温州瓯江北口大桥中塔钢沉井底节定位施工技术

Positioning Construction Technology for Bottom Segment Steel Caisson of Intermediate Tower of Wenzhou Oujiang Estuary Bridge

温州瓯江北口大桥主桥为三塔四跨双层钢桁梁悬索桥,中塔基础采用深水巨型钢沉井。钢沉井由锚墩平台、重力锚、拉缆系统、收缆系统组成的定位系统精确定位。锚墩平台布置在主墩的上下游,重力锚设置在主墩的横水流两侧,辅以纵横向锚固系统,通过GPS实时监测系统实现沉井精确定位。论文介绍了上下游锚墩平台、重力锚及施工流程中的关键技术。与传统定位技术相比,锚墩平台加重力锚定位技术可运用于往复流、大流速、高潮差的河段及近海跨江跨海特大型桥梁深水基础施工,定位精度高、工期短、施工可控。

The main bridge of Wenzhou Oujiang Estuary Bridge is a double-deck and steel truss suspension bridge with triple towers and four main spans.The intermediate tower of the bridge is located in the deep water in the river center and the foundation of the tower is a very deep and huge steel caisson structure.The steel caisson is accurately located by the positioning system composed of anchor pier platform,gravity anchor,cable drawing system and cable collecting system.The platform of anchor pier is set up upstream and downstream of the main pier.The gravity anchor arranged north and south sides of the main pier.Also in the aid of the cable system transverse and longitudinal to the river translate into the steel caisson adjustment and positioning.The accuracy of the positioning and landing of the caisson to the riverbed is controlled by the GPS real-time monitoring.This paper introduces the upstream and downstream anchor pier platform,gravity anchor and the key technologies in the construction process.Comparing with traditional location technology,the anchor pier platform weighting force anchor positioning technology can be applied to the river reach with reciprocating flow,large velocity and high tidal range,as well as the deep-water foundation construction of the offshore super-large bridge across river and sea,with high positioning accuracy,short construction period and controllable construction.