Soil structure interaction

About: Soil structure interaction is a research topic. Over the lifetime, 3653 publications have been published within this topic receiving 48890 citations.

Inelastic dynamic analysis of RC bridges accounting for spatial variability of ground motion, site effects and soil–structure interaction phenomena. Part 1: Methodology and analytical tools

Abstract: During strong ground motion it is expected that extended structures (such as bridges) are subjected to excitation that varies along their longitudinal axis in terms of arrival time, amplitude and frequency content, a fact primarily attributed to the wave passage effect, the loss of coherency and the role of local site conditions. Furthermore, the foundation interacts with the soil and the superstructure, thus significantly affecting the dynamic response of the bridge. A general methodology is therefore set up and implemented into a computer code for deriving sets of appropriately modified time histories and spring–dashpot coefficients at each support of a bridge with account for spatial variability, local site conditions and soil–foundation–superstructure interaction, for the purposes of inelastic dynamic analysis of RC bridges. In order to validate the methodology and code developed, each stage of the proposed procedure is verified using recorded data, finite-element analyses, alternative computer programs, previous research studies, and closed-form solutions wherever available. The results establish an adequate degree of confidence in the use of the proposed methodology and code in further parametric analyses and seismic design. Copyright © 2003 John Wiley & Sons, Ltd.

Kinematic soil-structure interaction from strong motion recordings

Abstract: Earthquake strong motion recordings from 29 sites with instrumented structures and free-field accelerographs are used to evaluate variations between foundation-level and free-field ground motions. The focus of the paper is on buildings with surface and shallowly embedded foundations. The foundation/free-field ground motion variations are quantified in terms of frequency-dependent transmissibility function amplitude uHu. Procedures are developed to fit to uHu analytical models for base slab averaging for the assumed conditions of a rigid base slab and a vertically propagating, incoherent incident wave field characterized by ground motion incoherence parameter k. The limiting assumptions of the model are not strictly satisfied for actual structures, and the results of the identification are apparent k values ~denoted k a) that reflect not only incoherence effects, but also possible foundation flexibility and wave inclination effects. Nonetheless, a good correlation is found between k a values and soil shear wave velocity for sites with stiff foundation systems. Based on these results, recommendations are made for modifying free-field ground motions to estimate base slab motions for use in response analyses of buildings.

Nonlinear ground response at lotung lsst site

Abstract: A fully nonlinear finite-element (FE) model is developed to investigate the impact of hysteretic and viscous material behavior on the downhole motion recorded by an array at a large-scale seismic test site in Lotung, Taiwan, during the earthquake of May 20, 1986. A stick model with the same spatial interpolation accuracy as a three-dimensional FE model is used for vertical wave propagation analysis. The constitutive model is based on a three-dimensional bounding surface plasticity theory with a vanishing elastic region, and accounts for shear stiffness degradation right at the onset of loading. The model is cast in a time-domain nonlinear FE code SPECTRA and is used to analyze the 1986 earthquake data. It is shown that the recorded downhole motion of Lotung was dominated by nonlinear response. Results of the fully nonlinear analysis are compared with the predictions of the program SHAKE so that the performance of the nonlinear model may be assessed relative to that of an equivalent linear model.