大体积腔体混凝土结构温度及裂缝分析与控制  

Analysis and control of temperature and crack inside and outside mass concrete cavity structure

作　　者：于天佑 吴亚平[1] 杨青山 杨玫[2] 金省华 蒋勇 YU Tianyou;WU Yaping;YANG Qingshan;YANG Mei;JIN Shenghua;JIANG Yong(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Hangzhou Railway Design Institute Co.,Ltd,Hangzhou 310006,China;Zhejiang Railway Construction Engineering Co.,Ltd,Hangzhou 310006,China;Hangzhou Local Railway Development Co.,Ltd,Hangzhou 310013,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070 [2]杭州铁路设计院有限责任公司,浙江杭州310006 [3]浙江铁道建设工程有限公司,浙江杭州310016 [4]杭州地方铁路开发有限公司,浙江杭州310013

出　　处：《铁道科学与工程学报》2020年第3期690-698,共9页Journal of Railway Science and Engineering

基　　金：中国铁路总公司科技研究开发计划项目(2015G005-C)。

摘　　要：大体积腔体结构混凝土温度裂缝多产生于内外温差较大处,为尽可能避免温度裂缝的发生,以宁波市下穿铁路框架桥涵大体积混凝土为依托,采用数值分析的方法,研究浇筑及养护过程中模板类型和环境温度对大体积混凝土腔体结构温度及裂缝的影响,并结合现场试验数据,对其进行分析和论证。研究结果表明:对于大体积腔体现浇整体式箱涵结构,易出现由最高温度向侧板内侧偏移所导致的翘曲现象,容易在侧板内侧产生翘曲裂缝;钢模板浇筑比木模板浇筑的混凝土最高温度低10℃,侧板最大温差低16℃左右,最大应力低约0.9 MPa,最高温度出现时间比木模板推迟1 d左右,采用钢模及采用内外同条件养护可以有效减少翘曲裂缝的产生;对于大体积腔2次浇筑框架桥结构,养护过程中在侧板长度方向易产生约0.2~0.4 mm竖向贯穿性裂缝。In order to avoid the occurrence of temperature cracks,the influence of template type and environmental temperature on the temperature and cracks of mass concrete cavity structure in the process of pouring and curing was studied by numerical analysis,based on mass concrete of bridge and culvert under railway in Ningbo city.Combined with the field test data,it was analyzed and demonstrated.The results show that the warping phenomenon caused by the maximum temperature shifting to the inner side of the side plate and the warping cracks are easy to occur in the inner side of the side plate for the integral frame bridge structure with large volume cavity.The maximum temperature of concrete poured by steel formwork is 10℃lower than that poured by wood form work.The maximum temperature difference of side slab is 16℃lower.The maximum stress is about 0.9 MPa lower,and the maximum temperature occurs one day later than that poured by wood formwork.The use of steel formwork and the maintenance under the same conditions inside and outside can effectively reduce the generation of warpage cracks.For the frame bridge structure with large volume cavity,vertical penetrating cracks of about 0.2~0.4 mm are easy to occur.

关 键 词：腔体混凝土结构 下穿铁路框架桥涵 模板类型 翘曲裂缝 

分 类 号：TU528.01[建筑科学—建筑技术科学]