The objective of this study is to develop the innovative application methodology of Geofoam for sustainable design of eco-bridges under deep soil cover. Traditionally, the soft maerial zone has been located on the top or above the buried conduit to reduce the earth pressures, which is called imperfect trench installation (ITI). There, however have been no previous studies for the application of ITI on buried arch structures. This study investigated the structural effects of Geofoam surrouding buried arch bridges, which was named as embedded trench installation (ETI). Various shapes and locations of Geofoam have been investigated for both ETI and ITI. The findings from this study showed that ETI could effectively increase the stability and sustainability of deeply buried eco-bridges.

FRP is a new material that has light, high strength and high durability characteristics and is emerging as a third construction material in and out of countries. However, very few studies have been done on curved FRP construction materials that can be used for tunnels or arched bridges. In particular, many joints are required for the application of curved panels to the open cut tunnel. Experimental data on the performance of the joint is required due to insufficient design criteria. The purpose of this study is to analyze the structural performance of real size, composite materials curved panels. To achieve this goal, curved panels were constructed and bending performance was tested. A numerical analysis was also performed and compared with the results of the test. The results of the test showed that the average load was 757.6 kN and the average displacement of bottom was measured at 53.12 mm. Compression stress on the upper flange and tensile stress on the lower flange were within acceptable limits of 50% of the allowable stress.

In order to solve the limitation of the long span arch structures, a numerical analysis was carried out to investigate the effects of embedded trench installation technique to the earth pressure of an underground arch-rib shaped structure. For the arch-rib shape, the parabolic curve and the circular shape were analyzed according to the span-rise ratio varying from 0.1 to 0.5. The finite element analysis program, ABAQUS (2016), was used to consider the soil - structure interaction. The results from the analysis was verified through comparison with the existing Geofoam application technique.

This research investigates the effects of trench installation methods with expanded polystyrene (EPS) geofoam on the behavior of buried corrugated steel arch structure. A universal finite element analysis program, ABAQUS, was used to model and analyze the structure. For this study, the S275 corrugated steel with a profile of 152x51mm and the arch has fixed boundary condition. The structure was analyzed for three different configurations, namely; without EPS geofoam, imperfect trench installation (ITI), and embedded trench installation (ETI). ITI and ETI cases were further divided depending on the width and height of EPS geofoam. The width of EPS geofoam varies from the span of the arch up to a 30% increase of the span of the arch while its height varies from the rise of the arch upto 100% increase of the rise of the arch. The results from the finite element analysis revealed that the ETI reduced the wall stresses by at least 53.95%. It is recommended to conduct further study regarding ETI to validate the results and to further improved the design criteria of buried corrugated steel arch as it is expected to bring about cost reduction and stability for buried structures.

In this study, the land use is analyzed by using the SWMM-LID (Low Impact Development) program to minimize the environmental damage caused by the development. In order to effectively utilize pre - development hydrological conditions, we analyzed the land use of existing industrial complex. The study areas selected were a completed industrial complex and an ongoing industrial complex in order to effectively identify the characteristics of the industrial complex and the water circulation system. Numerical simulation used SWMM-LID to enable quantitative hydrological impact assessment of penetration, storage facilities and LID planning elements. In the case of natural conditions, the infiltration amount was 16.3% and 1.5% of the total rainfall at B, C point, respectively. However, after applying the existing land use plan, the infiltration amount at point B was 12.1% and at point C was 3.9 %. In the case of point B, the amount of infiltration decreased due to the development of greenery as an impervious site. On the other hand, the amount of infiltration at point C increased as the existing industrial complex was replaced by greenery. Therefore, high infiltration amount can be secured when land use plan is redeveloped in green areas or parks in areas where the permeability coefficient is high according to the ground conditions in the complex. Two types of bio-polymer soil were developed to increase the LID effect and were tested to compare typical soil with these bio-polymer soils.

Over the years, several studies have been made for the improvement of the design criteria of stepped beams. However, studies on lateral-torsional buckling of stepped beams located at the midspan have been very limited. Hence, this study aims to evaluate the elastic lateral-torsional buckling strength of doubly symmetric singly stepped I-beam at midspan subjected to pure bending along the entire span. The I-beam measurements and specifications are in accordance with the AISC standards. For the analysis of stepped beams, the parameters α, β and γ are used. In this paper, singly stepped beams are defined as beams having an increased cross section at midspan. The unbraced length used for the simply supported stepped I-beams are 13.59m, 18.12m, and 22.65m while the parameters α, β and γ for the cross section varies from 0.167~0.333, 1.0~1.4, and 1.0~1.8, respectively. To model and perform the analysis for the I-beams, a universal finite element analysis program, ABAQUS, will be used. S4R elements will be used to model the simply supported beams and to check the accuracy of the models guide design specifications are used. The results from the finite element analysis will be shown in tables and plotted into graphs. Based from the obtained results, conclusions and new design guidelines are proposed.

