RESEARCH ON MONITORING AND CONTROLLING TECHNIQUES CONSIDERING EFFECTS OF SEISMIC SHOCK

Seismic shock is one of the main hazards of blasting engineering,therefore,for the safety guarantee of buildings in near-field blasting,tests and controlling measures on blasting vibration effects are necessary.Taking deep hole blasting on mining and foundation ditch controlling blasting in city for examples,speed and frequency of blasting vibration are tested.The relationships between vibration velocity and explosive charge and distance of dissemination are also regressed to disclose the law of blasting waves under such conditions.According to Safety Regulations for Blasting(GB6722–2003),the blasting parameters and blasting net are optimized;and the maximum charge of one section on the condition of safety and technical measures for reducing the blasting effect is given.The split-second blasting,excavation damping channel,or fully using existing free face and natural land forms,uch as mountain valleyf,arm pond,channel,are considered.At the same time,analytical results of blasting vibration frequency indicate that the main frequency of minor charge are mostly focused on the range of 20 to 100 Hz,which is greater than those of natural frequencies of buildings;so resonance will not happen generally,i.e.blasting has small influence on near-field buildings.