• Title/Summary/Keyword: Load-lateral displacement

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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.

A Study on Behavior Characteristics of Soft Ground by DCM Arrangement Type (DCM 배치 형상에 따른 연약지반 거동 특성에 관한 연구)

  • You, Seung-Kyong;Lee, Jong-Young;Hong, Gigwon
    • Journal of the Korean Geosynthetics Society
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    • v.20 no.4
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    • pp.125-131
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    • 2021
  • This study described the relationship of settlement-lateral displacement and settlement-heaving according to the DCM type using the model test results, in order to evaluate the behavioral characteristics of the soft ground improved with DCM. As a result, it was found that the total settlement of the model ground was relatively small in the soft ground, to which the DCM was applied, and the settlement was less in the order of the grid type, wall type, and pile type under the same load conditions. This trend was also the same for the lateral displacement and heaving. In addition, the relationship between settlement and lateral displacement of soft ground was analyzed to be similar to that of previous study (Leroueil et al., 1990). Therefore, the DCM of grid type was evaluated to be superior to other types for lateral flow and heaving in the improvement effect of soft ground.

Study on lateral behavior of digging well foundation with consideration of soil-foundation interaction

  • Wang, Yi;Chen, Xingchong;Zhang, Xiyin;Ding, Mingbo;Lu, Jinhua;Ma, Huajun
    • Geomechanics and Engineering
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    • v.24 no.1
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    • pp.15-28
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    • 2021
  • Digging well foundation has been widely used in railway bridges due to its good economy and reliability. In other instances, bridges with digging well foundation still have damage risks during earthquakes. However, there is still a lack of knowledge of lateral behavior of digging well foundation considering the soil-foundation interaction. In this study, scaled models of bridge pier-digging well foundation system are constructed for quasi-static test to investigate their lateral behaviors. The failure mechanism and responses of the soil-foundation-pier interaction system are analyzed. The testing results indicate that the digging foundations tend to rotate as a rigid body under cyclic lateral load. Moreover, the depth-width ratio of digging well foundation has a significant influence on the failure mode of the interaction system, especially on the distribution of foundation displacement and the failure of pier. The energy dissipation capacity of the interaction system is discussed by using index of the equivalent viscous damping ratio. The damping varies with the depth-width ratio changing. The equivalent stiffness of soil-digging well foundation-pier interaction system decreases with the increase of loading displacement in a nonlinear manner. The absolute values of the interaction system stiffness are significantly influenced by the depth-width ratio of the foundation.

Method of Reducing Lateral Displacement of Abutment Constructed on Marine Clay Deposits (해안 연약지반상의 교량 구조물 변위 억제)

  • 장용채
    • Journal of Korean Port Research
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    • v.12 no.2
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    • pp.337-348
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    • 1998
  • Since 1970s, though many effective construction methods have been established to solve soft ground problems which had occurred in the off shore land reclamation and on shore highway construction, lateral movement of structure on soft ground is still a big problem to engineers. In this study an applicability of criteria for determining the lateral movement of the structure in soft ground is examined and most measured data is obtained from 140 bridge abutments in highway construction sites. Characteristics and effectiveness of existing methods that used for deciding amount of lateral movements of abutment are analyzed using the obtained data. From the analysis, a proper method to prevent lateral movement is proposed. This method is confirmed on several case histories which were constructed on marine clay.

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A study on determining the minimum vertical spring stiffness of track pad considering running safety. (열차주행안전을 고려한 궤도패드의 최소 수직 스프링계수 결정에 관한 연구)

  • Kim Jeong-ll;Yang SinChu;Kim Yun-Tae
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.842-847
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    • 2004
  • This study presents the minimum spring stiffness of resilient track pad considering the safety of running train. A nonlinear static 3-D finite element is used for the modeling of railway superstructure, especially for the reflection of nonlinear resistance of rail fastening system. Moreover, ballast is considered as an elastic foundation. As the input load, eccentric wheel and lateral force are used and they are derived from ' Lateral-force/Wheel-load Estimation Equations '. Analysis results are compared with following two values : allowable lateral displacement of rail head (derived from the geometrical derailment evaluation of wheel/rail) and operation standard value (derived from the field test results of track).

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Behavior and Hysteresis Characteristics of Traditional Timber Framers under Lateral Load (전통 문화재 목조 프레임의 횡하중에 대한 거동 및 이력특성)

  • 이필성
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.10a
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    • pp.396-403
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    • 1999
  • This experimental study investigates the hysterestic behavior of traditional timber frames subjected to lateral loads. Prototype frames for this study were selected from one of typical national treasures for timber structures in Korea. For simplicity roof structures and braket systems were excluded from specimens and the joint behavior of beam-to-column system were presumed to have crucial effect on their global behavior. The experimental observation showed stiffness degradation and slip after experiencing initial yield and the first cycle at a new larger displacement due to inherent gaps in traditional timber connection and gradual indentation of interfaces, The cyclic behaviors of all specimens were similar to those os modern timber frames with bolt and nail connections. Additional structural members such as an upper beam and clay-filled wall increased the initial stiffness strength and energy dissipation. It is expected that collapse of Korean traditional timber frames under lateral load is mainly caused from P-$\Delta$ effects rather than local member failure.

