• Title/Summary/Keyword: transverse interaction

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Transverse and longitudinal partial interaction in composite bolted side-plated reinforced-concrete beams

  • Oehlers, D.J.;Nguyen, N.T.;Ahmed, M.;Bradford, M.A.
    • Structural Engineering and Mechanics
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    • v.5 no.5
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    • pp.553-563
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    • 1997
  • A procedure is being developed for bolting plates to the sides of existing reinforced concrete beams to strengthen and stiffen them. Unlike standard composite steel and concrete beams in which there is longitudinal-partial-interaction at the steel/concrete interface (that is slip along the length of the beam), composite bolted side-plated reinforced-concrete beams are unique in that they also exhibit transverse-partial-interaction, that is slip transverse to the length of the beam. In this work, the fundamental mathematical models for transverse-partial-interaction and its interaction with longitudinal-partial-interaction are developed. The fundamental models are then further developed to determine the number of connectors required to resist the transverse forces and to limit the degree of transverse-partial-interaction in bolted side-plated reinforced concrete beams.

Retrofitting reinforced concrete beams by bolting steel plates to their sides -Part 2: Transverse interaction and rigid plastic design

  • Oehlers, Deric John;Ahmed, Marfique;Nguyen, Ninh T.;Bradford, Mark Andrew
    • Structural Engineering and Mechanics
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    • v.10 no.3
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    • pp.227-243
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    • 2000
  • In a companion paper, tests on bolted side plated beams have shown that side plates can substantially increase the strength of existing reinforced concrete beams with little if any loss of ductility and, furthermore, induce a gradual mode of failure after commencement of concrete crushing. However, it was also shown that transverse interaction between the side plates and the reinforced concrete beam, that is vertical slip and which is a concept unique to side plated beams, is detrimental. Transverse interaction increases the forces on the bolt shear connectors and, hence, weakens the beam. It also reduces the ability of the composite plated beam to yield and, hence, to attain its full flexural capacity. The generic concept of transverse interaction will be described in this paper and the results used to develop a new form of rigid plastic analysis for bolted side plated beams which is illustrated with an application.

A piecewise linear transverse shear transfer model for bolted side-plated beams

  • Li, Ling-Zhi;Jiang, Chang-Jiu;Su, Ray Kai-Leung;Lo, Sai-Huen
    • Structural Engineering and Mechanics
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    • v.62 no.4
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    • pp.443-453
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    • 2017
  • The performance of bolted side-plated (BSP) beams is affected by the degree of transverse partial interaction, which is a result of the interfacial slip caused by transverse shear transfer between the bolted steel plates and the reinforced concrete beams. However, explicit formulae for the transverse shear transfer profile have yet to be derived. In this paper, a simplified piecewise linear shear transfer model was proposed based on force superposition principle and simplification of shear transfer profiles derived from a previous numerical study. The magnitude of shear transfer was determined by force equilibrium and displacement compatibility condition. A set of design formulae for BSP beams under several basic load cases was also derived. Then the model was verified by test results. A worked example was also provided to illustrate the application of the proposed design formulae. This paper sheds some light on the shear force transfer mechanism of anchor bolts in BSP beams, and offers a practical method to evaluate the influence of transverse partial interaction in strengthening design.

PM Interaction Diagram of RC Columns considering Confinement Effect of Transverse Steels (횡방향철근 구속효과를 고려한 철근콘크리트 기둥의 축력-모멘트 상관도)

  • Son, Hyeok-Soo;Yang, Byung-Hong;Yoon, Cheol-Kyun;Lee, Jae-Hoon
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.324-330
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    • 2005
  • The flexural strength and ductility capacity of reinforced concrete columns are largely dependent on the amount of transverse steel. However, current design code does not specify the confinement effect of transverse steels in strength calculation. A non-linear moment-curvature analysis of RC column sections was conducted in order to develop PM interaction diagram considering transverse reinforcement effects. In this paper, a more reasonable application method of PM interaction diagram considering transverse steel amounts is introduced and proposed, based on moment-curvature non-linear analysis. Also, we proposed simplified method to use. easily in practical design.

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3-D Numerical Experiment for Estimation of Equivalent Resistance Coefficient due to Multi-piers : Effect of Transverse Intervals (상당저항계수식 산정을 위한 3차원 수치실험 : 횡방향 이격거리의 영향)

  • Kim, Hyeong-Seok;Choi, Jun-Woo;Ko, Kwang-Oh;Yoon, Sung-Bum
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.3
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    • pp.216-223
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    • 2009
  • A transverse drag interaction coefficient of the equivalent resistance coefficient formula for square multi-piers higher than water depth and arranged with equal intervals was studied. From the assumption that the energy loss due to drag interaction according to transverse intervals of resistance bodies is essentially identical to the energy loss due to thick orifice according to porosities, the transverse drag interaction coefficient was derived by employing the orifice's energy loss coefficient. The equivalent resistance coefficient formula including the drag interaction coefficient was compared with the numerical experiments using FLOW-3D, the performance of which was verified by Kim et al.(2008) in the experimental condition with the multi-piers. The comparisons showed good agreement and thus, the equivalent resistance coefficient formula, which does not only consider frictional resistance but also consider the multi-piers' drag resistance varied according to the intervals in longitudinal or transverse direction, was verified.

