高速铁路简支箱梁的温差控制  

Temperature difference control for simply supported box girder of high-speed railway

作　　者：周勇政[1] 朱尔玉[1] 李学民[1,2] 钟明琳[1] 杨建民[3] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中铁四局集团有限公司,安徽合肥230023 [3]北京市官厅水库管理处,河北怀来075441

出　　处：《北京交通大学学报》2014年第1期88-93,共6页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：国家自然科学基金资助项目(51078025);中央高校基本科研业务费专项资金资助(2011YJS250);高等学校博士学科点专项科研基金资助(20110009110016)

摘　　要：针对高速铁路简支箱梁施工过程因混凝土内外温差过大出现温度裂缝的问题,提出了箱梁预应力孔道通水和内腔通风的温差控制措施.确定了混凝土温度应力场仿真参数的取值,并通过温度场仿真结果与试验结果的对比,验证了参数取值的准确性.对自然养护状态下和温度控制措施下简支箱梁温度应力场进行仿真分析的结果表明:通过温差控制措施,简支箱梁混凝土的最大压应力由支点截面段的2.77 MPa降至跨中截面段的2.21 MPa,最大拉应力由支点截面段的1.255 MPa降至跨中截面段的1.00 MPa,从而有效控制温度裂缝的产生.我国规范规定的15℃的温差限值显得过于严格,可放宽至20℃.The temperature difference control measures of circulating water through prestressed ducts and ventilating through the box girder cavity are put forward in the paper due to the temperature cracks resulted from excessive temperature difference between inside and outside the concrete.The parameters of the thermal stress field simulation are determined.Parameter values are verified accurately according to the comparison between simulation results and the test results.Thermal stress fields of simply supported box girder are simulated respectively in the state of nature curing and temperature control measures.The results show that the maximum compressive stress reduces from 2.77 MPa of fulcrum section to 2.21 MPa of mid-span section,and the maximum tensile stress reduces from 1.255 MPa of fulcrum section to 1.O0 MPa of mid-span section,which makes the temperature crack effectively controlled.In addition,the limited value of 15 ℃ of temperature difference of the specification appears to be too rigorous,and can be relaxed to 20 ℃.

关 键 词：桥梁工程 高速铁路 简支箱梁 温度应力场 裂缝 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]