考虑渗流–应力耦合作用的裂缝扩展追踪分析模型

应用无单元法,考虑渗流场与应力场的耦合作用,对岩体内初始裂缝的扩展进行追踪。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。首先采用断裂力学最大周向正应力理论,对裂缝的继续开裂扩展做出判断,并确定开裂角,然后对新的结构再进行渗流-应力耦合分析,直至裂缝稳定为止。算例分析表明,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 tracing crack propagation under coupled mechanical-hydrological environment

Based on the element-free method, the crack propagation in rock mass was traced under coupled mechanical-hydrological environment, in which the seepage field and stress field were coupled by the iterative computation and the interaction between two fields was considered mainly by seepage pressure and permeability coefficient. In addition, hauling force acted by water flow to crack wall was also taken into account. First, the theory of the maximum surrounding primary stress was applied to judge whether crack started splitting and continued or not and to get the propagation orientation of crack. Then the coupled analysis of seepage field and stress field was made for new structure until the crack stopped splitting. Calculation examples show that the present method can reflect the action of water flow to crack propagation and can approximately simulate the process of crack propagation under coupled mechanical-hydrological environment.