Sewerage age more rapidly than other facilities, leading to the destruction of the pipeline. Therefore, the replacement of old sewer pipes through long-term construction is costly. In order to solve this problem, this study investigated the ferronickel based sewer pipe with improved chemichal resistance and durability from concrete rigidity pipe. ABAQUS was used as the finite element analysis program and the load was calculated by the method given in the sewage facility standard. Therefore, the results of this study can be referenced in the design and construction of sewer pipes.

Cylindrical steel shell sections have been applied in various engineering fields particularly in recent installations of wind turbine towers. Hence, many researchers are interested in studying cylindrical steel shell structures. However, studies on the effect of the presence or absence of openings are insufficient. Thus, the design criteria for the opening as well as the behavior of wind turbine tower are not clearly presented. Therefore, this study examines the ultimate strength and the behavior of wind tower in consideration of openings, presence of stiffeners, changes in opening width, and thickness variation of stiffeners. ABAQUS, a universal finite element analysis program, was used in to conduct this research. Finally, the results of this study can be a reference for the design and production of wind towers with openings.

The initial production scale of wind tower is very few. But recently, the production scale of wind tower structure has increased gradually because it maximizes the efficiency in green energy. Many researchers are studying the wind tower, but there is no study about the difference of allowable buckling stress of the wind tower with and without opening. Guideline of codes and standards are very limited when designing a wind tower with an opening. It is also rarely that a study considers the design of the wind tower to be a tubular shell with or without an opening. ABAQUS, a general purpose finite element program, which provides safety evaluation and economical standards for the design and behavior of the wind tower considering the effect of opening was used in the study. Finally, results from this study can serve as reference for structural engineers, manufacturers and further studies of wind turbine when designing a tubular shell wind tower with an opening.

There are only 10 projects of the domestic greenhouse gas(GHG) emissions trading scheme in building sector (i.e., 1.5% of 652 registered projects) because the certified methodologies to reduce GHG emissions can not be applied to building sector. This study presents remodeling techniques to reduce GHG emissions in existing buildings. First of all, preconditions and related regulations were reviewed. And then, a pool of factors for GHG reduction are selected and evaluated with respect to factors for reducing energy consumption. This study also investigates the criteria and the decision making process for remodeling techniques to reduce GHG emissions. Finally, the remodeling techniques using the decision making process were grouped based on redundancy of each effect. If reducing methodologies for GHG offset program can be developed using the analyzed remodeling techniques in this study, registered projects in building sector would be increase.

Objective : Dementia prevention program has been applied in Center for dementia by the occupational therapists. We evaluated the efficacy of this program to the elderly non-demented women in senior citizens center for cognitive, physical function and depression.Methods : We applied this program to women subjects from a senior citizens centers in 12 sessions. Cognitive and physical functions and depression were compared between pre and post-intervention with Korean Mini-Mental State Examination (K-MMSE), Timed-Up and Go test (TUG), One Leg Standing Test (OLST) and Geriatric Depression Scale Short Form-Korea version (GDSSF-K).Results : We enrolled 26 non-dementia women from four senior citizens centers in Seoul Yangcheon-gu. The K-MMSE improved after the dementia prevention program significantly (p=.00). The GDSSF-K was significantly different between pre and post-intervention (p=.02). For physical function, TUG (p=.02) and OLST in opening eyes were significantly improved (respectively, p=.00 in right side, and p=.00 in left side). OLST in closed eyes were tend to be improved after the intervention, however, they were not significantly different.Conclusion : The dementia prevention program of Center for dementia has proved to improve cognitive and physical function and to reduce depression in the non-demented women from senior citizens centers. These findings suggest that the dementia prevention program that has led by occupational therapist in Center for dementia can be applied other setting in a community.

In curved I-girder systems, stability is mainly provided by interconnecting cross-frames or diaphragms. These members act as primary load carrying component thus proper design and analysis must be made. This study proposes improvement on the existing cross-frame spacing limit for horizontally curved girder systems utilizing buckling capacities. Eigenvalue analysis was conducted using the finite element program, ABAQUS. Maximum cross-frames spacing (Smax) was computed with varying degree of curvature, flange width-to-depth ratio ( ) and span length-to-depth ratio (L/d). Models were then generated and their buckling modes and critical buckling capacity ratios were obtained. Lastly, a suggestion was developed based on the results of the finite element analysis to provide a better guide on the design of cross-frame spacing limit. The suggested limit was then compared to the existing cross-frame limit to verify the improvement on the cross-frame spacing.

