大跨径连续刚构桥混凝土合理加载龄期  

Rational Loading Age of Long-Span Continuous Rigid Frame Bridge

作　　者：黄叙钦 李艺林[1] 安平和 郑鹏[1] 

机构地区：[1]长安大学桥梁与隧道陕西省重点实验室,陕西西安710064

出　　处：《沈阳大学学报（自然科学版）》2017年第3期233-237,共5页Journal of Shenyang University：Natural Science

基　　金：陕西省交通运输厅科技资助项目(13-25k)

摘　　要：为分析混凝土的收缩徐变对大跨度连续刚构桥在运营阶段受力性能的影响,通过统计分析陕西地区已建成的大跨径连续刚构桥成桥后的下挠情况,得出收缩徐变是导致连续刚构桥后期下挠的主要原因,而混凝土初始加载龄期是收缩徐变的主要影响因素.因此以某连续刚构桥为依托,采用按龄期调整的有效模量法考虑混凝土收缩徐变的影响,通过有限元软件模拟混凝土的收缩徐变对桥梁结构挠度的影响.结果表明,混凝土的加载龄期对连续刚构桥成桥后的挠度变形具有一定的影响,在施工过程中不能为了加快施工进度而盲目缩短混凝土的加载龄期,建议连续刚构桥混凝土的合理加载龄期取7d左右为宜.The influence of concrete shrinkage and creep on the mechanical performance of long-span continuous rigid frame bridge in the service phase is analyzed,based on the statistics data of the existing continuous rigid frame bridge in Shaanxi province.The results show that loading age is a main influence factor of concrete creep and shrinkage.Taking a continuous rigid frame bridge as an example and using the age-adjusted effective modulus to consider the concrete shrinkage and creep effects.The deflection of bridge caused by concrete shrinkage and creep is studied by the finite element software.The results indicate that the initial loading age of concrete has a certain influence on the deflection of the continuous rigid frame bridge.Therefore,it can not speed up the construction progress blindly and shorten the loading age of concrete.It is suggested that the initial loading age of the concrete of the continuous rigid frame bridge should be prolonged appropriately,and the recommended concrete loading age is about 7days.

关 键 词：连续刚构桥 收缩徐变 有效模量法 挠度变形 合理加载龄期 

分 类 号：U448.23[建筑科学—桥梁与隧道工程]