轻轨多种类型桥梁施工期竖向位移规律分析

Analysis of vertical displacement characteiristics of various construction methods for light rail bridges

由于施工工艺和所用材料的不同,不同类型桥梁施工期竖向位移存在较大的差异。本文以一个轻轨高架工程为实例,在介绍工程主要施工工艺和监测点布设状况的基础上,对预制小箱梁法、连续现浇箱梁法、挂篮悬臂施工法及转体施工法四种类型桥梁的竖向位移监测数据进行精细分析,总结出桥梁施工期竖向位移主要受结构自重、混凝土徐变及预应力张拉三大因素的影响,且对不同类型桥梁影响程度差异较大。另外,本文还给出了四种类型桥梁竖向位移变化范围,并提供了一些施工建议。

Due to the different construction technology and materials used,there are many differences among vertical displacements of various bridge consruction methods.Based on an elevated light rail project,main construction technology and layout of monitoring points are presented.Then monitoring data of vertical displacements on the basis of four types of bridges,including small precast box girder,continuous cast-in-site box girder,balanced cantilever construction and twist construction method,are analyzed precisely.It was concluded that vertical displacement of constructing bridges are influenced by three factors which are dead loads,concrete creep and prestressed tension.What is more,the impacts of the three factors on various bridge construction methods are discrepant largely.Besides,vertical displacement ranges of the four types of bridge construction methods are described and some advices for engineering construction are provided.