Blasting cushion pad of reducing vibration start a new era of decreasing disaster in civil and mining engineering explosion with micro-damage

Abstract

Millisecond delayed blasting has been widely used in reducing vibration of engineering blasting practice before. Pre-splitting blasting has been widely used in reducing vibration of rock slope excavation by blasting up to now. There was still damage to surrounding rock by millisecond delayed blasting and pre-split blasting even smooth blasting. The recurrent blasting vibration will produce cumulative damage to surrounding rock mass of underground and rock slope engineering, even induce rock mass fracture, collapse, roof fall or instability landslide . The damage area is much larger than the blasting excavation area, so rock mass would be damaged several times and result in accumulative damage. Not only the disturbance of single blasting on the surrounding rock should be controlled during blasting construction of anchorage roadway or tunnel, but the emphasis should be put on the accumulative vibration effect of surrounding rock induced by frequent circle short-distance blasting and the corresponding control measures should be taken. This paper introduces a cushion pad which has simple structure and is easy used in blasting engineering. This device can not only avoid large amount of cracks on the rock slope and cumulative damage to surrounding rock mass and rock mass of engineering to instability induced after blasting, but also cushion and hold up at large extent heavy detonation shock after blasting. It is first used in Panzhihua Xujiagou iron open pit, Huayinshan coal mine with gas in SiChuan province, Miaowei hydropower station in Yunnan province and Minshui tunnel blasting engineering in Xin-Fen highway in Hebei-Shanxi province. It effectively cushion the heavy detonation shock from explosion avoiding the damage surface of surrounding rock and accumulated damage of rock, thus improve stability of rock mass and save a large amount of support costs. The vibration velocity with cushion is 50% less than with pre-splitting blasting, even less than the threshold of blasting vibration accumulated damage. Ratio of semi--hole archive 95%. Achieve China patent, the number: ZL 201220107888.5, ZL201220230579.7, ZL 201220750552.0., ZL 201220016697.8.