Impact performance of a floating slab with a longitudinal connection track under fatigue loading  

疲劳荷载下的纵连式浮置板的冲击性能

作　　者：LI Pei-cheng ZENG Zhi-ping WANG Wei-dong LI Ping YE Meng-xuan LI Qiu-yi 李沛成;曾志平;王卫东;李平;叶梦旋;李秋义

机构地区：[1]School of Civil Engineering,Central South University,Changsha 410075,China [2]Key Laboratory of Engineering Structures of Heavy Haul Railway,Central South University,Changsha 410075,China [3]Guangzhou Metro Design and Research Institute Co.,Ltd.,Guangzhou 510010,China

出　　处：《Journal of Central South University》2025年第2期678-690,共13页中南大学学报(英文版)

基　　金：Project(2022-Major-14)supported by the Science and Technology Research and Development Program Project of China Railway Group Limited。

摘　　要：In order to accommodate higher speeds,heavier axle weights,and vibration damping criteria,a new floating slab structure was proposed.The new type of floating slab track structure was composed of three prefabricated floating slabs longitudinally interconnected with magnesium ammonium phosphate concrete(MPC).This study investigated the dynamic performance of the structure.We constructd a full-scale indoor experimental model to scrutinize the disparities in the impact performance between a longitudinally connected floating slab track and its longitudinally disconnected counterpart.Additionally,a long-term fatigue experiment was conducted to assess the impact performance of longitudinally connected floating slab tracks under fatigue loading.The findings are described in the following.1)The new structure effectively suppresses ground vibrations,exhibiting a well-balanced energy distribution profile.However,the imposition of fatigue loading leads to a reduction in the damping performance of the steel spring damping system,thereby reducing its capacity to attenuate structural vibrations and leading to an increase in ground vibration energy;2)After 107 loading cycles,the attenuation rate of the vibration acceleration for the MPC increases by 171.9%.Conversely,at the corresponding disconnected location,the attenuation rate of ground vibration acceleration decreases by 65.6%.In conclusion,longitudinally connected floating slab tracks exhibit superior vibration reduction performance.While the vibration reduction performance of longitudinally connected floating slab tracks may diminish to some extent during long-term service,these tracks continue to meet specific vibration reduction requirements.为了适应更高的速度、更重的轴重和减振标准,本文提出了一种新型浮置板结构。这种新型浮置板轨道结构由三块预制浮置板组成,三块浮置板之间用磷酸铵镁混凝土(MPC)纵向连接。构建了一个全尺寸室内实验模型,仔细研究了可以纵向连接的浮置板轨道与纵向断开的浮置板轨道在冲击性能上的差异。此外,还进行了长期疲劳实验,以评估纵向连接的浮置板轨道在疲劳载荷下的冲击性能。研究结果如下:1)新结构能有效抑制地面振动,能量分布均衡。然而,疲劳加载导致钢弹簧阻尼系统的阻尼性能下降,从而降低了其衰减结构振动的能力,并导致地面振动能量增加;2)1000万次加载循环后,MPC的振动加速度衰减率增加了171.9%。相反,在相应的断开位置,地面振动加速度的衰减率降低了65.6%。总之,纵向连接的浮置板轨道具有卓越的减振性能。虽然纵向连接浮置板轨道的减振性能在长期使用过程中可能会有一定程度的下降,但这些轨道仍能满足特定的减振要求。

关 键 词：longitudinally connected floating slab track full-scale experimental model fatigue experiment drop hammer in impact dynamic response 

分 类 号：U213.2[交通运输工程—道路与铁道工程]