Diagonal reinforced coupling beam of coupled shear walls can provide sufficient strength and stiffness to resist lateral force. However, the reinforcement details for coupling beams required by ACI 318 (2011) are difficult to construct because of the reinforcement congestion and confined interior area. This study presents experimental results about the seismic performance of coupling beams having bundled diagonal reinforcement to improve the workability. Experiments were conducted using half scaled precast coupling beams having an aspect ratio of 2.0. It was observed that the bundled diagonal reinforced coupling beams can develop seismic performance similar to the coupling beams with requirement details specified in ACI 318 (2011).

This study aims to give a brief summary of the development in the series of studies that have been made regarding the lateral-torsional buckling (LTB) capacity of beam spans with increased cross section at one end, also known as singly stepped beam (SSB), and at both ends, also known as doubly stepped beam (DSB). A three-dimensional program ABAQUS was used to analyze buckling through finite element method, while a statistical regression program MINITAB was used in developing and proposing simple design equations. The following topics discussed in this study include: (1) proposed design equation that account for change in cross section of stepped beams under uniform moment; (2) proposed design equation, with a corresponding moment gradient factor equation, of stepped beams under general loading conditions; (3) proposed design equation for stepped beam with continuous top flange lateral bracing; (4) proposed design equation for monosymmetric stepped beam subjected to uniform moment and to general loading conditions; (5) effect of inelastic buckling of stepped beams subjected to pure bending and general loading conditions considering combined effects of residual stress and geometrical imperfection; and (6) determination of LTB strength of monosymmetric stepped beam by conducting destructive test of subjecting a beam to concentrated load. The summary presented provides researchers information in understanding the subject matter; moreover, this provides a meaningful contribution to futures researches.

The paper presents an experimental result to characterize the behaviour of steel beams reinforcement by pultruded reinforced polymer strips. Steel beam members reinforced with different thick AFRP on bottom flange plate were tested under one point bending configuration. Test results showed that the member force of one ply reinforced specimen was increased as 11% than control specimen when the two ply overlapped specimen was increased as 14% as usual.

During a flood season, Bo region could be easily exposed to flood due to increase of ground water level and the water drain difficulty even the water amount of Bo can be managed. GFI for the flood risk is measured by mean depth to water during a dry season and minimum depth to water and tangent degree during a flood season. In this paper, a forecasting model of the target variable, GFI and predictors as differences of height between ground water and Bo water, distances from water resource, and soil characteristics are obtained for the dry season of 2012 and the flood season of 2012 with empirical data of Gangjungbo and Hamanbo. Obtained forecasting model would be used for keep the value of GFI below the maximum allowance for no flooding during flooding seasons with controlling the values of significant predictors.

강도 한계상태 설계에서는 균열이 일어난 이후 철근콘크리트 부재의 인장영역에서 철근이 모든 인장력을 부담하는 것으로 가정한다. 그러나 균열 사이의 콘크리트가 실제 콘크리트 부재에서는 특히 사용하중 수준에서의 어느 정도의 인장 응력을 견디는데, 일조 하는 것으로 보고 있다. 이러한 효과를 Tension stiffening 효과라 한다. 본 연구에서는 Tension stiffening 모델과 고강도 철근 콘크리트 보의 휨 실험결과의 비교를 통해 해석모델의 유효성을 평가 하고자 한다. 이를 통해 선정 된 6가지의 Tension stiffening 모델과 실험에 의한 모멘트-곡률, 하중-처짐등을 관계를 평가하였다. 실험결과 설계기준에서는 ACI 318이 Tension stiffening 모델에서는 Owen & Damjanic이 실험 값과 가장 적은 오차율을 보이며 높은 신뢰도를 보였다.

This study presents an experimental study of the structural behavior for steel plate-concrete column-to-steel girder connections. Experiments were carried out to investigate the moment-rotation characteristics, failure behavior and ultimate moment capacity of these connections. The results of this experimental study involving three welded moment-resisting connections subjected to cyclic loading are presented. The specimens were fabricated at full scale to evaluate their hysteretic behavior. A description of the test specimens, the details of the joint, the test system and the testing methods are described. The test results showed that the structural behavior of these composite connections was influenced by the connection details.

