裂隙岩体渗流场与应力场动态全耦合参数反演

 考虑到裂隙岩体渗流和力学行为的发生与发展往往是一个动态过程，同时现场观测资料也是一个动态的时间序列，为能及时利用现场量测的新增信息使参数反演更为合理，基于求解非恒定渗流场与弹性位移场动态全耦合正分析理论与方法，应用建立的混合遗传算法作为优化算法，同时利用水头、位移等多类型动态观测资料，建立了裂隙岩体渗流场与应力场动态全耦合的参数反演思路。为避免在耦合反问题中由于利用多类型量测资料所带来的量纲问题，采用了各时刻水头、位移的相对值来构造量纲一的目标函数。待反演参数同时考虑了力学参数与渗流参数两种类型，包括岩块的弹性模量、各组裂隙的切向与法向刚度系数、各组裂隙的初始等效渗透系数等。最后以一简单裂隙岸坡为算例，针对库水位快速上涨情况，以各时刻的动态全耦合正分析结果作为“假想”的实测数据，进行动态全耦合参数反演。反演结果表明，利用不断新增的实测资料可提高反演精度，最终获得的参数反演解与理论解吻合很好。

INVERSE ANALYSIS OF FULLY COUPLED DYNAMIC WATER FLOW AND STRESS IN FRACTURED ROCK MASSES

Due to the dynamic process of water flow and deformation in fractured rock masses as well as time-dependent characteristics of in-situ monitoring data，a dynamic inverse method for fully coupled problem of water flow and stress is presented，in which a hybrid genetic algorithm is used for optimization；and two different types of monitoring data about water head and displacement are taken into account. In order to avoid the dimension problem caused by different types of monitoring data，related values of water head and displacement at each time step are used in building objective function. In the coupling inverse analysis，both mechanical and seepage parameters are regarded as unknown variables，such as elastic modulus of rock block，shear stiffness and normal stiffness of each fracture set，and initial equivalent permeability coefficient of each fracture set. Finally，the presented inverse method is applied to a simple example of fractured rock bank slope in case that water level of reservoir rises quickly，while the forward calculated results at each time step are regarded as the assumed monitoring data. It is indicated that the accuracy of parameters¢ identification can be improved if using the continuously increasing monitoring data in time；and the inverse results of parameters are in good agreement with theoretical solution.