• Title/Summary/Keyword: lateral section

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A Relative Study on Safe Factor by Different Analyses of Slope Stability (EPS공법에 의한 측방유동 저감효과에 관한 해석적 연구)

  • An, Joon-Hee;Jang, Jeong-Wook;Park, Choon-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1181-1186
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    • 2006
  • This study analyzed the reductive effect of lateral flow by the section and height of reinforcement of EPS. The conclusions of the study are as follows. (1) The lateral flow increased as the section of reinforcement decreased. The reinforcement section that satisfied the allowable range of the lateral flow turned out to beapproximately 80% of the standard reinforcement section. (2) As reinforcement height was decreasing, the lateral flow increased. The reinforcement heigh that satisfied the allowable range of the lateral flow turned out to be approximately 50% of the total lateral height of abutment.

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Lateral-torsional buckling of functionally graded tapered I-beams considering lateral bracing

  • Rezaiee-Pajand, Mohammad;Masoodi, Amir R.;Alepaighambar, Ali
    • Steel and Composite Structures
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    • v.28 no.4
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    • pp.403-414
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    • 2018
  • In this paper, the lateral-torsional buckling of axially-transversally functionally graded tapered beam is investigated. The structure cross-section is assumed to be symmetric I-section, and it is continuously laterally supported by torsional springs through the length. In addition, the height of cross-section varies linearly throughout the length of structure. The proposed formulation is obtained for the case that the elastic and shear modulus change as a power function along the beam length and section height. This structure carries two concentrated moments at the ends. In this study, the lateral displacement and twisting angle relation of the beam are defined by sinusoidal series. After establishing the eigenvalue equation of unknown constants, the beam critical bending moment is found. To validate the accuracy and correctness of results, several numerical examples are solved.

Stability Analysis of Marine Structure Foundation Constructed by Deep Mortar Piles (심층몰탈파일로 조성된 항만구조물 기초의 안정성 검토)

  • 천병식;여유현;김경민;양진석;김도식
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.05a
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    • pp.228-233
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    • 2001
  • In this case study, under conideration of field situations, such as increase of water level, height increment of the marine structure, dredging and backfill, the stability analysis of sliding and lateral flow of the marine structure in OOOharbor was carried out, and foundation reinforcement methods was presented. based on the results of site investigation, the stability analysis of slope sliding and lateral flow was performed as following. In section BH-1, 2, the analysis was performed in two cases that the marine structure was heightened and filled, and not heightened and filled. In section BH-1, 4, heightened and filled. The analysis results showed that the stabilities of slope sliding and lateral flow in section BH-1, 2, 3, 4 were unstable. After additional reinforcements with Deep Mortar Pile, the stabilities in section BH-1, 2, 3, 4 were evaluated as efficiently large.

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Experimental study on laterally restrained steel columns with variable I cross sections

  • Cristutiu, Ionel-Mircea;Nunes, Daniel Luis;Dogariu, Adrian Ioan
    • Steel and Composite Structures
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    • v.13 no.3
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    • pp.225-238
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    • 2012
  • Steel structural elements with web-tapered I cross section, are usually made of welded thin plates. Due to the nonrectangular shape of the element, thin web section may be obtained at the maximum cross section height. The buckling strength is directly influenced by lateral restraining, end support and initial imperfections. If no lateral restraints, or when they are not effective enough, the global behaviour of the members is characterized by the lateral torsional mode and interaction with sectional buckling modes may occur. Actual design codes do not provide a practical design approach for this kind of elements. The paper summarizes an experimental study performed by the authors on a relevant number of elements of this type. The purpose of the work was to evaluate the actual behaviour of the web tapered beam-columns when applying different types of lateral restraints and different web thickness.

Lateral Buckling Analysis of Open Section Composite Laminated Beam Under End-Moment (단모멘트를 받는 개단면 박벽 복합재 보의 횡좌굴 해석)

  • 김만호;신동구
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2000.04b
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    • pp.51-58
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    • 2000
  • Lateral buckling behavior of laminated composite thin-walled I-section beams subjected to bending moment is investigated by applying the nonlinear anisotropic thin-walled beam theory. The constituent laminated thin-walled elements of I-section are assumed to be symmetrically laminated. The bending, twisting, and warping stiffnesses of the cross section are obtained based on the definitions of these stiffnesses In the thin-walled anisotropic beam theory In numerical examples, singly-symmetric I-beams with specially orthotropic, quasi-isotropic, angle-plys and various boundary conditions are considered. To validate the proposed theoretical approach, present analytical solutions are compared with three dimensional finite element solutions.

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On the evaluation of critical lateral buckling loads of prismatic steel beams

  • Aydin, R.;Gunaydin, A.;Kirac, N.
    • Steel and Composite Structures
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    • v.18 no.3
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    • pp.603-621
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    • 2015
  • In this study, theoretical models and design procedures of the behavior of thin-walled simply supported steel beams with an open cross section under a large torsional effect are presented. I-sections were chosen as the cross section types. Firstly, the widely used differential equations for the lateral buckling for the pure bending moment effect in a beam element were adopted for the various moment distributions along the span of the beam. This solution was obtained for both mono-symmetric and bisymmetric sections. The buckling loads were then obtained by using the energy method. When using the energy method to solve the problem, it is possible to locate the load not only on the shear center but also at several points of the section depth. Buckling loads were obtained for six different load types. Results obtained for different load and cross section types were checked with ABAQUS software and compared with several standard rules.

