桥梁多灾害设计荷载系数确定方法探讨

英文篇名：Method of load factor determination for multi-hazards bridge design
中文刊名：土木工程学报
英文刊名：China Civil Engineering Journal
作者：孙得璋 ; 孙柏涛 ; George C.Lee
英文作者：Sun Dezhang 1 Sun Baitao1 George C.Lee2(1.Key Laboratory of Earthquake Engineering and Engineering Vibration ; Institute of Engineering Mechanics ; China Earthquake Administration ; Harbin 150080 ; China ; 2.University at Buffalo ; The State University of New York ; New York 14260 ; USA)
中文关键词：多灾害 ; LRFD ; 地震 ; 随机过程 ; 荷载系数 ; 失效概率
英文关键词：multi-hazards ; LRFD ; earthquake ; random process ; load factor ; failure probability
出版日期：2012-08-15
机构：中国地震局工程力学研究所,地震工程与工程振动重点实验室;纽约州立大学布法罗分校;
年：2012
期：S2
出版单位：土木工程学报

摘要

目前美国的桥梁设计多采用荷载与抗力系数法规范(LRFD),其荷载系数和抗力系数是以概率为基础的极限状态方程的形式求得的。荷载与抗力系数规范(LRFD)主要标定常规荷载和单个极端荷载,没有考虑多个极端荷载的情况,而且LRFD对于单个极端荷载的考虑并没有基于概率基础。该文针对多种极端荷载下荷载系数设计存在的问题,将多种极端荷载视为随机过程,以失效概率为纽带,提出荷载系数设计的分项失效概率概念。基于LRFD极限状态方程的形式,提出解决多种极端荷载作用下的MH-LRFD荷载系数计算方法,并给出当仅有两种极端荷载下,桥梁结构多灾害设计荷载系数的一般计算步骤。
LRFD guide specification for bridge design is mostly used in the United States,where the load and resistance factors are based on probability and limit states equations.LRFD guide specification for bridge design mainly calibrates common loads and single extreme load,and does not involve multiple hazards.Besides,it has no probabilistic basis dealing with single extreme loads.This paper presents a concept of partial failure probability for load factor design based on failure probability and random processes,analyzing the problems of multi-hazards load factors design.And a method of MH-LRFD load factors design is brought about on the framework of LRFD limit states equation,and the calculation procedure of load factors for multi-hazard bridge design is given on the basis of two extreme loads subjected to bridges.

引文

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