基于MGZZ准则的弹塑性模型隧道围岩参数敏感性分析

Sensitivity analysis of surrounding rock parameters based on elasto-plastic model with MGZZ strength criterion

广义三维非线性强度准则弹塑性模型中涉及的隧道围岩参数主要有弹性模量E、泊松比μ、地质强度指标GSI、岩石单轴抗压强度σci、岩石扰动系数D、完整岩石参数mi。通过有限元试验研究分析新奥法、新意法下各参数对拱顶沉降、周边收敛、掌子面挤出最终位移值的影响程度,以确定各参数对隧道围岩变形的敏感程度。结果表明:E,μ为极高敏感度参数,GSI为中敏感性参数;基于广义三维非线性强度准则的隧道围岩稳定性能研究与支护设计时应注重E,μ的赋值,并慎重调整。

In the elasto-plastic model with Modified Generalized Zhang- Zhu（ MGZZ） strength criterion, elastic modulus E , PoissonJ s ratio uniaxial compressive strength crd , geological strength index GSI, intact rock parameter mi , disturbance factor D are main parameters of surround-ing rock. The sensitivity of these parameters has been analyzed by FEM in view of New Austrian Tunneling Method and ADECO-RS Method. The results show that the elastic modulus E and Poisson＇s ratio μ are extremely high sensitivity parameters, geological strength index GSI is the medi-um sensitivity parameters. Parameters E and μ should be specially emphasized and carefully adjusted in the tunnel support design.