城区地铁控制爆破对地表框架结构的振动影响

Influence of controlled blasting on vibration of ground frame structure in urban subway

针对城区隧道钻爆开挖产生的爆破振动有害效应,以胶州湾海底隧道青岛端接线工程为背景,根据现场情况采用LS-DYNA数值模拟研究方法,从接近—穿越—远离建筑物的过程中开展隧道掌子面爆破对地面建筑物的振动影响研究。结果表明:当爆源接近建筑物时,建筑角柱位置处垂直、合峰值振速出现明显的上下波动现象,在建筑顶层的水平峰值振速放大1.10~2.09倍,垂直峰值振速放大1.31~1.60倍;当爆源到达建筑物正下方时,距爆源水平距离大约27m,成洞区和非成洞区水平峰值振速放大1.12~2.25倍,成洞区垂直、合峰值振速放大1.87倍,各峰值振速在建筑正中处达到最大值;当爆源远离建筑物时,建筑角柱位置处垂直、合振动峰值速度未出现明显的上下波动现象,建筑顶层水平切向、垂直和合峰值振速放大1.06~1.78倍,迎爆侧角柱位置水平径向峰值振速放大1.12倍,在其余位置水平径向峰值振速均出现0.69~0.79倍的降低特征。

In view of the harmful effect of blasting vibration caused by drilling and blasting excavation of urban tunnels,based on the connection engineering of Qingdao end of JiaoZhou Bay undersea tunnel as the background,LS-DYNA numerical simulation method was used to study the vibration effect of tunnel face blasting on ground buildings during the process of approaching,passing through and away from buildings.The results show that when the detonation source is close to the building,the vertical and peak vibration velocity of the corner column of the building fluctuates obviously.The horizontal peak vibration velocity of the top floor of the building increases by 1.10~2.09 times,and the vertical peak vibration velocity increases by 1.31~1.60 times.When the explosion source reaches directly below the building,the horizontal distance from the explosion source is about 27m,and the horizontal peak vibration velocities of the cavity forming area and non-cavity forming area are amplified by 1.12~2.25 times,and the vertical and combined peak vibration velocities of the cavity forming area are amplified by 1.87 times.Each peak vibration velocity reaches the maximum value at the center of the building.When explosive source away from buildings,building Angle location not present obvious vertical velocity and vibration peak fluctuating phenomenon,building the top horizontal tangential and vertical peak velocity amplification and 1.06~1.78 times,to meet critical side Angle of horizontal radial peak velocity 1.12 x magnification,in the rest position horizontal radial peak velocity were 0.69-0.79 times.