본 연구는 4대강 사업으로 건설된 낙동강 보 구간의 플랑크톤 군집에 대한 정보를 제공하고, 플랑크톤 군집에 영향을 미치는 주요 환경요인에 대한 기초적인 평가를 위해 2013년 9월과 10월에 걸쳐 낙동강 8개 보 구간에서 식물 및 동물플랑크톤 종조성과 생체량을 조사하고 수온, 유량, 총인, 총질소, 화학적산소요구량(COD) 등의 환경요인과의 상관관계를 CCA분석을 통해 평가하였다. 조사기간 중 식물플랑크톤 생체량과 종조성은 유량, 총인 및 총질소 농도에 의해 영향을 받는 것으로 나타났다. 동물플랑크톤의 경우 유량이 낮았던 9월에는 지점별 종조성이 상이하게 나타났으나 유량이 높았던 10월에는 모든 지점에서 윤충류가 우점하는 경향을 나타내었다. 동물플랑크톤 군집조성은 식물플랑크톤 생체량(클로로필 농도)과 COD 및 총질소에 의해 주로 영향을 받는 것으로 분석되었다.

수변 보 구조물의 내진설계는 ‘하천설계기준2009’에 따라 수행되어져야 하는데, 기본적인 내진설계 방법과 절차에 따르고 보 구조물은 기타 하천시설물로 구분되어 교량 설계기준이나 댐 설계기준을 준용할 수 있도록 규정하고 있다. 그리고 위에서 일반설계에서도 언급했듯이 보와 댐의 차이가 미미해지고 있어 댐 설계기준에 따라 적용해야 할 것으로 판단된다. 또한, 수변 보 구조물은 댐 설계기준에서 댐체, 여수로 및 부대시설물의 내진성능을 확보하기 위하여 필요한 기준을 규정하는 것으로서 신설되는 높이 15m 이상인 댐의 내진설계에 적용하고, 또한 높이 15m 미만인 소규모댐과 부대시설에 적용할 수 있다는 항목에 해당되는 것으로 보인다. 댐 설계는 “내진성능기준(1997)”에서 제시된 내진설계 성능기준을 기본으로 한다. 댐에 상당한 변형과 부분적손상이 발생하는 것은 허용할 수 있으나 지진시 또는 지진경과 후에도 댐의 저수기능은 유지되어야 하며 통제 불가능한 저수량의 유출상태는 있어서는 안 된다. 내진등급은 내진특등급 댐, 내진 I등급 댐2개의 등급으로 분류하나 고려하는 설계지진의 재현주기는 각각 1000년, 500년이어서 내진성능기준의 내진 I등급, 내진Ⅱ등급에 해당한다. 댐의 붕괴시 엄청난 인명피해와 재산피해를 고려할 때 내진등급을 내진특등급, 내진I등급으로 고려하는 것이 타당하나 댐의 거동특성으로 보아 완전한 소성설계를 할 수 없어 재현주기 2400년 지진에 대해 붕괴방지 수준으로 설계하는 것은 지나치게 지진하중을 크게 고려하게 된다. 따라서 이를 반영한 규정으로 생각할 수 있다. 지진하중은 설계진도로 산정하며 설계진도가 0.2g 이상이어서 우리나라보다 지진규모나 발생빈도가 훨씬 높은 나라에서 적용하는 진도보다 과다하다고 판단되는 경우에는 설계자는 적용설계진도를 0.2g이하로 조정할 수 있다.

Beam string structures(BSS) are one kind of efficient structure system because the bending moment in the beams is reduced greatly through the struts and the strings. As the struts in BSS are used as middle supports to the beam and always in compression, the buckling of the struts should be avoided. This paper investigates the lateral buckling of the struts in BSS. Firstly, the strut of a one-strut BSS is simplified into an analytical model by considering load is formulated and some special cases of the model are analyzed. Finally, the lateral buckling load of the strut is numerically examined by means of parameter studies. It is known that, because on end of the struts is jointed to the beam while the other end is connected to the strings, the buckling of the struts not only depends on the length of the struts and the stiffness of the joints, but also depends on the rise and the lateral stiffness of the beam, the layout of the strings and the number of the struts.

