• Advances in Computational Design
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• 제3권1호
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• pp.49-69
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• 2018

This paper shows an optimal design for reinforced concrete rectangular combined footings based on a criterion of minimum cost. The classical design method for reinforced concrete rectangular combined footings is: First, a dimension is proposed that should comply with the allowable stresses (Minimum stress should be equal or greater than zero, and maximum stress must be equal or less than the allowable capacity withstand by the soil); subsequently, the effective depth is obtained due to the maximum moment and this effective depth is checked against the bending shear and the punching shear until, it complies with these conditions, and then the steel reinforcement is obtained, but this is not guaranteed that obtained cost is a minimum cost. A numerical experimentation shows the model capability to estimate the minimum cost design of the materials used for a rectangular combined footing that supports two columns under an axial load and moments in two directions at each column in accordance to the building code requirements for structural concrete and commentary (ACI 318S-14). Numerical experimentation is developed by modifying the values of the rectangular combined footing to from "d" (Effective depth), "b" (Short dimension), "a" (Greater dimension), "${\rho}_{P1}$" (Ratio of reinforcement steel under column 1), "${\rho}_{P2}$" (Ratio of reinforcement steel under column 2), "${\rho}_{yLB}$" (Ratio of longitudinal reinforcement steel in the bottom), "${\rho}_{yLT}$" (Ratio of longitudinal reinforcement steel at the top). Results show that the optimal design is more economical and more precise with respect to the classical design. Therefore, the optimal design presented in this paper should be used to obtain the minimum cost design for reinforced concrete rectangular combined footings.

• 건축역사연구
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• 제17권4호
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• pp.97-112
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• 2008

In this study, I attempted to the architectural design characteristics of Daeung-Jeon in Sudeok Temple. For this purpose, After I set up several assumptions in the basis of the general characteristics of Korean wood architecture, and then, analyzed floor plan, structural formation and section sizes of structure and bracket members in relation to module and unit. As the results, the characteristics of the design process of plan and structure are follows. (1) 1 ja(尺), the unit applied to this building is measured $307.6{\sim}318.3mm$) and the average is 312.9mm (2) It is estimated that the floor plan designed on the basis of the top of columns. By the applied unit, every bay of the front side and the side is each designed by 15 ja and 8.5 ja. (3) The section is composed of piled members which have same section size. As basic module of section size called 'jae(재;材)', it is estimated at width 0.45 ja by height 0.75 ja. And as the secondary module, height between jae and is called 'gyoe(계;)' and it wes designed by three height size of 0.25 ja, 0.27 ja and 0.30 ja, (4) It is estimated that the section plan was designed by the order as follows. Firstly, the horizontal position of purlins wes decided on the basis of the intersection point of long and short rafters, and then the position and the section size of purlins and jangheyo(長舌) wes decided on the basis of the slope of roof and rafters. Secondly, going down from purlins, the members of structure composed of 'jae' and 'gyoe' was repeated. Lastly, for the purpose of linking the structure members located on the center line of adjacent purlins organically, the height of whaban(화반) was controlled.

• Structural Engineering and Mechanics
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• 제59권3호
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• pp.387-401
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• 2016

This paper takes a half-through steel truss arch bridge as an example. A seismic analysis is conducted with nonlinear finite element method. Contrast models are established to discuss the effect of simplified method for main girder on the accuracy of the result. The influence of seismic wave direction and wave-passage on seismic behaviors are analysed as well as the superstructure and arch ring interaction which is mostly related with the supported bearings and wind resistant springs. In the end, the application of cable-sliding aseismic devices is discussed to put forward a layout principle. The main conclusions include: (1) The seismic response isn't too distinctive with the simplified method of main girder. Generally speaking, the grillage method is recommended. (2) Under seismic input from different directions, arch foot is usually the mostly dangerous section. (3) Vertical wave input and horizontal wave-passage greatly influence the seismic responses of arch ring, significantly increasing that of midspan. (4) The superstructure interaction has an obvious impact on the seismic performance. Half-through arch bridges with long spandrel columns fixed has a less response than those with short ones fixed. And a large stiffness of wind resistant spring makes the the seismic responses of arch ring larger. (5) A good isolation effectiveness for half-through arch bridge can be achieved by a reasonable arrangement of CSFABs.

