강바닥판 종리브와 횡리브 교차부의 피로거동에 대한 종리브내 다이아프램의 영향

최동호,최항용,최준혁,Choi, Dong Ho,Choi, Hang Yong,Choi, Jun Hyeok 한국강구조학회 2000 韓國鋼構造學會 論文集 Vol.12 No.3

본 연구에서는 강바닥판의 실물 대형시험체를 제작하여 정적시험 및 피로시험을 실시하였다. 정적 및 영향면 재하시험 결과를 통하여 다이아프램의 유무에 따른 강바닥판 슬릿부의 면내와 면외응력을 검토하였으며, 피로시험결과로부터는 강바닥판의 피로거동, 피로균열의 발생과 진전에 대한 연구를 수행하였다. 다이아프램이 설치된 상세는 설치되지 않은 상세에 비하여 지점조건에 상관없이, 종리브 횡리브 교착부의 종리브측으로는 약 50%의 응력경감효과가 있으나, 횡리브측 하단부에는 오히려 상당히 큰 응력을 야기함을 알 수 있었으며, 피로균열 진전해석결과로부터는 슬릿부의 노치에 의한 초기균열길이가 피로균열성장에 상당한 영향을 끼치고 있음을 알 수 있었다. 측정자료와 FEM 해석을 통하여 공칭응력과 핫스폿응력에 의한 피로강도를 추정한 결과, 다이아프램이 설치되지 않은 상세는 규정된 피로등급에서 안전한 것으로 판단되나 다이아프램이 설치된 상세는 피로등급이하의 거동을 보였다. This study investigates the mechanical behavior on trough rib to crossbeam joint in orthotropic steel plate decks, specially emphasizing on the effect of diaphragm inside trough rib on the fatigue behavior of slit by static and fatigue tests. In particular, the effects of diaphragm on in-plane stress and out-of-plane stress, stress concentration, propagation of fatigue cracks at the silt are studied. With the result of experiment and numerical analysis, we have estimated the fatigue strength using the nominal stress and hot-sport stress. The details with diaphragm have occurred about 50% stress reduction at trough rib part of trough rib to crossbeam joint than the detail without diaphragm, however, the lower parts of crossbeam have occurred much more stress. Initial crack size or slit have an considerable influence on the propagation of fatigue cracks due to V-notch. The fatigue strength category of the details without diaphragm has higher value than fatigue limit, whereas that of the details with diaphragm is estimated lower than fatigue limit.

논 관개수, 담수 및 유출수의 용존인과 총인 농도 변화

최동호,조소현,정재운,박현규,최우정,윤광식,김영석,Choi, Dongho,Cho, Sohyun,Jung, Jaewoon,Park, Hyunkyu,Choi, Woojung,Yoon, Kwangsik,Kim, Youngsuk 한국물환경학회 2017 한국물환경학회지 Vol.33 No.4

In order to understand the characteristics of phosphorus in the paddy field, this study analyzed $PO_4-P$ and T-P concentrations of irrigation water, flooding water, and runoff from 2008 to 2010. The variation of phosphorous form within hydrologic cycle around the rice paddy field was investigated using the ratio of $PO_4-P$ to TP. In addition, the correlation between pH, EC, and DO in flooding water was analyzed and the factors affecting phosphorus form in paddy field were investigated. The concentration of T-P in flooding water was high during the survey period, and the concentration of T-P in runoff was assumed to be decreased by dilution due to irrigation and rainfall. On the other hand, the ratio of $PO_4-P$ to T-P was lower in flooding water than those of irrigation water and runoff, which was interpreted to be due to the fact that the phosphorus fertilizer was applied in the paddy field but the adsorption was rapidly occurred to the paddy field by the soil. The similar proportions of $PO_4-P$ to T-P in flooding water and runoff suggest that the form of phosphorus outflowed from the paddy is influenced by the form of phosphorus in the flooding water of paddy field. In addition, DO concentration in flooding water showed negative correlation with the concentrations of $PO_4-P$ and T-P. The effort to survey frequent irrigation water quality data is required for the analysis of phosphorus behavior in the paddy water system since concentration of phosphorous and DO in irrigation water would influence rhe form of phosphorous in flooding water and subsequent runoff.

