Research On Vibration Characteristics Of Vibration Isolation System Of Building Floor Caused By Train

With the continuous development of China’s economy,the advancement of urbanization and the growth of the population,the demand for ground transportation is also increasing day by day.With the development of the transportation industry towards more comfortable,convenient,safe,and intelligent,the impact of environmental vibration caused by various types of public transportation operations is becoming more and more prominent.In this paper,the isolation measures of floor vibration caused by train operation are taken as the starting point and research the theoretical derivation and numerical simulation.Based on the theoretical research of the single-layer single-degree-of-freedom vibration isolation system,the dynamic model of four-degree-of-freedom multidimensional vibration isolation slab under multi-point excitation is established.The horizontal and vertical vibration response of the vibration isolation slab system is studied theoretically and compared with the simulation results for verification.The train-track interaction model and the three-dimensional finite element model of the soil-buildingvibration isolation system are established.The vibration isolation performance of the system on the floor of the building and the influence of parameter changes on the vibration isolation effect of the system is analyzed comprehensively.The main research results are as follows:(1)Under the action of uniform excitation,the displacement response of the three translational degrees of freedom of the isolation slab system can be regarded as the superposition of the displacement response of the single degree of freedom system under the action of external excitation.Under the action of non-uniform excitation,the vertical displacement response of the isolation slab system changes with the change of the position on the slab and the rotation angle of the isolation slab.(2)Increasing the number of isolators,increasing the length of the isolator,and placing the horizontal isolator and the center of gravity of vibration slab at the same height can effectively improve the stability of the isolator system.(3)The vibration isolation slab system has an obvious effect on the vibration isolation of the building floor caused by the train,and it has the best effect on the vibration isolation of the acceleration response and the worst effect on the displacement response.The secondary vibration isolation slab system on the floor has a strong filtering effect on the medium and high-frequency vibration caused by the train operation and also has a certain inhibition effect on the low-frequency vibration.The isolation effect of the vibration slab system on the floor vibration response caused by the train is not affected by the distance of the vibration source.(4)The thickness,spring stiffness,damping ratio,and the number of isolators all have an obvious influence on the isolation effect of the floor isolator system.