• Title, Summary, Keyword: soil-structure interaction

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Earthquake Response Analysis of Bridges with Soil-Structure Interaction and Pier Nonlinearity (지반-구조물 상호작용과 교각의 비선형성을 고려한 교량의 지진응답해석)

  • 이종세;최준성;권오신
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.415-421
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    • 2003
  • With the increasing possibility of earthquake occurrence, seismic safety of bridges has become one of the most important social issues in Korea. In this study, a nonlinear earthquake response analysis is carried out for a real bridge by incorporating soil-structure interaction and pier nonlinearity. The material nonlinearity of the bridge pier is realized by utilizing SAP2000 whereas the soil-structure interaction is analized in time domain by adapting KIESSI. The numerical results are compared to those of the models without considering the effects.

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New coefficients to find natural period of elevated tanks considering fluid-structure-soil interaction effects

  • Maedeh, Pouyan Abbasi;Ghanbari, Ali;Wu, Wei
    • Geomechanics and Engineering
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    • v.12 no.6
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    • pp.949-963
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    • 2017
  • The main purpose of the current study is to develop the new coefficients for consideration of soil-structure interaction effects to find the elevated tank natural period. Most of the recommended relations to find the natural period just assumed the fixed base condition of elevated tank systems and the soil effects on the natural period are neglected. Two different analytical systems considering soil-structure- fluid interaction effects are recommended in the current study. Achieved results of natural impulsive and convective period, concluded from mentioned models are compared with the results of a numerical model. Two different sets of new coefficients for impulsive and convective periods are developed. The values of the developed coefficients directly depend to soil stiffness values. Additional results show that the soil stiffness not only has significant effects on natural period but also it is effective on liquid sloshing wave height. Both frequency content and soil stiffness have significant effects on the values of liquid wave height.

Seismic Response of Base-Isolated Liquid Storage Tanks Considering Liquid-Structure-Soil Interaction (유체-구조물-지반 상호작용을 고려한 면진된 유체저장탱크의 3차원 지진응답)

  • 조성용;김문겸;임윤묵
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.98-105
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    • 2002
  • The effects of the base-isolation system and elastic soil foundation on the behavior of a liquid storage tank are studied. To evaluate the seismic response of liquid storage tank accurately, the coupled dynamic system considering base isolation and soil interaction problem is formulated in time domain. Results show that the base isolation system reduces effectively the radial displacements, base shears, overturning moments, axial resultant stresses and the hydrodynamic pressure by providing flexibility and energy dissipation capability. Base Isolation may, however, increase the relative liquid sloshing amplitude due to the effect of liquid-structure interaction and cause excessive large relative displacements between structure and foundation. In addition to base-isolator, the dynamic behavior of liquid storage tank is related to the flexibility of base foundation, so the analysis of soil-structure interaction s achieved.

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Review of static soil-framed structure interaction

  • Dalili S., Mohammad;Huat, B.B.K.;Jaafar, M.S.;Alkarni, A.
    • Interaction and multiscale mechanics
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    • v.6 no.1
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    • pp.51-81
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    • 2013
  • A wide literature review on Static Soil-Structure-Interaction (SSI) is done to highlight the key impacts of soil complexity on structural members of framed structures. Attention is paid to the developed approaches, i.e., conventional and Finite Element Method (FEM), to emphasize on deficiencies and merits of the proposed methods according to their applicability, accuracy and power to model and idealization of the superstructures as well as the soil continuum. Proposed hypothesis are much deeply discussed herein for better understanding which is normally neglected in literature review papers due to the large number of references and limit of space.

Wavelet analysis of soil-structure interaction effects on seismic responses of base-isolated nuclear power plants

  • Ali, Shafayat Bin;Kim, Dookie
    • Earthquakes and Structures
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    • v.13 no.6
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    • pp.561-572
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    • 2017
  • Seismic base isolation has been accepted as one of the most popular design procedures to protect important structures against earthquakes. However, due to lack of information and experimental data the application of base isolation is quite limited to nuclear power plant (NPP) industry. Moreover, the effects of inelastic behavior of soil beneath base-isolated NPP have raised questions to the effectiveness of isolation device. This study applies the wavelet analysis to investigate the effects of soil-structure interaction (SSI) on the seismic response of a base-isolated NPP structure. To evaluate the SSI effects, the NPP structure is modelled as a lumped mass stick model and combined with a soil model using the concept of cone models. The lead rubber bearing (LRB) base isolator is used to adopt the base isolation system. The shear wave velocity of soil is varied to reflect the real rock site conditions of structure. The comparison between seismic performance of isolated structure and non-isolated structure has drawn. The results show that the wavelet analysis proves to be an efficient tool to evaluate the SSI effects on the seismic response of base-isolated structure and the seismic performance of base-isolated NPP is not sensitive to the effects in this case.