충돌하중을 받는 U-채널 교량 측보의 구조적 안정성에 관한 연구

최동호,나호성,이광원,Choi,Dong-Ho,Na,Ho-Sung,Lee,Kwang-Won 한국방재학회 2008 한국방재학회 학술발표대회논문집 Vol.2008 No.1

U-Channel Bridge is effective bridge type, because its edge beam performs role of barrier and enables to reduce additional dead loads. Nevertheless, there is possibility of bridge collapse under impact load due to car crash. Also, edge beam must have ability to induce safe driving and prevent falling accidents. Therefore, this study carries out analysis of behavior of edge beam and slab and evaluation of structural stability under impact loads, based on Korean Highway Bridge Design Specifications and AASHTO LRFD Bridge Design Specification. According to analysis result, the maximum stress of edge beam and slab satisfies specification of allowable stress.

단자유도 시스템의 선형응답과 비탄성응답에 미치는 PSD함수의 영향

최동호,이상훈,김용식,고정훈,Choi,Dong-Ho,Lee,Sang-Hoon,Kim,Yong-Sik,Koh,Jung-Hoon 한국방재학회 2008 한국방재학회 학술발표대회논문집 Vol.2008 No.1

Acceleration time history (ATH) used in the seismic analysis should envelop a target power spectral density (PSD) function in addition to the design response spectrum in order to have sufficient energy at each frequency for the purpose of ensuring adequate load. Even though design regulations require the ATH used in seismic analysis to meet a target PSD function, the reason that ATHs meet to a target PSD function is not described. Thus, artificial ATHs for high PSD function and artificial ATHs for low PSD function are generated. And then elastic and inelastic single-degree-of-freedom (SDOF) systems are loaded with these artificial time histories as the earthquake load. As a result, linear response and inelastic response of SDOF systems are affected by PSD function.

대규모 실내경기장의 동계 온열환경 특성 실측조사 - 인체부하 미고려 조건 -

최동호,정성진,석호태,Choi, Dong-Ho,Jeong, Seong-Jin,Seok, Ho-Tae 한국공간구조학회 2007 한국공간구조학회지 Vol.7 No.3

The purpose of this study is to provide fundamental heating design data for the large public enclosures as gymnasium. This study executed indoor thermal environment verification of the existing gymnasium by measuring temperature distribution with and without heating the space in winter. Heating loads from human body was not considered. We examined various indoor thermal environment factors of the large enclosed space in this study which include vertical and horizontal temperature distribution, supply and return air flow feature, thermal comfort environment feature, amount of ventilation and etc. 본 연구에서는 기존 대공간의 난방시에 발생될 수 있는 분포상의 문제점을 실측실험을 통해 확인하여, 궁극적으로는 대공간의 열환경 개선과 효율적인 난방설계를 위한 기초데이터를 제시하고자 하였다. 본 연구에서는 인체부하 미고려시의 동절기 대공간의 실내온열환경 실측실험을 비난방시와 난방시로 구분하여 실시하였으며 공간내 수평 및 상하온도분포특성, 취출기류의 거동특성, 실내쾌적온열환경 특성, 환기량 평가 등 대공간의 실내열환경을 포괄적으로 검토하였다.

비선형 진동특성을 고려한 케이블 교량 장력 추정

최동호,박완순 한국구조물진단유지관리학회 2011 한국구조물진단학회 학술발표회논문집 Vol.2011 No.9

Although the existing formulas are widely used in the field, the total tension force estimated using these formulas is not accurate. The existing formulas do not consider the exact deflection curve, features of nonlinear oscillation, and stretching force due to self-weight. In this study, a new method was developed to calculate the total tension force of the cable. In the new method, the total tension force of the cable consists of the applied axial load and the stretching force due to self-weight. A field test showed that it is necessary to add the stretching force due to self-weight to the estimated axial load and that the new method can be used to calculate the total tension force of cables in cable supported bridges such as the extradosed bridge and the cable stayed bridge.