• 건축역사연구
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• 제18권1호
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• pp.7-29
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• 2009

In understranding the essence of the Korea traditional Architecture, it is important to consider the jointing methods of architectural members, architectural technologies, etc. Especially the purpose of this study is understanding on the Jointing Method of Wooden Members in the period of Unified Silla Architecture. It's conclusion is summarized as follows. 1. A section of column has very close to do with the foundation stone. The structures of foundation stone and column are generally concluded by butt joint, arrow-head joint, housed joint by Grang-e method. Judu is structured by arrow-head joint And, in general, beam is structured by Sagaematchum Chumcha and sagaljudu of Don direction. At the head of Pyungju and the body of Goju, Changbang is structed by Jangbumachum with arrow-head joint or by jumukchang-machum. Also, it is surmised that Gyisoseum and Anssolim methods had been applied to columns from former ages. The example can be found at Bagjae Mireuksaji stone pagoda. Bagjae Mireuksaji stone pagoda taking wooden-pagoda form adopts Gyisoseum and Anssolim methods. We can also find such a sort of methods from other stone constructions like Budo, etc. 2. Injahwaban is structured by short Changbumachum with arrowed-head joint at upper members, and by Anjangmachum at the lower part. This sort of Gongpo style can be seen in the mural painting of tomb of Koguryo and in Buplyungsa, Buplyunsa, Bupkisa-located in Japan, which are influenced by Bakjae or Unified Silla. It is considered that at the end of the late United Silla, Injawhaban had been replaced with Chumcha and Soro on the Pyungbang under influence of Dapo style from China.

• 콘크리트학회논문집
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• 제15권3호
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• pp.425-432
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• 2003

콘크리트 시공 이음부는 콘크리트 시공시 발생되는 기술적 문제들 중의 하나이다. 이 시공 이음부는 콘크리트의 구조적 측면뿐만 아니라 누수 등의 중대한 결함을 초래하게 되는 요인으로 작용한다. 본 연구에서는 이러한 콘크리트 구조물의 시공 이음부를 비파괴적으로 검사하기 위해 레이더법과 적외선법을 이용하였다. 대상부재로서는 콘크리트 기둥을 선정하여 본 방법들의 적용에 따른 여러 가지 형태의 시공 이음부의 검출특성에 대하여 검토하였다. 그 결과, 레이더법의 경우는 해석모델에 의한 모의해석을 실시하여 실제 측정치와 비교하여 해석할 경우, 시공 이음부에 대한 검출 정도를 보다 향상시킬 수 있음을 알 수 있었다. 또한, 적외선법의 경우는 빛의 작용을 받지 못하는 실내조건 하에서도 측정 표면부를 사전 가열하여 측정하면 결함의 형상까지도 뚜렷이 식별하여 검출 가능함을 알 수 있었다. 따라서, 이들 두 방법을 병행할 경우, 육안으로는 검사가 곤란한 콘크리트 시공 이음부에 대해 빠른 시간내에 넓은 대상의 구조물에 대해 효율적인 검사가 가능함이 입증되었다.

• Geomechanics and Engineering
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• 제30권6호
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• pp.565-577
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• 2022

In this study, a series of three-dimensional numerical parametric study was conducted to investigate deformation mechanisms of an existing box culvert due to an adjacent multi-propped basement excavation in clays. Field measurements from an excavation case history are first used to calibrate a baseline Hardening Soil Small Strain (HS-small) model, which is subsequently adopted for parametric study. Results indicate that the basement-box culvert interaction along the basement centerline can be considered as a plane strain condition when the length of excavation (L) reaches 14 H_e (i.e., final excavation depth). If a plane strain condition (i.e., L/H_e=12.0) is assumed for analyzing the basement-box culvert interaction of a short excavation (i.e., L/H_e=2.0), the maximum settlement and horizontal movement of the box culvert are overestimated significantly by up to 15.7 and 5.1 times, respectively. It is also found that the deformation of box culvert can be greatly affected by the basement excavation if the distance between the box culvert and retaining wall is less than 1.5 H_e. The induced deformation in the box culvert can be dramatically reduced by improving the ground inside the excavation or implementing other precautionary measures. For example, by adding jet grouting columns within the basement and installing an isolation wall behind the retaining structures, the maximum settlements of box culvert are shown to reduce by 37.2% and 13.4%, respectively.

