中文摘要：

为研究CRTSⅠ型板式无砟轨道板端脱空对轨道动力特性的影响,铺设无砟轨道实尺模型,人工凿除CA砂浆模拟板端脱空,采用激振车对轨道施加振动荷载,测试并分析轨道振动位移和加速度等动力响应。结果表明：板端脱空对轮重减载率影响明显;板端脱空对钢轨和轨道板位移有一定影响,对底座板位移影响较小;脱空区钢轨和底座板均出现强烈振动,振动加速度约为无脱空的3倍;脱空造成轨道板剧烈振动,振动加速度增加10倍以上;底座板振动在脱空长度30cm时出现峰值,钢轨及轨道板在脱空长度大于70cm时振动加剧明显;随着激振频率的增加,轨道板板端脱空对轨道结构动力响应的影响更加明显。

英文摘要：

In order to study the influence of contact loss beneath the track slab end on the dynamic characteristics of CRTSⅠ slab track,the full scale model of CRTSⅠ slab track was applied,where CA-mortar under the track slab was excavated to simulate the contact loss.The dynamic responses of track vibration displacement and acceleration of the CRTSⅠslab track with different lengths of contact loss were tested under the vibration loading of the ZSS50 excitation vehicle.All the results showed that the contact loss beneath track slab had significant impact on the reduction rate of wheel-rail load and had certain effect on the displacement of rail and track slab,while it had slight effect on the displacement of concrete roadbed.The rail and concrete roadbed around the contact loss area showed strong vibration,with the vibration accelerations being 3times as much as the rail and concrete roadbed in the area without contact loss.The contact loss led to the strong vibration of the slab track,with its vibration acceleration increasing more than 10 times.When the contact loss length was30 cm,the vibration of the concrete roadbed reached its peak value.When the contact loss was longer than70 cm,the vibration of the rail and track slab intensified significantly.With the increase of vibration frequency,the influence of contact loss on the dynamic responses of track structure significantly increased.