• Journal of Welding and Joining
• /
• 제20권4호
• /
• pp.551-556
• /
• 2002

Solid particle erosion wear characteristics of high Cr white iron hardfacing were investigated using the erosion wear test method according with the ASTM G76-95. Wear experiments, where the blast angle, blast distance and blast pressure were selected as test variables, were planned and analyzed by response surface method (RSM to evaluate the wear loss statistically and quantitatively. The measured wear losses well coincided with the calculated ones by the experimental equation. The wear loss of high Cr cast iron hardfacing was increased with blasting pressure, but affected in a complicated way by the blasting angle and distance. Erosion wear of high Cr cast iron hardfacing could be well predicted by RSM analysis of wear variables.

• Geomechanics and Engineering
• /
• 제15권6호
• /
• pp.1227-1236
• /
• 2018

From all of the environmental problems, blast-induced vibrations often cause concern to surrounding residents. It is often claimed that damage to building superstructures is due to blasting, and sometimes the building owner files a lawsuit against the company that perform blasting operations. The blast-vibration problem has been thoroughly investigated in the past and continues to be the subject of ongoing research. In this study, a tunnel construction has been performed by a construction company, according to their contract they must have used drilling & blasting method for excavation in tunnel inlet and outlet portal. The population is very condensed with almost tunnel below in the vicinity houses of one or two floors, typically built with stone masonry and concrete. This situation forces the company to take extreme precautions when they are designing blasts so that the blast effects, which are mainly vibration and aerial waves, do not disturb their surrounding neighbors. For this purpose, the vibration measurement and analysis have been carried out and a new methodology in minimizing the blast induced ground vibrations at the target location, was also applied. Peak particle velocity and dominant frequencies were taken into consideration in analyzing the blast-induced ground vibration. The methodology aims to employ the most suitable time delays among blast-hole groupings to render destructive interference of surface waves at the target location.

• Structural Engineering and Mechanics
• /
• 제66권6호
• /
• pp.713-727
• /
• 2018

Thin-walled mental tubes under lateral crushing are desirable and reliable energy absorbers against impact or blast loads. However, the early formations of plastic hinges in the thin cylindrical wall limit the energy absorption performance. This study investigates the energy absorption performance of a simple, light and efficient energy absorber called the ring stiffened tube. Due to the increase of section modulus of tube wall and the restraining effect of the T-stiffener flange, key energy absorption parameters (peak crushing force, energy absorption and specific energy absorption) have been significantly improved against the empty tube. Its potential application in the offshore blast wall design has also been investigated. It is proposed to replace the blast wall endplates at the supports with the energy absorption devices that are made up of the ring stiffened tubes and springs. An analytical model based on beam vibration theory and virtual work theory, in which the boundary conditions at each support are simplified as a translational spring and a rotational spring, has been developed to evaluate the blast mitigation effect of the proposed design scheme. Finite element method has been applied to validate the analytical model. Comparisons of key design criterions such as panel deflection and energy absorption against the traditional design demonstrate the effectiveness of the proposed design in blast alleviation.

• 한국군사과학기술학회지
• /
• 제8권4호
• /
• pp.120-129
• /
• 2005

To analyze a blast effect of developed explosives, three different kinds of aluminized tastable explosives and melted cast explosive TNT were used. Conventional explosive TNT was used as a reference. Each tested explosive charge of 340mm diameter spherical type was initiated at the charge center with DXD-65(${\sim}750g$) booster and RP-87 EBW detonator. Thirteen piezo type pressure sensors were located at a range from 4 to 50m away from the charge. From the blast wave profiles, we calculated a peak blast pressure and impulse of the explosion. The calculated pressures and in pulses were converted to TNT Equivalent Weight(TEW) factor by the scaling ]aw method. The average TEW factors based on the blast pressure of TX-01, TX-02, TX-03, TX-04 were 1.298, 1.05, 1.266, 1.274 and the average TEW factors based on impulse were 1.504, 1.686, 1.640, 1.679. From the results, we concluded that TEW factors based on blast pressure and based on impulse of aluminized explosives were superior to TNT. This results are owing to the high contents of aluminum in formulations.

