulated annealing algorithm and the method of geometric controlling parameters is introduced in.On this basis,the exact implementing procedure of soil nailing's optimum design method is researched.And then the corresponding programs are developed.The analysis of engineering cases shows that this method has both safety and evident economy,and have certain theoretical and engineering practical value.