立井直眼微差爆破模型试验振动测试与分析

为降低立井爆破施工的振动效应,以立井爆破中两圈直眼为原型,实施三种不同起爆延期的直眼微差爆破模型试验,并用UBOX-5016型爆破振动智能监测仪测试混凝土模型的爆破振动效应。实测爆破振动波表明,微差爆破可减少单段起爆药量、明显降低爆破振动效应;起爆延期25 ms时I段、Ⅱ段爆破振动波形彼此叠加,测点形成干扰降振效应,爆破峰值振动速度较小;起爆延期为50 ms时I段、Ⅲ段爆破振动波形彼此独立,峰值振动速度由单段起爆药量决定。竖向爆破振动波形频谱分析表明,微差爆破振动幅值明显低于齐发爆破,且波形复杂。微差爆破能显著降低爆破振动效应,主振频率较高。

Blasting vibration measurement and analyses of millisecond blasting model test for shaft

With two-circle blast holes in vertical shaft blasting as the prototype, three kinds of parallel millisecond blasting model tests with two-circle vertical blast holes were conducted to investigate the way to reducing the blasting vibration effect in vertical shaft blasting construction. The blasting vibration on the concrete model was monitored by blasting vibration intelligent monitor UBOX-5016. The actual blasting vibration indicated that blasting vibration effect was reduced significantly by millisecond blasting by reducing maximum charge per delay. When detonation delay was 25ms, two blasting vibration waves, segment I and segment Ⅱ overlaid each other and the actual peak blasting vibration velocity is smaller by interference effect of vibration reduction. When detonation delay was 50ms, two blasting vibration waves, segment I and segment Ⅲ were almost independent and the actual peak blasting vibration velocity was determined by maximum charge per delay. Spectrum analyses were implemented for vertical blasting vibration of three millisecond blasting model tests. The amplitude spectrum of millisecond blasting was much lower than simultaneous blasting and spectrum waveform of millisecond blasting was also more complex. The blasting vibration effect could be reduced remarkable by millisecond blasting which presented a higher blasting vibration frequency.