中文摘要：

砂浆脱空是CRTSⅠ型板式无砟轨道典型病害之一,其与温度梯度荷载共同作用下,轮轨系统受力状态将受到较大影响。本文运用轮轨系统动力学原理和有限元法,建立列车-无砟轨道-路基系统耦合动力空间模型,计算分析温度荷载、脱空长度对车辆及轨道系统动力响应的影响。结果表明：温度梯度荷载仅对轨道结构动力响应影响较大;温度梯度荷载与板下脱空同时存在,脱空长度超过0.8m时,其对车辆及轨道系统动力响应影响较大,尤其当轨道板存在正温度梯度110℃/m、行车速度350km/h、脱空长度1.2m时,轮重减载率为1,严重威胁行车安全。建议高速铁路无砟轨道脱空长度不超过0.8m,并加强极端气候下的损伤检测。

英文摘要：

Mortar void,as one of the typical track diseases of CRTS I prefabricated slab track,together with the action of temperature gradient load,will greatly affect the stress state of wheel-rail and track system.In this paper,the coupling dynamic space model of train-ballastless track-roadbed system was established by using the principle of wheel-rail system dynamics and finite element method,to calculate and analyze the influence of temperature load and the length of void on the dynamic response of vehicle and track system.The results showed that the dynamic response of the track structure was affected only by the temperature gradient load.The co-existence of the temperature gradient load and void,with the void length of more than 0.8m,had greater impact on the dynamic response of vehicle and track structure.This is particularly the case when the track slab temperature gradient was at 110 ℃/m,the speed was 350km/h,the void length was 1.2 m,and the wheel load-reduction ratio was 1,which seriously threatened the safety of train operation.