T形刚构桥桥墩参数对车-桥动力响应影响研究

为研究T形刚构桥桥墩参数对车-桥动力响应的影响,以某高速铁路（77m+144m+77m）T形双薄壁连续刚构桥为研究对象,基于刚柔耦合理论,采用多体动力学和有限元联合仿真技术,建立考虑桩土效应的列车-桥梁动力相互作用模型,计算分析T形刚构桥墩宽度、厚度及混凝土强度等级变化对车-桥耦合系统的动力响应影响。结果表明:T形刚构桥墩宽度、厚度及混凝土强度等级的改变,对桥上车辆系统的安全性指标、舒适性指标影响较小;T形刚构桥墩参数改变,对桥梁系统横向位移、垂向加速度、横向加速度影响较小,而对垂向位移影响较大,但变化幅值均在高速铁路设计规范要求的范围内;在其他条件参数不变的情况下,可通过将桥墩宽度降低到设计宽度的75%—80%,或厚度降低到设计厚度的80%—85%,或桥墩混凝土强度等级降低为C35—C40对该高速铁路T形双薄壁连续刚构桥进行优化设计。

Study on Influence of Pier Parameters of T-shaped Rigid Frame Bridge on Vehicle Bridge Dynamic Response

In order to study the influence of the parameter variation of the T-shaped rigid frame bridge on the dynamic response of the vehicle-bridge, taking a high-speed railway (77m+144m+77m) T-shaped double thin-wall continuous rigid frame bridge as the research object, using a multi-body dynamics and finite element co-simulation technology based on rigid-flexible couping theory a vehicle-bridge dynamic interaction model considering pile-soil effect is established, and using this model to calculate and analyze the influence of the width, thickness and concrete strength grade of T-shaped rigid frame pier on the dynamic response of the vehicle-bridge coupling system. the results show:the variation of the width, thickness and concrete strength grade of the T-shaped rigid frame pier has little effect on the safety index and comfort index of the vehicle system on the bridge; parameters of the T-shaped rigid frame piers have little influence on the lateral displacement, vertical acceleration and lateral acceleration of the bridge system, and have a great influence on the vertical displacement, but the variation amplitude is within the requirements of the code for design of high speed railway; For the high-speed railway (77m+144m+77m) T-shaped double thin-wall continuous rigid frame bridge, under the condition that other conditions are unchanged, the optimum design can be made to reduce the pier width to 75-80% of the designed width, or to reduce the thickness to 80-85% of the designed thickness, or to reduce the strength class of pier concrete to C35-C40.