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研究目的:成都博物馆紧邻地铁2号线,如果减振措施采取不当,地铁所致振动极有可能对博物馆正常使用产生影响。同时,为满足地铁通行条件下成都博物馆内文物振动安全的要求,结合实测数据,采用有限元软件MIDAS/GTS建立“浮置板-隧道-土体”三维有限元模型,选取隧道壁的竖向振动为控制参量,对浮置板、钢弹簧刚度和隧道壁厚度的减振效果进行量化分析和参数优化研究。研究结论:(1)浮置板具有阻碍高频、放大低频的减振特性,当其钢弹簧刚度为6 900 kN/m时,其综合减振效果达12.1 dB;(2)降低钢弹簧刚度可以有效降低隧道壁Z振级,弹簧刚度由9 000 kN/m降低到3 000 kN/m时,隧道壁Z振级降低了5.6 dB;(3)增加隧道壁厚度可以降低隧道壁Z振级,当隧道壁厚度由0.2 m增加到0.8 m时,隧道壁Z振级降低了2.7 dB,减振效果不明显;(4)该研究成果可为地铁所致振动的振源减震提供参考。
Research purposes: Chengdu Museum is close to Metro Line 2. If the vibration mitigation measures are taken improperly, the vibration caused by the subway is likely to have an impact on the normal use of the museum. At the same time, in order to meet the vibration safety requirements of the Chengdu Museum under subway traffic conditions, combined with the measured data, finite element software MIDAS / GTS was used to establish the “three-dimensional finite element model of floating plate-tunnel-soil” The vertical vibration is the control parameter, and the vibration effect of the floating plate, the steel spring and the thickness of the tunnel wall are quantitatively analyzed and the parameters are optimized. The conclusions are as follows: (1) The floating plate has the damping characteristics of hindering the high frequency and amplifying the low frequency. When the stiffness of the steel spring is 6 900 kN / m, the integrated vibration damping effect reaches 12.1 dB. (2) Which can effectively reduce the Z vibration level of the tunnel wall. When the spring rate decreases from 9000 kN / m to 3000 kN / m, the Z vibration level of the tunnel wall decreases by 5.6 dB. (3) Increasing the tunnel wall thickness can reduce the Z vibration level When the thickness of the tunnel wall increases from 0.2 m to 0.8 m, the Z vibration level of the tunnel wall is reduced by 2.7 dB and the damping effect is not obvious. (4) The research results can provide reference for the vibration reduction of the vibration caused by subway.