重力坝抗滑稳定可靠度分析:(二)强度指标和分项系数的合理取值研究

Reliability analysis on sliding stability of gravity dams: Part Ⅱ,determination of shear strength parameters and partial factors

岩土材料抗剪强度参数的合理选用是开展可靠度分析的重要一环。本文认为,在确定岩土参数变异系数的过程中,需要在现行规范建议值的基础上,综合考虑项目本身的试验成果和以往工程的经验选用设计指标。本文通过对1000多组试验结果统计及工程实例敏感性分析等途径对岩体抗剪强度参数变异系数做了比较和分析,并提出了初步的建议值。通过典型重力坝算例分析及工程实例的反演分析,对岩体的抗剪强度参数的分项系数进行了敏感性分析,对重力坝设计规范的建议值的合理性进行了评价。

Determination of strength parameters for geotechnical materials is a major concern in reliability studies.It is argued that this work should be based on a comprehensive study of the criteria suggested in the codes,testing data and past experiences.This paper gives a comprehensive review over more than 1000 sets of test data and back-analysis results for eight case histories of concrete dam,evaluates the impact of variation coefficients on calculations of reliability indices through a careful study,and puts forward a set of coefficients of variation for various materials.Finally,these coefficients are verified by a sensitivity study of partial factors by using concrete dam codes.