跨线桥梁桥墩在车辆撞击作用下的结构性能研究

随着我国立体交通的快速发展,跨越既有高速的桥梁结构迅速增加。按传统结构设计方法设计的桥梁结构,一旦遭遇严重的车辆撞击事故,不仅会造成车辆损坏与人员伤亡,而且由于跨线桥多处于交通网络的重要节点,还会造成大面积的交通瘫痪,直接或间接地导致巨大的经济损失。因此,进行跨线桥梁在车辆撞击作用下的结构性能研究是十分必要的。现以杭绍台高铁线跨越段桥梁为背景,对跨越段铁路桥梁下方高架桥和城市快速路上车辆撞击桥墩对结构安全的影响进行了研究。结合铁路桥梁门式墩、高架桥路面和城市快速路路面的相对位置和可能出现车辆撞击的位置,选取了两个典型工况展开了数值模拟分析。分析结果表明,车辆撞击对桥梁结构整体安全性能影响较小,但会造成桥墩局部混凝土破坏,建议采取选择高防撞等级的道路护栏或在墩底采取加固及防撞等措施来降低高铁跨越段桥梁遭受邻近道路车辆撞击的安全风险。

Research on the Structural Performance of Bridge Piers under the Impact of Vehicles

With the rapid development of national three-dimensional transportation,the number of bridge structures crossing existing high-speed increases rapidly.The bridge structure designed according to the traditional structure design method will not only cause vehicle damage and casualties if it encounters a serious vehicle collision accident,but also will cause a large area of traffic paralysis because the flyovers are mostly at important nodes of the transportation network,directly or indirectly leading to huge economic losses.Therefore,it is very necessary to study the structural performance of crossline bridge structures under vehicle impact.This paper took the bridge of the crossing section of the Hangzhou-Shaoxing-Taiwan high-speed railway line as the background and studied the impact on structural safety of the viaduct under the crossing section of the railway bridge and the impact of vehicles on the pier on the urban expressway.Combining the relative positions of railroad bridge gate piers,viaduct pavement and urban expressway pavement and the position where vehicles might collide,two typical working conditions were selected to carry out numerical simulation analysis.The analysis results showed that the impact of vehicle impact on the overall safety of the bridge structure was small,but it would cause local concrete damage to the pier.It is recommended to adopt road guardrails with high anti-collision levels or take reinforcement and anti-collision measures at the bottom of the pier to reduce the high-speed rail crossing bridge safety risk of being hit by a nearby road vehicle.