特殊地质区域海底隧道长期稳定性研究

根据F4风化槽强风化花岗岩的三轴流固耦合试验以及三轴流变试验成果,建立Mohr-Coulomb模型来描述风化槽岩石的弹塑性硬化及塑性流动行为,采用Nelder-Mead最优化方法得到力学模型各参数。应用三轴流变试验建立强风化花岗岩的非线性流变模型并拟合相关流变参数,在此基础上将流固耦合流变模型编制Creep子程序嵌入到ABAQUS软件。通过现场反演证明试验所得模型与参数可以很好地描述实际的情况。根据反演的围岩力学参数,模拟海底隧道F4风化槽段(ZK8+900m)隧道结构的长期稳定性,为海底隧道的设计和运营管理提供理论依据。

STUDY OF LONG-TERM STABILITY OF SUBSEA TUNNEL IN SPECIAL GEOLOGICAL REGION

Based on triaxial hydro-mechanical compressive tests and triaxial creep tests of the strongly weathered granite，a constitutive model with Mohr-Coulomb yield criterion is established to describe the elastoplastic hardening and plastic flow behavior of the weathered granite. Parameters of the mechanical model are obtained from back analysis combining Nelder-Mead algorithm and finite element method. A nonlinear creep model is established by using triaxial creep tests and relative creep parameters are obtained. On the basis，the model is imbedded into ABAQUS by writing creep subprogram. The models and parameters derived from laboratory tests are justified through field inversion analysis. Based on the developed models and the obtained parameters，long-term stability of tunnel located in F4 is studied. The numerical simulation results provide some reasonable suggestions for tunnel design and long-term operation management.