• Title/Summary/Keyword: Main Building Shape

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A Study on Stability of Levee Revetment in Meandering Channel (만곡수로 내의 호안 안정성 연구)

  • Kim, Sooyoung;Yoon, Kwang Seok;Kim, Hyung-Jun
    • Journal of Korea Water Resources Association
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    • v.48 no.12
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    • pp.1077-1087
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    • 2015
  • The levee protect lifes, houses, and properties by blocking overflow of river. The revetment is forced to be covered on the slope of levee in order to prevent erosion. The stability of revetment is very important enough to directly connected to the stability of levee. In this study, the weak points of revetment on meandering channel were found by movable revetment experiment and the velocity and the water surface elevation (WSE) were measured at main points. The 3-D numerical simulations were performed under same conditions with experiment. And unclear flow characteristics by the limit of measuring instruments were analyzed through numerical simulation. Consequently, the section of large wall shear stress and the failure section are almost the same. Despite of small wall shear stress, the revetments located at right bank were carried away because of circulation zone due to secondary flow by meandering. With existing riprap design formula, the sizes of riprap determined using maximum local velocity were 1.5~4.7 times greater than them using mean velocity. As a result of this study, it is necessary to calculate the size of riprap in other ways for meandering and straight channel. At a later study, if the weighted value considered the radius of curvature and shape of hydraulic structure is applied to riprap design formula, it is expected that the size of revetment was evaluated rationally and accurately.

Research on Fire Safety of Mortar-Containing Waste Tire Powders and Flame Retardant (폐타이어 분말과 난연제가 혼입된 모르타르의 화재안전에 관한 연구)

  • Park, Jeong-Jin;Son, Ki-Sang
    • Fire Science and Engineering
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    • v.24 no.4
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    • pp.12-17
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    • 2010
  • The purpose of this study is to determine how effectively waste tire recycled material mixed with flame retardant work in combating fire. As discovered in the previous study, waste tire mixed with cement mortar has more insulation capacity. However, this mortar is weak against fire. Therefore flame retardant, with a specific proportional mix, will be added to increase its fire prevention capacity. Tests will be made in accordance with ISO 5657 procedures for measuring fire ignition time, flame and shape variation of test pieces at the Building Material Test Institute. The test piece will be set up with horizontal levels having a constant radiation heat of $1{\sim}5W/cm^2$. Temperature transfers and increases from the surface into the interior. Combustible gases result due to pyrolysis, and regular contact is maintained between the fire source and the center of the test piece for assessment purposes. Ignition has not been occurred without adding retardant meaning that there is almost no possibility of ignition of waste tire particle. This fact can be considered as fire load to appreciate a volume of combustion materials. Flame is not occurred due to heat-absorbing effect by adding non-organic series retardant into waste tire particle. Conclusions have been summarized as follows; 1) Combustion of building material can be decreased by adding retardant to waste tire-mixing mortar. But compressive strength and insulation capacity of the material should be measured later. 2) Firing prevention and ignition are main points of building fire. Reasonable fire engineering assessment of interior material should be made for establishing effective disaster prevention system.

Application technique on thrust jacking pressure of shield TBM in the sharp curved tunnel alignment by model tests (축소모형실험을 통한 급곡선 터널에서의 Shield TBM 추진 압력 적용 기술에 대한 연구)

  • Kang, Si-on;Kim, Hyeob;Kim, Yong-Min;Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.2
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    • pp.335-353
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    • 2017
  • This paper presents the application technique on thrust jacking pressuring of shield TBM in the sharp curved tunnel alignment by model tests. Recently, the application of shield TBM method as mechanized tunnelling is increasing to prevent the vibration and noise problems, which can be occurred in the NATM in the urban area in Korea. However, it is necessary to plan the sharp curved tunnel alignment in order to avoid the building foundation and underground structures, to develop the shield TBM operation technique in the shape curved tunnel alignment. Therefore, the main operation parameters of shield TBM in the curved tunnel alignment are reviewed and analyzed based on the case study and analytical study. The results show that the operation of shield jacking force system is the most important technique in the shape curved tunnel alignment. The simplified scaled model tests are also carried out in order to examine the ground-shield TBM head behaviour. The earth pressures acting on the head of shield TBM are investigated according to two different shield jacking force systems (uniform and un-uniform pressure) and several articulation angles. The results obtained from the model tests are analysed. These results will be very useful to understand the shield TBM head interaction behaviour due to the shield jacking operation technique in the shape curved tunnel alignment, and to develop the operation technique.

