• Title/Summary/Keyword: dynamic foundation

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Dynamic analysis of structure/foundation systems

  • Penzien, Joseph
    • Structural Engineering and Mechanics
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    • v.17 no.3_4
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    • pp.281-290
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    • 2004
  • A review of current procedures being used in engineering practice to analyze the response of structure/foundation systems subjected separately to different types of dynamic excitation, such as earthquake, sea-wave action, wind, or moving wheel loads, is presented. Separate formulations are given for analyzing systems in the time and frequency domains. Both deterministic and stochastic forms of excitation are treated. A distinction is made between demand and capacity analyses.

Comparative dynamic analysis of axially loaded beams on modified Vlasov foundation

  • Hizal, Caglayan;Catal, Hikmet Huseyin
    • Structural Engineering and Mechanics
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    • v.57 no.6
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    • pp.969-988
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    • 2016
  • Vibration analysis of the beams on elastic foundation has gained the great interest of many researchers. In the literature, there are many studies that focus on the free vibration analysis of the beams on one or two parameter elastic foundations. On the other hand, there are no sufficient studies especially focus on the comparison of dynamic response including the bending moment and shear force of the beams resting on Winkler and two parameter foundations. In this study, dynamic response of the axially loaded Timoshenko beams resting on modified Vlasov type elastic soil was investigated by using the separation of variables method. Governing equations were obtained by assuming that the material had linear elastic behaviour and mass of the beam was distributed along its length. Numerical analysis were provided and presented in figures to find out the differences between the modified Vlasov model and conventional Winkler type foundation. Furthermore, the effect of shear deformation of elastic soil on the dynamic response of the beam was investigated.

Vibration Analysis of Stiffened Thick Plate Subjected to Static Inplane Stress Using Finite Element Method (면내응력을 받는 보강 후판의 유한요소법에 의한 진동해석)

  • 오숙경;김일중;이용수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.952-956
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    • 2004
  • The soil-structure interactions are caused by the point sources of explosions, deriving piles, compaction of foundations and excavations those are frequently arose in the construction sites. Thus the analysis of soil-structure interactions is one of the most important subjects in the fields of dynamic analysis and vibration control. From this viewpoint, the aim of this study is to collect the basic data for designing foundation structures throughout understanding the dynamic structural behavior, which is embodied by the dynamic analysis of soil-structure systems. In this study, the dynamic analyses of stiffened thick plates subjected to in-plane stress on elastic foundations are carried out. The foundation is modeled as Pasternak foundation that includes the continuity effect of foundations. Also both the Mindlin plate theory and Timoshenko beam-column theory are used for analyzing the thick plates and beams, respectively.

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An Impact Test for investigating the Dynamic Characteristics of Actual Bridge Foundation (교량기초의 동적특성 파악을 위한 충격실험)

  • Kim, Hak-Soo;Lee, Sang-Hee;Yang, Kyung-Taek;Kim, Saeng-Bin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.1 no.2
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    • pp.115-122
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    • 1997
  • Although most bridge foundations are usually constructed by Caisson, terrain difficulties sometimes bring about constructing bridge foundations by Jacket piles. This study investigated the dynamic characteristics of Caisson and Jacket by testing the impact applied to actual bridge foundations. The test result showed that the damping ratio of the foundation constructed by Jacket and Caisson were measured 1-2% and 3-6%, respectively. Considering the lateral deflection measured by the impact test, the rigidity of foundations constructed by Jacket was assessed about 1/5 - 1/6 of those constructed by Caisson. It implies that designing bridge foundations should include and reflect the dynamic analysis of bridge foundation.

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Nonlinear dynamic behavior of functionally graded beams resting on nonlinear viscoelastic foundation under moving mass in thermal environment

  • Alimoradzadeh, M.;Akbas, S.D.
    • Structural Engineering and Mechanics
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    • v.81 no.6
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    • pp.705-714
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    • 2022
  • The aim of this paper is to investigate nonlinear dynamic responses of functionally graded composite beam resting on the nonlinear viscoelastic foundation subjected to moving mass with temperature rising. The non-linear strain-displacement relationship is considered in the finite strain theory and the governing nonlinear dynamic equation is obtained by using the Hamilton's principle. The Galerkin's decomposition technique is utilized to discretize the governing nonlinear partial differential equation to nonlinear ordinary differential equation and then the governing equation is solved by using of multiple time scale method. The influences of temperature rising, material distribution parameter, nonlinear viscoelastic foundation parameters, magnitude and velocity of the moving mass on the nonlinear dynamic responses are investigated. Also, the buckling temperatures of the functionally graded beams based on the finite strain theory are obtained.

