论文部分内容阅读
重力坝的深层抗滑稳定分析多采用刚体极限平衡法和非线性有限元法,但刚体极限平衡法不能反映坝基岩体渐进失稳过程和破坏的力学机制,非线性有限元法模拟岩体不连续效率低,且还未有统一的失稳判据。基于离散块体边界应力计算结果,提出重力坝坝基多滑面抗滑稳定安全系数计算公式,并探讨了以坝体-坝基系统能量突变作为坝基失稳判据的物理意义。通过与非线性有限单元法、刚体极限平衡法计算结果的比较,验证了所提方法及判据的可靠性及合理性。结合向家坝水电站重力坝泄12#坝段进行计算分析,结果表明:基于离散元强度储备系数法搜索的坝基失稳通道由坝基岩体屈服区和结构面滑移带组成,所提计算方法与判据适用于实际工程的坝基深层抗滑稳定计算分析,且计算结果偏安全。
The rigid-body limit equilibrium method and nonlinear finite element method are mostly used in the analysis of deep-level anti-sliding stability of the gravity dam. However, the rigid-body limit equilibrium method can not reflect the mechanical mechanism of gradual destabilization process and failure of dam foundation. Nonlinear finite element method Continuous low efficiency, and there is no uniform instability criterion. Based on the calculation results of the boundary stress of discrete blocks, the formulas for calculating the safety coefficient of anti-sliding stability of the multi-sliding surface of gravity dam are proposed and the physical meaning of dam-dam foundation system energy mutation as the instability criterion of dam foundation is discussed. By comparing with the results of nonlinear finite element method and rigid body limit equilibrium method, the reliability and rationality of the proposed method and criterion are verified. Combined with the calculation and analysis of the 12 # dam section of the gravity dam of Xiangjiaba Hydropower Station, the results show that the instability channel of the dam foundation based on the discrete element strength reserve coefficient method is composed of the yield zone and the slip band of the structural surface of the dam foundation. And the criterion is applied to the practical dam deep foundation stability analysis and calculation, and the results are partial safety.