A study for the performance evaluation of concrete block assembly wall without using mortar (무모르타르로 건식조립된 콘크리트블록 벽체의 성능평가 연구)

  • Lee, Joong-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.203-210
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    • 2019
  • A recent earthquake on the Korean Peninsula caused much damage to masonry buildings, and research on performance evaluation has been underway. A masonry building is generally constructed using wet construction and is affected by temperature, which reduces the efficiency of the construction. In this study, we propose a dry construction technique for assembling concrete blocks without using mortar and evaluated its performance through experimental and analytical research. To evaluate the performance, experiments were carried out for the prismatic compressive strength, direct terminal strength, and diagonal tensile strength of the dry construction wall. The adequacy of the cross section shape was also reviewed through FEM analysis. The results show that the compressive strength and diagonal tensile strength could exert a certain intensity or higher. Furthermore, the H-type module of a key block acted as a shear key for the entire concrete block, which resulted in excellent shear strength performance. In addition, the shape and thickness of the main block have a major effect on the strength performance of each block. Therefore, an optimal shape and the proposed dry construction method could be applied to replace the wet method by studying the construction or seismic performance of the proposed method.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

Large eddy simulation of wind loads on a long-span spatial lattice roof

  • Li, Chao;Li, Q.S.;Huang, S.H.;Fu, J.Y.;Xiao, Y.Q.
    • Wind and Structures
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    • v.13 no.1
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    • pp.57-82
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    • 2010
  • The 486m-long roof of Shenzhen Citizens Centre is one of the world's longest spatial lattice roof structures. A comprehensive numerical study of wind effects on the long-span structure is presented in this paper. The discretizing and synthesizing of random flow generation technique (DSRFG) recently proposed by two of the authors (Huang and Li 2008) was adopted to produce a spatially correlated turbulent inflow field for the simulation study. The distributions and characteristics of wind loads on the roof were numerically evaluated by Computational Fluid Dynamics (CFD) methods, in which Large Eddy Simulation (LES) and Reynolds Averaged Navier-Stokes Equations (RANS) Model were employed. The main objective of this study is to explore a useful approach for estimations of wind effects on complex curved roof by CFD techniques. In parallel with the numerical investigation, simultaneous pressure measurements on the entire roof were made in a boundary layer wind tunnel to determine mean, fluctuating and peak pressure coefficient distributions, and spectra, spatial correlation coefficients and probability characteristics of pressure fluctuations. Numerical results were then compared with these experimentally determined data for validating the numerical methods. The comparative study demonstrated that the LES integrated with the DSRFG technique could provide satisfactory prediction of wind effects on the long-span roof with complex shape, especially on separation zones along leading eaves where the worst negative wind-induced pressures commonly occur. The recommended LES and inflow turbulence generation technique as well as associated numerical treatments are useful for structural engineers to assess wind effects on a long-span roof at its design stage.

Test Result on Embedded Steel Column-to-Foundation Connection for Modular Unit Structural System (유닛 모듈러 기둥 매입형 기초 접합부에 대한 실험 연구)

  • Lee, Sang Sup;Bae, Kyu Woong;Park, Keum Sung;Hong, Sung Yub
    • Journal of Korean Society of Steel Construction
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    • v.26 no.6
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    • pp.537-547
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    • 2014
  • A steel modular unit structural system has been used increasingly for mid and high-rise buildings, since the building can be easily constructed by assembling the pre-made modular unit structures. For this structural system, each modular unit structures have to be properly connected to the foundation to transfer the axial force and the bending moment that are generated from external load to the ground. In this study, a new type of the embedded steel column-to-foundation connection was proposed, and its flexural behavior was evaluated through a series of experimental study. Five full scale specimens for the proposed connections were constructed and tested. The effect of the main parameters that affect the flexural behavior of the proposed connection, such as embedment length and shape of end plate, were studied. From the results, it was found that the flexural stiffness of the proposed connection was higher than that of the semi-rigid connection for all test specimens, and 200 mm of embedment length was proper for the given test specimens in this study.

