高速铁路CRTSⅢ型板式无砟轨道车辆荷载横向传递规律研究

Study on lateral transmission law of vehicle load on CRTS Ⅲ ballastless track of high-speed railway

为获取高速铁路CRTSⅢ型板式无砟轨道底部荷载横向传递规律,通过实车试验并建立多车-无砟轨道-路基空间耦合分析模型开展研究,对不同行车速度下扣件支点反力和复合板与底座板下荷载横向分布规律进行了分析.研究结果表明:仿真分析模型能够较好地模拟现场行车荷载效应.行车速度对扣件支反力和板下荷载横向分布影响较小;建议轮轴作用点处扣件荷载承担比例选取为40%,与其相邻的两个扣件由近及远依次取为25%和5%;实测复合板底部荷载在横向上呈典型的双峰型分布,峰值处压应力最大为149.5kPa;实测底座板底部荷载在横向上呈M型分布,峰值处压应力最大为16.2kPa;既有规范在无砟轨道底部荷载取值时缺乏对扣件支反力影响范围、不同无砟轨道厚度及结构特征、基础刚度、各动车组参数等影响因素的考虑,建议开展针对性研究,完善无砟轨道设计参数体系.

In order to obtain the lateral transmission law of vehicle load at the bottom of the CRTS III ballastless track of high-speed railway.We use the real vehicle test,and establish a multi vehicle-ballastless track-subgrade spatial coupling analysis model to analysis the reaction force of fasteners and the lateral distribution law of vehicle load under the composite plate and base plate when vehicle running at different speeds.The results show that the simulation analysis model can work well in simulating the effect of the on-site traffic load.The driving speed has little influence on the fastener reaction force and the lateral distribution of the load under track slab.It is recommended that the load bearing ratio of the fastener where the axial load action is 40%,and the two adjacent fasteners are 25% and 5% respectively.The measured load at the bottom of composite plate presents a typical bimodal distribution in the lateral direction,and the maximum compressive stress at the peak is 149.5 kPa.The measured load at the bottom of the base plate presents an M-shaped distribution in the lateral direction,and the maximum compressive stress at the peak is 16.2 kPa.The existing codes show less consideration to influencing factors such as the influence range of the fastener reaction force,the thickness and structural characteristics of dif-ferent ballastless tracks,the foundation stiffness,and the parameters of different types of EMUs.It is recommended to carry out targeted research and improve the design parameters system of the ballastless track.