PURPOSES: This study aimed to measure the skid resistance of the sidewalk in order to find out the relationship between different surface types and skid resistance. By using British Pendulum Tester, skid resistance of sidewalk was measured in a wet after snow-melt, sludgy, and snowy conditions. METHODS : The skid resistance was measured on surfaces including Concrete Interlocking Block Paving, Colour Asphalt Pavement, Granite Block Paving, Manhole, and Tactile Paving for Visually Impaired. Five trials at each measurement were made, and the average and standard deviation were derived. RESULTS: The skid resistance measured in wet after snow-melt, sludgy, and snowy conditions for the various surface types are summarized and compared. Reduction rates of skid resistance of sludgy and snowy against wet after snow-melt are also analysed. The skid resistance variation between measurement points which mimic pedestrian route in study site are analysed to check out the consistency of the skid resistance along the sidewalk. CONCLUSIONS : The study concluded that the skid resistance of sidewalk surfaces varied depending on the surface types and weather conditions. Secondly, reduction rates of skid resistance according to weather changes are varied depending on the surface types, Thirdly, consistency of skid resistance along the pedestrian route is hardly acquired in the study site at least. So, future study on the consistency evaluation for skid resistance along sidewalk is strongly recommended.

The hysteretic behavior of diagonal reinforced coupling beams is excellent during earthquakes. However, construction of the diagonal reinforced coupling beams is difficult due to complex reinforcement details required by current code procedures (ACI 318-11). Due to the detail requirement, reinforcement congestion and interference among transverse reinforcement always occur during construction field. When the aspect ratio of the beam is large, the interference of reinforcement becomes more serious. The objective of this paper is to simplify the reinforcement details of slender coupling beams by reducing transverse reinforcement around the beam perimeter. For this purpose, high- performance fiber reinforced cementitious composites are used for making coupling beams. Experiments were conducted using three specimens having aspect ratio 3.5. Test results showed that HPFRCC coupling beams with half the transverse reinforcement required by ACI 318-11 provided identical seismic capacities to the corresponding coupling beams having requirement satisfying the requirement specified in ACI 318-11.

In recent years, the construction of high-rise buildings are promoted. According to these, there are many needs about new technologies to strengthen the building performance and high-strength steel is regarded as one of these for promoting building performance. In Korea, high-strength steels which stress are over 600MPa are on market and in aborad, super high-strength steels over 1000MPa are developing and they expected to promote the building performance. But there are still doubts about applying high-strength steel members because of size effect and worry of brittle fracture. In this reports, we propose results of performance and analysis tests for use with general steel. We propose the characteristic of high-strength steels first and next the results of performance test to show they satisfy the performance that designers expect. And last, we compare the results of test and analysis for acquire the alanysis reliability in non-linear analysis with high-strength steels.

철근 및 FRP Bar를 보강재로 사용한 콘크리트 보의 전단 거동을 실험적으로 평가하였다. 실험 변수는 특성이 다른 보강근을 휨 및 전단 보강한 것과 전단보강근비이다. 콘크리트 보의 전단강도 산정에 일반적으로 널리 이용되는 수정트러스 이론의 타당성을 실험 결과의 분석을 통하여 평가하였다. CFRP 및 GFRP를 휨 및 전단 보강한 콘크리트 보에 그대로 적용하는 것은 적절하지 않음을 알 수 있었다. 실험결과는 FRP Bar를 보강근으로 사용한 콘크리트 보의 전단 문제에 수정트러스 이론을 그대로 적용하는 것은 타당하지 않다는 것을 알 수 있었다.

