摘要
本文以广州市某沉管隧道工程为依托,借助温度传感器、应变传感器、收敛计等测试工具对全断面整体式浇筑沉管进行了温度、应变监测,分别监测了顶板、侧墙、底板受温度发展历程所引起变形情况,以实测温度、变形数据分析了典型沉管顶板、侧墙、底板内部应力发展及开裂风险,在综合温度、应变基础之上,评估了沉管易开裂部位。结果表明:受早期水化温升阶段影响,沉管顶板、侧墙、底板分别在60,51,50h达到最大温升值64.4,61.7,60.9℃,但由温度变化产生内外约束应力均小于混凝土抗拉强度,开裂风险较小;沉管顶板、侧墙、底板最大收缩应力分别为1.50,0.29,0.33MPa,顶板最大收缩应力远大于底板和侧墙;新浇筑沉管有向旧沉管反方向移动趋势,56d位移量为0.23mm,因收缩产生应变均小于混凝土抗拉强度值,混凝土开裂风险较小。
This paper is based on an immersed tube tunnel project in Guangzhou.The temperature and strain of the full-section monolithic cast immersed pipe were monitored by temperature sensor,strain sensor and convergence meter.The stress development and cracking risk in the roof,side wall and floor of typical immersed pipe are analyzed based on measured temperature and deformation data.Based on temperature and strain,the cracking position of immersed tube was evaluated.Under the influence of early hydration temperature rise stage,the maximum temperature rise of the roof,side wall and floor of the immersed pipe reaches 64.4,61.7,60.9℃at 60,51,50 h,respectively.However,the internal and external confining stresses generated by temperature change are all less than the tensile strength of concrete and the risk of cracking is small.The maximum shrinkage stress of the immersed pipe roof,side wall and floor is 1.50,0.29,0.33 MPa,respectively.The maximum shrinkage stress of roof is much greater than that of floor and side wall.The newly cast immersed pipe has a tendency to move in the opposite direction to the old immersed pipe,and the 56 d displacement is 0.23 mm.The strain generated by shrinkage of each part is less than the tensile strength of concrete and the risk of concrete cracking is small.
作者
屠建伟
丁平祥
于方
李凯
TU Jianwei;DING Pingxiang;YU Fang;LI Kai(Guangzhou City District Transportation Project Management Center,Guangzhou 510030,China;CCCC Forth Harbor Engineering Institute Co.,Ltd.,Guangzhou 510230,China)
出处
《建筑结构》
CSCD
北大核心
2021年第S01期1742-1747,共6页
Building Structure
关键词
变形监测
温度
应力
约束
开裂
deformation monitoring
temperature
stress
constraint
craze
