基于Hoek-Brown准则的围岩参数DE-FEM反演程序及应用

DE-FEM method for back analysis of rock mechanical parameters based on Hoek-Brown criterion and its application

针对Hoek-Brown(H-B)准则在数值计算中的奇异点问题,论述了主应力空间中H-B屈服准则的应力回映算法,给出了应力回映区域的判定方法、应力更新方程式和一致切线模量的表达式。采用C++语言编制了节理围岩弹塑性有限元求解程序,通过与FLAC软件计算结果的对比,得出计算位移最大误差为5.36%,验证了所编程序的正确性。针对岩石材料力学参数难以确定的问题,引入差异进化算法,自主开发了DE-FEM位移反分析程序,并将其应用于吉林省高丽沟隧道洞口段工程。结果表明,通过反演所得位移最大误差为8.96%,反演程序具有较高的精确性和实用性,该方法能够为类似工程的安全设计提供参考和帮助。

The stress mapping method for Hoek-brown criterion is discussed. The determination method, stress updating formulation and consistent tangent operator expression is established. The elasto-plastic FEM program for joint rock is compiled by C++. The calculation result compared with Flac software proves the program accuracy. The differential evolution method is brought in to establish DE-FEM method for rock mechanical parameters back analysis. The method is applied to Gaoligou tunnel in Jinlin province, and the result obtained show that the back analysis program has high accuracy and practicability and this method can provide reference and help for safety design of similar engineering.