Dynamic Stability Analysis of Stiffened Tapered Thick Plate with Concentrated Mass on Pasternak Foundations (Pasternak지반에 지지된 집중질량을 갖는 보강된 변단면 후판의 동적안정해석)

  • Lee, Yong-Soo;Kim, Il-Jung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.12
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    • pp.1296-1305
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    • 2009
  • This paper has the object of investigating dynamic stability of stiffened tapered thick plate with concentrated mass on Pasternak foundation by means of finite element method and providing kinematic design data for mat of building structures. Finite element analysis of stiffened tapered thick plate is done by use of rectangular finite element with 8-nodes. In order to analysis plate which is supported on Pasternak foundation, the Winkler foundation parameter is varied with 10, 100, 1000 and the shear foundation parameter is 5, 10, concentrated mass is $0.25m_c$, $1.0m_c$, tapered ratio is 0.25, 0.5. The ratio of In-plane force to critical load is applied as $0.4\sigma_{cr},\;0.6\sigma_{cr},\;0.8\sigma_{cr}$ respectively. This paper analyzed varying tapered ratio.

Dynamic Stability Analysis of Tapered Thick Plate (변단면 후판의 동적안정해석)

  • Kim, Il-Jung;Oh, Soog-Kyoung;Lee, Yong-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.894-897
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    • 2004
  • This paper has the object of investigating dynamic stability of opening thick plates on Pasternak foundation by means of finite element method and providing Kinematic design data for mat of building structures. Finite element analysis of Tapered Thick plate is done by use of rectangular (mite element with 8-nodes. In order to analysis plate which is supported on Pasternak foundation, the Winkler foundation parameter is varied with $10^2,\;10^3$ and the shear foundation parameter is 5, 10. The ratio of In-plane force to critical load is applied as 0.4, 0.6, respectively. This paper analyzed varying Tapered Ratio.

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Review of Design Guide and Case Study on Bored Prefabricated Piling Method in Architectural Building Foundation (건축기초에서의 매입말뚝 설계기준 및 사례)

  • Lee, Won-Je
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.549-558
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    • 2008
  • Well known and widely used in urban area and limited installation condition, a low noise and vibration piling method which has being called Bored Prefabricated Piling Method was reviewed in terms of design guide, and introduced a few case as well. Among the areas being applied of that method, a structural guide of architectural foundation was reviewed and compared to civil engineering foundation area to provide wider information for the foundation engineers. With introducing a few case application including pile load testing review especially dynamic testing in normal building foundation work, engineers may have a useful information on the design and construction of the piling method even different engineering area. It may also make enhancement a view of foundation engineering knowledge to various pile foundation area.

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A Study on the Finite Element Modeling and Analytical Parameters for the Dynamic Stiffness Evaluation of Shipboard Equipment Foundations (선박 장비 받침대의 동강성 평가를 위한 유한요소 모델링과 해석 인자에 관한 연구)

  • Kim, Kook-Hyun;Kim, Yun-Hwan;Choi, Tae-Muk;Choi, Sung-Won;Cho, Dae-Seung
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.6
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    • pp.808-812
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    • 2010
  • This paper studies the finite element modeling and analytical parameters for the numerical evaluation of dynamic stiffness of large foundation for shipboard equipments such as marine diesel engine. For the purpose, numerical method and procedure to evaluate the dynamic stiffness are established based on the impact test method, which are applied for the dynamic stiffness evaluation of a real diesel generator foundation of ship. Numerical investigations compared with the measured data are carried out to evaluate the effects of modeling ranges of ship substructure, finite element sizes, lower support structures and damping coefficients. From the results, modeling and analytical parameters for proper evaluation of dynamic stiffness of large foundation of shipboard equipment are suggested.

Mechanical characteristics + differential settlement of CFG pile and cement-soil compacted pile about composite foundation under train load

  • Cheng, Xuansheng;Liu, Gongning;Gong, Lijun;Zhou, Xinhai;Shi, Baozhen
    • Geomechanics and Engineering
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    • v.20 no.2
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    • pp.155-164
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    • 2020
  • In recent years, the stability, safety and comfort of trains has received increased attention. The mechanical characteristics and differential settlement of the foundation are the main problems studied in high-speed railway research. The mechanical characteristics and differential settlement of the foundation are greatly affected by the ground treatment. Additionally, the effects of train load and earthquakes have a great impact. The dynamic action of the train will increase the vibration acceleration of the foundation and increase the cumulative deformation, and the earthquake action will affect the stability of the substructure. Earthquakes have an important practical significance for the dynamic analysis of the railway operation stage; therefore, considering the impact of earthquakes on the railway substructure stability has engineering significance. In this paper, finite element model of the CFG (Cement Fly-ash Gravel) pile + cement-soil compacted pile about composite foundation is established, and manual numerical incentive method is selected as the simulation principle. The mechanical characteristics and differential settlement of CFG pile + cement-soil compacted pile about composite foundation under train load are studied. The results show: under the train load, the neutral point of the side friction about CFG pile is located at nearly 7/8 of the pile length; the vertical dynamic stress-time history curves of the cement-soil compacted pile, CFG pile and soil between piles are all regular serrated shape, the vertical dynamic stress of CFG pile changes greatly, but the vertical dynamic stress of cement-soil compacted pile and soil between piles does not change much; the vertical displacement of CFG pile, cement-soil compacted pile and soil between piles change very little.