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综合运用岩体结构力学、几何损伤力学及岩石流体力学理论,建立裂隙岩体渗流–损伤–断裂耦合数学模型(扩展FLAC3D模型),在FLAC现有计算模块的基础上,通过Fish研制了其分析程序。该模型的耦合机理:渗透水力梯度作为渗透体积力作用于损伤应力计算单元,裂隙渗透压作为面力作用于裂纹张开部分引起断续岩石裂纹的起裂,扩展导致岩体损伤演化;岩体裂纹的扩展引起岩体渗透系数的增加,导致渗流场的改变。对一复杂裂隙岸坡蓄水加载过程进行渗流–损伤–断裂耦合分析,得到不同蓄水时期,裂隙岸坡渗流场分布、损伤场的演化,初步探讨了水库蓄水过程中岸坡山体变形机制。耦合分析认为:山体变形是增量渗透力和增量浮托力共同作用于岸坡的结果;对蓄水相对高程较大的裂隙岸坡而言,库水位上升,裂隙渗透水压增加导致岩体裂纹起裂扩展,岩体损伤区增大且向岸坡深部扩展。高渗透压诱发岸坡不利断层带损伤区扩展,甚至贯通,可能是导致岸坡失稳的重要原因。
Based on the combined application of structural mechanics of rock mass, geometrical damage mechanics and rock hydrodynamics theory, the seepage-damage-fracture coupled mathematical model of fractured rock mass is established (FLAC3D model is extended). Based on FLAC’s existing computational module, program. The coupled mechanism of the model: the infiltration hydraulic gradient acts as the permeate volume force on the damage stress calculation unit, and the osmotic pressure acts as the surface force on the open part of the crack to cause the initiation of the intermittent rock crack, which leads to the damage evolution of the rock mass. The crack growth causes the permeability coefficient of rock mass to increase, resulting in the change of seepage field. The seepage-damage-fracture coupling analysis of the reservoir loading process of a complex fractured bank slope is carried out, and the distribution of the seepage field and the damage field at different water storage periods and fractured bank slopes are obtained. The deformation mechanism of the bank slope during the reservoir impoundment is discussed . Coupling analysis shows that the deformation of the mountain is the result of the incremental infiltration force and the incremental floating force acting together on the bank slope. For the fractured bank with relatively high water level, the reservoir water level rises and the fracture infiltration hydraulic pressure increases, The body crack starts to expand and the damaged area of the rock mass increases and expands to the deep side of the bank. High osmotic stress induced bank fault zone damage zone extension, or even through, may be the main reason leading to bank instability.