基于早期温度应力的道床板施工方式  

Study about the construction methods of bed slab based on the early temperature stress

作　　者：赵坪锐[1] 向芬[1] 邓非凡[1] 刘观 龚闯[1] 

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]中国铁建国际集团有限公司,北京100855

出　　处：《铁道科学与工程学报》2017年第10期2082-2090,共9页Journal of Railway Science and Engineering

基　　金：国家重点基础研究发展计划(973计划)项目(2013CB036202);国家自然科学基金资助项目(U1434208);中国铁路总公司重大项目(Z2013 G001.2014G001-A)

摘　　要：建立考虑水化热、混凝土收缩和弹性模量等时变参数的双块式无砟轨道道床板早期温度应力瞬态分析有限元模型,分析道床板内部水化热与外部环境温度共同作用下的道床板早期温度应力分布特征,比较不同施工季节、浇筑时刻以及钢模支撑条件对道床板早期温度应力的影响。研究结果表明:道床板早期温度应力受水化热和外界环境温度影响较大,内部应力主要受控于水化热,表面应力主要受控于环境温度,轨枕侧边是容易产生早期温度裂缝的薄弱环节。在施工温度降低条件下,道床板侧边和顶面容易产生裂纹。为减少混凝土早期裂缝的开展,应选择在傍晚时分浇筑混凝土,适当延长拆模时间,气温较低时拆模至少为3 d后,浇筑温度较高时拆模至少为4 d后。Considering the heat of hydration, shrinkage of concrete, elasticity modulus and other time-variableparameters, a finite element model of early transient analysis of temperature stress of two-block ballastless trackbed was established. The distribution of early temperature stress was then analyzed under the combined action ofinternal heat of hydration and external ambient temperature of bed slab. The different construction seasons, timeand supporting conditions of steel model and their influence on early temperature stress of bed slab was compared,the results show that heat of hydration and external ambient temperature have a greater influence on earlytemperature stress of bed slab. The internal stress is mainly controlled by the heat of hydration, while surfacestress is mainly controlled by ambient temperature. Side of sleeper is the weak point which is prone to occur earlytemperature cracks. When the construction temperature decreases, the side and the top of bed slab is easy to crack.In order to reduce the development of early crack of concrete, it is necessary to elongate from removal time whenpouring in evening, at least 3 days at low temperature, and at least 4 days at high temperature after pouring.

关 键 词：双块式无砟轨道 道床板 早期温度场 温度应力 养护 

分 类 号：U213[交通运输工程—道路与铁道工程]