Numerical and field investigation of dynamic soil-structure interaction at full-scale
File(s)
Author(s)
Koronides, Marios
Type
Thesis
Abstract
This PhD thesis details the numerical and field investigation of Soil-Structure Interaction (SSI) and foundation rocking effects on the dynamic response of a steel-frame structure that was founded on a surface foundation. The main focus of the study is on the impact of nonlinearities associated with soil hysteresis and foundation detachment from the adjacent soil domain. For this purpose, an experimental campaign was specifically designed and carried out, consisting of real-scale free and forced vibration experiments on the prototype structure of EUROPROTEAS.
The local site conditions are investigated in the first part of the thesis, where both equivalent linear and fully nonlinear one-dimensional site response analyses are carried out. The calibration of the numerical model benefits from strong motion seismic data recorded by a permanently installed downhole array of accelerometers. The second part of the thesis involves a thorough investigation of the SSI effects and foundation rocking by interpreting the experimental data.
The third part of the thesis presents three-dimensional analyses that simulate the field experiments, explicitly modelling the soil domain and accounting for soil nonlinearity and foundation rocking. The numerical model is calibrated against experiments that induced various levels of SSI effects, soil strains and foundation uplift. A comprehensive discussion is conducted on the modelling of the soil-foundation interface. The study’s major contribution relates to a novel approach proposed to simulate areas where the foundation and the soil are not in contact (gap areas). The proposed interface model enables the rigorous simulation of either permanent interface gaps or successions of gap opening and closure. An additional significant novelty is the suggested method to manipulate interface stresses under static conditions, which are crucial for the rocking behaviour of structures. The numerical results highlight the significant influence of interface gaps, interface static normal stresses and soil nonlinearity on the SSI response, under specific circumstances.
The local site conditions are investigated in the first part of the thesis, where both equivalent linear and fully nonlinear one-dimensional site response analyses are carried out. The calibration of the numerical model benefits from strong motion seismic data recorded by a permanently installed downhole array of accelerometers. The second part of the thesis involves a thorough investigation of the SSI effects and foundation rocking by interpreting the experimental data.
The third part of the thesis presents three-dimensional analyses that simulate the field experiments, explicitly modelling the soil domain and accounting for soil nonlinearity and foundation rocking. The numerical model is calibrated against experiments that induced various levels of SSI effects, soil strains and foundation uplift. A comprehensive discussion is conducted on the modelling of the soil-foundation interface. The study’s major contribution relates to a novel approach proposed to simulate areas where the foundation and the soil are not in contact (gap areas). The proposed interface model enables the rigorous simulation of either permanent interface gaps or successions of gap opening and closure. An additional significant novelty is the suggested method to manipulate interface stresses under static conditions, which are crucial for the rocking behaviour of structures. The numerical results highlight the significant influence of interface gaps, interface static normal stresses and soil nonlinearity on the SSI response, under specific circumstances.
Version
Open Access
Date Issued
2023-06-22
Date Awarded
01/11/2023
License URL
Advisor
Kontoe, Stavroula
Zdravković, Lidija
Sponsor
Imperial College London
A.G. Leventis Foundation
Cyprus. State Scholarships Foundation
European Seismology & Earthquake Engineering Research Infrastructure Alliance for Europe
Grant Number
Grant agreement ID: 730900
Publisher Department
Civil and Environmental Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)