• Title, Summary, Keyword: Deck Charge

Search Result 24, Processing Time 0.046 seconds

Comparison of Blast Fragmentation Efficiencies from Conventional Bench and Double Air Deck Charge Blast Methods in Limestone Mine (석회석 광산에서 기존 일반발파와 이중분상 Air Deck 발파공법의 비교연구)

  • Kang, Dae-Woo;Hur, Won-Ho;Yang, Kook-Jung;Park, Dong-Chul
    • Explosives and Blasting
    • /
    • v.29 no.2
    • /
    • pp.13-31
    • /
    • 2011
  • Air deck charge blast methods have been applied to improve the fragmentation in open cut bench blastings for mining developments. However, during large scale bench blasting operations, there exist some problems such as boulder productions due to explosive charge concentration. Especially, in case of lime stone mining, when air deck method is applied, there has been unintentionally concentrated on charging because the inside holes are often broken by erosion and decomposition. In this study, compared with general blasting, air deck blasting has been focused in lime stone mining. In other to maximize its efficiency, inside hole was examined by endoscope in advance and deck charge using air tube was applied to the section in which concentration might be taken place. Blasting efficiency, fragmentation, charging reduction rate, and total working hours (from charging to blasting) were the main object for comparing, and as a result, air deck was more efficient then the general blasting in all aspects except total working hours.

Numerical Analysis on Controlled Tunnel Blasting by Heck Charge (다단 장약에 의한 터널 진동제어 발파의 수치해석)

  • 양형식;두준기;조상호;김원범
    • Tunnel and Underground Space
    • /
    • v.13 no.5
    • /
    • pp.403-411
    • /
    • 2003
  • Controlled tunnel blasting by deck charge was suggested and simulated by PFC and FEM analyses. Analyzed results showed that suggested method is efficient in fragmentation and able to decrease in vibration level because of decreased amount of charge per delay and dispersion of deck charge. This phenomena was explained by failure mechanism and proved that it can be successfully applied to tunnel blasting.

A Study on the Efficiency of Horizontal Direction Deck-charge Blasting Method Using Electronic Detonator (전자뇌관을 이용한 수평방향 데크차지 발파공법의 효율성검토 연구)

  • Yoon, Ji-Sun;Hahn, Suk-Ju;Bae, Sang-Hun
    • Journal of the Korean Geotechnical Society
    • /
    • v.29 no.4
    • /
    • pp.5-11
    • /
    • 2013
  • In close to downtown construction, the main problem is complaints caused by blasting vibration and noise. To reduce blasting vibration and noise, deck-charge blasting method using electronic detonator can be more secure because there is no cut-off problem. And in this method it is possible to blast in horizontal direction. In this study, the efficiency of horizontal direction deck-charge blasting method using electronic detonator is compared to that of the existing blasting method. And the possibility of applying the construction site is evaluated. As a result, the reduction of blasting vibration, noise and secondary breaking has been determined, as well as large-scale blasting in the vibration criterion can be regulated by the overall increase in blasting efficiency.

Electronic Blasting Case Study Method Using Deck Charge (분상장약공법을 이용한 전자발파 시공사례)

  • Kim, Gab-Soo;Son, Young-Bok;Kim, Jae-Hoon;Choi, Hyung-Bin
    • Explosives and Blasting
    • /
    • v.33 no.1
    • /
    • pp.27-34
    • /
    • 2015
  • Recently, the residence complaints have been increased by blast vibration and noise issue due to increased urban blasting works so that the trouble between construction company and residence have been continuously increased. Deck-charge blasting method using electronic detonator provided not only blast vibration and noise control but also minimized residence complaints through shortening of the blasting period. This blasting method will be widely used for maximizing urban blasting productivity.

Application of Electronic Deck Charge Blasting Method to a Vertical Shaft Excavation (수직구 굴착시 전자뇌관을 이용한 Deck-Charge 발파 시공사례)

  • Kim, Jae-Hong;Kim, Hee-Do;Lee, Jun-Won;Kim, Gab-Soo;Son, Young-Bok;Kim, Jae-Hoon
    • Explosives and Blasting
    • /
    • v.31 no.1
    • /
    • pp.64-75
    • /
    • 2013
  • This case study deals with an excavation blasting carried out at "Sooseo-Pyeongtek ${\bigcirc}$-${\bigcirc}$ section construction site" in the vicinity of residential area. Originally, the sequential blasting (multi-stage blasting) using electric detonators was planed in this area. However, there was a concern that the sequential blasting method could increase the construction cost by delaying the construction period due to possible complaints from local residents. As an alternative, electronic deck blasting technique was taken in order to meet the ground vibration regulation (0.2cm/s, in apartment area) and to keep the construction schedule. The performance of the electronic deck charge blasting was two times better than the sequential blasting with electric detonators and the level of ground vibration was also within the regulatory value (0.2cm/s). In particular, it was shown that the use of electronic detonater eDevII, which was developed for tunnel, could provide more convenient and electrically safer working condition.

