重力坝深层抗滑稳定强度折减弹塑性有限元法

摘要

Combined with engineering requirements of the Qingyu Reservoir,the ANSYS finite element software was used to establish overflow grav-ity dam deep sliding stability elastic-plastic calculation model which considered the mechanical properties of weak structural plane of rock in the dam foundation. An analysis of the continuous variation of the distribution of horizontal displacement of dam foundation rock,the characteristics of the magnitude of change of feature points’displacement and the process of the dam foundation rock plastic zones developing to through the founda-tion was took to get the deep sliding stability safety factor of gravity dam by gradually increasing the shear strength reduction coefficient. The safety factor of Qingyu gravity dam analyzed by the strength reducing elastic-plastic finite element method is 3. 0-3. 2,and it is consistent with the limit equilibrium dual ramp stability calculation results 3. 039-3. 667 recommended by specifications. It shows that taking the slip plane displacement mutation and plastic zone perforation as the criterion to judge dam foundation instability and failure is reasonable.%结合清峪水库实际工程设计要求，运用ANSYS有限元软件，建立考虑坝基岩体软弱结构面力学特性的溢流重力坝深层抗滑稳定弹塑性计算模型。通过逐步增大抗剪强度的折减系数，分析研究坝基岩体的水平位移分布连续性变化规律、特征点位移变化幅度特性和坝基岩体塑性区域发展贯通过程。清峪水库重力坝深层抗滑稳定使用强度折减弹塑性有限元分析得到的安全系数为3．0～3．2，与规范推荐的刚体极限平衡双斜面稳定计算结果3．039～3．667具有一致性，表明采用滑移面上位移发生突变及塑性区贯通作为坝基失稳破坏的判断准则是合理的。