Frozen Section Biopsy to Evaluation of Obscure Lateral Resection Margins during Gastric Endoscopic Submucosal Dissection for Early Gastric Cancer

  • Kang, Eun-Jung;Cho, Joo-Young;Lee, Tae-Hee;Jin, So-Young;Cho, Won-Young;Bok, Jin-Hyun;Kim, Hyun-Gun;Kim, Jin-Oh;Lee, Joon-Seong;Lee, Il-Hyun
    • Journal of Gastric Cancer
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    • v.11 no.3
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    • pp.155-161
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    • 2011
  • Purpose: To determine the diagnostic utility of a frozen section biopsy in patients undergoing endoscopic submucosal dissection (ESD) for early gastric neoplasms with obscure margins even with chromoendoscopy using acetic acid and indigo carmine (AI chromoendoscopy). Materials and Methods: The lateral spread of early gastric neoplasms was unclear even following AI chromoendoscopy in 38 patients who underwent ESD between June 2007 and May 2011. Frozen section biopsies were obtained by agreement of the degree of lateral spread between two endoscopists. Thus, frozen section biopsies were obtained from 23 patients (FBx group) and not in the other 15 patients (AI group). Results: No significant differences were observed for size, histology, invasive depth, and location of lesions between the AI and FBx groups. No false positive or false negative results were observed in the frozen section diagnoses. Adenocarcinoma was revealed in three patients and tubular adenoma in one, thereby changing the delineation of lesion extent and achieving free lateral margins. The rates of free lateral resection margins and curative resection were significantly higher in the FBx group than those in the AI group. Conclusions: Frozen section biopsy can help endoscopists perform more safe and accurate ESD in patients with early gastric neoplasm.

An evaluation of stream naturalness for Close-to-nature stream restoration -In case of Suwon stream- (자연형 하천복원을 위한 하천자연도 평가 -수원천을 중심으로-)

  • Kim, Dong-Chan;Lee, Jung;Park, Il-Su
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.5
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    • pp.138-149
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    • 2000
  • The purpose of this study is to evaluate Suwon stream naturalness Index(S.N.I). and tofind out stats, problems and opportunities of the Suwon stream by assessment standard. Assessment standard is mainly based on physical structure of stream environment. the purpose evaluating sectors and elements are physical form and structure restoration of stream. To find out assessment standard of stream naturalness index, conceptual frame of assessment standard has been established, for which four sections, for example, longitudinal section, lateral section, stream bottom structure and water environment, have been selected. Overall stream naturalness index of the Suwon stream has been distributed at 3rd to 4th grade, and 3.3 of assessment index and mode were 3rd grade respectively. stream naturalness index of each section was as follows: Longitudinal section accounted for 3.7in average to be 4th grade, lateral section did 3.8 to be 4th grade, and water environment did 2.4 to be 2nd grade. Analysis of assessment outcome of stream naturalness index has checked status, problems and opportunities of corresponding stream. Assessment of stream naturalness index of the study provides useful information for restoration of close-to-nature stream, and furthermore has its meaning in checking problems and opportunities of Suwon stream.

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Lateral Drift Control and Resizing Technique for Tall Buildings using Lateral-Stiffness Influence Matrix (횡강성 영향행렬을 이용한 고층건물의 횡변위 제어 및 단면 재산정 방안)

  • 이한주;김치경;김호수
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.2
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    • pp.271-279
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    • 2002
  • This study develops the module to find the lateral stiffness influence matrix of each story and performs the displacement sensitivity analysis by virtual load method for the efficiency of optimal design using lateral stiffness influence matrix. Also, resizing technique based on the estimated lateral stiffness increment factors is developed to apply directly the results of optimal design. To this end, resizing technique is divided into the continuous and discrete section design methods. And then the relationships between section properties and section size are established. Specifically, an initial design under strength constraints is first performed, and then the lateral load resistant system is designed to control lateral displacements yet exceeding the drift criteria. Two types of 45-story three dimensional structures we presented to illustrate the features of the lateral drift control and resizing technique for tall buildings proposed in this study.

Inelastic distortional buckling of hot-rolled I-section beam-columns

  • Lee, Dong-Sik
    • Steel and Composite Structures
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    • v.4 no.1
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    • pp.23-36
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    • 2004
  • The inelastic lateral-distortional buckling of doubly-symmetric hot-rolled I-section beam-columns subjected to a concentric axial force and uniform bending with elastic restraint which produce single curvature is investigated in this paper. The numerical model adopted in this paper is an energy-based method which leads to the incremental and iterative solution of a fourth-order eigenproblem, with very rapid solutions being obtained. The elastic restraint considered in this paper is full restraint against translation, but torsional restraint is permitted at the tension flange. Hitherto, a numerical method to analyse the elastic and inelastic lateral-distortional buckling of restrained or unrestrained beam-columns is unavailable. The prediction of the inelastic lateral-distortional buckling load obtained in this study is compared with the inelastic lateral-distortional buckling of restrained beams and the inelastic lateral-torsional buckling solution, by suppressing the out-of-plane web distortion, is published elsewhere and they agree reasonable well. The method is then extended to the lateral-distortional buckling of continuously restrained doubly symmetric I-sections to illustrate the effect of web distortion.