地铁致某近代建筑振动分析及减隔振措施研究

Vibration analysis of a modern building caused by metro and research on vibration reduction measures

地铁运行引起的振动通过土层传播,会对邻近建筑物产生不利影响。以某地铁沿线近代历史保护建筑为背景,依据建筑结构参数及土层实测数据建立“隧道⁃土体⁃保护建筑”精细化三维数值模型,并结合振动响应预测分析方法对地铁运行时建筑物振动响应进行评估。从振源减振及过程阻振两方面对其减振效果进行量化分析和参数优化研究。结果表明:在未采取减隔振措施的情况建筑物振动超限,优化轨道类型的减振效果最为显著,使用弹性长枕轨道时结构Z振级可降低8.2~11.2 dB;使用钢弹簧浮置板轨道可使结构Z振级降低14.9~18.9 dB。过程阻振措施中,隔振墙的隔振性能对墙体材料特性最为敏感,深度及厚度其次;其中EPE泡沫材质墙体隔振效果最优,可使结构Z振级降低10.6~11.5 dB,水平速度峰值约75%;增加隔振墙厚度及埋深在一定程度上提升了隔振性能,但隔振效果增量不显著。提出了一种快速计算隔振墙隔振效果的预测方法,该研究可为类似工程的振动分析以及减隔振措施设计提供参考依据。

The vibration caused by subway will adversely affect the adjacent buildings.Based on the background of a modern histor⁃ical protection building along the newly-built subway line,a fine three-dimensional finite element model of"tunnel-soil-protection building"is established based on relevant parameters and measured data,and the vibration response of the building during subway operation is analyzed.The damping effect is quantitatively analyzed and the parameters are optimized from two aspects of vibration source damping and process damping.The results show that the vibration of the building exceeds the limit when no vibration reduc⁃tion and isolation measures are taken.The vibration reduction effect of the optimized track type is the most remarkable.When the elastic long sleeper track is used,the Z vibration level of the structure can be reduced by 8.2 dB and 11.2 dB,and the Z vibration level can be reduced by 14.9~18.9 dB by using steel spring floating plate track.Among the vibration isolation measures in the pro⁃cess,the performance of the vibration isolation wall is the most sensitive to the characteristics of the wall material,followed by the depth and thickness.The properties of the wall material have a great influence on the vibration isolation performance,among which the EPE foam wall has the best vibration isolation effect,which can reduce the Z vibration level of the structure by 10.6 to 11.5 dB,and the peak horizontal velocity is about 75%.Increasing the thickness of the wall can improve the vibration isolation perfor⁃mance to a certain extent,but the vibration isolation effect is not significant.Finally,a fast prediction method for calculating the iso⁃lation effect of diaphragm wall is proposed,which can provide a reference for the vibration analysis of similar projects and the de⁃sign of vibration reduction measures.