• Journal of the Korea Concrete Institute
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• v.19 no.1
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• pp.103-111
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• 2007

Experimental study was carried out to investigate the structural performance of composite beams with steel fiber concrete and angle. For this purpose, seven specimens composed of two RC beams with or without steel fiber and five composite beams with steel fiber and angle were constructed and tested. All specimens had no web shear reinforcement. Main variables for the specimens were tensile reinforcement ratio and fiber volume fraction. Based on the test results, structural performance such as strength, stiffness, ductility and energy dissipation capacity was evaluated and compared with the predicted strength. The prediction of flexure and shear strength gives a good relationship with the observed strength. The strength, ductility and energy dissipation capacity are increased, as the fiber volume fraction is increased. Meanwhile, high tensile reinforcement ratio resulted in the reduction of ductility and energy dissipation capacity for the composite beams.

• Journal of Korean Society of Steel Construction
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• v.22 no.4
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• pp.313-324
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• 2010

In this study, an unbraced five-story steel-framed structure was designed in accordance with KBC2005 to understand the features of structural behavior for the arrangement of semi-rigid connections. An inelastic time history analysis of structural models was performed, wherein all the connections were idealized as fully rigid and semi-rigid. Additionally, horizontal and vertical arrangements of semi-rigid connections were used for the models. A fiber model was utilized for the moment-curvature relationship of a steel beam and a column, a three-parameter power model for the moment-rotation angle of the semi-rigid connection, and a three-parameter model for the hysteretic behavior of a steel beam, column, and connection. The base-shear force, top displacement, story drift, required ductility for the connection, maximum bending moment of the column, beam, and connection, and distribution of the plastic hinge were investigated using four earthquake excitations with peak ground acceleration for a mean return period of 2,400 years and for the maximum base-shear force in the pushover analysis of a 5% story drift. The maximum base-shear force and story drift decreased with the outer vertical distribution of the semi-rigid connection, and the required ductility for the connection decreased with the higher horizontal distribution of the semi-rigid connection. The location of the maximum story drift differed in the pushover analysis and the time history analysis, and the magnitude was overestimated in the pushover analysis. The outer vertical distribution of the semi-rigid connection was recommended for the base-shear force, story drift, and required ductility for the connection.

• Journal of Korean Society of Steel Construction
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• v.11 no.4 s.41
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• pp.425-433
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• 1999

Structural analysis and design of steel frames is usually conducted under the assumption that beam-to-column connections are either fixed or pinned. In reality, each connection possesses a certain rotational stiffness. In this study, structural analysis program is developed, which takes into account the nonlinear behavior of framed structures including flexibility of semi-rigid connections and member geometric nonlinearity. Effective semi-rigid connections for a 6-story unbraced steel frame are suggested and the effect of flexible connections on the behavior of the structure are studied.

• Magazine of the Korea Concrete Institute
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• v.2 no.4
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• pp.53-60
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• 1990

Investigations on the behavior of steel fiber reinforced high strength concrete beams with shear confinement are accomplished to determine their ultimate shear strength including diagonal tension strength. The parameters varied were the shear confinement ratio(Ps), and fiber volume fraction(Vs). Ultimate shear strength increased significantly in steel fiber reinforced concrete beam without shear confinement. In steel- fiber reinforced high strength concrete beams with shear confinement, there is no increase of ultimate shear strength but shows much beneficial effects of Ductility Capacity.

• Journal of the Korean GEO-environmental Society
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• v.10 no.3
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• pp.47-52
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• 2009

The comparative analysis on physico-chemical characteristics of municipal solid waste from dwelling site and landfill site were performed to provide the fundamental information of waste management in Chungju city. It was analysed and evaluated the bulk density, physical component, three major component, chemical component, and heating value of MSW. The physical components depended on the sampling site in dwelling site and landfill site. But, by the ultimate analysis, the chemical composition was almost similar to result for municipal solid waste from dwelling site and landfill site. Therefore, it is necessary to investigate the physical components according to sampling site for the MBT to introduce for combustible municipal solid waste pre-treatment, but it needs the chemical composition from landfill site to design the incinerator. The physical composition showed that the combustible and the noncombustible occupied 87.4% and 12.6% respectively. In case of three component analysis, the moisture, the combustible, and the ash were 27.6, 60.5, 11.9% respectively. The chemical composition through the element analysis were C (50.1%), H (6%), O (39.5%), N (1.9%), S (0.5%), and Cl (1.3%).

