• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.161-162
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• 2010

In this study, the impact load on concrete compression member was considered to assess the quantitative damage index. The case study was carried out using the LS-DYNA, on explicit finite element analysis program. The parameters for the case study were impact load angle, slenderness ratio, etc. Using the analysis results, the performance based design method for impact load was developed using Bayesian probabilistic method, which can be applied to reinforced concrete column design for impact loads.

• Explosives and Blasting
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• v.14 no.1
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• pp.49-63
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• 1996

Blasting is a work that destruct an object by use of explosive. Its use covers a wid range, and it is applicable to blast the rocks, minerals, coal, steel and concrete structures, bridges, etc. To execute the blast plan most effectively, the properties of the object and the explosives should be well understood, and all the other conditions must ve incorporated in its design and plan. A safe blasting pattern and procedure should be selected considering the envirinmental effects and dther conditions. At the same time, a protective protective pricedures should be utilized to prevent the safety hazards such as the excessive blast vubration, air pressure, and the flying fragments. This study reviews the controlled blasting techniques in these regards.

• Journal of Korean Association for Spatial Structures
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• v.23 no.1
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• pp.25-34
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• 2023

This paper presents a computational fluid dynamics (CFD) analysis to investiagate the effect of expansion chamber on overpressure reduction in protective tunnels subjected to detonation of high explosives. A commercial CFD code, Viper::Blast, was used to model the blast waves in a protective tunnel with a length of 160 m, width of 8.9 m and height of 7.2 m. Blast scenarios and simulation matrix were establihsed in consideration of the design parameters of expansion chamber, including the chamber lengths of 6.1 m to 12.1 m, widths of 10.7 m to 97 m, length to width ratios of 0.0 to 5.0, heights of 8.0 m and 14.9 m, and ratios of chamber to tunnel width of 1.2 to 10.9 m. A charge weight of TNT of 1000 kg was used. The mesh sizes of the numerical model of the protective tunnel were determined based on a mesh convergence study. A parametric study based on the simulation matrix was performed using the proposed CFD tunnel model and the optimized shape of expansion chamber of the considered tunnel was then proposed based on the numerical results. Design recommendations for the use of expansion chamber in protective tunnel under blast loads to reduce the internal overpressures were finally provided.

• Explosives and Blasting
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• v.28 no.2
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• pp.108-118
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• 2010

Soongeui complex stadium is a reinforced concrete frame structure composed of columns, slabs and beams. The stadium, however, is also a special structure because it has a tall tower of electronic display board and slabs inside its own structure which is different from the structures that had been demolished using blasting by then. Explosive demolition for the stadium was carried out from the left-hand side of the outfield stand to the right considering 2 rows of columns supporting the stand as a blasting unit. An overturning demolition method was applied to the tower of electronic display board. Water bags that played the role of multipurpose protection were applied to control the dust. As a result, the demolition project of the special structure of Soongeui complex stadium was judged to be a great success.

• Explosives and Blasting
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• v.23 no.3
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• pp.83-89
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• 2005

It follows in deterioration of the steel frame structure and becomes remodeling and removal. The construction work characteristic, economical efficiency and stability environment characteristic are planned and considered hereafter control plan of the steel frame structure which is deteriorated currently to cutting mettled plentifully sued on gas cutting of H beam. However it will not be able to apply from the explosives demolition which is makes a weak instantaneously and then collapses the building at the time. In this study, shape charge was used for cutting of the H-beam. That is the element testing to estimate explosives demolition for steel frame structure. As a result, it is found for single-side rutting method, both-sides rutting methods by H-beam thickness and pre-rutting process. It confirmed an affix method and an ease characteristic by fixing tool. Also, it is shown that air blasting decreased about 8dB(A) in order to reduce air blasting used by sand box. However, it will be required to reduce air blasting little more because explosives demolition will be done in urban site.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.35-43
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• 2006

