基于声发射技术的无砟轨道混凝土开裂演化规律分析  

Analysis of Cracking Evolution Law of Ballastless Track Concrete Based on Acoustic Emission Monitoring Technology

作　　者：曹瑞恒 肖杰灵[1,2] 陈醉 郭恒[1,2] 杨荣山 刘学毅[1,2] CAO Ruiheng;XIAO Jieling;CHEN Zui;GUO Heng;YANG Rongshan;LIU Xueyi(MOE key Laboratory of High-speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学高速铁路线路工程教育部重点实验室,成都610031 [2]西南交通大学土木工程学院,成都610031

出　　处：《铁道标准设计》2022年第7期65-70,共6页Railway Standard Design

基　　金：国家自然科学基金项目(51978584,51778543)。

摘　　要：深入研究混凝土结构开裂行为及伤损演变规律,是进行高速铁路无砟轨道科学运维的基础。为研究无砟轨道混凝土开裂伤损演化规律,采用声发射监测技术,开展列车动荷载和准静态荷载作用下混凝土弯曲梁的损伤演化现场监测试验,通过比较累计振铃计数等声发射特征参数,对比研究动荷载及准静态荷载对混凝土裂缝演化规律的影响,并结合裂点空间坐标定位,进一步分析试件裂隙分布及演化规律。结果表明:无砟轨道混凝土裂缝发展过程表现出三阶段特性;列车动荷载作用下无砟轨道混凝土伤损发展明显快于准静态荷载作用下,动荷载有助于加快无砟轨道混凝土伤损的发展;由于准静态荷载作用下混凝土内裂缝得到充分释放,因此在进入伤损快速发展的第三阶段时,静载条件下累计振铃计数相较于动载增大67.1%;列车动荷载更容易引起无砟轨道伤损,在无砟轨道结构设计与检算时采用列车动荷载更符合实际工况。It is the basis of scientific operation and maintenance of ballastless track to conduct in-depth research on cracking behavior and damage evolution law of concrete structure. In order to study the cracking and damage evolution law of ballastless track concrete, acoustic emission monitoring technology is used to conduct field monitoring tests on the damage evolution of concrete bend beam under the train dynamic load and quasi-static load. By comparing the total acoustic emission characteristic parameters such as ringing count, comparative study is made on the effects of the dynamic load and quasi static load on concrete crack evolution law. The distribution and evolution of cracks in specimens are further analyzed with the spatial coordinate location of crack points. The results show that: the development of concrete cracks in ballastless track shows three stages;the damage of ballastless track concrete under dynamic train load develops faster than that under quasi-static load, and the dynamic load conduces to speed up the damage;due to the fact that the cracks in the concrete are released completely under quasi-static load, the accumulated ringing count is increased by 67.1% compared with that under dynamic load, in the third fast grow stage;the train dynamic load is more likely to cause the damage of ballastless track, and in the design and checking of ballastless track structure, the train dynamic load is more in line with the actual working conditions.

关 键 词：无砟轨道混凝土 声发射 伤损演化 列车动荷载 准静态荷载 

分 类 号：U213.2[交通运输工程—道路与铁道工程]