滑触式荡移法与拉锯法合龙技术在浅滩海域及滩涂区叠合梁斜拉桥施工中的应用

Application of Sliding Contact Sway Method and Chain Saw Method About Closure Technology in Cable-stayed Bridge with Composite Girder Construction in Shoal Area and Beach Area

鳌江特大桥主桥为(52+88+320+88+52) m双塔双索面叠合梁斜拉桥,该工程中大部分结构位于鳌江入海口的浅滩海域及滩涂区,边跨及中跨合龙段均采用配切法施工。针对浅滩海域及滩涂区叠合梁斜拉桥施工难度大、地质差、风险高、工期紧及受台风、雨雾与雷暴等恶劣环境因素影响时间长等特点,提出一种新型的合龙施工工艺。该合龙工艺在普通工艺的基础上进行优化设计,采用无支架存梁平台、装配式吊耳及滑触式限位装置进行边跨合龙施工;中跨合龙利用桥面板及钢箱梁共用式桥面吊机进行单侧提升合龙。其在鳌江特大桥主桥中的应用结果表明,该合龙施工技术的应用对工程质量、进度、安全、成本及环保等方面均能产生较大效益。

The main bridge of Aojiang Super Large Bridge is a(52+88+320+88+52)m doubletower and double-cable plan cable-stayed bridge with composite girder.Most of the structures in the project are located in the shoal area and beach area of Aojiang River estuary.Both the side span and the middle span closure section are constructed by the match cutting method.In view of the characteristics of the cable-stayed bridge with composite girders in the shoal area and beach area,including difficult construction,poor geology,high risk,tight construction period and long time affected by severe environmental factors such as typhoon,rain fog and thunderstorm,a new closure construction technology is proposed.The new closure technology is optimized on the basis of common technology,and is carried out by using the beam storage platform without support,the assembly lifting lug and the sliding contact limit device;the middle span closure is lifted and closed on one side by using the deck crane shared by the deck slab and steel box girder.The application results in the main bridge of Aojiang Super Large Bridge show that the application of the closure construction technology can produce greater benefits in terms of project quality,progress,safety,cost and environmental protection.