• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1997.04a
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• pp.257-264
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• 1997

Seismic responses of the Hualien large scale seismic test model on a layered soil site are estimated for two recorded earthquakes and the analysis results are then compared and evaluated with the recorded responses. The method adopted for the analysis is based on substructuring method using a lumped parameter model in both the frequency and time domain. the study results indicate that the proposed method can reasonably estimate the earthquake responses of a soil-structure interaction system for engineering purposes.

• Geomechanics and Engineering
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• v.16 no.3
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• pp.309-320
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• 2018

In this paper, a numerical study using finite element method with considering soil-structure interaction was conducted to investigate the stress and deformation behavior of a sheet pile wall structure. In numerical model, one of the nonlinear elastic material constitutive models, Duncan-Chang E-v model, is used for describing soil behavior. The hard contact constitutive model is used for simulating the behavior of interface between the sheet pile wall and soil. The construction process of excavation and backfill is simulated by the way of step loading. We also compare the present numerical method with the in-situ test results for verifying the numerical methods. The numerical analysis showed that the soil excavation in the lock chamber has a huge effect on the wall deflection and stress, pile deflection, and anchor force. With the increase of distance between anchored bars, the maximum wall deflection and anchor force increase, while the maximum wall stress decreases. At a low elevation of anchored bar, the maximum wall bending moment decreases, but the maximum wall deflection, pile deflection, and anchor force both increase. The construction procedure with first excavation and then backfill is quite favorable for decreasing pile deflection, wall deflection and stress, and anchor forces.

• Advances in Computational Design
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• v.9 no.1
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• pp.25-38
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• 2024

This paper presents an advanced analytical approach for the design and analysis of fixed offshore structures with soil structure interaction considered. The proposed methodology involves conducting case studies to illustrate and assess the structural response of a structure considering seven different earthquakes, with the primary goal of ensuring there is no global collapse in the structures. The case studies focus on developing a model for structural analysis and its topside, incorporating nonlinear axial and lateral springs to capture soil-pile interaction. Additionally, mass and damping ratios are considered through the use of dashpots in the analyses. Finite Element Software was employed for structural analyses with detailed modeling, with soil spring nodes applied in the entire structure across various depths. After the finite element analysis was carried out, a sensitivity analysis was conducted to quantify and report the effects of different parameters.

• Structural Engineering and Mechanics
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• v.20 no.4
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• pp.421-434
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• 2005

In this paper, the finite element method is applied to investigate the effect of the lateral boundary in homogenous soil on the seismic response of a superstructure. Some influencing factors are presented and discussed, and several parameters are identified to be important for conducting soil-structure interaction experiments on shaking tables. Numerical results show that the cross-section width L, thickness H, wave propagation velocity and lateral boundaries of soil layer have certain influences on the computational accuracy. The dimensionless parameter L/H is the most significant one among the influencing factors. In other words, a greater depth of soil layer near the foundation should be considered in shaking table tests as the thickness of the soil layer increases, which can be regarded as a linear relationship approximately. It is also found that the wave propagation velocity in soil layer affects the numerical accuracy and it is suggested to consider a greater depth of the soil layer as the wave propagation velocity increases. A numerical study on a soil-structure experimental model with a rubber ring surrounding the soil on a shaking table is also conducted. It is found the rubber ring has great effect on the soil-structure interaction experiments on shaking table. The experimental precision can be improved by reasonably choosing the elastic parameter and width of the rubber ring.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.257-266
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• 1999

This paper presents a method of seismic analysis for a cylindrical liquid storage structure on/in horizontally layered half.space considering the effects of the interior fluid and exterior soil medium in the frequency domain. To capture the essence of fluid-structure-soil interaction effects effectively, a mixed finite element with two-field (u, p) approximation is employed to model the compressive inviscid fluid, while the structure and soil medium are presented by the 3-D axisymmetric finite elements and dynamic infinite elements. The present FE-based method can be applied to the system with complex geometry of fluid region as well as with inhomogeneous near-field soil medium, since it can directly model both the fluid and the soil. For the purpose of verification, dominant peak frequencies in transfer functions for horizontal motions of cylindrical fluid storage tanks with rigid massless foundation on a homogeneous viscoelastic half.space are compared with those by two different added mass approaches for the fluid motion. The comparison indicates that the Present FE-based methodology gives accurate solution for the fluid-structure-soil interaction problem. Finally, as a demonstration of versatility of the present study, a seismic analysis for a real-scale LNG storage tank embedded in layered half.space is carried out, and its member forces along the height of the structure are compared with those by an added mass approach developed by the present writers.

