研究目的:重载列车轴重的增加使轨枕的服役环境大大恶化,为探究运行40 t轴重列车的轨枕关键设计参数,本文建立更为精确的三维轮轨接触与轨道有限元模型,分析轨枕应力变化规律,并提出提升轨枕承载能力的措施,以期为我国未来大轴重轨道结构设计提供数据支持.研究结论:(1)当40t轴重重载列车以120 km/h的速度通过时,轨枕承轨槽处的最大应力达9.21 MPa,但仍小于C60混凝土12 MPa的抗压限值;(2)轨枕的承载能力由轨枕提供的抗正弯力矩控制,速度达到120 km/h时,轨枕最大正弯矩极值增加至18.99 kN·m,非常接近Ⅲ型轨枕的抗弯限值19.05 kN·m;(3)通过加宽或加长改进的Ⅲ型轨枕,重量增加至350 kg以上,可满足运行40 t轴重重载列车的要求;(4)考虑到建造成本和道床限界等因素,优先考虑加宽轨枕,加宽10 cm后的轨枕至少可承受23.52 kN·m和-22.87kN.m的最大正、负弯矩;(5)该研究结果可为40 t轴重重载铁路轨枕设计提供参考.%Research purposes:The increases of axle load deteriorate service environment of concrete sleeper greatly on heavy haul track.For inquiring the key design parameters of sleeper with the effect of 40 t axle load,more accurate three-dimensional wheel-rail contact and track finite element models were established.By analyzing the stress change rule of sleeper,some measures to improve the carrying capacity of sleeper were put forward,which could provide valuable data for future designs of heavy haul track structures.Research conclusions:(1) When 40 t axle-load heavy haul train passed with the speed of 120 km/h,maximum stress on rail seat of sleeper was 9.21 MPa,within compressive strength limit 12 MPa of C60 concrete.(2) The carrying capacity of sleeper was controlled by its sagging moment.With the speed of 120 km/h,the sagging moment of sleeper could achieve 18.99 kN · m,which was very close to the maximum sagging moment 19.05 kN · m of type Ⅲ sleeper.(3) By widening or lengthening type m sleeper,as well as its weight should be increased to more than 350 kg,it could meet the requirements of 40 t axle-load heavy haul train.(4) Taking into account the construction costs and ballast gauges and other factors,widening sleeper should be prior.After widening 10 cm,the sleeper could bear at least the maximum sagging moment 23.52 kN · m,the maximum hogging moment-22.87 kN · m.(5) The research results could provide the references for the concrete sleeper design of 40 t heavy haul railway.
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