某特大桥加固分析

摘要

Cracks on prestressed concrete continuous beam (rigid frame) bridge closure section soleplate has now become the common bridge disease. This paper reviewed the causes of floor cracks. Taking the longitudinal crack in soleplate of closure section as the research object, the paper establishes closure section transverse model using Dr. bridge software, considering self-weight, prestress load, vehicle load and temperature, and analyzes lateral stress loads distribution under the combination of three kinds of load. According to the calculation of pulling stress of box girder floor, it analyzes the causes of floor cracks. In order to avoid the transverse cracks in the box girder floor, this paper puts forward the problems that should be paid attention to in design and construction, providing reference for similar bridge.%　　国内很多预应力混凝土连续梁（刚构）桥合拢段底板出现纵向裂缝，现已成为比较常见的桥梁病害。本文对底板裂缝发生的原因进行综述，并以某特大桥合拢段箱梁底板纵向裂缝为研究对象，采用桥梁博士软件建立合拢段横向模型，考虑自重、预应力荷载、车辆荷载和温度等因素，分析了三种荷载组合下的横向应力分布情况。根据箱梁底板拉应力的计算结果，讨论了导致底板横向裂缝形成的主要原因。为避免箱梁底板横向裂缝的产生，提出设计和施工时应注意的问题，以供类似桥梁参考借鉴。