关于呼和浩特市某既有城市桥梁拼宽改造的技术分析

根据目前工程实践情况,需拼宽改造的桥梁多为预制空心板、预制小箱梁、现浇箱梁等,传统拼宽方式主要采用与原结构相同的材质,有利于拼宽后的协同变形,但混凝土自重较大,拼宽时对原有结构承载能力安全储备要求较高;现浇混凝土构件满堂支架施工周期长,环境污染严重,质量难以保证;混凝土预制构件重量大,对运输安装要求高;新建混凝土桥与旧桥的收缩徐变和沉降差异较大,在这种情况下有必要尝试采用一种突破传统的拼宽方式。钢板梁桥相比混凝土梁具有自重轻、建筑高度低、强度高、绿色环保等优点,本文以呼和浩特市某既有城市桥梁拼宽改造工程为背景,通过采用钢板梁桥进行拼宽设计,解决了施工工期紧、现有旧桥承载能力不足等问题。

Technical Analysis on the Widening and Reconstruction of an Existing City Bridge in Hohhot

According to the current engineering practice,the bridges that need to be widened are mostly prefabricated hollow slabs,prefabricated small box beams,and cast-in-place box beams.The traditional widening method mainly uses the same material as the original structure.Coordinated deformation,but the concrete has a large self-weight,which requires higher safety reserves for the original structure’s carrying capacity when it is widened;cast-in-situ concrete components have long construction periods,serious environmental pollution,and quality is difficult to guarantee;the weight of concrete prefabricated components is heavy,which is difficult for transportation The installation requirements are high;there is a large difference in shrinkage,creep and settlement between the new concrete bridge and the old bridge.In this case,it is necessary to try to break through the traditional method of widening.Compared with concrete beams,steel plate girder bridges have the advantages of light weight,low building height,high strength,and environmental protection.This paper takes the existing wide bridge reconstruction project in an existing city in Hohhot as the background.The problems of tight construction period and insufficient bearing capacity of the existing old bridge were addressed.