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30 cm时出现峰值,钢轨及轨道板在脱空长度大于70 cm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.%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 CRTS Ⅰ 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 CRTS Ⅰ slab 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 sig-nificant impact on the reduction rate of w heel-rail load and had certain effect on the displacement of rail and track slab , w hile it had slight effect on the displacement of concrete roadbed . T he rail and concrete roadbed a-round the contact loss area showed strong vibration , with the vibration accelerations being 3 times 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 was 30 cm , the vibration of the concrete roadbed reached its peak value . When the contact loss was longer than 70 cm , the vibration of the rail and track slab intensified significantly . With the increase of vibration frequen-cy , the influence of contact loss on the dynamic responses of track structure significantly increased .
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