岩体裂缝扩展的渗流-应力耦合分析模型

应用无单元法,对渗流场和与应力场耦合作用下的岩体裂缝扩展进行追踪。裂缝扩展计算采用断裂力学最大周向正应力理论。应力场和渗流场的耦合作用通过以渗透压力和渗透系数为交互因子的迭代计算考虑,其中裂缝区还考虑了裂缝中水对缝壁的拖曳力。裂缝扩展计算每一步所产生的新结构都要进行渗流-应力耦合分析,直至裂缝稳定为止。算例结果表明,所建数值模型能较真实地反映水流对裂缝扩展的影响,并能较好地模拟渗流-应力耦合作用下的裂缝扩展过程。

Analytic model for crack propagation under coupled mechanical hydrological environment

Based on element-free method(EFM),the propagation of initial crack in rock mass is traced under coupled mechanical-hydrological environment.The propagation of crack is calculated by the theory of maximum surrounding primary stress.Seepage field and stress field are coupled by iterative computation,with seepage pressure and permeability coefficient as components of interaction.In addition,hauling force is considered in crack.The coupled analysis of the seepage field and stress field is made for every new structure during crack propagation.Two calculation examples,rectangular rock with single crack and one with double cracks,show that the method adopted in the paper can reflects the action of water flow to crack propagation and can approximately simulate the process of crack propagation under coupled mechanical-hydrological environment.