新型钢管混凝土枕式无砟轨道动力响应试验研究

Experimental study on dynamic response of a new type of concrete-filled steel tube sleeper ballastless track

采用钢管混凝土构件连接轨枕块形成钢管混凝土轨枕,基于钢管混凝土轨枕设计城市轨道交通用钢管混凝土枕式无砟轨道结构。为掌握钢管混凝土枕式无砟轨道结构在城市轨道交通列车运行条件下的力学性能,验证结构设计的安全性、合理性,分别在减振地段、普通地段铺设钢管混凝土枕式无砟轨道,通过行车试验,测试分析不同列车行驶速度下无砟轨道钢轨、轨枕、道床结构的动力响应。研究结果表明:在列车车速为40、60和80 km/h运行条件下,轮轨垂向力最大值为86.18 kN,横向力最大值为13.99 kN,脱轨系数最大值为0.21,轮重减载率最大值为0.23,测试值均明显小于相应的安全限值,无砟轨道结构满足行车安全性要求;在列车动荷载作用下,钢管混凝土轨枕钢管压应力最大值为3.55 MPa,拉应力最大值为3.77 MPa;轨枕块压应力最大值为1.32 MPa;道床钢筋压应力最大值为2.30 MPa,拉应力最大值为3.54 MPa;道床底压应力最大值0.22 MPa。这些动力响应结果均满足材料的的限值,表明结构保持了良好的力学性能,结构设计合理可行。

The concrete-filled steel tube(CFT)sleeper was formed by connecting the sleeper block with the concrete-filled steel tube member.Based on the CFT sleeper,the CFT sleeper ballastless track structure for urban rail transit was designed.In order to master the mechanical properties of CFT sleeper ballastless track structure under the condition of train operation and verify the safety and rationality of structural design.CFT sleeper ballastless track structure including vibration reduction section and ordinary section was constructed.The dynamic response of rail,sleeper and bed structure of ballastless track at different train speeds was tested and analyzed.The results show that under the operating conditions of train speeds of 40,60 and 80 km/h,the maximum wheel-rail vertical force is 86.18 kN,the maximum lateral force is 13.99 kN,the maximum derailment coefficient is 0.21,and the maximum wheel load reduction rate is 0.23,the test values are significantly less than the corresponding safety limits values,and the ballastless track structure meets the requirements of traffic safety.Under the dynamic load of the train,the maximum compressive stress of the concrete-filled steel tube sleeper steel tube is 3.55 MPa,and the maximum tensile stress is 3.77 MPa,the maximum compressive stress of the sleeper block is 1.32 MPa,the maximum compressive stress of the steel bar in the ballast bed is 2.30 MPa,and the maximum tensile stress is 3.54 MPa,the maximum compressive stress at the bottom of the ballast bed is 0.22 MPa.These dynamic response are meet the stress limit of materials,including that the structure maintains good mechanical performance.The structural design is reasonable and feasible.