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裂隙的剪胀特性及扩展演化规律对岩体的渗流特性具有重要影响。为揭示裂隙剪胀及扩展演化对岩体渗流的影响,基于残余强度提出了一种能较好描述岩石硬化-软化特性的全剪切本构关系;结合剪切变形与裂隙开度的关系,利用最小势能原理和立方定律,建立了压剪作用下考虑裂隙剪胀特性的渗流应力耦合模型;假定压剪作用下裂隙发生Ⅰ型扩展,提出了伴有翼型裂纹的渗流模型,该模型不仅考虑了岩石的剪胀特性,更反映了裂隙扩展过程渗流的演化规律。对不同裂隙粗糙度的剪切应力-位移曲线进行分析,全剪切本构模型表现出较高的拟合精度。在剪切应力-位移关系基础上,通过剪切渗流试验数据对压剪作用下渗流模型进行验证,结果表明,该模型能较好地描述岩体剪胀阶段渗透性演化规律。利用等效裂隙简化裂隙网络,并通过试验数据进行验证,证实了裂隙扩展过程渗流-应力耦合模型的准确性与适用性。
The dilatancy characteristics and evolution of fractures have an important influence on the seepage characteristics of rock mass. In order to reveal the influence of crack dilatancy and expansion evolution on the seepage of rock mass, a full shear constitutive relationship that can describe the hardening and softening properties of rock well is proposed based on the residual strength. Combining the relationship between shear deformation and fracture opening, By using the principle of minimum potential energy and the cubic law, a seepage stress coupling model considering the dilatancy of fractures under pressure and shear is established. The model of seepage induced by airfoil cracks Considering the dilatancy characteristics of rock, it also reflects the evolution of percolation in the crack propagation process. The shear stress-displacement curves of different fracture roughness are analyzed, and the full-shear constitutive model shows higher fitting accuracy. Based on the shear stress-displacement relationship, the shear flow test data are used to verify the seepage model under pressure and shear. The results show that the model can well describe the permeability evolution law during the dilatancy stage of rock mass. The fracture network was simplified by using equivalent fractures and verified by experimental data. The accuracy and applicability of coupled seepage - stress model for fracture propagation were verified.