Bridge Foundations: Modeling Large Pile Groups and Caissons for Seismic Design

摘要: The report synthesizes and summarizes current Federal Highway Administration (FHWA) sponsored bridge research related technical reports ion the seismic design of large pile groups caissons into one design-oriented guideline on design, suitable for applications to retrofit existing long span bridges, or a new design. characterization ground motions soil-foundation-structure interaction analyses is an important component foundation modeling process discussed in detail. Discussion includes methods generating spectrum compatible time histories, spatial variations motion effects local soil conditions site response. Modeling approaches focus use substructuring approach, p-y curves associated group develop linearized Winkler springs assembly stiffness matrices. analysis approach illustrated with several case history examples, including San Francisco-Oakland Bay Bridge East Span project. complexity kinematic soil-pile as modification input also described. caisson foundations often employed piers over-water bridges are detail, emphasis linear matrices, nonlinear lumped spring distributed approaches. influence Two examples used illustrate approaches, Tacoma Narrows Bridge.