航道疏浚临河高层建筑爆破振动高程效应分析

Analysis of Elevation Effect of Blasting Vibration on High-rise Buildings near River in Channel Dredging

根据某航道水下钻孔爆破工程邻近高层建筑同一水平距离、不同竖向位置处底部、中部和顶部三个三向监测点开展的连续爆破振动监测结果,分析爆破振动速度、振动频率和振动能量高程效应三维空间规律,探究高层建筑爆破振动高程效应机理。分析结果表明:①爆破振动速度受“面波椭圆运动”、“能量衰减”和“鞭梢效应”共同作用,在高层建筑中的传播呈现出明显的三维空间效应,垂直向Z“面波椭圆运动”和“鞭梢效应”作用占主导,表现为明显的高程放大效应,而水平向X、切向Y“面波椭圆运动”和“能量衰减”作用占主导,表现为高程衰减效应;②爆破振动频率在高程建筑中的传播主要受墙体垂直距离影响,在水平向X、切向Y和垂直向Z三个方向均表现为高程衰减效应;③垂直向Z爆破振动能量分布从建筑底部、中部至顶部呈现明显的逐步高程放大效应,高频能量比例中部、顶部相对底部表现为高程衰减效应,低频能量比例中部、顶部相对底部表现为高程放大效应,而中部和顶部各频带能量比例高程效应不明显。研究结论对高层建筑的爆破振动控制具有借鉴意义。

According to continuous blasting vibration monitoring results carried out on three monitoring points(bottom,middle,and top)at different vertical positions at the same horizontal distance from an underwater blasting project in a channel adjacent to high-rise buildings,the three-dimensional spatial patterns of blast vibration velocity,vibration frequency,and vibration energy were analyzed,and the elevation effect mechanism of blasting vibrations on high-rise buildings was explored.The analysis results show that:(1)Blasting vibration velocity is influenced by the combined action of the elliptical motion of Rayleigh wave,energy attenuation,and whiplash effect.It presents a significant three-dimensional spatial effect in the propagation among high-rise buildings,in which the vertical direction is dominated by Rayleigh wave elliptical motion and whiplash effect,showing a significant elevation amplification effect,while the horizontal and tangential directions are dominated by Rayleigh wave elliptical motion and energy attenuation,exhibiting an elevation attenuation effect.(2)The propagation of blasting vibration frequency in high-rise building is mainly affected by the vertical distance from the wall,showing an elevation attenuation effect in all three directions.(3)The distribution of vertical blasting vibration energy presents a significant elevation amplification effect from the bottom,middle to the top of the building.Specifically,the high-frequency energy proportion shows an elevation attenuation effect in the middle and top relative to the bottom,while the low-frequency energy proportion exhibits an elevation amplification effect in the middle and top relative to the bottom.