• Explosives and Blasting
• /
• v.21 no.2
• /
• pp.15-19
• /
• 2003

터널 및 지하공동 설계에 이용된 16개 지역 23개 구간의 578개의 시추공 진동 data와 일반터널 4개 지역으로부터 221개 data를 이용하여 시추공발파의 진동전달 특성을 분석하였다. 시추공발파와 일반발파의 진동속도 감쇠 경향을 비교분석한 결과 시추공발파의 입지상수들이 크게 나타났다. 환산거리 증가에 따른 두 진동식의 최대 허용장약량은 시추공발파가 적었다. 이러한 결과로부터 시추공발파 자료를 터널발파 설계에 사용할 수는 있으나 조심스러운 통계적 처리가 불가피할 것으로 판단된다.

• Explosives and Blasting
• /
• v.29 no.2
• /
• pp.43-50
• /
• 2011

This study measured a vibration level at each distance of construction fields where blasts occur using Lion measuring instrument and used BlastmateIII to measure vibration velocity at the same distance. A total 130 blasts occurred with the weight of a total of 5,180 kg and the number of blast holes per blast was 5, 10 and 20. The weight of 4 kg was used for each hole. Vibrations caused by blast was measured at the distance with the same velocity and level. Measurements were carried 15~102 m away from the blast source. and 273 data on vibration velocity and level were obtained from eight measurements. It analysed data on vibration velocity measured based on existing correlation formulas and compared them to real measurements to analyse interrelationship.

• Journal of the Korean Professional Engineers Association
• /
• v.23 no.2
• /
• pp.81-93
• /
• 1990

The blasting to construct subways in Seoul, Korea. have often increased complaints of ground vibration. In order to prevent the damage to structures, it was necessary to predict the level of blasting induced vibration and to determine the maximum charge weight per delay within a allowable vibration level. A total of 109 blasts were recorded at ten sites. Blast-to-structure distances ranged from 8 to 84.2 meter, where charge weight varied from 0,1125 to 7.85 kg per delay. The data from blast were studied to determine the effect of explosives type on the vibration constants(k). Vibration constants were also analyzed in terms of compressive strength of rock and blasting patterns.

• Explosives and Blasting
• /
• v.27 no.2
• /
• pp.48-55
• /
• 2009

In the process of identifying the earth's crust structures to accurately locate the seismic epicenter, man-made earthquakes need to be generated. Such a large-scale ground vibration can be generated by a deep borehole blasting, but it can also accompany some environmental impacts on the surroundings. In this respect, a borehole test blasting was carried out to determine the maximum charge weight that could be used without affecting the various structures around the blast site. Total 400kg of gelatine-type dynamites was used in the test blast. As a result, a prediction equation for ground vibrations was derived from the measured data. With the allowable level of 3.0 mm/s for residential structures, the maximum charge weight was determined to be 677kg if military structures near the site were considered. But if the military structures were not considered, it was found that up to 2100kg of explosives could be used without affecting old houses in the nearby village.

• Explosives and Blasting
• /
• v.19 no.3
• /
• pp.59-65
• /
• 2001

암반발파작업에서 발생되는 발파진동은 주변의 생활환경과 인접한 구조물에 영향을 미쳐 공해를 발생시킨다. 계단발파와 터널발파에서 발생되는 발파진동은 진동에 영향을 미치는 요소들의 일부는 동일하게 작용하고 일부는 서로 다르게 작용하여 진동의 크기가 결정된다. 일반적으로 발파진동의 크기에 영향을 미치는 요소 중에서 암반의 조건과 폭약종류, 장약량 등 제 요소가 동일한 경우에는 최소저항선 거리와 자유면의 수에 의해 발파진동이 결정되는 것으로 알려져 있다. 그러나 터널 발파에서는 최소저항선거리와 자유면의 수 외에 자유면의 크기가 발파진동의 크기를 결정하는 주된 요소로 작용하게 된다. 본고에서는 자유면의 크기가 발파진동에 미치는 영향을 고찰하여 터널발파의 진동제어방법을 제시하였다.

• Journal of Industrial Technology
• /
• v.21 no.A
• /
• pp.263-271
• /
• 2001

Blast-vibration tests were carried out to determine the effects of the number of free face on the level of blast vibration. Frequency chatacteristics were also examined by using FFT analysis. To check the effects of the number of free face, charge weight per delay, drilling length, burden and space were applied uniformly and the number of free face was only changed from one to four. The results from tests were checked by regression analysis and K-value.

