발파공내 기폭위치가 지반진동에 미치는 영향

Abstract

ABSTRACT

Influence of priming location on the ground vibration

By Kim, Jae Woong Adv. Prof. : Kang, Choo Won, Ph.D. Dept. of Energy & Resource Engineering, Graduate School of Chosun University

The ground excavation by use of various kinds of commercial explosives has been widely employed in mining, civil engineering and construction works such as surface mining, deep mining for extracting useful mineral, driving tunnels for subway and public transportation, excavation of the basement in urban area, and the construction of huge underground storage caverns. Excavation by blasting in densely populated urban areas, however, has caused various public grievances, which urges blasting engineers to use the blasting methods which could reduce the ground vibration effectively. At the same time, the safety has become a key design parameter in preference to the efficiency and reliability. The influence of the priming location on the ground vibration has been studied in this thesis. In the most of previous studies dealing with the ground vibration, the effect of the priming location was neglected or considered in a limited way which is plausible only in the relevant site. Considering the fact that the mechanism of ground vibration caused by blasting is quite complex, the priming location can have a considerable effect on the ground vibration in certain situations and can be an important parameter in a blasting design. This study was carried out to identify the characteristics of the rock in laboratory experiments. For the experiment, samples were collected in the study areaⅠ(quartz porphyry of area), study areaⅡ(schist of area), study areaⅢ(gneiss of area). In order to identify the characteristics of blasting according to the priming location of each study area (quartz porphyry, schist, gneiss) and blasting conditions (top priming, middle priming, bottom priming), this study was carried out 9 cases single hole test blasting and was derived the formula to predict blast vibration. And in order to identify the characteristics of the propagation depending on priming location, test blasts were carried out a total of 72 times using different spacing, burden, drilling length, charge and was derived the formula to predict blast vibration. This study investigated the characteristics of vibration by analysis of the nomogram about particle velocity, peak particle velocity(PPV) and peak vector sum(PVS) from priming location (transverse, vertical, longitudinal component) by the formula to predict blast vibration. And it analyzed the trends of vibration damping by standards charge 0.5, 1.6, 5, 15kg. Standards charge is "Blasting design and construction guidelines to road construction" by the Ministry of land, transport and maritime affairs. The result of this study can be summerized as follows. (1) In top priming, vibration velocity were predicted by an average ground vibration prediction equation of particle velocity(T, V, L) at 10～100m distance. As a result, longitudinal component of vibration velocity from charge within 3.8kg were predicted higher. More than 3.8kg, vertical component in the near distance was predicted higher and longitudinal component in the long distance were predicted higher. The case of transverse component and vertical component depending on the amount of charge reversal of the two components were tend to be different, but vibration velocity of transverse component in the near distance were predicted lower and vibration level of vertical component in the long distance was predicted lower. (2) In middle priming, vibration velocity were predicted by an average ground vibration prediction equation of particle velocity(T, V, L) at 10～100m distance. As a result, longitudinal component of vibration velocity from charge were predicted higher. The case of transverse component and Vertical component depending on the amount of charge reversal of the two components were tend to be different, but vibration velocity of transverse component in the near distance were predicted lower and vibration level of vertical component in the long distance was predicted lower. (3) In bottom priming, vibration velocity were predicted by an average ground vibration prediction equation of particle velocity(T, V, L) at 10～100m distance. As a result, longitudinal component of vibration velocity from charge within 8.1kg were predicted higher. More than 8.1kg, Vertical component in the near distance was predicted higher and longitudinal component in the long distance were predicted higher. The case of transverse component and Vertical component depending on charge within 8.7kg reversal of the two components were tend to be different, but vibration velocity of transverse component in the near distance were predicted lower and vibration level of vertical component in the long distance was predicted lower. And more 8.7kg, vibration level of longitudinal component was predicted lower. (4) Vibration velocity were predicted from an average ground vibration prediction equation of peak particle velocity(PPV) depending on the priming location at the vibratory rate of 10～100m distance. As a result, vibration level of the top priming from charge within 1.1kg was predicted higher. More than 1.1kg, the bottom priming was predicted higher in the near distance and the top priming was predicted higher in the long distance. The middle priming and the bottom priming depending on charge were tend to be different reversal of the two components, but the middle priming in the near distance was predicted lower and the bottom priming in the long distance was predicted lower. (5) Vibration velocity were predicted from an average ground vibration prediction equation of peak vector sum(PVS) depending on the priming location at the vibratory rate of 10～100m distance. As a result, vibration velocity from charge within 1.3kg was predicted higher. From vibration velocity from charge more 1.3kg, the bottom priming was predicted higher in the near distance and the top priming in the long distance was predicted higher. The middle priming and the bottom priming depending on charge were tend to be different reversal of the two components, but the middle priming in the near distance was predicted lower and the bottom priming in the long distance was predicted lower.