土质边坡渐进破坏过程的近似模拟

Simulation of Progressive Failure Process of Soil Slope

用有限元强度折减法对边坡进行计算,分析滑动面上典型位置单元应力状态变化规律,建立单元应力状态和边坡整体稳定性之间关系,提出单元失稳判据.将判据的有限元语句程序化,对天然边坡进行有限元强度折减计算,应用所提判据和程序对边坡渐进破坏过程进行有限元数值模拟,采用不同失稳判据和极限平衡法计算结果进行比较,验证了本文单元判据的合理性,本文判据能解释和模拟边坡的渐进破坏过程.将本文方法与位移突变判据结合使用,既能描述边坡渐进破坏,又便于工程中对边坡、基坑工程的安全性进行实时监测与反馈.

Finite element strength reduction method is applied in progressive failure simulation.Stress states of typi- cal elements on the potential sliding surface are analyzed.The relationship between the stress state of the element and the stability of the slope is established.Furthermore,the criterion of element instability based on Mohr-Coulomb theory is proposed.The criterion is programmed and applied to simulate the progressive failure process of natural soil slope.Traditional limit equilibrium methods are applied to conduct stability evaluation.Various criteria,including iteration non-convergence,plastic zone penetration,displacement mutation,and the criteria proposed in this paper are compared.Results prove that the different criteria are unified.Numerical analysis program is coded with the proposed criterion using Fortran 95 language.Strength reduction calculation is conducted on the soil slope.The proposed criterion can explain and simulate the progressive failure process of the slope.Combining the method with the displacement mutation criterion not only enables description of the progressive failure of the slope but also helps in monitoring the safety of the slope during construction.