加厚筏板基础建筑物底板对地铁所致振动的影响

Influence of thickened base floor of raft foundation building on vibration caused by metro operation

为降低地铁运行所致临近建筑物振动的危害,提出了加厚筏板基础建筑物底板的减振方法,研究了加厚筏板基础建筑物底板的减振效果。建立“隧道-土体-建筑物”三维模型,通过实测数据和经验公式对所建模型及振源荷载进行验证。在此基础上,研究了在普通道床、弹性长枕道床、钢弹簧浮置板道床条件下加厚筏板基础建筑物底板的减振效果,并分析了建筑物中心距离地铁隧道中心的水平距离对加厚底板减振效果的影响。结果表明:加厚筏板基础建筑物底板可有效消耗地铁所致振动能量,从而降低邻近建筑物的振动响应;当地铁线路采用减振道床时,其减振作用会有一定减弱;加厚筏板基础建筑物底板的减振效果与建筑物距隧道中心线的水平距离有关,距离越近减振效果越好。最后提出了能快速计算加厚筏板基础建筑物底板减振效果的预测方法,该方法为地铁临近建筑物加厚底板的实施提供参考。

To reduce the vibration hazard of adjacent buildings caused by metro operations,a vibration reduction method of thickening the base floor of raft foundation buildings was proposed,and the vibration reduction effect of the thickened floor was studied.The three⁃dimensional model of“tunnel⁃soil⁃building”was established,and the model and vibration source load were verified using measured data and empirical formula.The vibration reduction effect of the thickened base floor of raft foundation building under the conditions of ordinary track bed,elastic long sleeper track bed,and steel spring floating slab track bed was examined.The influence of the horizontal distance between the building center and the metro tunnel center on the vibration reduction effect of the thickened floor was analyzed.Results showed that the thickened raft foundation effectively consumed the vibration energy caused by metro,reducing the vibration response of adjacent buildings.When the damping track bed was employed in the metro line,the damping effect was weakened to a certain extent.The vibration reduction effect of the thickened base floor was related to the horizontal distance between the building and the tunnel centerline.The closer the distance was,the better the vibration reduction effect was.Finally,a prediction method for quickly calculating the vibration reduction effect of the thickened base floor of raft foundation building was proposed,which can provide a reference for practical engineering.