• 한국건설관리학회논문집
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• 제5권5호
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• pp.183-192
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• 2004

현재 국내에도 건물의 특성에 알맞은 가변적이며 대공간 확보가 가능하고 사용부재의 두께가 수mm에서 100mm에 이르는 극후판 두께의 건축 철골구조의 건축물 및 Box형 강재교량으로 구축되는 사례가 증가하면서 철골부재의 제작 및 가공기술이 예전보다 더욱 향상되고 구조물로서의 품질관리에 대한 신뢰성의 요구도 증가되고 있는 실정이다, 그러나 국내의 철골조 건축부재의 구조설계는 설계사대로 각기 이루어지고 해당 부재는 공장별로 제작진행되어 그 기술수준에는 보이지 않는 상당한 격차가 있다고 보여지며 업체별로 경제성 등을 고려하여 기본적이며 일반적 철골제작기법을 간결하게 적용하는 것에 머물러 고도한 선진적인 기술의 채용은 대부분 주저할 수 밖에 없는 상황이다 또한, 중소규모의 빌딩 건축물들의 철골조 설계적용을 고려해볼 때 수많은 접합부의 표준화를 비롯하여 구조체 전체의 표준화 및 내$\cdot$외장재까지 포함된 시스템건축의 건축물설계와 부재의 제작 및 설치기술 개발경향도 엿보이고 있는 가운데 특히, 철골부재의 공장제작과 현장설치의 보다 경제적이고 짧은 공기내에 완전한 품질을 확보할 수 있는 부재간의 접합부 설계에 대한 연구검토는 철골분야에 종사하는 업계는 물론 현장 관계자에게도 의미있는 일일 것이다. 본 논문에서는 철골조 건축물의 특성을 알아보고 철골구조물 공장제작 및 현장설치공기를 최대한 단축할 수 있는 철골기둥과 기둥, 기둥과 큰보부재 접합부 변경사례 및 Box Column의 용접자동화, 로봇화에 의한 철골기둥 부재제작사례와 금후 철골구조물 제작상의 문제점과 대응방안에 대하여 서술하고자 한다.

• 콘크리트학회논문집
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• 제18권2호
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• pp.257-266
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• 2006

최근 공기단축, 낮은 층고, 자유로운 평면계획 등의 많은 장점을 가지는 플랫플레이트 구조형식이 고층주거건물의 구조형식으로 많이 사용되고 있다. 특히 국내에서 건설되고 있는 플랫플레이트 구조시스템은 횡력에 대한 저항성을 크게 하기 위하여 기둥의 단면이 매우 크며 직사각형 형태를 가지는 벽기둥(wall-column)을 사용하는 경우가 많으므로 접합부 강도산정모형에서는 이러한 기둥의 형태적 요소를 적절히 반영해야 한다. 기둥단면형상에 따른 플랫플레이트-기둥 접합부의 거동특성을 분석하기 위하여 기존의 강도모델을 검토하고 비선형 유한요소해석을 실시하였다. 기존 강도모델은 위험단면에서의 전단응력분포를 가정함에 있어서 기둥단면형상의 영향을 고려하지 못하여 플랫플레이트-기둥 접합부의 강도를 정확하게 예측하지 못하였다. 비선형 유한요소해석 결과, 하중가력방향과 평행한 기둥폭이 길어질수록 위험단면 측면에서 비틀림 전단을 받는 유효영역과 측면 최대전단강도가 줄어들어 접합부의 강도가 큰 폭으로 감소한다. 따라서 플랫플레이트-기둥 접합부의 강도를 정확히 산정하기 위해서는 하중가력방향과 평행한 기둥폭의 길이($c_1$)이 접합부 거동에 미치는 영향을 적절히 반영해야 할 것이다.

