Effects Of Subway Vibration On Chengdu Museum

ABSTRACT:Along with the rapid development of metro construction, people pay more attention to the severe problem of ambient vibration caused by metro operation. This issue focuses on three aspects:the vibration sources model of the metro, the propagation theory of the vibration in the soil and the interaction between the structure and soil. Actually, the structure vibration caused by subway, damping design and vibration isolation have great value on theory and engineering application. Combining with the proposed project in Chengdu Museum, the problem of building vibration caused by subway is studied by field test and numerical simulation method. In this paper, the study includes these three aspects:1.In the paper the experiment on vibration of site background, vibration propagation of ground and vibration propagation of ground-tunnel wall are carried out for analysing the vertical vibration wave in the field. The results show that:the vertical vibration wave is great influencing when the vertical vibration wave's frequency is 35Hz to 45Hz.Besides the environmental impact is relatively large. Though the attenuation of high frequency wave and low frequency wave are from fast to slow, the attenuation of high frequency wave is faster than the low frequency wave. When the vibration wave's propagation from the ground to tunnel wall, the attenuation is as much as 114 times.2.The model of Chengdu Museum for analysing the characteristic of the museum under the vertical vibration wave has been built by MIDAS to study the transfer function about foundation-upper. The result shows that under the low frequency vertical harmonic wave, the acceleration magnification coefficient is larger than high frequency vertical harmonic wave.3.The effect of vibration-isolating slot and the affection caused by the depth of the vibration-isolating slot have been studied. The result shows that the vibration-isolating slot can obtain certain isolation effect, low-frequency wave's isolation effect is not apparent, and high-frequency wave's isolation effect is slightly better. The effect of vibration-isolating slot with the increase of depth shows increasing trend. The isolation effect and, the depth of vibration-isolating slot have less impact on isolation effect because of the complexity of the Chengdu museum.4. The paper studied the vertical vibration of the structure caused by the subway circulation under the influence of stiffness of vibration isolator. Besides, the vibration-coupling researching is also studied in this paper. The result shows on these three aspects:First, the horizontal stiffness of vibration isolator has no influence on vertical vibration. Second, the vertical stiffness of vibration isolator has some influence on vertical vibration. As the vertical stiffness of vibration isolator is rising, the vertical acceleration is decline because of the specialty of Chengdu museum. Third, the coupling of vibration from three directions is not well.