Occurrence mechanism of recent large earthquake ground motions at nuclear power plant sites in Japan under soil-structure interaction

  • Kamagata, Shuichi;Takeqaki, Izuru
    • Earthquakes and Structures
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    • v.4 no.5
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    • pp.557-585
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    • 2013
  • The recent huge earthquake ground motion records in Japan result in the reconsideration of seismic design forces for nuclear power stations from the view point of seismological research. In addition, the seismic design force should be defined also from the view point of structural engineering. In this paper it is shown that one of the occurrence mechanisms of such large acceleration in recent seismic records (recorded in or near massive structures and not free-field ground motions) is due to the interaction between a massive building and its surrounding soil which induces amplification of local mode in the surface soil. Furthermore on-site investigation after earthquakes in the nuclear power stations reveals some damages of soil around the building (cracks, settlement and sand boiling). The influence of plastic behavior of soil is investigated in the context of interaction between the structure and the surrounding soil. Moreover the amplification property of the surface soil is investigated from the seismic records of the Suruga-gulf earthquake in 2009 and the 2011 off the Pacific coast of Tohoku earthquake in 2011. Two methods are introduced for the analysis of the non-stationary process of ground motions. It is shown that the non-stationary Fourier spectra can detect the temporal change of frequency contents of ground motions and the displacement profile integrated from its acceleration profile is useful to evaluate the seismic behavior of the building and the surrounding soil.

Stochastic analysis of seismic structural response with soil-structure interaction

  • Sarkani, S.;Lutes, L.D.;Jin, S.;Chan, C.
    • Structural Engineering and Mechanics
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    • v.8 no.1
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    • pp.53-72
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    • 1999
  • The most important features of linear soil-foundation-structure interaction are reviewed, using stochastic modeling and considering kinematic interaction, inertial interaction, and structural distortion as three separate stages of the dynamic response to the free-field motion. The way in which each of the three dynamic stages modifies the spectral density of the motion is studied, with the emphasis being on interpretation of these results, rather than on the development of new analysis techniques. Structural distortion and inertial interaction analysis are shown to be precisely modeled as linear filtering operations. Kinematic interaction, though, is more complicated, even though it has a filter-like effect on the frequency content of the motion.

Effect of soil-structure interaction for a building isolated with FPS

  • Krishnamoorthy, A.
    • Earthquakes and Structures
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    • v.4 no.3
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    • pp.285-297
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    • 2013
  • The effect of soil structure interaction (SSI) on seismic response of a multi-degree-of-freedom structure isolated with a friction pendulum system (FPS) is studied. In the analysis, the soil is considered as an elastic continuum and is modeled using the finite element method. The effect of SSI on response of the structure is evaluated for twenty far-field and twenty near-fault earthquake ground motions. The effect of friction coefficient of sliding material of FPS on SSI is also studied. The results of the study show that the seismic response of the structure increases for majority of the earthquake ground motions due to SSI. The sliding displacement and base shear are underestimated if SSI effects are ignored in the seismic analysis of structures isolated with FPS.

Analysis of settlements of space frame-shear wall-soil system under seismic forces

  • Jain, D.K.;Hora, M.S.
    • Earthquakes and Structures
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    • v.8 no.5
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    • pp.1255-1276
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    • 2015
  • The importance of considering soil-structure interaction effect in the analysis and design of RC frame buildings is increasingly recognized but still not penetrated to the grass root level owing to various complexities involved. It is well established fact that the soil-structure interaction effect considerably influence the design of multi-storey buildings subjected to lateral seismic loads. The shear walls are often provided in such buildings to increase the lateral stability to resist seismic lateral loads. In the present work, the linear soil-structure analysis of a G+5 storey RC shear wall building frame resting on isolated column footings and supported by deformable soil is presented. The finite element modelling and analysis is carried out using ANSYS software under normal loads as well as under seismic loads. Various load combinations are considered as per IS-1893 (Part-1):2002. The interaction analysis is carried out with and without shear wall to investigate the effect of inclusion of shear wall on the total and differential settlements in the footings due to deformations in the soil mass. The frame and soil mass both are considered to behave in linear elastic manner. It is observed that the soil-structure interaction effect causes significant total and differential settlements in the footings. Maximum total settlement in footings occurs under vertical loads and inner footings settle more than outer footings creating a saucer shaped settlement profile of the footings. Each combination of seismic loads causes maximum differential settlement in one or more footings. Presence of shear wall decreases pulling/pushing effect of seismic forces on footings resulting in more stability to the structures.

Development and Applications of Infinite Elements for Dynamic Soil-Structure Interaction Analysis (동적 지반-구조물 상호작용해석을 위한 무한요소법의 개발 및 응용사례)

  • Yun, C.B.;Yang, S.C.;Kim, J.M.;Choi, J.S.;Kim, D.K.;Seo, C.G.;Chang, S.H.;Park, K.L.
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.14-19
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    • 2008
  • This paper presents dynamic infinite element formulations which have been developed for soil-structure interaction analysis both in frequency and in time domains by the present authors during the past twenty years. Axisymmetric, 2D and 3D layered half-space soil media were considered in the developments. The displacement shape functions of the infinite elements were established using approximate expressions of analytical solutions in frequency domain to represent the characteristics of multiple waves propagating into the unbounded outer domain of the media. The proposed infinite elements were verified using benchmark examples, which showed that the present formulations are very effective for the soil-structure interaction analysis either in frequency or in time domain. Example applications to actual interaction problems are also given to demonstrate the capability and versatility of the present methodology.

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