市域铁路路基地段双块式无砟轨道结构设计

我国市域铁路的建设尚处于起步阶段,需要对160 km/h速度的市域铁路设计标准和轨道结构进行相关研究。依托北京新机场线工程实践应用,着重研究了双块式无砟轨道结构在160 km/h市域铁路路基地段的稳定性和安全性,基于极限状态法计算了多种荷载组合下的受力情况,并对道床板和底座板进行了配筋设计和裂缝检算。研究表明:①160 km/h速度条件下,路基地段轨道结构各动力响应指标均在限值范围内,车体脱轨系数和轮重减载率指标数值均较小,能够保证轨道结构的稳定性和列车行驶的安全性。②温度作用对道床板和底座板的受力影响较大,在设计荷载中占据主导因素。③道床板和底座板底部纵向弯矩均在荷载偶然组合作用下达到最大值,配筋时应以裂缝宽度为控制指标进行设计。

Double-block Ballastless Track Structure Design for Suburban Railway Subgrade Section

The construction of suburban railway in our country is only in its infancy,the design criteria and track structure of the suburban railway,which can reasonably match the speed of 160 km/h,are urgently needed to be developed.Relying on Beijing New Airport Line engineering practice application,this paper focuses on the stability and safety of the double-block ballastless track structure in the subgrade section of the160 km/h suburban railway,and carries out the stress calculation for multiple load combinations,reinforcement design and crack check for the track bed and base plate using limit state design method of railway track.Research shows:①Under the condition of speed of 160 km/h,the dynamic response indexes of the track structure of the subgrade section are within the limits.The derailment coefficient of vehicle body and the reduction rate index of wheel weight are small.The structure can ensure its stability and the safety of train travel.②The temperature effect has a great influence on the force of the roadbed slab and the base plate,and it plays a dominant role in the design load.③The longitudinal bending moments at the bottom of the roadbed slab and the base plate are maximized by the accidental combination of loads,and the reiLforcement should be designed with the crack width as the control index.