• 유통과학연구
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• 제14권5호
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• pp.107-114
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• 2016

Purpose - Loading can decrease the productivity due to the possibility of carrying out with the opposite order of storage in container terminal. When the container is to be taken out, it is needed to move the container stacked upon the container to be carried out to other place temporarily. It is called as rehandling. Remarshalling, with the loading plan, is the arranging the containers before the ship arrives in order to avoid the rehandling during the carrying out. The present study tried to find out the factors affecting the efficiency when building the remarshalling plan with the utilization of neighboring storage space as a outer slot, and analyzed the efficiency of several remarshalling algorithms with the combination of those factors. Research design, data and methodology - The present study used, when the remarshalling plan is prepared for utilizing the outer slot, the simulation methods in order to compare the efficiency of the remarshalling algorithms which made with the factors affecting the efficiency. The factors affecting the efficiency are the method of making the child node, method of arrangement, and possibility of application of FIX. In order to analyze the affecting factors on the efficiency, several algorithms are prepared with the combination of production of the child node and the arrangement method with the availability of FIX application. With this algorithm, the effect of the factors on the efficiency after building up of remarshalling plan with the target on the bay with 10 rows, 8 columns, and 10 indices. Results - The method of rearrangement and making of a child node as the factor affecting the efficiency of remarshalling utilization of the outer bay were studied. It is efficient to combine the method of making a child node with MCS in order to reduce the number of moving the containers. For reducing the time in carrying out, it was found that all arrangement methods should be combined with RCS for the efficiency. The result of experiment shows the application of FIX with good result in case of succession ratio. In addition, when FIX was not applied, all of the most combinations resulted in short time in remarshalling. As a result, it can be concluded that the algorithm with proper combination of making the child node and the arrangement can increase the job efficiency based on the importance. Conclusion - The present study suggested and analyzed the algorithms with the combination of the arrangement method, the making of child node, and FIX. It is needed to develop the algorithm to judge the possibility whether the best remarshalling plan can be built or not within the bay in order to find a better method between the two cases such as within the bay and outer the bay. As a method for extending the study on the factors affecting the efficiency, it is possible to find out the way to build the remarshalling plan within the permitted time under any storage situation.

• 한국잡초학회지
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• 제18권4호
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• pp.325-332
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• 1998

미사질식토와 사양토 중 fenoxaprop-P-ethyl의 흡착성과 이동성에 대하여 연구 검토하였다. 두 토양 중 fenoxaprop-P-ethyl은 진탕 30분 후에 약 15%가 흡착되었으며 8~14시간 후에는 의사평형에 도달하였고 50%가 흡착되는 시간은 미사질식토에서 15.8시간, 사양토에서 19.3시간이었다. 본 제초제의 흡착은 Freundlich식에 따랐으며 흡착분배계수(Kd)값은 미사질식토에서 3.86, 사양토에서 2.32이었다. 두 토양의 컬럼에서 fenoxaprop-P-ethyl은 처리 7일 후에는 6cm, 21일 후에는 8cm까지 이동되었으나, 이동성은 누수량의 증가와 더불어 증가되었다. 포장조건의 두토양 중 fenoxaprop-P-ethyl은 처리 14일 후에는 6cm층위까지, 56일 후에는 8cm 층위까지 이동되었다. 그러나 어느 경우이든 처리된 fenoxaprop-P-ethyl의 대부분은 0-2cm 층위에 존재하였다. Fenoxaprop-P-ethyl의 반감기는 1주 이내이었으며 처리 4주 후에는 처리량의 약 90%정도까지 분해되었다. 이상의 결과를 종합하여 볼 때 토양 중 fenoxaprop-P-ethyl은 비교적 이동성이 작고 분해가 빠른 편인 바 주변환경에 대한 위해성이 낮을 것으로 사료된다.