• Structural Engineering and Mechanics
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• v.9 no.2
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• pp.127-139
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• 2000

The isoparametric element method is used for a plate on non-homogenous foundation. The surface displacement due to a point force acting on the non-homogeneous foundation is the fundamental solution. Based on this analysis, the interaction between the foundation and plate can be determined and the reaction of the foundation can be treated as the external force to the plate. Therefore, only the plate needs to be divided into some elements. The method presented in this paper can be used in cases such as thin or thick plate, different plate shapes, various loading, homogenous and non-homogenous foundations. The examples in this paper show that this method is versatile, efficient and highly accurate.

• Structural Engineering and Mechanics
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• v.33 no.5
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• pp.573-588
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• 2009

In this paper a four-node hybrid stress element is proposed for analysing arbitrarily shaped plates on a two parameter elastic foundation. The element is developed by combining a hybrid plate stress element and a soil element. The formulation is based on Hellinger-Reissner variational principle in which both inter element compatible boundary displacement and equilibrated stress fields for the plate as well as the foundation are chosen separately. This formulation also allows a low order polynomial interpolation functions. Numerical examples are presented to show that the validity and efficiency of the present element for the plate analysis resting on an elastic foundation. In these examples the effect of soil depth, interaction between closed plates on soil parameters, comparison with Winkler hypothesis is investigated.

• Smart Structures and Systems
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• v.16 no.1
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• pp.81-100
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• 2015

This paper presents nonlinear analysis of an arbitrary functionally graded circular plate integrated with two functionally graded piezoelectric layers resting on the Winkler-Pasternak foundation. Geometric nonlinearity is considered in the strain-displacement relation based on the Von-Karman assumption. All the mechanical and electrical properties except Poisson's ratio can vary continuously along the thickness of the plate based on a power function. Electric potential is assumed as a quadratic function along the thickness direction. After derivation of general nonlinear equations, as an instance, numerical results of a functionally graded material integrated with functionally graded piezoelectric material obeying two different functionalities is investigated. The effect of different parameters such as parameters of foundation, non homogenous index and boundary conditions can be investigated on the mechanical and electrical results of the system. A comprehensive comparison between linear and nonlinear responses of the system presents necessity of this study. Furthermore, the obtained results can be validated by using previous linear and nonlinear analyses after removing the effect of foundation.

• Steel and Composite Structures
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• v.44 no.4
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• pp.557-567
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• 2022

Nonlinear free vibration analysis of a functionally graded beam resting on the nonlinear viscoelastic foundation is studied with uniform temperature rising. The non-linear strain-displacement relationship is considered in the finite strain theory. The governing nonlinear dynamic equation is derived based on the finite strain theory with using of 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 is solved by using of multiple time scale method. The influences of temperature rising, material distribution parameter, nonlinear viscoelastic foundation parameters on the nonlinear free response and phase trajectory are investigated. In this paper, it is aimed that a contribution to the literature for nonlinear thermal vibration solutions of a functionally graded beam resting on the nonlinear viscoelastic foundation by using of multiple time scale method.

• Structural Engineering and Mechanics
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• v.5 no.1
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• pp.1-19
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• 1997

A numerical procedure for dynamic analysis of structures including lateral-torsional coupling, axial force effect and soil-structure interaction is presented in this study. A simple soil-structure system model has been designed for microcomputer applications capable of reflecting both kinematic and inertial soil-foundation interaction as well as the effect of this interaction on the superstructure response. A parametric study focusing on inertial soil-structure interaction is carried out through a simplified nine-degree of freedom building model with different foundation conditions. The inertial soil-structure interaction and axial force effects on a 20-storey building excited by an Australian earthquake is analysed through its top floor displacement time history and envelope values of structural maximum displacement and shear force.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.398-403
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• 2002

The low slump mortar grouting is widely used in reinforcement of structural foundation and ground improvement in soft ground. It also has merit that construction is possible in insufficient space. In this study, the main purpose is to evaluate effects for contiguous structures that can be happened along with soft ground improvement by the low slump mortar grouting. To estimate these effects, numerical analysis using finite difference method was applied. It was performed to analyze settlement, upheaval and horizontal displacement of surrounding ground and to measure horizontal stress variation by the first and the second grouting in the pile foundation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.1
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• pp.9-20
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• 2002

The purpose of this research is to develop computational procedures for studying nonlinear soil-structure interaction Problems. In orders to study soil-structure interaction behavior, the finite element analysis for the strip footing subjected to both vortical and lateral loads, and foundation layer reinforced with sheet pile are considered, interface elements are used between the footing and the soil to model the interaction behavior The main analyzed results are as follows; 1. For the prediction of settlement and lateral displacement, the result due to interface element was evaluated larger then without interface element. 2. For the determination of ultimate bearing capacity, the value using interface element appeared smaller by 12%, which was safe. 3. The horizontal and vertical displacement of strip footing affected by the presence of interface element.

• Journal of the Korean GEO-environmental Society
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• v.21 no.5
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• pp.13-21
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• 2020

In this study, the reliability of the lateral spring constant (k1) applied during design of pile foundation for bridge abutment was evaluated. To do this, the reliability of the factors related to the prediction of the lateral displacement of the abutment pile foundation, which was designed based on the displacement method proposed by Chang (1937), was analyzed. The data used for analysis were the design statements of ◯◯ bridge and ◯◯ IC2 bridge. Then, it was derived by comparing with the numerical analysis (p-y analysis) based on the basic data.

• Journal of the Korean GEO-environmental Society
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• v.5 no.1
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• pp.5-12
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• 2004

Soft foundation is extensively distributed in coastal areas including our local regions. Embankment load on such soft foundation causes displacement due to lack of base ground supports. Long-term consolidation can result in settlement and destruction of shear failure and structure. Therefore, a variety of vertical drain methods are applied to construction sites to prevent base from breaking and changing for secure construction. This study analyzed the patterns of changes displacement to determine efficient range of improvement since range of vertical drain material determines vertical and horizontal changes based on the width range of under ground improvement. Changes of intensity with distance from embankment edge were also analyzed in the field study of embankment slope.

• Geomechanics and Engineering
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• v.21 no.1
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• pp.73-84
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• 2020

In the seismic design of bridges, formation of plastic hinges plays an important role in the dissipation of seismic energy. In the case of conventional fixed-base bridges, the plastic hinges are allowed to form in the superstructure alone. During seismic event, such bridges may be safe from collapse but the superstructure undergoes significant plastic deformations. As an alternative design approach, the plastic hinges are guided to form in the soil thereby utilizing the inevitable yielding of the soil. Rocking foundations work on this concept. The formation of plastic hinges in the soil reduces the load and displacement demands on the superstructure. This study aims at evaluating the seismic response of bridge pier supported on rocking shallow foundation. For this purpose, a BNWF model is implemented in OpenSees platform. The capability of the BNWF model to capture the SSI effects, nonlinear behavior and dynamic loading response are validated using the centrifuge and shake table test results. A comparative study is performed between the seismic response of the bridge pier supported on the rocking shallow foundation and conventional fixed-base foundation. Results of the study have established the beneficial effects of using the rocking shallow foundation for the seismic response analysis of the bridge piers.