Deep beam shall be designed either by taking into account nonlinear distribution of strain or by Appendix A of Strut-and-Tie Models (STM ) according to ACI 318(M ) from version of 2002. Although STM is accepted as tool in design Discontinuity region (D-region) which mostly exist in Deep beam, Corbels, Dapped ends etc., it has been modified by many researchers. In this study we design deep beam by STMs which use simple truss for load distribution and the model of complex truss for load distribution compare with the ACI traditional which is designed by flexure design method and shear provided by concrete(Vc) as provided in special provisions section of 11.8 in ACI 318-99 [1]. This study aims to find the different and efficiency of deep beam design based on variation of parameter compiled from many samples selected from ACI traditional and two model of STMs, simple and complex load distribution.

아토피성 피부염은 만성 재발성 염증성 피부질환으로 피부장벽기능의 이상과 환경유발인자에 대한 피부과민성과 연관되어 있다. 이전의 연구에서는 아토피성피부염에 효과적인 약용식물 추출물을 발굴하기 위하여 노회, 자회지정, 석류, 석곡 추출물들의 세포독성, 항산화, 항염, 항알레르기 효과를 검토하였다. 본 연구에서는 지질다당류로 활성화시킨 대식세포 RAW26.7 에 대한 약용식물 추출물들의 항염작용을 보다 상세하게 검토하여 항염작용의 근본적인 분자기전을 확인하고자 하였다. 역전사중합효소연쇄반응분석(reverse transcription polymerase chain reaction analysis) 결과, 석류, 석곡, 노회는 염증성 사이토카인인 IL-6 와 IL-1β 유전자발현을 현저하게 억제시켰으며 자화지정은 영향이 없었다. 형질주입과 발광효소분석(transfection and luciferase analysis) 결과, 약용식물 모두가 전사 핵인자 카파비(NF-kB)의 활성화를 억제시켰다. 웨스턴 블럿 분석(western blot analysis) 결과, 노회는 JNK MAP 인산화효소의 활성화를 차단하였지만 p38 MAP 인산화효소의 활성화는 차단하지 못하였다. 반면에 자화지정, 석류, 석곡은 JNK MAP 인산화효소뿐만 아니라 p38 MAP 인산화효소의 활성화도 차단하였다. 이들 실험결과들은 노회, 자화지정, 석류, 석곡은 항염효능을 가지고 있으며 따라서 아토피성 피부염의 증상을 경감 또는 완화시키는 잠재력이 있음을 보여 준다.

The concrete-filled tube (CFT) column has the excellent structural performance. But it is difficult to connect with column and beam because of closed section. Its Solution, 2 members of ㄷchennel in which Internal diaphragm is installed were welded beforehand and the method of making Rectangular Steel Tube was proposed. According to upside and downside junction shape, Internal diaphragm suggested as symmetric specimen and asymmetric specimen. The upper and lower diaphragm of the Symmetric specimen used the same horizontal and The upper diaphragm of the Asymmetric specimen used the horizontal plate and the lower diaphragm used the vertically plate. In this research, 4 T-shape column to beam steps connections were tested with cyclic loading experiment in order to evaluate the structural capability of the offered connection. Symmetric specimens be a failure in 0.03rad from beam flange. And Asymmetric specimens be a failure in 0.05rad from column interface. The comparison results of All specimens shown similar to energy absorption capacity in 0.02rad.

This paper describes the structural design and optimization of sinusoidally corrugated web girder by using EUROCODE (EN 1993-1-5). The optimum design methodology and characteristics of the optimal cross-section are discussed. We investigate a shear buckling and the concerned standards for corrugated web and explain the equations to obtain a critical stress according to buckling type. In order to perform optimization, we consider an objective function as minimum weight of the girder and use the constraint functions as slenderness ratio and stresses of flanges as well as corrugated web and deflection. Genetic Algorithm is adopted to search a global optimum solution for this mathematical model. For numerical example, the clamped girder under the concentrated load is considered, while the optimum cross-sectional area and design variables are analyzed. From the results of the adopted example, the optimum design program of the sinusoidally corrugated web girder is able to find the suitable solution which satisfied a condition subject to constraint functions. The optimum design shows the tendency to decrease the cross-sectional area with the yielding strength increase and increase the areas with load increase. Moreover, the corrugated web thickness shows a stable increase concerning the load.