A macro‐element model for non‐linear soil–shallow foundation–structure interaction under seismic loads: theoretical development and experimental validation on large scale tests

Abstract

SUMMARYIn this paper, different formulations of a macro-element model for non-linear dynamic soil-structure interaction analyses of structures lying on shallow foundations are first reviewed, and secondly, a novel formulation is introduced, which combines some of the characteristics of previous approaches with several additional features. This macro-element allows one to model soil-footing geometric (uplift) and material (soil plasticity) non-linearities that are coupled through a stiffness degradation model. Footing uplift is introduced by a simple non-linear elastic model based on the concept of effective foundation width, whereas soil plasticity is treated by means of a bounding surface approach in which a vertical load mapping rule is implemented. This mapping is particularly suited for the seismic loading case for which the proposed model has been conceived. The new macro-element is subsequently validated using cyclic and dynamic large-scale laboratory tests of shallow foundations on dense sand, namely: the TRISEE cyclic tests, the Public Works Research Institute and CAMUS IV shaking table tests. Based on this comprehensive validation process against a set of independent experimental results, a unique set of macro-element parameters for shallow foundations on dense sand is proposed, which can be used to perform predictive analyses by means of the present model.

A shaking table real-time substructure experiment of an equipment–structure–soil interaction system

“…Accounting for deformation of soil and foundation, full-coupled soilstructure shaking table tests [5][6][7][8] and numerical analysis [9][10][11][12] were conducted and gained deeper insight into the seismic performance of structures. With soil intervention, vibration period of the whole model extends and thus influences authentic seismic responses of superstructures.…”

Effects of Equipment-Structure-Soil Interaction on Seismic Response of Equipment and Structure via Real-Time Dynamic Substructuring Shaking Table Testing

“…Most studies of the ES subsystem were based on the rigid foundation assumption with no account taken of the soil effect, which is at odds with engineering reality and impairs the seismic performance research validity. The soil-structure interaction problem had also been investigated by using the shaking table test [3][4][5] and numerical analysis of soilstructure interaction [6][7][8]. These studies treated soil and structure as a fully coupled interaction system to elucidate the interaction effects.…”

A simplified Nonlinear Sway-Rocking model for evaluation of seismic response of structures on shallow foundations

“…It has been shown that nonlinearities in the soil (corresponding to large strains) and at the soilfoundation interface are almost unavoidable in strong seismic events [8]. Performance-based seismic design methodology embraces these nonlinearities, provided that the responses of both structural and geotechnical components satisfy the performance targets.…”