scholarly journals Full 3D modeling of soil structure interaction by using solid finite elements

2021 ◽  
Author(s):  
Halmat Ahmed Awla ◽  
◽  
Muhammet KARATON ◽  
Keyword(s):  
Poisson’S Ratio ◽  
Seismic Behavior ◽  
Soil Structure ◽  
Time History ◽  
Steel Structure ◽  
Poisson's Ratio ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Numerical Studies ◽  
Solid Finite Elements

Numerical studies for considering soil-structure interaction (SSI) are widely used to providing a better understanding of the seismic behavior of structures. The outcomes of these numerical studies are strongly depending on the input parameters. Back to the literature, for modelling different types of soil, there are convenient procedures whereby a single value of the Poisson's ratio is estimated for each type of soil, however a range limitation between (0.10 to 0.40) is possible, and then other required parameters determined utilizing the tables of the international seismic codes and the equations of the literature. In this article, a comprehensive parametric study was carried out with the aim of evaluating influences of the Poisson’s ratio on the seismic behavior of structures, sixteen values of Poisson’s ratios were interpolated between (0.11 to 0.41) in order to examine all possible trails. For achieving this goal a 4 story steel structure was analyzed on four different soil types (soft, stiff, very dense, and rock soils) under the El Centro acceleration record. The results in terms of time history top displacement and base shears have been discussed.

Effect of Structure-Soil-Structure Interaction (SSSI) between Three Dissimilar Adjacent Bridges

2021 ◽  
Author(s):  
Mohanad Talal Alfach ◽  
Ashraf Ayoub
Keyword(s):  
Seismic Response ◽  
Seismic Behavior ◽  
Soil Structure ◽  
Soil Structure Interaction ◽  
Numerical Analyses ◽  
Seismic Responses ◽  
Structure Interaction ◽  
Internal Forces ◽  
Isolated Bridge ◽  
Effect Of Structure

Abstract The present study assesses the effect of Structure-Soil-Structure-Interaction (SSSI) on the seismic behavior of three dissimilar adjacent bridges by comparing their seismic responses with the seismic response of the isolated bridge including Soil-Structure-Interaction (SSI). To this end, an extensive series of numerical analyses have been carried out to elicit the effects of Structure-Soil-Structure-Interaction (SSSI) on the seismic behavior of three dissimilar bridges with different superstructure masses. The studied bridges are based on groups of piles founded in nonlinear clay. A parametric study has been performed for configurations of three dissimilar bridges with superstructure masses ratios of 200% and 300%, concentrating on the influence of the inter-bridge spacing, and the geometrical position of the bridges towards each other and towards the seismic excitation direction. The numerical analyses have been conducted using a three-dimensional finite difference modeling software FLAC 3D (Fast Lagrangian analysis of continua in 3 dimensions). The results of the numerical simulations clearly show that the seismic responses of the dissimilar grouped bridges were strongly influenced by the neighboring bridges. In particular, the results reveal a salient positive impact on the acceleration of the superstructure by a considerable drop (up to 90.63%) and by (up to 91.27%) for the internal forces induced in the piles. Comparably, the influence of bridge arrangement towards the seismic loading were prominent on both of superstructure acceleration and the internal forces in the piles. The responses were as much as 27 times lesser for the acceleration and 11 times smaller for the internal forces than the response of the isolated bridge. Contrarily, the inter-bridge spacing has a limited effect on the seismic response of the grouped bridges.

Seismic behavior of structures considering uplift and soil–structure interaction

2017 ◽  
Vol 20 (11) ◽  
pp. 1712-1726
Author(s):  
Farhad Behnamfar ◽  
Seyyed Mohammad Mirhosseini ◽  
Hossein Alibabaei
Keyword(s):  
Seismic Behavior ◽  
Soil Structure ◽  
Nonlinear Dynamic Analysis ◽  
Steel Structures ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Nonlinear Seismic Response ◽  
Tensile Forces ◽  
Fixed Base ◽  
Flexible Base

A common assumption when analyzing a structure for earthquake forces is that the building is positively attached to a rigid ground so that it can sustain possible tensile forces without being detached, or uplifted, from its bearing points. Considering the facts that almost no tension can be transferred between a surface foundation and soil and soft soils interact with the supported structure during earthquakes, in this research, the effects of uplift and soil–structure interaction on nonlinear seismic response of structures are evaluated. Several reinforced concrete and steel structures under different suits of consistent ground motions are considered. The base of the buildings is modeled with vertical no-tension springs being nonlinear in compression. The total soil–structure interaction system is modeled within OpenSees, and the seismic behavior is evaluated using a nonlinear dynamic analysis. The nonlinear responses of buildings are determined and compared between three cases: fixed base, flexible base without uplift, and flexible base with uplift. The cases for which uplift in conjunction with soil–structure interaction should be considered are identified.

scholarly journals Investigation Of Soil Structure Interaction Problem For A Masonry Building

2018 ◽  
Vol 1 (1) ◽  
pp. 1010-1018
Author(s):  
Asuman Işıl Çarhoğlu ◽  
Pınar Usta
Keyword(s):  
Soil Structure ◽  
Time History ◽  
Masonry Structure ◽  
Soil Structure Interaction ◽  
Masonry Building ◽  
Structure Interaction ◽  
Motion Data ◽  
Earthquake Effect ◽  
Stone Material ◽  
Interaction Problem

When the behaviors of the structures under the earthquake effect are examined, they are assumed as fixed foundation. Since the differentiation of the soil characteristics effects the behavior of the structures, the soil structure interaction should be taken into account in the earthquake analyzes. The main objective of this research is to examine the soil structure interaction. In this research, the masonry structure with two stories constructed from the stone material is handled. In addition to this, the soil is taken into consideration as sand, clay, rock, and fixed support. The masonry structure with two stories and the different soil layers have been modeledthree-dimensionally by with SAP 2000 program. In the scope of research, Kobe ground motion data was applied to the soil-masonry structure systems by using time history method in the analysis.

Application of 3d Time Domain Method for Seismic Soil-Structure Interaction Analysis of Spatial Grid Structure

2011 ◽  
Vol 383-390 ◽  
pp. 3713-3718
Author(s):  
Hai Shan Li ◽  
Yang Ding
Keyword(s):  
Time Domain ◽  
Soil Structure ◽  
Interaction Analysis ◽  
Time History ◽  
Element Model ◽  
Soil Structure Interaction ◽  
Grid Structure ◽  
Structure Interaction ◽  
Spatial Grid ◽  
Structure Plane

This paper proposes a direct three-dimensional (3D) numerical method in time domain for seismic soil-structure interaction (SSI) analysis of spatial grid structure. First, a finite element model including soil, foundation and typical spatial grid structure is developed. Then, the precisions of equivalent viscous-spring artificial boundary element (VSABE) and size effect of site soil region are discussed. Finally, under different site types, time history analyses for models with or without considering SSI effect are implemented respectively under horizontal seismic excitation. The results show that VSABE has the same precision as infinite element boundary and plane size of truncated soil region can be five times of structure plane size for SSI analysis of spatial grid structure. Moreover, except for hard site, it is shown that horizontal acceleration and displacement of spatial grid roof increases substantially when SSI effect is considered. Therefore, it is suggested that SSI influence should be taken into account in engineering design of spatial grid structure.

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