中远区微差爆破振动叠加效应影响因素分析

Analysis on Influential Factors of Vibration Superposition in Middle and Far Field of Millisecond Blasting

微差爆破中先后起爆的炮孔产生的地震波相互叠加是一种常见现象。从单孔爆破振动特性出发,对中远区微差爆破振动叠加效应的产生及其影响因素进行了分析。微差爆破的振动波形在近区主振相持续时间短,波形窄,叠加效应不明显,各分段爆破的波形基本独立,而中远区振动波形主振相持续时间长,波形拉宽,叠加效应较明显,难以辨别各分段爆破的波形。中远区微差爆破振动叠加效应产生的主要因素是介质的衰减慢。振动叠加强度与爆源结构特性、爆心距和间隔时间有关。

The earthquake wave from different section of millisecond blasting would be superposed in middle and far field most condition. By analysing the characteristics of the single-section blasting vibration, this paper analyzes the relationship of the vibration superposition and influential factors, and indicates the attenuation of blasting seismic wave propagation in rock mass is the main reason which vibration superposition in middle and far field is generated. The intensity of vibration superposition is affected by the characteristics of explosion source ,millisecond delay interval and distance between explosion source and measuring point.