复杂环境条件下跨河铁路桥梁拆除施工技术

Construction Technology for Demolishing Cross-river Railway Bridges under Complex Environmental Conditions

摘要:

上海南联络线工程涉及到对既有沪春下行线跨淀浦河桥梁的拆除，拆除工程包括桥梁附属设施、上部结构T梁、钢板梁，以及下部墩台结构，其中32 m跨度的钢板梁拆除是拆除实施过程的关键。待拆除的桥梁南北两侧紧邻铁路营业线，北侧为沪春上行线64 m跨度的单线钢桁梁桥，南侧为新建上南联络线64 m跨度的3线钢桁梁桥。拆除施工空间狭小，环境条件复杂，安全风险高。结合实际条件，32 m跨度的钢板梁采用桥面吊机将切割完成的钢板梁吊装下放至下方浮船，由浮船将梁体运输至附近码头处停靠，再采用大型汽车吊将钢板梁吊运至岸边陆域，然后用分段割除的工艺进行拆除。该方案在施工安全性、便利性、成本投入等方面具有一定优势，适用于狭小复杂环境下桥梁的拆除施工。

Abstract:

The Shanghai South Connection Link Project involves the demolition of the existing bridge spanning the Dianpu River on the downward line of Huchun. The demolition project includes the ancillary facilities, superstructure T-beams, steel plate beams and lower pier abutment structures, in which the demolition of the 32 m span steel plate beam is the key in the demolition process. The north and south sides of the bridge to be demolished are adjacent to the operating railway lines. On the north side is a 64-meter single-track steel truss girder bridge in the upward line of Huchun, and on the south side is a 64-meter three-track steel truss girder bridge of the newly-built Shangnan Connection Line. The demolition construction space is narrow, the environmental conditions are complex, and the safety risks are high. Based on actual conditions, the 32-meter steel plate beam is hoisted and lowered to the floating boat below by a bridge deck crane after cutting. The beam body is transported to the nearby wharf by floating boats for docking. And then, the large truck cranes are used to lift the steel plate beams to the land area along the shore. Afterwards, the process of segmented cutting is used for the demolition. This scheme has some advantages in terms of construction safety, convenience and low cost investment, and is suitable for the demolition construction of bridges in narrow and complex environments.