基于非线性Molar-Coulomb破坏准则,结合极限分析上限法和拟静力分析法,建立功能方程,推导了地震效应下裂缝边坡的安全系数计算方程。采用数学规划方法,计算了不同参数组合条件下的边坡安全系数值,详细分析了非线性条件下一系列参数对边坡稳定性的影响。研究表明,边坡安全系数随非线性参数和地震效应的增大而减小。对比分析可知,在非线性破坏准则下,裂缝深度较大时,裂缝对边坡稳定性影响显著,且边坡越陡影响越大;当裂缝深度超过某个值后,临界破坏面起始端可能不穿过裂缝最底端,而是从裂缝中间某部位穿过。在地震效应作用下,非线性抗剪强度参数对安全系数影响显著。研究成果进一步完善了裂缝边坡稳定性分析内容,所列图表为边坡的设计与施工提供有益参考。
The expression of safety factor for slopes with cracks subjected to seismic forces is deduced through establishing an energy equation using upper bound limit analysis and pseudo-static analysis based on nonlinear Mohr-Coulomb failure criterion. Safety factors are calculated using mathematical programming method with combinations of different parameters. A detailed parametric study is performed to determine the influence of slope angle, upper slope angle, horizontal seismic coefficient, vertical seismic coefficient, crack depth, geotechnical parameters on slope stability based on nonlinear failure criterion. Results show that safety factor decreases as the nonlinear parameter and seismic forces increase. Cracks can significantly influence on slope stability under nonlinear failure criterion when crack depth is large, especially for steep slope. When the value of crack depth exceeds a certain value, the beginning of critical failure surface may not pass through the lowest end of crack, but cross at a middle part the crack. It is also observed that when slopes is subjected to seismic effect, the safety factor depends significantly on the nonlinear shear strength parameters. Research results perfect the contents of stability analysis of slopes with cracks and the charts provide an useful reference for design and the construction of slop parameters on stability of slopes with cracks.