路堤帮宽既有-新建组合支挡结构荷载传递机理及应用研究

Study on Load Transfer Mechanism and Application of Existing-New Combined Retaining Structure for Embankment Widening

中兰客专引入兰州枢纽工程崔家崖特大桥至陈官营车站路基区段,由于受地形条件限制,需在既有路堤支挡结构边坡上进行路堤帮宽。为保证既有线路的安全、稳定和充分利用既有挡土结构物,依据既有支挡结构型式,提出了三种既有-新建组合支挡结构型式,分别为既有-新建并排组合桩板墙、既有-新建前后组合桩板墙和两级既有-新建悬臂式挡土墙;对三种组合结构的设计思路、土压力计算方法以及荷载传递机理进行了研究,提出了既有支挡结构服役状态评估的方法。研究成果可为类似工程既有线改建及临近既有线新建项目的设计和建造提供理论依据和工程参考。

The subgrade section from CuiJiaYa Bridge to ChenGuanYing Station,which is introduced into Lanzhou hub project by Zhongwei-Lanzhou passenger dedicated railway,due to the limitation of terrain conditions,it is necessary to fill in new embankment on the existing embankment retaining structure slope.In order to ensure the safety,stability,and full utilization of existing retaining structures for the existing line,three types of existing-new composite retaining structures are proposed based on the existing retaining structure types,namely existing-new side-by-side composite pile slab wall,existing-new front and rear composite pile slab wall and two-stage existing-new cantilever retaining wall.A study was conducted on the design ideas,soil pressure calculation methods,and load transfer mechanisms of three types of composite structures,and a method for evaluating the service status of existing retaining structures was proposed.The research results can provide theoretical basis and engineering reference for the design and construction of the reconstruction of existing lines and the new projects of adjacent existing lines.