CRTSⅢ型板式无砟轨道底座凹槽四角裂缝成因分析  

Cracking Causes Analysis for Base Groove Four Corners of CRTS Ⅲ Slab Ballastless Track

作　　者：李浩宇[1] Li Haoyu(China Railway 17^th Bureau Group Co. Ltd. , Taiyuan Shanxi 030006 , China)

机构地区：[1]中铁十七局集团有限公司

出　　处：《铁道建筑技术》2019年第4期142-146,共5页Railway Construction Technology

基　　金：中国铁建股份有限公司科技研发计划项目(16-C23)

摘　　要：针对京沈铁路客运专线CRTSⅢ型板式无确轨道底座凹槽四角开裂的普遍现象,采用现场调研、理论分析和仿真计算相结合的方法,并利用ABAQUS有限元仿真软件建立底座凹槽四角开裂分析模型,从温度变化和混凝土收缩两方面对其进行了研究,得出了在温度梯度和混凝土收缩作用下底座凹槽四角的应力分布情况,揭示了其开裂的原因(当负温度梯度超过25℃时,即底座顶面温度低于底面温度5℃时,凹槽四角处应力就达到混凝土抗拉强度标准值,且混凝土收缩对底座凹槽四角开裂也有一定的促进作用),从而确定了相应的防控措施(加强底座养护以控制温差和混凝土收缩、优化底座凹槽四甬形状减少应力集中、掺加合适的纤维提高混凝土抗拉强度等),取得了良好的控制效果,以期为同类工程提供参考和借鉴。In light of the crack phenomenon of base groove four corners of CRTSIII slab ballastless track in Beijing-Shenyang High-speed Railway, the ABAQUS finite element software was used to establish crack of base groove four corners analysis model, the analysis was carried out from the temperature change and concrete shrinkage by means of site investigation, theoretical analyses and numerical simukition. The stress distribution in the four comers of the groove under the action of temperature gradient and concrete shrinkage was obtained. The reasons for cracking of base groove four comers were studied (when the negative temperature gradient exceeded 25℃, in other words, when the upper surface temperature of the base was lower than the bottom surface temperature by 5 ℃,the stress at the four corners of the groove reached the standard value of the concrete tensile strength, and the concrete shrinkage load also promoted the cracking of the four comers of the base groove), and corresponding control measures were given in aspects from strengthening maintenance to control temperature difference and concrete shrinkage, optimizing the shape of the four comers of the groove to reduce stress concentration, adding suitable fiber to increase concrete tensile strength and so on. Good control effects were obtained, hoping to provide some reference for similar projects.

关 键 词：底座凹槽 开裂 温度梯度 混凝土收缩 成因分析 防控措施 

分 类 号：U213.244[交通运输工程—道路与铁道工程]