公路开挖边坡的稳定性分析方法研究

Research on stability of excavated slopes

针对山区修筑公路常遇开挖自然斜坡坡脚而诱发边坡失稳的情况,对某边坡的粘土进行卸荷路径下的三轴试验,以获得边坡稳定分析的计算参数。用这些参数对开挖边坡作非线性有限元分析,可获得边坡塑性区形态和确定滑移面位置。现场监测边坡在渗流期的地下水位变化,采用极限平衡法计算边坡的安全系数,并对其稳定性进行评价。研究认为边坡的危险期是汛期,宜采用有效应力法估算其稳定。

The natural slope failures often occurred after constructing highways at mountain areas. Clay tests from an illustration were conducted under the unloading stress?path condition using a triaxial equipment in order to obtain the computation parameters for stability analysis of the slope. A non?linear FEM for analysis of stability of excavated slope was established. The calculation results provided the form of plastic zone and the location of slide plane after the excavation of mountain slope. The variation data of ground water inside the slope were monitored in field during seepage. The limit equilibrium method was used to calculate the safety factors of slope; herefrom its stability was estimated. The study results showed that the dangerous period of failure is in flood season, and in this case the effective stress method suits to calculate its stability.