• Title/Summary/Keyword: variable foundation

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Shear Design of Deep Beam with Variable Depth (변단면 깊은 보의 전단설계)

  • Choi, Jeong-Ho;Kim, Tae-Wan;Lee, Seung-Hun;Eom, Jang-Sub;Jin, Chi-Sub
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.377-380
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    • 2004
  • Reinforced concrete deep beams are commonly used in many structural applications, including transfer girders. pile caps, foundation walls. and offshore structures. In this paper. the shear behavior and reinforcement effects of simply supported reinforced concrete deep beam with variable depth subject to concentrated loads have been scrutinized using strut-and-tie model to verify the effects of variable depth. The analysis results show that strut-and-tie Model of ACI 318-02 code is very effective method to design of simply supported reinforced concrete deep beam with variable depth.

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A Study on the Quality of Variable Space for the Museum Space - Focused on Educational Space - (뮤지엄 공간의 가변적 활용 특성에 관한 연구 - 교육공간을 중심으로 -)

  • Zheng, Hua;Lee, Sung-Hoon
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2008.05a
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    • pp.220-225
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    • 2008
  • Museum has been advanced according to the change of the society, playing a role of social education for people as a public place. However, many museum have limited which does not allow the museum to act various roles for public needs such as resting, entertaining, educating. Accordingly, this research has intention to solve the problem that the museum cannot satisfy public various needs by functional adaptation of the space; the theory of variable space. The objective of this research is to try to find the problems and solutions from museum space through research about Spatial variability and to analyze expression special quality of museum that is used as variable. Therefore, this research is to lay the foundation of Variable application technique of educational space of museum hereafter.

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Benchmark test of large scale offshore wind turbine with jacket foundation

  • Baek, Jaeha;Park, Hyunchul;Shi, Wei;Lee, Jusang;Lee, Jongsun
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.37.2-37.2
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    • 2011
  • Nowadays, offshore wind energy experiences a rapid development because of its wind condition and no noise impact problem. Different from Europe, offshore wind is just started in Asia. More work and research are needed in Korea. In this work, a three-bladed upwind variable speed pitch controlled 5MW wind turbine on a jacket support structure is used. During the simulation, several design load cases are investigated in two different fully coupled aero-hydro-servo-elastic codes. Some critical loads on the foundation are compared and analyzed.

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Eigen analysis of functionally graded beams with variable cross-section resting on elastic supports and elastic foundation

  • Duy, Hien Ta;Van, Thuan Nguyen;Noh, Hyuk Chun
    • Structural Engineering and Mechanics
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    • v.52 no.5
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    • pp.1033-1049
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    • 2014
  • The free vibration of functionally graded material (FGM) beams on an elastic foundation and spring supports is investigated. Young's modulus, mass density and width of the beam are assumed to vary in thickness and axial directions respectively following the exponential law. The spring supports are also taken into account at both ends of the beam. An analytical formulation is suggested to obtain eigen solutions of the FGM beams. Numerical analyses, based on finite element method by using a beam finite element developed in this study, are performed in order to show the legitimacy of the analytical solutions. Some results for the natural frequencies of the FGM beams are given considering the effect of various structural parameters. It is also shown that the spring supports show the greatest effect on the natural frequencies of FGM beams.

Analysis of circular plates on two - parameter elastic foundation

  • Saygun, Ahmet;Celik, Mecit
    • Structural Engineering and Mechanics
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    • v.15 no.2
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    • pp.249-267
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    • 2003
  • In this study, circular plates subjected to general type of loads and supported on a two-parameter elastic foundation are analysed. The stiffness, elastic bedding and soil shear effect matrices of a fully compatible ring sector plate element, developed by Saygun (1974), are obtained numerically assuming variable thickness of the element. Ring sector soil finite element is also defined to determine the deflection of the soil surface outside the domain of the plate in order to establish the interaction between the plate and the soil. According to Vallabhan and Das (1991) the elastic bedding (C) and shear parameters ($C_T$) of the foundation are expressed depending on the elastic constants ($E_s$, $V_s$) and the thickness of compressible soil layer ($H_s$) and they are calculated with a suitable iterative procedure. Using ring sector elements presented in this paper, permits the generalization of the loading and the boundary conditions of the soil outside the plate.

A third-order parabolic shear deformation beam theory for nonlocal vibration analysis of magneto-electro-elastic nanobeams embedded in two-parameter elastic foundation

  • Ebrahimi, Farzad;Barati, Mohammad Reza
    • Advances in nano research
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    • v.5 no.4
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    • pp.313-336
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    • 2017
  • This article investigates vibration behavior of magneto-electro-elastic functionally graded (MEE-FG) nanobeams embedded in two-parameter elastic foundation using a third-order parabolic shear deformation beam theory. Material properties of MEE-FG nanobeam are supposed to be variable throughout the thickness based on power-law model. Based on Eringen's nonlocal elasticity theory which captures the small size effects and using the Hamilton's principle, the nonlocal governing equations of motions are derived and then solved analytically. Then the influences of elastic foundation, magnetic potential, external electric voltage, nonlocal parameter, power-law index and slenderness ratio on the frequencies of the embedded MEE-FG nanobeams are studied.