In this paper, procedures and research results involved in the development of glass reinforced composite bridge deck of hollow section were presented. Laminate design for the 3 cell deck section was performed. Structural characteristics such as serviceability, strength, failure and stability for DB24 load were analytically studied through the finite element analysis for the composite deck plate girder bridge. Composite deck tube was fabricated with pultrusion and extensive tests such as flexural test, girder-connection test, barrier-connection test, compression fatigue test and flexural fatigue test were carried out to evaluate structural behavior experimentally. Also, field load test was conducted for the demonstration plate girder bridge with composite deck and requirements for the strength and serviceability were reviewed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.141-147
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• 2010

Liquefied natural gas(LNG) is natural gas that has been converted temporarily to liquid form for ease of storage and transport it. Natural gas is the worlds cleanest burning fossil fuel and it has emerged as the environmentally preferred fuel of choice. In Korea, the demand of this has been increased since the first import from the Indonesia in 1986. LNG takes up about 1/600th the volume of natural gas in the gaseous state by cooling it to approximately $-162^{\circ}C(-260^{\circ}F)$. The reduction in volume therefore makes it much more cost efficient to transport and store it. Modern LNG storage tanks are typically the full containment type, which is a double-wall construction with reinforced concrete outer wall and a high-nickel steel inner tank, with extremely efficient insulation between the walls. The insulation will be installed to LNG outer tank for the isolation of cryogenic temperature. The insulation will be installed in the base slab, wall and at the roof. According to the insulation's arrangement, the different aspects of temperature transmission is shown around the outer tank. As the result of the thermal & stress analysis, by the installing cellular glass underneath the perlite concrete, the temperature difference is greatly reduced between the ambient temperature and inside of concrete wall, also reducing section force according to temperature load.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.426-433
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• 2019

After an earthquake, fire and gas explosions are more likely to cause more casualties in cities with many apartment buildings and large complex buildings. In order to prevent this, seismic design is necessary for the fire protection sprinkler system. However, most systems currently use stainless-steel pipes, although synthetic resin pipes are used in some special places. These materials are susceptible to vibration and earthquakes. This study evaluated the displacement absorption flexibility of polyethylene (PE) and aluminum (Al) multi-layered composite pipes to increase the seismic performance in a vibration environment and during earthquakes. The seismic performance was compared with that of a stainless-steel and PE pipes. The seismic characteristics can be measured by measuring the amount and extent of vibration transmitted by the sprinkler pipe. This method can be used to judge the seismic characteristics to attenuate the vibration during an earthquake. The seismic characteristics of the pipe were verified by comparing the logarithmic attenuation rate to the initial response displacement of the vibration generated by the transverse vibration measurement method.

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.49-55
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• 2001

This paper presents the design safety analysis of the inner tank structure, which is manufactured by 9 percent nickel steel sheets in the full containment type LNG storage tank. The FEM computed results indicate that top girder and several stiffener rings of the inner tank play an important role for controlling the deformation and stress intensity of the inner tank structure. The hydrostatic pressure due to cryogenic fluids gave more influential to the deformation of the inner tank wall compared with that of a cryogenic temperature of $-162^{\circ}C$. But, the deformation and stress of the inner tank. which is produced by the buckling loads, are very small because the external load is not applied to the top of the inner tank. This indicates the role of top girder and stiffener rings of the inner tank model is not important in full containment LNG storage tank.

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.85-91
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• 2001

This paper presents safety analysis of LNG leakage in a prestressed concrete outer tank, which is strongly related on the leak checking effects of the PC structure with and without a residual compression zone based on the BS 7777 codes. The full containment type outer tank which is constructed by a prestressed concrete may be destroyed by leaked cryogenic fluids. The FE calculated results show that the total leak checking time of the PC structure with $10\%$ residual compression zone is about 9 days for $-162^{\circ}C$ liquids. But, three primary pumps in an inner tank may operate to send cryogenic fluids for 6 days, which are stored in an inner tank of $140,000m^3$ capacity This means that the prestressed concrete outer tank may be safe for $-162^{\circ}C$ cryogenic fluids leaked from the demolished inner tank.