Limit Equilibrium Method of Slope Stability Analysis Considering Spatial Variability of Soil Properties
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摘要: 为考察土体参数空间变异性条件下极限平衡法用于求解边坡稳定问题的适应性,用极限平衡法计算了边坡截面的稳定性.采用K-L方法确定边坡土体的空间样本取值,生成空间随机场;用瑞典圆弧法、简化Bishop法、Morgenstern-Price法和Spencer法对边坡截面的安全系数进行了计算比较.此外,对一个边坡的概率失稳进行了分析.计算结果表明:简化Bishop法、Morgenstern-Price法和Spencer法得到的安全系数值非常接近,总体上比瑞典圆弧法的计算结果好;对于圆弧滑面边坡,为简化求解,可用简化Bishop方法代替Morgenstern-Price方法;同时用边坡安全系数和破坏概率2个指标,能使边坡安全评价更具定量化表述.Abstract: In order to evaluate the adaptability of the limit equilibrium method (LEM) to assess the stability of spatially variable soil slope, stability analysis of slope sections was conducted using the LEM (limit equilibrium method) considering the spatial variability of soil property. The Karhunen-Loève (K-L) method was adopted to generate the spatial samples of soil slope, i.e., random fields. The Fellenius method, the simplified Bishop method, the Morgenstern-Price method and the Spencer method were utilized to calculate the safety factors of the slope sections. In addition, the failure probability of a given slope was analyzed. The calculated results show that the safety factors calculated with the later three methods are very close to each other. And basically, they are much better than the Fellenius method. For simplicity, the Bishop method can take the place of the Morgenstern-Price method under the condition that the critical slip surface is circular. The combined use of safety factor and failure probability can evaluate slope safety more quantitatively.
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Key words:
- slope stability /
- probability /
- spatial variability /
- limit equilibrium method
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