Nonlinear stability analysis of porous sandwich beam with nanocomposite face sheet on nonlinear viscoelastic foundation by using Homotopy perturbation method

  • Rostamia, Rasoul;Mohammadimehr, Mehdi
    • Steel and Composite Structures
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    • v.41 no.6
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    • pp.821-829
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    • 2021
  • Nonlinear dynamic response of a sandwich beam considering porous core and nano-composite face sheet on nonlinear viscoelastic foundation with temperature-variable material properties is investigated in this research. The Hamilton's principle and beam theory are used to drive the equations of motion. The nonlinear differential equations of sandwich beam respect to time are obtained to solve nonlinear differential equations by Homotopy perturbation method (HPM). The effects of various parameters such as linear and nonlinear damping coefficient, linear and nonlinear spring constant, shear constant of Pasternak type for elastic foundation, temperature variation, volume fraction of carbon nanotube, porosity distribution and porosity coefficient on nonlinear dynamic response of sandwich beam are presented. The results of this paper could be used to analysis of dynamic modeling for a flexible structure in many industries such as automobiles, Shipbuilding, aircrafts and spacecraft with solar easured at current time step and the velocity and displacement were estimated through linear integration.

Analysis and Design of Mat Foundation for High -Ribe Buildings (초고층 건물의 전면기초(MAT 기초) 해석 및 설계)

  • Hong, Won-Gi;Hwang, Dae-Jin;Gwon, Jang-Hyeok
    • Geotechnical Engineering
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    • v.11 no.2
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    • pp.51-70
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    • 1995
  • Types of foundation of high rise buildings are primarily determined by loads transmitted from super structure, soil bearing capacity and available construction technology, The use of deep foundation of the buildings considered in this study due to the fact that rock of enough bearing capacity is not found down until 90~l00m. When a concentration of high soil pressure must be distributed over the entire building area, when small soft soil areas must be bridged, and when compressible strata are located at a shallow depth, mat foundation may be useful in order to have settlement and differential settlement of variable soils be minimized. The concept of mat foundation will also demonstrate some difficulties of applications if the load bearing demand directly carried down to the load -bearing strata exceeds the load -bearing capacity. This paper introduces both the analysis and design of mat type foundation for high rise buildings as well as the method-ology of modelling of the soil foundation, especially, engineered to redistribute the stress exceeding the soil bearing capacity. This process will result in the wide spread of stresses over the entire building foundation.

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Experimental evaluation of back-to-back anchored walls by double-plates anchors

  • Amir, Najafizadeh;AmirAli, Zad
    • Geomechanics and Engineering
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    • v.31 no.6
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    • pp.599-614
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    • 2022
  • One of the methods of stabilizing retaining walls, embankments, and deep excavations is the implementation of plate anchors (like the Geolock wall anchor systems). Back-to-back Mechanically Stabilized Earth (BBMSE) walls are common stabilized earth structures that can be used for bridge ramps. But so far, the analysis of the interactive behavior of two back-to-back anchored walls (BBAW) by double-plates anchors (constructed closely from each other and subjected to the limited-breadth vertical loading) including interference of their failure and sliding surfaces has not been the subject of comprehensive studies. Indeed, in this compound system, the interaction of sliding wedges of these two back-to-back walls considering the shear failure wedge of the foundation, significantly impresses on the foundation bearing capacity, adjacent walls displacements and deformations, and their stability. In this study, the effect of horizontal distance between two walls (W), breadth of loading plate (B), and position of vertical loading was investigated experimentally. In addition, the comparison of using single and equivalent double-plate anchors was evaluated. The loading plate bearing capacity and displacements, and deformations of BBAW were measured and the results are presented. To evaluate the shape, form, and how the critical failure surfaces of the soil behind the walls and beneath the foundation intersect with one another, the Particle Image Velocimetry (PIV) technique was applied. The experimental tests results showed that in this composite system (two adjacent-loaded BBAW) the effective distance of walls is about W = 2.5*H (H: height of walls) and the foundation effective breadth is about B = H, concerning foundation bearing capacity, walls horizontal displacements and their deformations. For more amounts of W and B, the foundation and walls can be designed and analyzed individually. Besides, in this compound system, the foundation bearing capacity is an exponential function of the System Geometry Variable (SGV) whereas walls displacements are a quadratic function of it. Finally, as an important achievement, doubling the plates of anchors can facilitate using concrete walls, which have limitations in tolerating curvature.

Physical modelling of sliding failure of concrete gravity dam under overloading condition

  • Zhu, Hong-Hu;Yin, Jian-Hua;Dong, Jian-Hua;Zhang, Lin
    • Geomechanics and Engineering
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    • v.2 no.2
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    • pp.89-106
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    • 2010
  • Sliding within the dam foundation is one of the key failure modes of a gravity dam. A two-dimensional (2-D) physical model test has been conducted to study the sliding failure of a concrete gravity dam under overloading conditions. This model dam was instrumented with strain rosettes, linear variable displacement transformers (LVDTs), and embedded fiber Bragg grating (FBG) sensing bars. The surface and internal displacements of the dam structure and the strain distributions on the dam body were measured with high accuracy. The setup of the model with instrumentation is described and the monitoring data are presented and analyzed in this paper. The deformation process and failure mechanism of dam sliding within the rock foundation are investigated based on the test results. It is found that the horizontal displacements at the toe and heel indicate the dam stability condition. During overloading, the cracking zone in the foundation can be simplified as a triangle with gradually increased height and vertex angle.