The blast hole has a space between explosive and hole wall, and blast forces reaches the hole wall face with a large amount of loss during passing through this space. The loss ratio of blasting forces are different to this packing material of space like air, water, etc. In this study, the effect of packing materials is investigated by the numerical simulation analysis. The simulation is carried out to two phases; 1st phase is to compute the impacting forces reaching on the wall face passing through packing materials(air, water), 2nd phase is to study the blasting effect(block size of cracking, direction of driving forces, etc.) in real site. The reaching force at the wall face in the water is larger than in the air. This study shows that the water as packing materials is superior to the air.
In the blast work inevitably exists a vacant space between drilling hole wall and explosive. So it cause an blast inefficiency called on a decoupling effect. In this study, For enhancing the detonation efficiency and reducing the environmental problem(vibration, noise, etc.), water is used to fill the vacant space. Water filling has many advantages such as efficiency, low price and workability. In the comparison analysis the field test is carried out. It result on an aspect of the effectiveness and safety. The result measured in the field is as follows; First, the water tube blast reduces the vibration by 16.5% and lessen the noise by 1% comparing to general blast. Secondly, water tube blast makes a separation distance shortened by maximum 15m. Thirdly, in the case that the same quantities of explosive are used, the amount of crushing per hole increased by about 12.8% in water blast method. The quantity of the explosive is reduced by about 11.4% comparing with general blast.
최근에 도시화와 산업화 및 교통망의 지속적인 확보로 인하여 발파공사를 시행하는 공사장이 증가하고 있다. 발파공사는 주변 주 민들의 주거환경과 인접시설물들의 안전에 큰 영향을 미치므로 이에 대한 대책이 필요하다. 본 연구에서는 발파피해를 줄이기 위한 방법 중에 서 발파공내의 발파메커니즘을 규명하고 개선하였다. 일반적인 공법에서 발생하는 천공경과 폭약경 사이의 차이로 인한 공간에서 디커플링효 과를 규명하고, 이 공간의 매질을 변화시킴으로서 발파 시 진동발생의 규모를 규명하였다. 발파시험은 도로, 철도, 산업단지에서 실시하고, 발 파진동을 측정하였다. 측정된 진동속도를 회귀분석하여 발파진동추정식을 산정하고 이를 이용하여 이격거리를 산정하였다. 공내 매질이 공 기보다는 물처럼 비중이 큰 경우에 충격력은 크나 폭발 지연시간이 짧아 진동전달거리가 작아 이격거리를 크게 확보할 수 있다. 핵심용어 :