论文部分内容阅读
在岩土工程中,裂隙岩体经常处于峰后变形状态,研究裂隙岩体的峰后应力-应变关系对预测结构的稳定性有重要意义。基于峰后软化阶段强度参数的逐渐演化行为,首先提出一个求岩石峰后应力-应变关系和裂隙峰后应力-切向位移关系的一般方法。然后采用摩尔-库仑强度准则,以岩石的最大主应变和裂隙的切向位移作为软化参数,假设强度参数为软化参数的分段线性函数,分岩体沿裂隙滑移破坏和沿岩石剪切破坏两种情况,提出多组贯穿裂隙岩体峰后应力-应变关系式的求法。最后,在算例中,分岩体沿裂隙滑移破坏和沿岩石剪切破坏两种情况给出了裂隙岩体的峰后应力-应变曲线,讨论了裂隙的平均间距、法向刚度和剪切刚度对峰后应变的影响。结果表明,裂隙的平均间距、法向刚度和剪切刚度越小,裂隙岩体的轴向应变越大。
In geotechnical engineering, the fractured rock mass is often in the post-peak deformation state. It is of great significance to study the post-peak stress-strain relationship of the fractured rock mass to predict the structural stability. Based on the gradual evolvement of strength parameters in the post-peak softening stage, a general method to find out the post-peak post-peak stress-strain relationship and post-peak stress-tangential displacement is proposed. Then, using the Mohr Coulomb strength criterion, the maximum principal strain of rock and the tangential displacement of the fracture are taken as the softening parameters. The strength parameter is a piecewise linear function of the softening parameter, the slip damage of the rock mass along the fracture and the shear failure along the rock In both cases, several sets of post-peak stress-strain relationship formulas are proposed. Finally, in the example, the post-peak stress-strain curves of the fractured rock mass are given in terms of the slip failure along the rock mass and the shear failure along the rock mass. The average spacing, normal stiffness and shear of the fracture are discussed Effect of shear stiffness on post-peak strain. The results show that the smaller the average spacing, the normal stiffness and the shear stiffness of the fractures, the larger the axial strain of the fractured rock mass.