斜拉桥桥塔不同龄期混凝土结合面收缩效应分析  

Analysis on Shrinkage Effects of Concrete in a Cable Stayed Bridge Tower

作　　者：苏祥亚[1] 石雪飞[1] 李森[1] 

机构地区：[1]同济大学桥梁工程系,上海200092

出　　处：《结构工程师》2012年第6期166-170,共5页Structural Engineers

摘　　要：以六冲河斜拉桥为背景,采用空间有限元与理论分析相结合的方式,研究斜拉桥桥塔不同龄期混凝土结合面的收缩应力分布规律,并比较不同分层浇筑时间间隔、环境年平均相对湿度、配筋率以及中美规范下的收缩效应。研究结果表明:依据中国《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTG D62—2004),桥塔截面突变及环境年平均相对湿度对桥塔结合面的收缩效应影响显著;浇筑时间间隔、配筋率对桥塔结合面的收缩效应影响较小。对于大体积混凝土构件,美国AASHTO规范计算的收缩效应明显高于JTG D62—2004,并建议对JTG D62—2004中规定的构件理论厚度h加以修改。With the Liuchonghe Cable Stayed Bridge, the finite element method and theoretical analysis shrink- age stress distribution characteristics at interfaces between concrete with different ages were used together to in- vestigate. Shrinkage effects at interfaces under various factors were compared such as different casting time inter- vals, different annual average environmental relative humidity, different reinforcement rations and effects under different codes. Results show that effects on shrinkage stress at interfaces caused by section property break and humidity are more obvious than that induced by different ages of concrete. Studies also found that shrinkage stress increases with a small increment as casting time interval and reinforcement ratios increase. Shrinkage stress level calculated by using AASHTO is much more reasonable than that obtained by using code JTG D62--2004 in concrete members with large thickness. Establishing a limit on theoretical thickness in JTG D62--2004 is proposed.

关 键 词：斜拉桥桥塔 混凝土结合面 收缩效应 混凝土龄期 

分 类 号：U445.57[建筑科学—桥梁与隧道工程]