温升作用下CRTSⅡ型板宽窄接缝受力及损伤分析  

Analysis of Internal forces and Damage of Broad-Narrow Joint of CRTSⅡ Slab Track Under Temperature Rise

作　　者：刘笑凯[1,2,3] 刘学毅 肖杰灵[1,2] 董佳佳[1,2] LIU Xiaokai;LIU Xueyi;XIAO Jieling;DONG Jiajia(MOE Key Laboratory of High-Speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Science,North University of China,Taiyuan 030051,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,四川成都610031 [2]西南交通大学土木工程学院,四川成都610031 [3]中北大学环境与安全工程学院,山西太原030051

出　　处：《西南交通大学学报》2024年第2期273-280,共8页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金(51978584,51778543);山西省基础研究计划(20210302124452)。

摘　　要：为研究宽窄接缝在温升作用下的受力和损伤,根据混凝土塑性损伤理论和内聚力理论,建立考虑新旧混凝土界面的宽窄接缝细部的有限元模型;计算不同温升条件下的宽窄接缝应力和损伤因子,并分析宽窄接缝强度和窄接缝宽度的影响.研究结果表明:窄接缝挤碎是一种渐变受压损伤,宽、窄接缝交界处断裂是一种脆性受拉损伤;与宽、窄接缝交界处断裂相比,窄接缝挤碎对结构受力影响更大;宽窄接缝尺寸不均匀导致宽、窄接缝交界处垂向受拉,这是宽窄接缝产生损伤的主要原因;提高宽窄接缝的混凝土强度可有效降低垂向拉应力和受拉损伤,但对纵向应力和受压损伤影响较小;为改善受力并降低损伤,建议宽窄接缝混凝土与轨道板等强,并且宽窄接缝上下等宽.In order to study the internal forces and the damage of broad-narrow joint under a temperature rise,a detailed finite element model with the interface between old and new concrete is established on the basis of concrete damaged plasticity model and cohesive zone model.The damage parameters and stress under different temperature rises are calculated,and the effects of the concrete strength at broad-narrow joint and the narrow joint width are analyzed.The results show that the fracture at the junction between broad and narrow joints is a brittle tension failure,and the breakage of narrow joint is a gradual compression failure.Compared with the fracture at the junction between broad and narrow joints,the breakage of narrow joint has a greater impact on the structural stress.The vertical tension stress arising from the uneven geometry at the junction between broad and narrow joints is the main cause for the damaged broad-narrow joint.Increasing the broad-narrow joint strength reduces the longitudinal compression stress and the compression damage,but contribute less to the vertical tension stress and the tension damage.To reduce damage and improve strength,it is recommended to equate the widths for the broad and narrow joints and the strengths for the concrete at the broad-narrow joint and the slab.

关 键 词：无砟轨道 CRTSⅡ型板式轨道 宽窄接缝 

分 类 号：U213.212[交通运输工程—道路与铁道工程]