共和隧道围岩为薄层状灰岩,岩样试件单轴压缩全过程曲线表现为明显的各向异性,且隧道现场监测发现围岩屈服破坏也具有明显的方向性。据此选择合适的屈服准则及其强度参数随岩层倾角(与最大主应力的夹角)变化规律。结合各向异性弹性本构方程,获得横观各向同性弹塑性本构关系并利用C++语言实现。利用该本构模型对共和隧道进行数值模拟,计算结果与破坏特征基本吻合,验证了该模型的正确性,可以用于该隧道支护设计及稳定性分析。
Surrounding rock of Gonghe Tunnel is lamellar limestone. Its rock specimens have distinct anisotropy from complete stress-strain curve in uniaxial compression test; and yield failure of surrounding rockmass has remarkably directional property from in-situ monitoring results. According to these results and characters, selecting appropriate yield function and suitable strength parameters vary with angle between layered rockmass or maximum principal stress, combining elastic constitutive function of anisotropy; then elastoplastic constitutive function of anisotropy is obtained and implemented with C++ language. Gonghe Tunnel is numerically modeled by utilizing this constitutive function; and numerical simulation results essentially coincide with failure character. It is shown that the elastoplastic constitutive function of anisotropy is correct; and it can be used for analyzing support design and stability of the tunnel.