基于试验的Q460GJ钢焊接截面压弯构件可靠度分析  

Reliability analysis of compression-bending member welded by Q460GJ steel based on test

作　　者：聂诗东[1,2] 李静尧 戴国欣[1,2] 杨波[1,2] NIE Shidong;LI Jingyao;DAI Guoxin;YANG Bo(Key Laboratory of New Technology for Construction of Cities in Mountain Area(Chongqing University),Ministry of Education,Chongqing 400045,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China)

机构地区：[1]山地城镇建设与新技术教育部重点试验室(重庆大学),重庆400045 [2]重庆大学土木工程学院,重庆400045

出　　处：《建筑结构学报》2021年第5期206-214,共9页Journal of Building Structures

基　　金：国家自然科学基金面上项目(51578089)。

摘　　要：建筑结构用钢板已在国内多个重大工程中得到应用,GB 50017—2017《钢结构设计标准》中已经给出了Q345GJ钢的设计强度指标,更高强度等级建筑结构用钢板的设计指标亟待研究。为此,对厚度t≤50 mm范围内Q460GJ钢的材料性能进行了统计分析,得到了第一组厚度(t≤16 mm)、第二组厚度(16 mm<t≤50 mm)的材料不确定性统计参数,并接受其屈服强度服从正态分布。基于焊接箱形截面和焊接H形截面压弯构件整体稳定承载力试验结果,获得了Q460GJ钢压弯构件的计算模式不确定性统计参数,并通过进一步的统计分析得到了Q460GJ钢压弯构件的抗力不确定性统计参数:对于第一、二厚度分组,其抗力不定性均值分别为1.156和1.138,变异系数分别为0.119和0.113。根据GB 50068—2001《建筑结构可靠度设计统一标准》及GB 50068—2018《建筑结构可靠性设计统一标准》,采用可靠度方法提出两个厚度分组对应的压弯构件抗力分项系数,并建议Q460GJ压弯设计强度取为425 MPa。Steel plates for building structures have been used in many major domestic projects.There are already design values for Q345 GJ steel in GB 50017—2017‘Standard for design of steel structures’.The design values of high-strength steel plate for building structures need to be studied urgently.In this paper,the material properties of Q460 GJ steel with the thickness t≤50 mm were statistically analyzed,and the statistical parameters of its uncertainty of the first set thickness(t≤16 mm)and the second set thickness(16 mm<t≤50 mm)were obtained.It is adopted that the yield strength of Q460 GJ steel obeys normal distribution.Based on the bearing capacity test results of box section and H-shaped section compression-bending members welded by Q460 GJ steel,the statistical parameters of model uncertainty of Q460 GJ steel compression-bending member were obtained,and the statistical parameters of the resistance uncertainty were obtained by further statistical analysis.The mean values of the resistance uncertainty of the first set and the second set are 1.156 and 1.138 respectively,and the variable coefficients are 0.119 and 0.113 respectively.According to GB50068—2001‘Unified standard for reliability design of building structures’and its latest version GB50068—2018,reliability method was adopted to propose the resistance factor of Q460 GJ steel compression-bending member.Finally,the design value was recommended to be 425 MPa.

关 键 词：Q460GJ 压弯构件 箱形截面 H形截面 抗力分项系数 可靠度 

分 类 号：TU391[建筑科学—结构工程]