Geoscience Reference
In-Depth Information
CHAPTER 9
SHALLOW AND DEEP FOUNDATIONS UNDER FAULT RUPTURE
OR STRONG SEISMIC SHAKING
George Gazetas, Ioannis Anastasopoulos, and MariosApostolou
Laboratory of Soil Mechanics
National Technical University of Athens, Greece
Abstract.
Two topics of interest in soil-foundation-structure interaction are presented: the first
referstotheconsequencesonshallowanddeepfoundationsandtheirsuperstructuresfromaseismic
faultruptureemergingdirectlyunderneaththem;thesecondtopicaddressestheseismicresponseof
tall structures resting on shallow foundations that experience uplifting and inducing large inelastic
deformations in the soil. The numerical and analytical methodologies developed for each topic
havebeencalibratedwithcentrifugeexperiments.Theoutlinedparametricresultsprovidevaluable
insight to the respective soil-foundation interplay, and could explain qualitatively the observed
behaviour in a number of case histories fromrecent earthquakes.
1. Introduction
Thirtyyearsagoresearchandpracticeondynamicsoil-structureinteraction(SSI)meant
primarily the study of how soil compliance influences the dynamic response of super-
structures(buildings,bridges,criticalfacilities).Determiningthefoundationstiffnessand
damping for various modes of vibration, foundation geometries, and soil profiles under
essentially elasticconditions was a key intermediate stepinsuch analyses.
In recent years the term has expanded to encompass studies related to all aspects of soil
and foundation design against earthquakes, including the response of retaining systems
and underground structures, the influence of liquefaction and lateral spreading, and the
effectsofgrounddeformationarisingfromarupturingfaultemergingunderafoundation.
Therehasbeenanevolutionaryprogressfromidealisedlinearviscoelasticsoilsandelas-
tic structural system, to nonlinear inelastic response of soils and structures. This chapter
highlights two such problems in which an interplay between the soil and structure takes
place under conditions of large soildeformations and even failure.
A number of unresolved soil-foundation-structure interaction (SFSI) problems were
the subject of investigation in a joint research project titled “Fault-Rupture and Strong
Shaking Effects on the Safety of Composite Foundations and Pipelines” (acronym:
QUAKER) that provided many of the findings reported in this paper. Conducted by
research teams from the University of Dundee, G´eodynamique et Structure, LCPC-
Nantes, Studio Geotechnico Italiano, and National Technical University of Athens,
the study of each topic was undertaken using an integrated approach, comprising
