【摘要】 以上海市某大型基坑内支撑机械拆除为例,在大量振动监测的基础上,研究了基坑内支撑机械拆除过程中产生的振动在基坑内部和基坑边缘挡土墙、高层建筑物竖直方向上的传播规律,监测同时考虑了临近建筑对机械振动的动力响应。研究表明:机械拆除基坑内支撑对周围建筑物所产生的振动速度较小,不足以影响构筑物结构安全,但由于振动信号的主频较低,接近于建筑物的固有频率,地震效应仍应该引起足够重视;利用小波包技术可得到振动信号各频带上的能量分布,从能量角度研究振动信号可以直观地了解信号在传播过程中的衰减特性。更多还原

【Abstract】 Taking the mechanical demolition of foundation pit supporting in Shanghai as an example,a research was carried out on the propagation law of vibration caused by mechanical demolition of foundation pit support at different places,such as the inner of foundation pit,edge of foundation pit,different heights of the same building,based on a great number of vibration monitoring.During the monitoring,dynamic response of buildings around the foundation pit is taken into consideration simultaneously.Results show that the vertical vibration velocity of the constructions around caused by the mechanical demolition is very small and the velocity was not high enough to damage the constructions around.However,as the dominant frequency of vibration signal is low and closed to the natural frequency of buildings,the influence of vibration should be taken into consideration.The energy distribution at different frequency bands of the vibration signals with wavelet packet technique(WPT) and the propagation law of vibration could be directly achieved with energy analysis method.更多还原