铁道科学与工程学报2025，Vol.22Issue(2)：770-782,13.DOI:10.19713/j.cnki.43-1423/u.T20240674
基于PHI2方法的重载铁路PC简支T梁抗裂时变可靠度研究
Time-dependent reliability analysis of crack resistance in PC simply supported T-beams of heavy-haul railways based on PHI2 method
摘要
Abstract
The cracking of simply supported prestressed concrete(PC)T-beams in heavy-haul railways under the long-term action of heavy-axle weight and high-frequency train load have frequently occurred and severely affected the durability of bridges.To explore the reliability of cracking resistance in simply supported PC T-beams during the service of heavy-haul railway,research on time-dependent reliability of crack resistance in normal and inclined sections was conducted.First,considering the fatigue-induced prestress loss and time-dependent characteristic,the limit state functions for crack resistance of normal and inclined sections were established.Second,the effect of train load was analyzed,and the fatigue-induced prestress loss model related to load history was established.Next,statistical information of concrete tensile limit strength,instantaneous prestress loss,first-stage and second-stage dead loads,and train load were summarized based on literature review.Finally,based on PHI2 method,the time-dependent reliability analysis for crack-resistance of simply supported PC T-beams of a heavy-haul railway and parametric analysis were carried out.The results indicate that under the same train axle load,the reliability index of crack resistance in inclined section is lower than that in normal section,the adverse effect of increasing train axle weight on crack-resistance reliability of inclined section is greater than that of normal section;the effect of the train axle weight on crack-resistance reliability is much larger than the daily train frequency;with the same annual freight volume,the combination of small axle weight and high daily train frequency corresponds to a higher crack-resistance reliability;the influence of instantaneous prestress loss on crack-resistance reliability of normal section is stronger than that of inclined section;and the mean value of the load parameter has a greater impact on the reliability index than the coefficient of variation.This study can provide reference for the design,maintenance and repair of heavy-haul railway PC simply supported T-beams.关键词
重载铁路预应力混凝土简支T梁/开裂失效/疲劳预应力损失/时变可靠度分析/敏感性分析Key words
prestressed concrete simply supported T-beams of heavy-haul railway/cracking failure/fatigue-induced prestress loss/time-dependent reliability analysis/sensitivity analysis分类
建筑与水利引用本文复制引用
宋泽伟,卢朝辉,张升旺,李纯清..基于PHI2方法的重载铁路PC简支T梁抗裂时变可靠度研究[J].铁道科学与工程学报,2025,22(2):770-782,13.基金项目
朔黄铁路发展有限责任公司资助项目(SHGF-18-50) （SHGF-18-50）
