考虑参数空间变异性多层土坡系统可靠度分析

Reliability analysis of multilayered soil slopes system considering spatial variability of soil properties

多层土坡在岩土工程实际中十分常见,不仅土体参数存在一定的空间变异性,而且土体框架呈现明显的层状分布特征,然而目前对考虑土体参数空间变异性的多层土坡稳定可靠度研究的远远不够。提出了基于多重响应面边坡系统可靠度分析的蒙特卡洛模拟(MCS)方法,给出了计算流程图,系统地研究了考虑土体参数空间变异性的多层土坡系统可靠度问题。结果表明,提出方法能够有效地分析考虑参数空间变异性低失效概率水平的多层土坡系统可靠度问题,并且具有较高的参数敏感性分析计算效率。

The multilayered soil slopes are very common in geotechnical practice. Not only there exists inherent spatial variation for soil properties, but also there shows obvious multilayered distribution characteristics within the natural soil profile. However, few attempts have been made to study the reliability of multilayered soil slope stability in spatially variable soils. This paper proposes a Monte-Carlo simulation(MCS) based slope system reliability analysis approach using multiple response surfaces. The flow chart for the proposed approach is presented. The reliability of a multilayered soil slope system considering spatial variability of soil properties is systematically investigated using the proposed approach. The results indicate that the proposed approach properly evaluates the slope system reliability at small probability levels(i.e., pf,s < 0.001) considering spatial variability of soil properties and achieves high computational efficiency in parametric sensitivity analysis.