This study analyzes buckling in the lower segment of a tubular steel shell that exhibits the characteristics of a 3MW wind tower with opening and reinforcement. Analytical method using parametric equations based on Eurocode 3 - Design of Steel Structures and numerical method of finite element are used to analyze the critical meridional buckling stress. ABAQUS, a finite element program, is used for the numerical method analysis. Four different cases of tubular steel tower is modeled: without door opening and without reinforcement; with door opening and without reinforcement; without door opening and with reinforcement; and with door opening and with reinforcement. Using the ABAQUS, a linear buckling analysis is done for all cases to recognize five of its buckling mode shapes and its corresponding eigenvalues. Mode shapes from the previous analysis are considered in performing the non-linear analysis using Static Riks. Buckling capacity and its trends in the localized area near the opening is investigated, tabulated and shown in illustrative charts. Moreover, comparison is made between the parametric and finite element analyses.

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.

This study investigates web shear buckling behavior of composite box girder according to the aspect ratio. The nonlinear finite element analyses on composite box girder model having shell elements and solid elements were performed. Also, the steel was modeled as an elasto-plastic material. Ultimate web shear buckling behavior of composite box girder was analyzed, and were compared the inelastic analysis results with shear buckling behavior of plate.

PURPOSES : The purpose of the study was to examine dynamic features of concrete after mixing a little macro fiber with small aspect ratio and long length utilized for bridge, tunnel and shotcrete for tensile performance and crack control in domestic/overseas countries with cement concrete pavement mix. METHODS : Coarse aggregates with small aspect ratio and macro fibers with maximum length of approximately 32 mm are introduced in small quantities in the mix proportions of concrete pavement so as to prevent loss of the workability. Then, this study intends to evaluate the applicability of macro fibers in the mix proportions of concrete pavement by examining the basic construction performance, as well as the change of toughness, the equivalent bending strength and the flexural toughness index caused by compression, bending, tension and the flexural stress-displacement curve. RESULTS : As the results, in each kind of macro fiber, polyvinyl alcohol fiber and steel fiber displayed a good performance. CONCLUSIONS : In 0.2 and 0.3% of fiber contents, it is appeared that polyvinyl alcohol fiber has a large effect on improvement of tensile performance and steel fiber on improvement of deforming performance of bending stress.

본 연구에서는 유비쿼터스 식물공장의 재배환경에 필요한 요소들의 센서 네트워크를 구성하고 자동으로 감지하여 적응형 뉴로-퍼지 추론시스템을 통하여 환경변화를 추론하여 식물공장의 재배환경을 적절하게 제어할 수 있는 새로운 자동제어시스템의 프레임워크를 제안하고, 이를 설계하였다. 유비쿼터스 식물공장 환경을 제어하기 위하여 식물공장의 재배환경에 영향을 미치는 환경요소인 실내온도, 근권온도, 습도, 광도, CO2 농도를 측정할 수 있는 센서 네트워크를 구성하고 측정된 환경요소의 변화에 따라 램프, 환기, 습도, CO2 농도, 온도를 제어할 수 있는 장치를 자동으로 제어할 수 있는 식물공장 자동제어시스템을 설계하였다. 이를 위하여 본 연구에서는 센서를 통하여 받아들이는 입력값을 퍼지소속함수로 변화하고 적응형 뉴로-퍼지시스템에 따라 추론하고 평가하여 보다 정밀하게 식물공장을 자동으로 제어할 수 알고리즘을 개발하였고 이를 구현하였다. 개발된 자동제어시스템을 상추 식물공장에 적용한 결과 만족스러운 시험결과를 얻을 수 있었다. 향후 연구로는 식물공장에서 재배하고 있는 작물별 생장모델의 적합도 검정 및 개선을 위하여, 작물별 재배규칙을 보다 상세히 도출하는 것이 필요하고, 작물의 재배에 필요한 지식을 보다 정량적으로 표현하고 지식상에 내포하고 있는 불확실성을 해결하는 것이 필요하다. 더 나아가 식물공장에서 환경인자간의 상호관련성을 보다 정밀하게 수식화하고 이를 추론할 수 있는 정밀하고 과학적인 자동제어시스템의 개발이 필요하다.