• Structural Engineering and Mechanics
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• v.55 no.1
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• pp.161-189
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• 2015

Soil-pile raft-structure interaction is recognized as a significant phenomenon which influences the seismic behaviour of structures. Soil structure interaction (SSI) has been extensively used to analyze the response of superstructure and piled raft through various modelling and analysis techniques. Major drawback of previous study is that overall interaction among entire soil-pile raft-superstructure system considering highlighting the change in design forces of various components in structure has not been explicitly addressed. A recent study addressed this issue in a broad sense, exhibiting the possibility of increase in pile shear due to SSI. However, in this context, relative stiffness of raft and that of pile with respect to soil and length of pile plays an important role in regulating this effect. In this paper, effect of relative stiffness of piled raft and soil along with other parameters is studied using a simplified model incorporating pile-soil raft and superstructure interaction in very soft, soft and moderately stiff soil. It is observed that pile head shear may significantly increase if the relative stiffness of raft and pile increases and furthermore stiffer pile group has a stronger effect. Outcome of this study may provide insight towards the rational seismic design of piles.

• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.5
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• pp.227-236
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• 2017

This study reviews concepts, theories and formulas included in standards on soil-structure interaction and also shows practical example of application for engineers. Real structures are 3 dimensional and multi degree of freedom but they are often idealized to single degree of freedom for convenience. In this study, detailed procedures to calculate soil spring constants and damping coefficients and method to model soil-structure system are explained. Additionally, case studies to judge fixed base condition and evaluation of applicability of simple analysis method based on response spectra are performed.

• Interaction and multiscale mechanics
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• v.3 no.1
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• pp.55-79
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• 2010

The effect of soil-structure interaction on a single-storey, two-bay space frame resting on a pile group embedded in the cohesive soil (clay) with flexible cap is examined in this paper. For this purpose, a more rational approach is resorted to using the finite element analysis with realistic assumptions. Initially, a 3-D FEA is carried out independently for the frame on the premise of fixed column bases in which members of the superstructure are discretized using the 20-node isoparametric continuum elements. Later, a model is worked out separately for the pile foundation, by using the beam elements, plate elements and spring elements to model the pile, pile cap and soil, respectively. The stiffness obtained for the foundation is used in the interaction analysis of the frame to quantify the effect of soil-structure interaction on the response of the superstructure. In the parametric study using the substructure approach (uncoupled analysis), the effects of pile spacing, pile configuration, and pile diameter of the pile group on the response of superstructure are evaluated. The responses of the superstructure considered include the displacement at top of the frame and moments in the columns. The effect of soil-structure interaction is found to be quite significant for the type of foundation considered in the study. Fair agreement is observed between the results obtained herein using the simplified models for the pile foundation and those existing in the literature based on a complete three dimensional analysis of the building frame - pile foundation - soil system.

• Earthquakes and Structures
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• v.17 no.4
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• pp.373-385
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• 2019

In this article, different frequently adopted modeling aspects of linear and nonlinear dynamic soil-structure interaction (SSI) are studied on a pile-supported integral abutment bridge structure using the open-source platform OpenSees (McKenna et al. 2000, Mazzoni et al. 2007, McKenna and Fenves 2008) for a 2D domain. Analyzed approaches are as follows: (i) free field input at the base of fixed base bridge; (ii) SSI input at the base of fixed base bridge; (iii) SSI model with two dimensional quadrilateral soil elements interacting with bridge and incident input motion propagating upwards at model bottom boundary (with and without considering the effect of abutment backfill response); (iv) simplified SSI model by idealizing the interaction between structural and soil elements through nonlinear springs (with and without considering the effect of abutment backfill response). Salient conclusions of this paper include: (i) free-field motions may differ significantly from those computed at the base of the bridge foundations, thus put a significant bias on the inertial component of SSI; (ii) conventional modeling of SSI through series of soil springs and dashpot system seems to stay on the safer side under dynamic conditions when one considers the seismic actions on the structure by considering a fully coupled SSI model; (iii) consideration of abutment-backfill in the SSI model positively affects the general response of the bridge, as a result of large passive resistance that may develop behind the abutments.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.7
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• pp.379-390
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• 2018

In this study, a numerical approach based on mid-point integrated finite elements and a viscous boundary is proposed for time-domain wave-propagation analyses in infinite poroelastic media. The proposed approach is accurate, efficient, and easy to implement in time-domain analyses. In the approach, an infinite domain is truncated at some distance. The truncated domain is represented by mid-point integrated finite elements with real element-lengths and a viscous boundary is attached to the end of the domain. Given that the dynamic behaviors of the proposed model can be expressed in terms of mass, damping, and stiffness matrices only, it can be implemented easily in the displacement-based finite-element formulation. No convolutional operations are required for time-domain calculations because the coefficient matrices are constant. The proposed numerical approach is applied to typical wave-propagation and soil-structure interaction problems. The model is verified to produce accurate and stable results. It is demonstrated that the numerical approach can be applied successfully to nonlinear soil-structure interaction problems.