A Numerical Study on Pressure Variation Characteristics in Blasthole by Air-Deck (에어데크 적용 시 발파공 내 압력변화 특성에 대한 수치해석)

  • Kang, Dae-Woo;Hur, Won-Ho
    • Explosives and Blasting
    • /
    • v.29 no.1
    • /
    • pp.1-9
    • /
    • 2011
  • Air deck charge blasting method which has been generally used in a surface mine and large scale developing site is one of the improved techniques with blasting effectiveness. Many studies and experiments have been tried to investigate the characteristics of pressure distribution in a blasting hole and increase the effectiveness of air deck charge blasting method. In this study, changes of pressure occurred in sections of air deck installed in various ways was computed and also changes of pressure with the location and length of air deck was analyzed, using numerical analysis program. Basically, all the numerical analysis was 2-Dimensional analysis and equation of status of explosives was JWL-EOS. Only to evaluate the variations of pressure in blast hole, it was assumed that rock mass is homogeneous but rock mass has different density and intensity.

A Case Study on the Application of Self Supporting Air Tube (자립형 에어튜브의 현장적용에 관한 사례연구)

  • Lee, Shin;Kang, Dea-Woo
    • Tunnel and Underground Space
    • /
    • v.17 no.4
    • /
    • pp.248-254
    • /
    • 2007
  • Already, the air deck blasting method has been used to take many advantages of blasting. In the existing air deck blasting method, air deck is made usually on column charge. But in the case study, we analyzed about the effect of self supporting air tube which made air deck in column charge. As results of this case study, it was shown that blasting vibration was decreased about $20{\sim}26%$ and quantity of explosive was decreased about $10{\sim}20%$. Also, fragmentation was shown to be smaller than it of common blasting method.

A Case Study of Deck-Charge Blasting Using Electronic Blasting Systems In Urban Area (분산장약공법을 이용한 도심지 전자발파 시공사례)

  • Son, Young-Bok;Kim, Gab-Soo;Kim, Jae-Hoon
    • Explosives and Blasting
    • /
    • v.34 no.3
    • /
    • pp.21-26
    • /
    • 2016
  • In case of urban blasting works at near neighbors, the size of one blasting should be minimized to reduce the vibration and noise. However, the complaints is not decreased due to increased numbers of blasting per day so that the period of blasting works become long. This case study is related to urban apartment construction site. In order to overcome the weakness of general detonators which is required many blasting times to meet the day productivity, we have been applied deck-charge blasting method using electronic detonators and then we successfully increased the day productivity with much less blasting times. Hence, we had effectively achieved the declined neighbors'complaints and shortening construction period.

A Study on the Development of the Rock Blastability Classification and the Methods for Minimizing Overbereak in Tunnel (터널 굴착면 여굴 최소화를 위한 발파암 분류(안) 및 공법 개발 연구)

  • 이태노;김동현;서영화
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • /
    • pp.303-310
    • /
    • 2002
  • Overbreak occurred inevitably in a tunnel excavation, Is the main factor for increasing cost and time in tunnel projects. Furthermore the damage to the remained rock mass related to the overbreak can give rise to a serious safety problem in tunnels. As a rule of thumb, causes for the overbreak are inaccuracy in drilling, the wrong design of blasting and selection of explosives, and heterogeneity in rock mass. Specially, the geological features of the rock mass around periphery of an excavation are very important factors, so a lot of researches have been conducted to describe these phenomena. But the quantitative geological classification of the rock mass for the overbreak and the method for decreasing the amount of the overbreak have not been established. Besides, the technical improvement of the charge method is requested as explosives for the smooth blasting have not functioned efficiently. In this study, the working face around periphery of an excavation has been continuously sectionalized to 5∼6 parts, and the new Blastability Index for the overbreak based on 6 factors of RMD(Rock Mass Description), UCS(Uniaxial Compressive Strength) JPS(Joint Plane Spacing), JPO(Joint Plane Orientation), JPA(Joint Plane Aperture) and FM(Filling Material) is proposed to classify sections of the working face. On the basis of this classification, the distance between contour holes and the charging density are determined to minimize the overbreak. For controlling the charging density and improving the function of explosives, the New Deck Charge(N.D.C) method utilizing the deck charge method and detonation transmission in hole has been developed.

  • PDF

Failure Modeling of Bridge Components Subjected to Blast Loading Part II: Estimation of the Capacity and Critical Charge

  • Quintero, Russ;Wei, Jun;Galati, Nestore;Nanni, Antonio
    • International Journal of Concrete Structures and Materials
    • /
    • v.1 no.1
    • /
    • pp.29-36
    • /
    • 2007
  • The purpose of this paper is the assessment of the capacity of the reinforced concrete (RC) elements of an arch bridge when they are subjected to contact and near-contact explosive charges of various amounts, and the estimation of the critical charges for these components. The bridge considered is the Tenza Viaduct, a decommissioned structure south of Naples, Italy. Its primary elements, deck, piers and arches were analyzed. The evaluation was accomplished via numerical analyses that made possible to obtain the elements dynamic response when they are exposed to blast loading conditions. To evaluate the member's capacities, failure criteria for deck, piers and arches were proposed based on concrete damage parameters. Additionally, curves relating the explosive charge to the residual capacity and to damage level of the elements were also developed. The results of this work were taken into account to investigate the progressive collapse of the global structure.