Study On Vibration Effect And Control Of Excavation Per - Hole Initiation In Foundation Pit Excavation

A series of harmful effect with blasting process is a major issue in blasting engineering, among them especially the blasting seismic effect have attracted the most attention. Surrounding environment of the first phase of engineering that blasting excavation of basement deep foundation pit in the center of Anning Taihe district is complex,This thesis main research how to design the blasting technical scheme,the related factors how to influence the blasting vibration and how to predict and control the blasting vibration.Designed the shallow hole bench blasting by hole initiating loose blasting scheme in the open air combined with the blasting area surrounding environment,site geological terrain conditions and building security allowed velocity,through blasting vibration testing verified the feasibility of the design scheme.According to the blasting vibration data,find out the law of blasting seismic wave spreading in the engineeringAccording to the blasting vibration data,with the help of numerical analysis software MATLAB and statistical analysis software ORIGIN, through the theoretical analysis and the statistical data obtained,the velocity of blasting safety within the scope allowed,peak particle vibration velocity has little effect on the biggest single hole charge crease or decrease is less than0.4kg,area near blasting and central can respectively increase the total amount of3kg,4kg in the original volume basis.Through the HHT method concluded that the blasting seismic wave propagation in the mudstone,The dominant frequency mainly concentrated in the range of10-50hz,Along with the single biggest dosage, total quantity and the increase of the aperture,Within the scope of0-10hz low frequency energy increase.Studied in combination with actual biggest single hole charge and actual total dose of peak particle vibration velocity prediction method,that is theory single-hole maximum dose(z)With the actual single-hole maximum dose (x) and the actual total dosage(y) the function relation as:z=2.5503x-0.0366y-0.1652; the theory single-hole maximum dose is larger than the he actual single-hole maximum dose accuracy increased by11.1%. Studied of the blasting seismic wave propagation in the engineering forecast formula of main vibration frequency through the vibration spectrum analysis and HHT method obtained the optimum vibration damping ditch range is1-6m, the maximum vibration reduction ratio of77.5%.With the help of numerical simulation software ANSYS-LS/DYNA studied5millisecond delay interval of hole by hole initiation model, obtained the optimaldelay time for35ms or50ms.This paper has done research on urban complicated environment vibration prediction and control has great theoretical significance and practical value.