Response of soil–foundation–structure interaction of tall building (frame-wall) structural system under seismic effect

Qaftan, O

Abstract

The unavailability of standards or validated analysis techniques of estimating the soil -foundation-structure interaction (SFSI) lead to either simplifying or ignoring this interaction. The structural and geotechnical engineers consider the foundation effect on the multi-story building design. Where both the structural and geotechnical analysis is usually conducted individually. The geotechnical engineer may simplify a multi-degree of freedom to a single degree of freedom oscillator, and on the other hand, structural engineers may ignore the soil-foundation-structure interaction SFSI or
represent the nonlinear soil-foundation-Structure interaction with simple linear springs, where the nonlinear Interaction between the superstructure and the substructure is neglected. This study was carried out using experimental and numerical approaches to
analysis the Interaction of soil foundation structures under seismic effect.

Experimental work was performed through a series of shaking table test events for different parametric studies such as building height, soil density, and foundation type under the impact of shaking waves representing the soil vibration of seismic effect. Numerical simulation was performed using two popular software packages i.e.
ABAQUS and ETABS package to solve the three-dimensional problem of soil foundation structure response under seismic effect. The results obtained from the software will then be compared with those obtained by experimental work.

Based on the literature review, the following parameters (which are believed to have an influence on the Soil Structural Interaction response) were investigated in this study:
Building characteristics such as the height and mass,
Soil properties including the dynamic stiffness, damping ratio, shear, angle of internal friction and shear wave velocity,
Pile group configuration and the nonlinear interaction between piles and the Soil,
Type of the foundation such as Raft, and Raft-Pile foundations.
Characteristics of the input motion (earthquake type).

The main purpose of the experimental tests was to investigate the effect of the parameters on the structure and compare the outcome of those tests with the predictions from the software programme to validate the numerical model for further dynamic studies.

The experimental work was divided into four stages: Firstly, the fixed base stage. Secondly, the soil container stage. Thirdly, the soil-foundation-structure interaction (raft foundation). Fourthly, the soil-foundation-structure interaction (pile foundation). Comparing the results of the numerical model and the experimental measurements, it can be concluded that the employed numerical model is appropriate for the simulation of the soil-foundation - structure interaction under dynamic effect. The scale models
demonstrate some behaviour of the prototype in economical way without examining the prototype itself. Consequently, the proposed numerical model of raft foundation and pile foundation are valid and qualified method of simulation with sufficient accuracy which can be employed for further numerical dynamic soil-structure interaction
investigations. to consider the amplification of lateral deflections of soil-foundation-structure interactions under the seismic effect of the shear wall – columns structural system, a simplified calculation method of soil-structure interactions moment has been proposed.
The proposed procedure enables structural engineers to extract the response of soil structure interaction in more reliable ways to ensure the design safety and reliability.

Citation

Qaftan, O. (in press). Response of soil–foundation–structure interaction of tall building (frame-wall) structural system under seismic effect. (Thesis). University of Salford

• Thesis Type: Thesis
• Acceptance Date: Mar 29, 2019
• Deposit Date: Apr 9, 2019
• Publicly Available Date: Sep 29, 2019
• Award Date: Mar 29, 2019