• 한국구조물진단유지관리공학회 논문집
• /
• 제26권5호
• /
• pp.151-160
• /
• 2022

최근 폭발사고의 빈도수가 증가함에 따라 주요 구조부재의 손상을 저감시킬 수 있는 방호 구조물 설계에 대한 관심이 높아지고 있다. 그러나, 방호 구조물의 방호성능에 대한 국내 연구는 아직 미진한 실정이며, 아직 설계 가이드라인도 충분히 갖추어지지 못한 실정이다. 따라서, 본 연구에서는 FRP 시트 보강유무를 변수로 하여 RC 방호벽에 대한 해석적 연구를 수행하였다. 해석은 LS-DYNA 프로그램을 활용하여 수행되었으며, 해석을 통해 RC 방호벽과 FRP 시트로 보강된 RC 방호벽의 변위-시간이력곡선, 압력-충격량 도표, 취약도 곡선을 도출하였다. FRP 시트 보강방법은 RC 방호벽의 방호성능을 향상시키는데 매우 효율적인 것으로 나타났다. 또한, 폭발하중의 크기가 클수록 RC 방호벽에 대한 FRP 시트의 보강효과는 높아지는 것으로 나타났다.

• 한국전산구조공학회논문집
• /
• 제37권1호
• /
• pp.1-8
• /
• 2024

본 논문에서는 확률론적 처리기법을 적용하여 플랜트 시설물의 폭발 재현주기에 따른 폭발 위험도를 분석하였다. HSE에서 제공하는 누출 데이터, DNV에서 제시한 플랜트당 연간 누출 빈도, 다양한 연구진이 제시한 점화 확률을 고려하여 누출량에 따른 폭발 재현주기를 산정하였다. 산정된 폭발 재현주기를 통해 폭발 위험도를 증기운의 부피 및 반경, 폭발하중에 대하여 평가하였다. 재현주기에 따른 증기운의 반경과 과거 실제 증기운 폭발 사례, 내폭설계 가이드라인을 비교 분석하여 설계폭발하중 모델을 위한 기준거리를 제시하였다. 멀티에너지법을 통하여 폭발 재현주기에 따른 폭발하중의 범위를 분석하였으며, 설계폭발하중 모델의 기준이 되는 재현주기를 제안하였다. 본 연구의 결과로 플랜트 시설물에 대한 성능기반 내폭설계의 간략한 표준안으로 활용이 가능하다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
• /
• pp.761-766
• /
• 2002

This paper was peformed to verify the effect that granulated blast furnace slag gets in reinforcement corrosion resistance about chloride ion that invade from outside. An experiment accelerated for the reinforcement corrosion through repeat of brine digestion and dry. Reinforcement corrosion investigated half cell potential method of measurement by ASTM C876 and corrosion area ratio. If granulated blast furnace slag metathesis ratio is high generally that looked the corrosion of reinforcement decreasing as a result that evaluate reinforcement corrosion by ASTM C876 canon in this research. It showed high resistance about reinforcement corrosion that use normal portland cement and increase the metathesis rate of granulated blast furnace slag, as a result that evaluate metathesis rate effect of granulated blast furnace slag according to cement kind. when the test piece split destroying, area rate of reinforcement corrosion showed about result of half cell potential measurement.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2004년도 추계 학술대회논문집
• /
• pp.91-94
• /
• 2004

A numerical analysis was made to investigate the intensity diminution of a simple silencer for high pressure blast flow fields. Reynolds-Averaged Wavier-Stokes equations were solved for an axisymmetric computational domain constructed by multi block Chimera grids. A blast flow field without the silencer was also calculated to validate the present numerical method. The evolution of high pressure blast flow fields was observed by depicting calculated contours of pressure and Mach number. It was found that the tested silencer could achieve 76 percent intensity diminution.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2003년도 학술.기술논문 발표회
• /
• pp.5-8
• /
• 2003

As a part of efforts to obtain high quality and economical efficiency of concrete, blast-furnace slag has been utilized by means of cement replacement. Therefore superior performance can be ensured, environmental pollution can be prevented and economical advantage can be obtained with utilization by cement replacement. But the studies on the blast-furnace slag are not systematic and reasonable. So, it was planed that basic data in regard to technique of manufacturing and economic improvement of concrete is showed with experimental comparison and investigation of engineering properties of concrete utilizing blast-furnace, industry by-product, as cement replacement in this study.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2003년도 학술.기술논문발표회
• /
• pp.5-8
• /
• 2003

As a part of efforts to obtain high quality and economical of efficiency of concrete, blast-furnace slag has been utilized by means of cement replacement. Therefore superior performance can be ensured, environmental pollution can be prevented and economical advantage can be obtained with utilization by cement replacement. But the studies on the blast-furnace slag are not systematic and reasonable. So, it was planed that basic data in regard to technique of manufacturing and economic improvement of concrete is showed with experimental comparison and investigation of engineering properties of concrete utilizing blast-furnace, industry by-product, as cement replacement in this study.