Application Of Layered Periodic Structure In Subway Vibration Isolation

With the rapid development of urban rail transit system, the subway has brought us with great convenience, at the same time the environmental vibration from it affects human’s life and work environment, which cannot be ignored. Since the periodic structure exhibits a unique dynamic character, the so-called frequency band gap in which the wave vibration amplitude will suffer from attenuation. Based on this feature, the present thesis established a kind of layered periodic isolation wall structure to isolate the vibration caused by subway.This paper mainly includes the following four parts:1. Basic theories about the dispersion properties of periodic structures are introduced. The transfer matrix method is deduced and the correctness of this method is verified. Dispersion curves for waves shooting into layered periodic structure vertically are calculated drawing up the Matlab codes.2. Attenuation zone of layered periodic vibration isolation wall structure by using soil and concrete is calculated. The influences of physical and geometric parameters on the attenuation zone are analyzed, from which the material parameters and size of the structure are determined.3. By using AN SYS, numerical model is set up for the layered periodic vibration isolation wall structure to analyze the frequency response. It is found that there exists strong attenuation in periodic structure’s attenuation zone.4. Vibration responses of layered periodic vibration isolation wall structrue under two actual subway vibration acceleration records are analyzed. Three models, no wall, concrete wall and periodic vibration isolation wall, are considered for comparison. Good performance of layered periodic vibration isolation wall structure is found.