Abstract:
Railway bridge construation across the river is difficult to avoid. Bridges are the most common solutions which must be permitted by the river authority of local government according to the related flood control evaluation reports. This paper summarizes the experiences for related flood control problems and the solutions for about 200 river bridges encountered during the flood control evaluating of the sample high-speed railway by which four cities (Lianyungang, Huaian, Yangzhou and Zhenjiang) will be connected. The most common problems are all connected to the piers located on the rivers and channels, even on the dike-sections, in an improper way or direction. The basic reasons of the unreasonable layout include the lagged appointment of the flood control evaluation. The water resources mangement departments have no chances to deeply participate in the designing process to make it possible that the solutions will be consulted comprehensively concerning dyke safety, river stability, flood discharge unobstructed, etc. On the other side, it is not enough for river bridges designing only according to the plans published years ago. The related plans, especially the one to replace the current one, should be included as an important law of design to fit the permanent railway project. The railway bridge piers usually have a large size, which will guide the flow toward the bank of the river when they cross with the direction of runoff. This water erosion is a direct threat to the natural earth banks which can not keep stable in the flood. Increasings of bridge spans and bridge piers are two potential solutions. But the former will increase investment costs, while the latter is limited to the current bridge design theory. It is obviously not the best way to solve the problem. The increasing of the bridge span may be accompanied by construction difficulties. Therefore, the bridge design theory of “make the bridge pier axis cross the railway and follow the flow” needs further development.