摘要
各国规范普遍规定采用一次二阶矩法标定结构可靠度分析的安全指标。欧洲规范称其为"Level II"。为验证针对一个特定算例在目标可靠指标基础上标定的安全指标的普遍适用意义,提出"相对安全率"这一判据。简要回顾了使用一次二阶矩法计算相应目标可靠指标的允许安全系数和分项系数的原理和方法,然后改变被考核的算例的几何特征和岩土力学参数,要求"相对安全率"Rη,Fη,Pη互相接近(η为相对安全率,下标R,F,P分别定义可靠指标、安全系数、分项系数3个领域的相应参数)。根据Level II标定的安全指标如能通过此普适性检验,则在工程实践中可以得到较广泛的认可。同时,回顾了这一方法在土石坝、加筋边坡、挡土墙、混凝土重力坝和拱坝的抗滑稳定分析中成功应用的研究成果,并对标定的结果做了总结。
Calibrating safety criteria by the First Order Second Moment Method is a standard approach specified in codes. Euro Code I refers it as the‘Level Ⅱ approach＇. This paper presents a criterion called‘Ratio of safety margin＇that is used to assess the universal applicability of a calibrated safety criteria based on the target reliability index. Following a brief review of the theoretical background described in the existing codes,the author calibrated the equivalent factors of safety and partial factors based a target reliability index on a selected test example by the First Order Second Moment Method. The calibrated safety criterion was then examined by varying all the related geometrical and physical parameters of this selected example,making sure that the values of ηR,ηF,and ηP are approximately same. Formulations have been given for defining the‘Ratio of safety margin＇designated η for reliability index,factors of safety,and partial factors with subscripts R,F,P respectively. Having passed this universal applicability test,the calibrated values have been promoted for practical application with more confidence. The author reviews its successful applications in the area of stability analysis for embankment dams,reinforced slopes,retaining walls,and concrete gravity and arch dams. The author summarizes thecalibrated acceptable factors of safety and partial factors in these areas associated with the required reliability indices.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2018年第3期521-544,共24页
Chinese Journal of Rock Mechanics and Engineering
关键词
岩土工程
可靠度分析
可靠指标
安全系数
分项系数
相对安全率
geotechnical engineering
reliability analysis
reliability index
factor of safety
partial factor
ratioof safety margin