Study on The Estimation of Pipeline\ulcornerSoil Interaction Force during Transverse Permanent Ground Deformation (횡방향 영구지반변형 발생시 관$\cdot$지반 상호작용력의 산정에 관한 연구)

  • 김태욱;임윤묵;김문겸;장성희
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.165-173
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    • 2003
  • In this study, the applicability of currently used pipeline.soil interaction force and previously proposed analytical relationship for the response analysis of buried pipeline subjected to transverse permanent ground deformation (PGD) due to liquefaction is evaluated. Based on meaningful contemplation, the improvement of interaction force and proposition of analytical relationship is made. Improved interaction force includes various patterns of PGD or spatial distributions of interaction force caused by the decrease of soil stiffness, and proposed relationship based on improved formula is applicable without regard to the width of PGD. Through the comparison of numerical results by use of commercial FEM program, the rational applicability of proposed relationship is objectively confirmed.

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Effects of Blood Flow Restriction and Different Support Surfaces on the Thickness of Type-I Muscle Fibers in the Trunk

  • Park, Jae-Cheol;Oh, Seung-Keun;Jeong, Jin-Gyu
    • The Journal of Korean Physical Therapy
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    • v.29 no.2
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    • pp.69-73
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    • 2017
  • Purpose: This study was conducted to investigate the effects of blood flow restriction and different support surfaces for bridge exercises on the thickness of the transverse abdominis and multifidus, which are trunk-stabilizing muscles. Methods: The study's subjects were 45 adults who were divided into three groups that performed bridge exercises over a six-week period on their respective support surfaces after blood flow restriction. Changes in the thickness of the subjects' transverse abdominis and multifidus muscles were measured using ultrasonography before the experiment, then three and six weeks after the experiment. The changes in each variable over time were analyzed using a repeated-measures analysis of variance (ANOVA). Results: The transverse abdominis showed significant differences in muscle thickness with regard to time and the interaction between time and each group (p<0.05), but no significant differences with regard to changes among groups (p>0.05). The multifidus showed significant differences in muscle thickness with regard to time, the interaction between time and each group, and changes between groups (p<0.05). Conclusion: Blood flow restriction and different support surfaces for bridge exercises led to significant differences in the thickness of the transverse abdominis and multifidus. This study's results may be used as the basis for future studies and for rehabilitation in clinical practice.

Study on seismic behavior and seismic design methods in transverse direction of shield tunnels

  • He, Chuan;Koizumi, Atsushi
    • Structural Engineering and Mechanics
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    • v.11 no.6
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    • pp.651-662
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    • 2001
  • In order to investigate the seismic behavior and seismic design methods in the transverse direction of a shield tunnel, a series of model shaking table tests and a two-dimensional finite element dynamic analysis on the tests are carried out. Two kinds of static analytical methods based on ground-tunnel composite finite element model and beam-spring element model are proposed, and the validity of the static analyses is verified by model shaking table tests. The investigation concerns the dynamic response behavior of a tunnel and the ground, the interaction between the tunnel and ground, and an evaluation of different seismic design methods. Results of the investigation indicate that the shield tunnel follows the surrounding ground in displacement and dynamic characteristics in the transverse direction; also, the static analytical methods proposed by the authors can be used directly as the seismic design methods in the transverse direction of a shield tunnel.

Numerical Study on the Motion Characteristics of a Freely Falling Two-Dimensional Circular Cylinder in a Channel (채널 내 자유 낙하하는 2차원 원형 실린더의 운동 특성에 관한 수치적 연구)

  • Jeong, Hae-Kwon;Yoon, Hyun-Sik;Ha, Man-Yeong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.7
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    • pp.495-505
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    • 2009
  • A two-dimensional circular cylinder freely falling in a channel has been simulated by using immersed boundary - lattice Boltzmann method (IB-LBM) in order to analyze the characteristics of motion originated by the interaction between the fluid flow and the cylinder. The wide range of the solid/fluid density ratio has been considered to identify the effect of the solid/fluid density ratio on the motion characteristics such as the falling time, the transverse force and the trajectory in the streamwise and transverse directions. In addition, the effect of the gap between the cylinder and the wall on the motion of a two-dimensional freely falling circular cylinder has been revealed by taking into account a various range of the gap size. As the cylinder is close to the wall at the initial dropping position, vortex shedding in the wake occurs early since the shear flow formed in the spacing between the cylinder and the wall drives flow instabilities from the initial stage of freely falling. In order to consider the characteristics of transverse motion of the cylinder in the initial stage of freely falling, quantitative information about the cylinder motion variables such as the transverse force, trajectory and settling time has been investigate.

Effects of Bridge Exercise with Trunk Rotation on Trunk Muscle Thickness in Healthy Adults (몸통 회전을 이용한 교각운동이 정상 성인의 몸통 근육 두께에 미치는 영향)

  • Kwang Duk Park;Yong Nam Kim
    • Journal of Korean Physical Therapy Science
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    • v.30 no.3
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    • pp.41-48
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    • 2023
  • Background: This study examined the effects of the bridge exercise with trunk rotation on the thickness of body trunk muscles, including external oblique, internal oblique, and transverse abdominis in healthy male adults. Design: Randomized controlled trial Methods: Twenty-four men were evenly divided into a trunk rotation bridge exercise group and a basic bridge exercise group by drawing lots. The two groups performed the respective exercise for thirty minutes, three times a week for six weeks. repeated measure analysis of variance (ANOVA) was used after distinguishing between three different time points before the experiment, three weeks after the experiment, and six weeks after the experiment. The significance level was set at 0.05. In case an interaction between time and group existed, the paired t-test was used to examine the within-group difference. The independent-sample t-test was used to check the between-group difference. The significance level was set at 0.05. Results: All the men showed a significant change over time in their external oblique, internal oblique, and transverse abdominis muscles. An interaction between time and group was also found (p<0.05). Conclusion: The bridge exercise with trunk rotation causes a meaningful difference in the thickness of external oblique, internal oblique, and transverse abdominis muscles. Therefore, this study proposes the use of this exercise for lower-back stabilization in future research and clinical settings.