Research on the Vibration Law of Transverse Support Blasting in Ultra Deep Foundation Pit
Taking the blasting project of No.0-1 working well in Qianhai to Huanggang Port section of the Suiguan Shenzhen intercity railway as an example,the transverse support blasting process was monitored by a blasting vibra-tion meter.The vibration response law of the transverse support was studied.The research results show that:(1)the variation law of the transverse support blasting vibration wave has strong directionality in the ultra deep excavation working well.The amplitude variation along the vertical direction of the working well was much more severe than the one in other two directions.Among them,the amplitude of changes in the horizontal radial direction shows a trend of first decreasing and then increasing;While the amplitude of changes in the horizontal tangential directions is rela-tively smaller in various vibration monitoring waveforms;The amplitude of changes is relatively higher in vertical direction;Under the same horizontal support blasting conditions,the duration of blasting vibration is basically the same.(2)The maximum vibration wave velocity and main frequency have regularity in each direction.Among them,the maximum vibration wave velocity and main frequency have significant changes in horizontal tangential direction.The maximum amplitude of vibration waveform change is concentrated in a single direction.The values and wave-form shapes are basically the same in other directions.The vibration of foundation pit support blasting is verified to have significant directional characteristics.(3)The blasting vibration effect of the working well is good.The cracking and vibration of the supporting and supported structures are within the allowable range.The blasting effect meets the construction requirements.The result can provide reference for the transverse support blasting engineering of ultra deep foundation pits in future.
ultra deep foundation pitblasting vibration responsemonitoring technologytransverse support