桥梁桩基冲孔桩施工的微振动响应研究

Study on the Vibration Response to Punched Pile Construction of Bridge Pile Foundation

运用微地震监测系统对桥梁桩基冲孔桩施工的微振动响应进行了研究与探索。通过在施工现场进行的微震试验,分组采集施工荷载作用下的波形数据,对试验的数据进行相关分析,研究冲孔桩施工引起的地表振动加速度和能量的衰减规律,分析冲击能和桩孔深度对振动速度的影响。试验结果表明:冲孔桩施工时,岩土介质中冲击振动能量随传播距离的增加呈乘幂关系衰减;随着桩孔深度的增加,同一水平距离的振动速度逐渐降低,其衰减幅度与桩孔一定深度的地质条件有关。

The vibration response of punched pile construction of bridge pile foundation is studied and discussed for the first time,by use of the micro-seismic monitoring system,which is internationally advanced.Through the micro-seismic monitoring experiment on the construction site,wave data of loads acting on the construction is collected in group.Then the waveform of testing data is analyzed.According to the results,the weakening rules of vibration acceleration and energy are studied,and the effect of impact energy and pile depth on the vibration velocity is analyzed.Experiment results reveal that impact energy attenuates exponentially with the distance from the explosive center.Moreover,the vibration velocity of the same horizontal distance gradually decreases with increase of pile depth,and the attenuation amplitude is related to the geological conditions.