제주지역 호텔의 에너지 소비실태에 관한 연구

최동호,고영훈,박효순,Choi Dong-Ho,Ko Young-Hoon,Park Hyo-Soon 대한기계설비건설협회 2001 기계설비 Vol.127 No.-

The study focused on the analysis of energy consumption of hotel in Jeju. For this study, we regionally investigated the energy consumption in Jeju and Seogwipo by questionnaires. Based on the fundamental data, we classified the energy consumption accordi

벽체 구조 내화성능 분류체계 설정을 위한 실험적 연구

최동호,김대회,Choi. Dongho,Kim. Daehoi 한국방재학회 2012 한국방재학회논문집 Vol.12 No.4

건축물은 화재시 그 피해를 최소화하기 위해 건축물 주요 구조부를 일정 수준의 내화구조로 시공하고 있다. 현재 국내에서는 이러한 주요 구조부의 내화성능을 정부에서 확인하여 인정한 법정 내화구조를 규정하고 있으나 외국에 비하여 내화성능 및 구조의 구분없이 일률적으로 내화성능을 규정하고 있으며, 이경우도 규정된 후 상당한 시일이 경과되어 최근에 적용되는 건축재료 및 공법기술을 적절히 수용하지 못하고 있는 실정이다. 이에 따라 현재의 법정내화구조에 대한 성능확인 등을 통한 내화성능을 재설정할 필요가 있으며, 이에 본 연구에서는 국내 법정내화구조중 벽체 구조를 대상으로 내화성능을 평가한 후 각 구조별로 법정내화구조를 세분화한 기초자료를 제시하였다. To minimize the damages under fire conditions in buildings, the main structural members of buildings shall be fire-resistance-rated structural members. The relevant authority specifies the prescriptive fire-resistance-rated structural members which have 3-hour fire rating equally without any classification in building laws at present unlike foreign countries. But, these prescriptive fire-resistance-rated structural members don`t properly reflect the recent construction materials and the technical development of methods of construction as a long time has passed. Consequently, it is needed to specify so that the fire resistance performance of structural members can be departmentalized according to the detail design and applied part and to improve the relevant system based on the test materials of fire-resistance-rated structural members economically and efficiently. This study was intended to give the fundamental materials that prescriptive fire-resistance-rated walls are departmentalized as each structure by evaluating the fire resistance performance of prescriptive fire-resistance-rated walls.

100작품 - 개념의 건축화된 4카테고리 스케치 (우주.내용과 형식. 미메시스. 별자리)

최동호,Choi, Dong-Ho 대한건축사협회 2012 建築士 Vol.2012 No.2

승강기문, 방화유리창 성능기준 개선방향에 관한 연구

최동호,김대회,서희원,박수영,Choi. Dong Ho,Kim. Dae Hoi,Seo. Hee Won,Park. Soo Young 한국방재학회 2013 한국방재학회논문집 Vol.13 No.1

화재시 건물내의 연소확대를 방지하기 위한 방화구획 선상, 피난통로, 승강기 탑승 로비 등에는 방화문, 승강기 등을 설치하기 위한 개구부가 위치하게 된다. 건축물에서의 연소확대는 이와 같은 개구부를 통하여 이루어지기 쉬우므로 설치되는 개구부 방호 설비에 대한 관련 기준의 정비 및 보완이 중요하다. 특히 과거와는 달리 건물의 고층화, 대형화에 따라 피난용도로 사용되는 승강기의 용도가 중요시 되고 있으며, 이에 따른 승강기문에 대한 화재안전성이 요구되고 있으며, 또한 방화문 등에 설치되는 방화유리창도 화재시 연소확대방지를 위한 검토가 필요하다. 이에 본 연구에서는 외국의 방화용 승강기문과 방화유리창에 대한 성능기준을 검토하여 국내 관련 성능기준을 설정하기 위한 기초자료를 제시하고자 하였다. The openings for fire doors and elevator doors are installed on fire compartment to stem fire spreading, evacuation passage and elevator hoistway in building. Fire spreading tend to grow through these openings, so it is important to organize the standard related to opening protectives. Unlike in the past, due to being tall and large, the elevator for evacuation is being more important. For this reason, it is required for elevator door to be safe in fire and it is necessary for the glazing installed on fire doors to be reviewed with respect to fire spreading. In this study, foreign performance criterion of the fire elevator door and the fire-protection-rated glazing were reviewed and the base data for improving way about the fire performance criteria were suggested.