既有重载铁路32m预应力混凝土T梁运营性能检算评估  

Check Computation and Evaluation on Operation Performance of 32m Prestressed Concrete T-Girder of Existing Heavy Haul Railway

作　　者：李承君 葛凯 袁磊 许见超 赵体波 荣峤 马宏亮 LI Chengjun;GE Kai;YUAN Lei;XU Jianchao;ZHAO Tibo;RONG Qiao;MA Hongliang(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081

出　　处：《铁道建筑》2021年第9期24-28,共5页Railway Engineering

基　　金：中国铁道科学研究院集团有限公司基金(2019YJ043)。

摘　　要：以大秦重载铁路线上广泛应用的跨度32 m后张法预应力混凝土简支T梁为例,依据现行设计规范对病害较为集中的三种梁型的静力性能指标进行了检算。结果表明:运营荷载作用下梁体截面内力已超过设计荷载作用下内力;设计荷载作用下部分梁型跨中截面抗裂和抗弯强度安全系数不满足规范要求,下缘处于受拉状态;运营荷载作用下各梁型跨中截面上缘最大压应力均超过规范限值,且下缘均出现拉应力;部分梁型斜截面最大主拉应力已接近或超过规范限值,各梁型斜截面最大主压应力均满足规范要求;腹板过薄、主拉应力过大是重载铁路运营阶段梁体斜截面开裂的主要原因。Taking the 32 m span post-tensioned prestressed concrete simply supported T-girder widely used on Datong-Qinhuangdao heavy haul railway as an example,the static performance indexes of three types of girders with concentrated defects were computed according to the current design codes.The results show that the inner force caused by operation load exceeds that caused by the design load.Under the design load,the cracking resistance and flexural strength safety factors of some girder midspan sections do not meet the requirements of the code,and the lower edge the girder is in tension.Under the operation load,the maximum compressive stress at the upper edge of each girder midspan exceeds the limit value of the code,and the lower edge of the girder is in tension.The maximum principal tensile stress of some girder inclined sections has approached or exceeded the limit value of the code,and the maximum principal compressive stress of each girder inclined section meet the requirements of the code.The main causes of inclined section cracking of girder in the operation stage of heavy haul railway are too thin web and too large principal tensile stress.

关 键 词：重载铁路 设计荷载 运营荷载 正应力 主应力 抗裂性能 设计检算 预应力混凝土T梁 

分 类 号：U448.33[建筑科学—桥梁与隧道工程] U448.231[交通运输工程—道路与铁道工程]