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An Experimental and Numerical Sutdy oft Restraint Effects of Deformation in Model Foundation(1) (연약지반의 변형억제 효과에 대한 2차원 모형실험 및 수치계산)

  • 박병기;남진희
    • Geotechnical Engineering
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    • v.6 no.3
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    • pp.53-64
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    • 1990
  • Load tests for ten small-scale foundation models combined with geotextile and sand mat were conducted to study the effect of geotextile, sand mat, and foundation types on deformation of foundation soils. In addition, the experimental results were compared with those obtained from numerical analysis using a software program. The main conclusions were summarized as follows : 1. The restraint effect on GIT is more outstanding on the lateral displacement than on the vertical one. 2. The only use of SIM has better effect for the restraint of lateral displacement than vertical ogle. 3. The use of both SIM and GIT are required for the restraint of lateral and vertical displacement.

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A Study on Behavior of the Lateral Movement of Breakwater by Centrifuge model Experiments (원심모형실험에 의한 방파제의 수평변위 거동에 관한 연구)

  • Lee, Dong-Won;Kim, Dong-Gun;Jun, Sang-Hyun;Yoo, Nam-Jae
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1473-1478
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    • 2010
  • For the cassion type of breakwater under the condition of large wave loads, stability about lateral movement of breakwater was investigated by performing centrifuge model experiments. Prototype of breakwater was modelled by scaling down to centrifuge model and the soft ground reinforced with grouting was also reconstructed in the centrifuge model experiments. Sandy ground beneath breakwater was prepared with a soil sampled in field so that identical value of internal friction angle could be obtained. Centrifuge model experiments were carried out to reconstruct the construction sequence in field. Lateral static wave load was applied to the model caisson after the final stage of construction sequence was rebuilt and the measured lateral movement of caisson was compared with allowable value by the code to assess the stability about lateral movement of the breakwater.

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Effects of Bridge Bearings by Structure-Track Interaction for Continuous Bridge applied CWR with Rail Expansion Joint under Temperature Load (레일신축이음 설치된 장대레일 적용 연속교의 구조물-궤도 상호작용에 의한 온도하중이 교량 받침에 미치는 영향)

  • Chung, Jee-Seung;Lee, Jong-Soon
    • Journal of the Korean Society of Safety
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    • v.25 no.5
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    • pp.54-61
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    • 2010
  • The additional axial force of CWR(continuous welded rail) is occurred by structure-track interaction, in reverse, fixed supports of structure are applied the large load by that. Ratio of load which transferred on support through the bridge superstructure with one-side REJ by acceleration and braking load are stated in High-Speed Rail Design Criteria(2005). On the other hand the horizontal forces of support delivered to the load due to thermal loads has been no report about the criteria. Therefore, this study was performed the review of the reaction and displacement on support by structure-track interaction in a special bridge(composite brdiges, 45+55+55+45=200m) with REJ acting on the temperature load. As a result, because fixed support of a special bridge or a continuous bridge with REJ under the temperature load which is constant load has been acted the large lateral load by structure-track interaction, when determining the fixed bearing capacity of structure should be reflected in the results to secure the safety of structures was confirmed.

Comparative in-plane pushover response of a typical RC rectangular wall designed by different standards

  • Dashti, Farhad;Dhakal, Rajesh P.;Pampanin, Stefano
    • Earthquakes and Structures
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    • v.7 no.5
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    • pp.667-689
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    • 2014
  • Structural walls (also known as shear walls) are one of the common lateral load resisting elements in reinforced concrete (RC) buildings in seismic regions. The performance of RC structural walls in recent earthquakes has exposed some problems with the existing design of RC structural walls. The main issues lie around the buckling of bars, out-of plane deformation of the wall (especially the zone deteriorated in compression), reinforcement getting snapped beneath a solitary thin crack etc. This study compares performance of a typical wall designed by different standards. For this purpose, a case study RC shear wall is taken from the Hotel Grand Chancellor in Christchurch which was designed according to the 1982 version of the New Zealand concrete structures standard (NZS3101:1982). The wall is redesigned in this study to comply with the detailing requirements of three standards; ACI-318-11, NZS3101:2006 and Eurocode 8 in such a way that they provide the same flexural and shear capacity. Based on section analysis and pushover analysis, nonlinear responses of the walls are compared in terms of their lateral load capacity and curvature as well as displacement ductilities, and the effect of the code limitations on nonlinear responses of the different walls are evaluated. A parametric study is also carried out to further investigate the effect of confinement length and axial load ratio on the lateral response of shear walls.