• Explosives and Blasting
• /
• v.22 no.3
• /
• pp.27-33
• /
• 2004

Particle Velocity Equations were suggested in this paper for Korean surface blasting types, which were developed by Korean Society for Explosive Engineers (KSEE). Standard charges per delay for types and distances also were determined. USBM equation which was adopted by MOCT (Korean Ministry of Construction and Transportation) shows many problems for Korean situations.

• Explosives and Blasting
• /
• v.19 no.1
• /
• pp.31-40
• /
• 2001

일반적으로 장공발파(長孔發破) 방법(Long hole blasting method)은 그동안 주로 대규모 채탄막장이나 댐 기초굴착, 광산 등에서 행하여져 왔으나 최근 토목터널에서 시공 효율성 및 경제성을 목적으로 관심이 높아지고 있다. 기존의 터널설계 패턴은 I -Type을 기준으로 3.5~3.8m 천공이며 신공법 적용시 최대 4.Om까지 설계되는 것이 보통이었다. 과거 착암장비는 천공장이 늘어남으로서 슬러지에 의한 천공속도가 저하되어 천공비가 증가하기 때문에 빠른 슬러지 배제가 필요하고 Rod의 휨 현상에 의한 천공오차의 증대를 초래할 수 있는 단점이 있었다. 그러나 최근 장비의 발달로 인하여 천공각도 및 천공장 등을 Computer로 모니터링하여 제어할 수 있어 정밀한 천공이 가능하여 졌고 또한, 고성능 에멀젼계 폭약(Super Emulsion)의 개발로 그동안 극 경암터널에서 에멀젼계 폭약의 단점으로 여겨졌던 비 장약량의 증대와 사압현상의 발생, 굴진효율 저하문제론 극복할 수 있었다. 따라서 본 연구는 현재 건설중인 대상현장을 중심으로 장공 터널발파의 효율성과 경제성을 분석하고 나아가 암질에 따른 새로운 Type별 설계기준을 마련하는 기초자료로서 활용하고자 하였다. 된 연구의 대상현장은 충북 괴산군 영풍면 소재 중부내륙(여주-구미간) 고속도로 제 9공구 이화터널 건설공사현장으로 $\varphi{102mm}$ 무 장약공 Cylinder 4공을 이용한 심발법을 사용하였으며 천공장은 최대 5.0m로 2000년 11일 15일에서 동년 12월 15일까지 31일간 총 112회의 시험발파를 실시하여 평균 92%의 높은 굴진 효율을 기록하였다.

• Tunnel and Underground Space
• /
• v.9 no.1
• /
• pp.12-19
• /
• 1999

In this study, ground vibrations of a surface blasting for golf links and a tunnel blasting for highway construction were measured to investigate the effect of blasting conditions such as total charge and distance from blasting point. In surface blasting, site factor K and n were 74.1 and -1.37, respectively, which were analyzed by means of cube root scaled distance. The more were measuring distance, the higher were absolute value of K and n. Principal frequency was in range of 5~60 Hz in surface blasting, where that of 80 percent was in range of 10~30 Hz. On the other hand it was in range of 25~98 Hz in tunnel blasting, which showed higher than of surface blasting.

• Korean Journal of Weed Science
• /
• v.4 no.1
• /
• pp.79-87
• /
• 1984

Herbicidal effects of alachlor to peanuts were observed under different formulations (granule containing 5.0% a.i. and emulsifiable concentrate containing 43.7% a.i.) and levels (granule with 3 and 6kg/l0a and emulsion with 300㏄/l0a) with the transparent polyethylene (P.E.) film mulching. Formulations and levels of alachlor did not affect emergence ratio, time of emergence and flowering, and early growth of peanuts such as the number of leaves and branches, length of branches; and shoot dry weight at 20 and 40 days after planting, but early growth was enhanced by P.E. film mulching. At harvest, weed dry weight was positively correlated with length of branches, but negatively correlated with the number of branches and shoot dry weight. Acalyphu australis and Chenopodium album were not effectively controlled by the application of alachlor and growth of C. album was retarded under P.E. film mulching. Portulaca oleracea and Digitaria sanguinalis were effectively controlled by alachlor, but they were not affected by P.E. film mulching. At harvest, D. sanguinalis, A. australis, and Echinochloa crus galli were predominant weeds in all treatments; persistence of alachlor may not be long enough to control even sensitive weeds to alachlor such as D, sanguinalis in the field of peanuts of which canopy development was relatively slow. Weed dry weight at harvest was negatively correlated with the number of pods and grain yield of peanuts. Among the yield components only the number of nods per plant was positively correlated with grain yield. Hana weeding after July 1 increased grain yield of Peanuts even in alchlor applied plots.