列车荷载作用下准饱和地基波阻板隔振特性研究

Study on the isolation performance of WIB on nearly-saturated ground under moving load

基于Biot波动方程,推导准饱和多孔介质控制方程,建立高铁列车-准饱和地基-波阻板(WIB)隔振模型,研究高铁列车移动荷载作用下准饱和地基中WIB隔振性能。以秦沈客运专线工程实例进行算例分析,研究饱和度对WIB隔振性能影响规律及其力学机制,分析不同列车速度、不同饱和度条件下水平x方向、竖向z方向位移振幅衰减系数及频谱曲线。结果表明,饱和度变化对准饱和地基中波阻板隔振性能影响明显,具体表现为WIB振幅衰减系数AX随饱和度减小而增大,AR随饱和度减小而减小;WIB对准饱和地基中0~35 Hz频率有较好隔振效果,但2~4 Hz的频率加WIB隔振后仍衰减缓慢。另外,对饱和度为95%的准饱和地基中WIB埋深、宽度、厚度和弹性模量等参数进行了研究,研究成果可为准饱和地基高铁隔振设计提供理论依据。

To study the vibration isolation performance of nearly-saturated ground under the high-speed railway moving load,the governing equation of nearly-saturated porous media is derived based on Biot equation and model of high-speed railway train,nearly-saturated ground and wave impedance block(WIB)is established.Taking the Qinhuangdao-Shenyang high-speed railway line project as an example,the influence of saturation degree on WIB vibration isolation performance and its mechanical mechanism are studied.The displacement amplitude attenuation coefficient and spectrum curve in horizontal x direction and vertical z direction under different train speed and satu⁃ration conditions are analyzed.The results show that the change of saturation degree has an obvious effect on the vibration isolation performance of wave barrier plate in nearly saturated ground.The specific performance is that the WIB amplitude attenuation coefficient AX increases with the decrease of saturation and AR decreases with the decrease of saturation.The frequency of 0~35 Hz is good for vibration isolation,but it attenuates slowly at the frequency of 2~4 Hz.In addition,the parameters of WIB in nearly-saturated ground such as depth,width,thickness and elas⁃tic modulus are studied when the degree of saturation is 95%.The research results can be used for vibration isola⁃tion design of high-speed railway on nearly-saturated ground.