跨河道大桥防洪影响数学模型的研究与应用

采用集中质量的有限元方法建立数学模型，对天津至保定新建铁路特大桥梁工程对西河河道的防洪影响进行了模拟。在模型中提出了采用单元扣除法来对桥墩进行模化处理。为考察斜跨桥梁桥墩形状和布设方位对水流的阻碍作用和桥墩的局部冲刷深度，在桥墩附近进行加密模型计算。将此模型应用于西河特大桥防洪影响计算，通过分析可知该模型计算结果基本合理，为处理铁路桥及公路桥跨越河道的问题提供一个可行的解决途径。

Study on mathematical model for impact from huge river-crossing bridge on flood control and its application

The lumped mass finite element method is adopted to establish a mathematical model for simulating the impact from the huge bridge of the newly built Tianjin-Baoding Railway on the flood control of the channel of Xihe River. The unit deduction algorithm is proposed in the model to simulate the bridge pier. Moreover，the meshes around the bridge piers are locally refined，so as to investigate the obstructing-effects from the shape and the layout of the pier of the diagonal river-crossing bridge on the water flow and the local scouring depth around the piers. The mathematical model is adopted to simulate the impact from the huge bridge crossing Xihe River on the flood control therein and it is known that the simulated result is basically reasonable，thus provide a feasible way to solve the similar problems from the river-crossing of the railway or highway bridge concerned.