Applying of Indicators for Landscape Planning in Building Lots Development District around Urban Fringe (도시근교 택지개발지역의 경관계획지표 적용방안)

  • Kim, Yong-Soo;Park, Chan-Yong
    • Journal of Korean Society of Rural Planning
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    • v.13 no.3
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    • pp.51-60
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    • 2007
  • In terms of the indicators by the type for the landscape plan per the district nit, geographic ecology indicators were the items such as water, water system, topography and climate, while biological ecology indicators were the items such as green zone size, green zone ratio, biotope size and distribution. The sensory and visual indicators were the items such as view point, view axis and skyline, and the accessibility indicator items for the green zone were applied as the socially used indicators. As for the application method according to each indicator, the water or water system was expressed and applied through the slopes and elevation topographic analysis drawings, the climate was expressed and applied through the main direction of the wind and the cold wind pass alley drawings. As for the green zone size and green zone ratio, the land use according to the status and housing area development was compared to present the measured figures. In case of the biotop size and the distribution item, the range was limited to the preparation of the biotope drawings for the focused preservation. As for the view point and view axis, the view point was selected according to the view point to prepare and apply the view analysis drawing in which the view area to be preserved is analyzed. As for the skyline, its landscape photo was composed with the housing area shape, and then skyline photography was applied as the plan in order to propose and consider the various shapes of the skyline. As for the accessibility to the peen zone, the network drawing was drawn to reflect the users' accessibility and continuity of the green zone formed and preserved according to the land use plan and then the drawing was prepared and proposed as the applicable plan.

A Stduy on the Development of XML Schemata and STEP Model for Sharing Construction Drawings Information (건설도면정보 공유를 위한 XML 스키마 개발 및 STEP 연계기술에 관한 연구)

  • Kim, In-Han;Choi, Jung-Sik;Jo, Chan-Won
    • The Journal of Society for e-Business Studies
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    • v.9 no.3
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    • pp.57-77
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    • 2004
  • The main purpose of this study is to develop XML schemata and related STEP model for sharing construction drawings information. To achieve this purpose, the authors have developed a drawing information model based on STEP/AP202, the data searching mechanism based on STEP, and XML schemata for sharing and exchanging information between vector data and non-shape attribute information. Finally, the authors have suggested the way of sharing drawing information through linked STEP data and a XML schema using test cases of construction material information and code checking. The study shows a way of optimized managing and sharing construction information through the drawing information and external data for the whole building life-cycle, from early design stage to the construction stage.

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Interpretation of a Traditional Mansion, the Sunktyojang in Kangreung (상류(上流) 전통주거(傳統住居) 강릉(江陵) 선교장(船橋莊)의 해석(解釋))

  • Lee, Hee-Bong
    • Journal of architectural history
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    • v.8 no.4 s.21
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    • pp.39-62
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    • 1999
  • Basic concept of this study is that architectural form as a material at present has meaning for the dweller's life on the past historical plane. Main method to recover history is ethnographic interview to dwellers. Secondary method is to analyze ancestors' writings, buildings in the background of the family photos, and past drawings and then to relate them with architectural form at present. Taxonomy is a starting point: general name of the building by outside researcher is quite different from it by inside dwellers. 'Haengrang-chae', servant quarter, has never been used for servants. Function of the haengrang went outside thatched houses at the front village. Firsthand observation or simple analyses as results of several precedent research are reexamined and criticized through this study. The mansion has moaning when we synthesize with the site location based on farming land and tenant farmer, and decline of the Kyongpo Lake. Territoriality of the mansion is reinterpreted to 'In-Out Structure' by Yin-Yang thinking, Dwellers extend buildings gradually to outside village, surrounding rear hills, the lake, DongHae Sea, and finally goes to imaginative Taoist heaven beyond real nature through the literary life. Confucius principle, known to govern upper class house at Yi Dynasty also affect general composition of the buildings: perpetuation of the family by ancestor worship, elder dominance and male dominance, fraternity love in the extended family, charity display by reception of guests, Taoist scholarly life harmonized with nature. However, the study of the particular life and usage of the dwellers reinforces or corrects general supposition of precedent researches. Unique shape of the house has been formed by convenience of the dwellers' life style, early modernized free thought over the rigid Confucius design principle, and female power in male dominant society.

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