涵洞地段道砟垫的减振特性

为了给涵洞地段道砟垫的设计和优化提供理论依据,根据轮轨系统耦合动力学理论和有限元方法,建立了车辆-轨道-涵洞垂向耦合振动模型；采用大型通用显式动力分析程序LS-DYNA分析道砟垫对轨道和涵洞动力响应时频特性的影响,并对道砟垫的合理刚度进行了研究.结果表明:采用道砟垫不会加剧轮轨动力作用和影响行车安全,而且可显著减小涵洞的动力响应；道砟垫对钢轨振动的影响不大,对轨枕振动有一定减振作用,但对道砟振动有不利影响；道砟垫的合理面刚度为50～100 MPa/m.

Damping Characteristics of Ballast Mat on Culvert

In order to provide a theoretical basis for the design and optimization of ballast mat on railway culvert,a vertical coupling dynamical model for a vehicle-track-culvert system was established based on the wheel-rail coupling dynamics theory and the finite element method.LS-DYNA,a large-scale dynamical analyzing program,was used to analyze the time-frequency characteristics of dynamic responses of vehicle,track and culvert with and without using the vibration mitigation measure of ballast mat.In addition,the proper rigidity of the ballast mat was investigated.The results show that the adoption of the vibration mitigation measure does not aggravate wheel-rail dynamic interaction and affect the running safety of trains.Furthermore,the measure can evidently decrease the dynamic response of culvert,while rarely influence rail vibration.It has a certain damping effect on the vibration of sleeper,but has a negative influence on ballast vibration.The proper rigidity of ballast mat is suggested to be from 50 to 100 MPa/m.