小曲线中等跨度桥梁栈桥及钻孔桩平台设计

Design of the Trestle and Bored Pile Platform for Medium Span Bridge with Small Curve

温州特大桥3^#-7^#壤跨越通航河道,桥梁跨径为中等跨度且位于小曲线半径上,存在按常规直线法布置时栈桥最大偏距8.5 m导致钻孔平台工程数量加大、主线桥墩与栈桥临时支墩发生错位无法满足通航要求、钻孔平台作业面积过小不便于施工等难题。本着节约成本、满足施工需要及简单易行的原则,通过选择跨度较大的桥跨为临时通航孔、改变栈桥纵梁结构满足了临时通航净空要求;对栈桥设置临时双支墩实现栈桥偏转,避免了因主体桥梁平面位于小曲线上而造成的工程量增加;通过调整平台位置、设置连体平台方便了现场操作。很好地解决了小曲线中等跨度桥梁栈桥及钻孔平台设计难题,经检算整个体系受力经济合理,实际应用效果良好。

The No.3 to No.7 piers of the Wenzhou Bridge cross navigable rivers,and the bridge span is medium span and located on the small curve radius,resulting in the problems such as the increase of the number of drilling platform projects caused by the maximum deviation of the trestle of 8.5 m when it is arranged according to the conventional linear method,the dislocation between the main pier and the temporary pier of trestle cannot meet the navigation requirements,and the operation area of the drilling platform is too small to facilitate construction.In line with the principles of cost saving,meeting the needs of the construction and easy operation,the temporary navigation clearance requirements are met by selecting the large-span bridge span as the temporary navigation hole and changing the structure of the longitudinal beam of the trestle;the temporary double buttresses are set on the trestle to realize the deflection,which avoids the increase of engineering quantity caused by the main bridge plane located on the small curve;by adjusting the position of the platform and setting the conjoint platform,the site operation is convenient.Based on the above,the problems in the design of the trestle and drilling platform for medium span bridge with small curve are well solved,and the test results indicate that the force of the whole system is economic and reasonable,and the practical application is good.