Study On Vibration-isolation On The Propagation Process Of Chengdu Museum Induced By Metro

In recent years, due to the rapid development of our country’s urban metro, sometimes the metros are constructed closer to buildings inevitably, even some of them just pass through from the inferior of the buildings. In addition, because of the improvement of people’s living standards, the vibration restrictions on the surrounding environment are getting more and more rigorous. Therefore, the problem of environmental vibrations induced by subway is become more and more serious, therefore, the researches on environmental vibration induced by subway and the methods of vibration-isolation have great theoretical significance and practical engineering value.Based on the background of Chengdu Museum designed by China Aviation Planning and Construction Development Co., Ltd, the problems of vibration-isolation in the communication process are studied in this paper. The main contents included:Firstly, based on the theoretical analysis, the principles of vibration induced by metro, the propagation and attenuation law of shock wave in the soil, and the numerical methods of vibration of buildings induced by metro were studied in this paper. In addition, combined with the existing domestic vibration control standards, vibration control standards of Chengdu museum are given.Secondly, on the basis of existing studies, according to the "Chengdu New Museum Geotechnical Investigation Report" made by Aviation Survey and Design Institute, the soil stratification and the kinetic parameters of soil are selected to establish the analysis model. Besides, the impact of model size, cell size, time step and dynamic boundary on the numerical computation are discussed in numerical analysis methods. After verification, the simulation results and measured data have a good similarity, thereby the accuracy of the model is further validated.Thirdly, the principle of vibration-isolation and the basis of parameters selection of wave impeding block are analyzed, and the thickness, width and buried depth of wave impeding block are taken as parameters for analysis. Results suggest that: vibration-isolation effect of wave impeding block is significant, and increasing the thickness and width or reducing the buried depth of wave impeding block can improve the efficiency of vibration-isolation greatly. Furthermore, setting up wave impeding block has a more particular effect on the low frequency (0-40Hz). Fourthly, the principle of vibration-isolation and the basis of parameters selection of isolation trench are analyzed, and the depth and the length along the direction of tunnel of isolation trench are taken as parameters for analysis in this paper. It is concluded that taking isolation trench can achieve a better vibration isolation effect, and increasing the depth and the length of isolation trench are effective measures to improve the efficiency of vibration-isolation greatly. Moreover, setting up isolation trench has a more particular effect on the high frequency (40-80Hz).Finally, the principle of vibration-isolation and the basis of parameters selection of isolation piles are analyzed, and the side length and the depth of isolation piles are taken as parameters for analysis in this paper. Analysis results showed that the use of isolation piles can obtain better effect of vibration isolation, and the isolation piles’efficiency of vibration-isolation can be greatly improved by increasing the side length and the depth. Besides, the isolation piles obtain have a better attenuation effect not only for the low-frequency (0-20Hz), but also for the high frequency (20-80Hz).