预应力混凝土梁桥过火后破坏模式  

The Failure Mode of Prestressed Concrete Bridges after Fire

作　　者：甘亮丁 王力波[2] 郝朝伟 GAN Liangding;WANG Libo;HAO Chaowei(Guangdong Meiping Expressway Co.,Ltd.,Meizhou,Guangdong Province,514700 China;Jilin Provincial Transport Scientific Research Institute,Changchun,Jilin Province,130021 China;Research Institute of Highway,Ministry of Transport,Beijing,100088 China)

机构地区：[1]广东梅平高速公路有限公司,广东梅州514700 [2]吉林省交通科学研究所,吉林长春130021 [3]交通运输部公路科学研究院,北京100088

出　　处：《科技资讯》2023年第20期90-93,共4页Science & Technology Information

基　　金：山东省交通运输厅科技项目(项目编号:2017B62)。

摘　　要：为深入分析先张法预应力空心板过火后破坏模式,以在役桥梁过火后拆除的梁板为依托,对过火后混凝土、普通钢筋、钢绞线进行材质试验,结合相关理论和数值模拟分析其破坏模式改变的主要原因。结果表明:随着火灾灼烧程度的加重,预应力空心板梁发生剪切破坏的概率较纯弯破坏逐渐增大;有效预应力及钢绞线强度的降低是造成过火后空心板破坏模式变化的主要原因;先张法预应力空心板过火后评估应采取有效手段测试永存预应力,方可准确计算剩余承载力。To conduct a thorough analysis of the failure mode of pretensioned prestressed hollow slabs after fire,re‐lying on the dismantled beam plates of in-service bridges after fire,this paper conducts the material test of concrete,ordinary steel bars and steel strands after fire,and analyses the main reasons for the change of their failure modes in combination with relevant theories and numerical simulation.The results show that the probability of the shear fail‐ure of prestressed hollow slab beams gradually increased in comparison to pure bending failure with the aggravation of the degree of fire burning,the reduction of effective prestress and steel strand strength were main reasons for the changes of the failure modes of hollow slabs after fire,and that the evaluation of pretensioned prestressed hollow slabs after fire should take effective means to test permanent prestress to accurately calculate the remaining bearing capacity.

关 键 词：火灾 先张法 预应力 承载能力 破坏模式 

分 类 号：U442.55[建筑科学—桥梁与隧道工程] U448.23[交通运输工程—道路与铁道工程]