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.2
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• pp.169-178
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• 2016

The properties of wastes for melting need to be considered to minimize the maintenance of refractory and to discharge the molten slags smoothly from a plasma torch melter. When the nonflammable wastes from nuclear facilities such as concrete debris, glass, sand, etc., are melted, they become acid slags with low basicity since the chemical composition has much more acid oxides than basic oxides. A molten slag does not have good characteristics of discharge and is mainly responsible for the refractory erosion due to its low liquidity. In case of a stationary plasma torch melter with a slant tapping port on the wall, a fixed amount of molten slags remains inside of tapping hole as well as the melter inside after tapping out. Nonmetallic slags keep the temperature higher than melting point of metal because metallic slags located on the bottom of melter by specific gravity difference are simultaneously melted when dual mode plasma torch operates in transferred mode. In order to minimize the refractory erosion, the compatible refractories are selected considering the temperature inside the melter and the melting behavior of slags whether to contact or noncontact with molten slags. An acidic refractory shall not be installed in adjacent to a basic refractory for the resistibility against corrosion.

• Journal of the Korean Geotechnical Society
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• v.39 no.3
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• pp.5-16
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• 2023

The effect of raft flexibility on piled raft foundations in sandy soil was investigated using a numerical analysis and an analytical study. The investigation's emphasis was the load sharing between piles and raft following the raft rigidity (K_R), end-bearing conditions. The case of individual piles and subsequently the response of groups of piles was analyzed using a 3D FEM. This study shows that the α_pr, load-sharing ratio of piled raft foundations, decreases as the vertical loading increases and as the K_R decreases. This tendency is more obvious when using friction piles compared to using end-bearing piles. The effect of raft rigidity is found to be more significant for the axial force distribution - each pile within the foundations has almost similar axial forces of the pile head with a flexible raft; however, each pile has different values with rigid rafts, especially with the end-bearing piles. The axial force of the pile base with floating piles shows similar point-bearing resistance for all the piles; however, it shows different values with end-bearing piles. The differential settlement ratio of rafts showed a larger value with lower K_R.

• Journal of the Korean Institute of Gas
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• v.22 no.5
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• pp.46-52
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• 2018

Interest in fire prevention/fighting has been increased by large fire. It is important to install/manage the detector, alarm, firefighting facility, evacuation route and so on to minimize the damage from fire. Chemical plant is generally constructed by steel structure. So fireproofing is significantly required to chemical plant because steel structure should endure during fire. Currently, fireproofing should be applied up to 6m from ground by local regulation. But chemical plant can handle the large amount of flammable materials or only non-flammable materials. Required of fireproofing height by fire magnitude is studied in this thesis.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.190-197
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• 2016

Flash point is the one of the important properties for the safe handling of inflammable liquid solution. In this paper, flash points of binary liquid solutions, water+1-propanol and water+2-propanol, were been measured by using Seta flash closed cup aparatus. Flash point was estimated using regression analysis method. Flash points were also estimated by the method based on Raoul's law and the method optimizing the binary parameters of van Laar equation. Experimental results were compared with the calculated results. The regression analysis method is able to estimate the flash point fairly well for water+1-propanol and water+2-propanol mixture.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.210-210
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• 2013

본 연구는 산림 내 시설물의 산림환경 특성 분석을 위하여 2013년 3월 9일부터 10일 이틀 동안 280ha의 산림 피해면적과 57동의 시설물 피해를 준 울주산불에 대하여 현장조사를 실시하였다. 조사 대상물은 주택 15개소, 비닐하우스 1개소, 축사3개소 등 총 19개소에 대하여 2013년 3월부터 5월까지 현지조사를 실시하였다. 조사항목은 시설물의 입지여건, 임상분포, 주변 산불인자, 시설물 외벽구조제, 산불 등 화재진화를 위한 소방시설 여부, 기타 산불 등 화재방지를 위한 시설, 보호시설과 산림과의 거리 등 총 7개 항목을 작성하여 피해시설물 및 미피해시설물의 특성을 분석한 결과 입지여건의 경우 피해시설물과 미피해시설물은 1~2개의 진 출입로를 갖고 있었고, 도로 폭은 7m 내외로 비슷한 여건이었다. 주변 임상은 침엽수, 임분 밀도는 중, 밀임분이었다. 비가연성 외벽구조제는 피해시설물 보다 미피해시설물에 많았고, 피해시설물과 미피해시설물의 시설물 주변 가연물질 관리상태는 모두 양호하였다. 반면, 급수시설 및 스프링클러, 방화선, 방화벽 등 소방시설 및 화재방지 시설은 미피해시설물이 피해시설물보다 더 많이 구축되어 있었고, 산림과의 이격거리는 피해시설물 평균 20m, 미피해시설물 평균 25m로 조사되었다.