발파공 사이의 지연시차와 기폭위치가 지반진동에 미치는 영향

Abstract

ABSTRACT

Influence of delay time and priming location on the blast-induced ground vibration

Ryu, Bok Hyun Advisor : Prof. Kang, Choo Won, Ph.D. Department. of Energy & Resource Engineering, Graduate School of Chosun University

Due to population growth and industrial upgrading of ports, social infrastructure, such as dams and highways, railways, subways and other transportation networks are expanded. This continued to increase in the construction site for the excavation of rock, depending on the strength of explosive has been widely used as essential. In the past, rock blasting work for excavation work on the ground was limited. In recent years, a large building from the mountains wallpaper Dig site and construction of apartments for redevelopment for housing and crowded around the existing structures within the city center is underway. Furthermore, the underground reserve base, development of underground space has been expanded to in deep underground is increasing the demand. This specialization of blasting construction, enlargement, depending on the national scene with a large blast on the rise, and the use of explosives is increasing each year. Today, our society through the process of industrialization continued growth comes during a highly neglected environmental problems, especially in the field of construction noise and vibration issues are rapidly emerging in recent years. This quantitative growth to qualitative growth in the pursuit of change is the situation. In addition, the government, like in reality, considering the environmental impact of the regulatory environment, as a means of dispute conciliation committee established by the permanent organization is operating the sleep. So blasting operations are subject to the more stringent regulations. Blasting engineers compared to conventional blasting methods are looking for effective vibration control methods. And when the blasting was designed they considered a top priority to safety in efficiency, reliability and safety of design variables. Determinings the propagation characteristics of ground vibration factor are location and blasting conditions. Location means that the blasting site and the geometric shape of the structure, the target of rocks and geological features include the mechanical properties. Blasting conditions means that the type of using explosives, weight per delay, composition charging, blasting method, tamping condition, number of free face, distance. This study was carried out to identify the characteristics of the rock in laboratory experiments. For the experiment, the samples were collected in the study area. In order to identify the characteristics of the propagation depending on delay time(0, 20, 25ms) and priming location(top priming, middle priming, bottom priming), test blasts were carried out a total of 37 times using different spacing, burden, drilling length, charge per delay and was derived the formula to predict blast vibration. This study investigated the characteristics of vibration by analysis of the nomogram and prediction of ground vibration about component(transverse, vertical, longitudinal) particle velocity, peak particle velocity(PPV), peak vector sum(PVS) from delay time and priming location by the formula to predict ground 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. Depending on the charge in favor of vibration control method is proposed. Thus, when the design was to be used as a variable.

The result of this study can be summerized as follows (1) Vibration velocity were predicted by an average ground vibration prediction equation of particle(T, V, L) at 5～200m distance. - Case No. 1 : The case of longitudinal component of vibration level from charge within 0.6kg were predicted higher. More than 0.6kg, vibration level of vertical component in the near distance was predicted higher and vibration level of longitudinal component in the long distance were predicted higher. The case of transverse component were predicted the lowest vibration level. - Case No. 2 : The case of longitudinal component were predicted the highest vibration level. And the case of transverse component and vertical component depending on charge within 1.8kg reversal of the two components were tend to be different, but vibration level of vertical component in the near distance were predicted higher and vibration level of transverse component in the long distance was predicted higher. More than 1.8kg, vertical component of the vibration level is higher than the transverse component of the vibration levels are predicted. - Case No. 3 : The case of longitudinal component and vertical component depending on charge within 4.3kg reversal of the two components were tend to be different, but vibration level of vertical component in the near distance were predicted higher and vibration level of longitudinal component in the long distance was predicted higher. More than 4.3kg, longitudinal component of the vibration level is higher than the vertical component of the vibration levels are predicted. The case of transverse component were predicted the lowest vibration level. - Case No. 4 : The case of transverse component and vertical component reversal of the two components were tend to be different, but vibration level of vertical component in the near distance were predicted higher and vibration level of transverse component in the long distance was predicted higher. The case of longitudinal component in the long distance were predicted the lowest vibration level. - Case No. 5 : The case of longitudinal component and transverse component depending on charge within 19kg reversal of the two components were tend to be different, but vibration level of longitudinal component in the near distance were predicted higher and vibration level of transverse component in the long distance was predicted higher. More than 19kg, longitudinal component of the vibration level is higher than the transverse component of the vibration levels are predicted. The vibration level of vertical component of the vibration level is higher than the transverse component of the vibration levels in the near distance and the vibration level of vertical component of the vibration level is lower than the transverse component of the vibration levels in the long distance. - Case No. 6 : The case of longitudinal component and transverse component depending on charge within 20.7kg reversal of the two components were tend to be different, but vibration level of longitudinal component in the near distance were predicted higher and vibration level of transverse component in the long distance was predicted higher. More than 20.7kg, longitudinal component of the vibration level is higher than the transverse component of the vibration levels are predicted. The vibration level of vertical component of the vibration level is higher than the transverse component of the vibration levels in the near distance and the vibration level of vertical component of the vibration level is lower than the transverse component of the vibration levels in the long distance. - Case No. 7 : The case of transverse component and vertical component reversal of the two components were tend to be different, but vibration level of vertical component in the near distance were predicted higher and vibration level of transverse component in the long distance was predicted higher. The vibration level of longitudinal component of the vibration level is higher than the transverse component of the vibration levels in the near distance and the vibration level of longitudinal component of the vibration level is lower than the transverse component of the vibration levels in the long distance. - Case No. 8 : The case of transverse components, vertical component and longitudinal component reversal of the three components were tend to be different. In near distance, the case of vertical component were predicted the highest vibration level and the case of transverse component were predicted the lowest vibration level. In long distance, the case of transverse component were predicted the highest vibration level and the case of vertical component were predicted the lowest vibration level. - Case No. 9 : The case of transverse components, vertical component and longitudinal component reversal of the three components were tend to be different, but vibration level of longitudinal component in the near distance were predicted higher and vibration level of transverse component in the long distance was predicted higher. Charge increases, the case of vertical components compared to the other components were expected to increase the damping (2) Vibration velocity were predicted from an average ground vibration prediction equation of peak particle velocity(PPV) depending on the delay time and priming location at 5～200m distance. As a result, in less than 2.6kg, Case No. 7(delay time=25ms, top priming) in the near distance were predicted the lowest vibration level and Case No. 9(delay time=25ms, bottom priming) in the long distance were predicted the lowest vibration level. More than 3.0kg, Case No. 7(delay time=25ms, top priming) were predicted the lowest vibration level. (3) Vibration velocity were predicted from an average ground vibration prediction equation of peak vector sum(PVS) depending on the delay time and priming location at 5～200m distance. As a result, in less than 2.6kg, Case No. 7(delay time=25ms, top priming) in the near distance were predicted the lowest vibration level and Case No. 9(delay time=25ms, bottom priming) in the long distance were predicted the lowest vibration level. More than 2.6kg, Case No. 7(delay time=25ms, top priming) were predicted the lowest vibration level. (4) With a low level of vibration blasting method Case No. 7 and 9 is used vibration levels are reversed depending on the charge, the cross point of one expression was calculated as follows; . Where, X is a charge per delay(kg/delay), Y is a cross point(m) of vibration levels are reversed. The former cross point Case No. 7, cross point after the Case No. 9 the ground vibration level is low in terms of favorable ground vibration control method.