Numerical studies of soil–structure interaction using a simple interface model

1988 ◽  
Vol 25 (1) ◽  
pp. 158-162 ◽  
Author(s):  
D. V. Griffiths
Keyword(s):  
Soil Structure ◽  
Full Range ◽  
Interface Roughness ◽  
Soil Structure Interaction ◽  
Upper And Lower Bounds ◽  
Rational Approach ◽  
Interface Model ◽  
Closed Form Solutions ◽  
Structure Interaction ◽  
Interface Behaviour

The effect of interface roughness in problems of soil–structure interaction is demonstrated using a simple finite element interface model. Three examples of geotechnical interest are presented to demonstrate the approach, and comparisons are made with closed-form solutions where available. Both rough and smooth extremes of interface behaviour are analysed. The smooth interface modelling is performed without the use of specialized elements, and involves uncoupling and rotation of freedoms parallel to the proposed interface direction. It is suggested that, in view of the uncertainties often associated with interface properties, a rational approach for engineering purposes is to obtain solutions for the perfectly rough and perfectly smooth cases leading to upper and lower bounds on the full range of interface behaviour. Key words: finite elements, interfaces, soil–structure interaction, foundations, lateral loads, culverts, piles.

Investigation of Soil-Structure Interaction and Higher-Mode Effects on Dynamic Response of Base-Isolated Structure Founded on Half Space

2013 ◽  
Author(s):  
C. S. Tsai ◽  
H. C. Su
Keyword(s):  
Closed Form ◽  
Soil Structure ◽  
Dynamic Responses ◽  
Soil Structure Interaction ◽  
Entire System ◽  
Higher Mode Effects ◽  
Closed Form Solutions ◽  
Structure Interaction ◽  
Mode Effects ◽  
Isolated Structures

This paper attempts to investigate the effects of soil-structure interaction (SSI) and higher modes on the dynamic responses of base-isolated structures through closed-form solutions for a superstructure, seismic isolator, and soil system under various conditions, comprising the cases of rigid and half-space foundations. The proposed system considers continuum media for both the superstructure and soil foundation, which can take the effects of higher modes into account, along with a discontinuous layer with a governing equation that interprets the mechanical behavior of the base-isolation system. Then, the closed-form solutions in terms of well-known frequency and impedance ratios under various conditions of soil foundations were obtained through rigorous mathematical derivations and validations by collapsing the entire system to a single degree-of-freedom system in structural dynamics and well-known cases of wave propagation in elastic solids. The closed-form solutions derived in this study explicitly revealed the characteristics of the SSI and higher mode effects in influencing the seismic behavior of base-isolated structures. Furthermore, the SSI effects on the dynamic responses of the entire system were extensively evaluated. The conclusive results of this paper will be useful for understanding the SSI and higher mode effects on the dynamic responses of base-isolated structures.

Effects of Soil-Structure Interaction, Damping and Higher Modes on the Response of a Mid-Story-Isolated Structure Founded on Multiple Soil Layers

2014 ◽  
Author(s):  
Chong-Shien Tsai ◽  
Hui-Chen Su
Keyword(s):  
Soil Structure ◽  
Mechanical Impedance ◽  
Soil Structure Interaction ◽  
Entire System ◽  
Soil Layers ◽  
Higher Modes ◽  
Closed Form Solutions ◽  
Structure Interaction ◽  
Fixed Base ◽  
Beam Type

This paper focuses on investigating the effects of soil-structure interaction (SSI), higher modes, and damping on the response of a mid-story-isolated structure founded on multiple soil layers overlying bedrock. Closed-form solutions were obtained for the entire system, which consists of a shear beam type superstructure, seismic isolator, and multiple soil layers overlying bedrock, while subjected to ground motion. The proposed formulations simplify the problem in terms of well-known frequency and mechanical impedance ratios that can take into account the effects of SSI, higher modes, and damping in the entire system, and be capable of explicitly interpreting the major dynamic behavior of a mid-story-isolated structure interacting with the multiple soil layers overlying bed rock. The SSI effects on the dynamic response of a mid-story-isolated structure as a result of multiple soil layers overlying bedrock were extensively investigated through a series of parametric studies and physically explained by virtue of derived formulations. In addition, the results of numerical exercises show that higher damping provided by the isolator may provoke higher mode response of the superstructure; that the lower structure below the isolator may have significantly larger deformations compared to those of the upper structure above the isolator; and that isolator displacements may be amplified by the SSI effects while compared to those of mid-story-isolated structures with fixed-base.

Interface Model for Dynamic Soil‐Structure Interaction

1984 ◽  
Vol 110 (9) ◽  
pp. 1257-1273 ◽  
Author(s):  
Md. Musharraf‐uz Zaman ◽  
Chandrakant S. Desai ◽  
Eric C. Drumm
Keyword(s):  
Soil Structure ◽  
Soil Structure Interaction ◽  
Interface Model ◽  
Structure Interaction

scholarly journals SOIL-STRUCTURE INTERACTION ANALYSES OF PILE SUPPORTED BUILDING FRAME

2017 ◽  
Vol 25 (2) ◽  
pp. 457-467 ◽  
Author(s):  
H.S. Chore ◽  
R.K. Ingle
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Soil Structure ◽  
Salient Feature ◽  
Soil Structure Interaction ◽  
Rational Approach ◽  
Element Analysis ◽  
Interface Elements ◽  
Structure Interaction ◽  
Pile Cap

The effect of the soil-structure interaction on the simple single storeyed and two bayed space frame resting on pile group of two piles with flexible cap is examined in this paper by resorting to more rational approach and realistic assumptions. Initially, 3-D FEA is carried out independently for the frame on the premised of fixed column bases. Later, pile foundation is worked out separately. The stiffness so obtained for foundation is used in the interactive analysis of frame to quantify the effect of soil- structure interaction on the response of the superstructure. For modeling the foundation system two approaches of finite element analysis are used. In the first approach complete three dimensional finite element analysis is resorted to wherein pile, pile cap along with the soil are discretized into 20 noded isoparametric continnum elements and interface between pile and soil is idealized as  6 noded isoparametric interface elements. In the second approach simplified finite element analysis procedure is used wherein beam element, plate element and spring elements are used to model pile, pile cap and soil respectively.  The salient feature of the investigation is that the interaction between pile cap and soil underlying it is considered. In the parametric study presented here, effect of pile spacing and pile configuration is evaluated on the response of superstructure in the form top displacement in frame and bending moment at top as well as bottom of the superstructure columns. Results obtained by either analysis are compared.   

Sign in / Sign up

Export Citation Format

Share Document