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Soil-structure interaction may play a major role in the seismic response of a bridge structure. Specifically, soil layers of low stiffness and strength may result in permanent displacement of the abutments and foundations, thus imposing important kinematic conditions to the bridge structure. A study to illustrate such phenomena is undertaken based on three-dimensional nonlinear dynamic finite-element (FE) modeling and analysis (for a specific bridge configuration under a given seismic excitation). A bridge-foundation-ground model is developed based on the structural configuration and local soil conditions of the Humboldt Bay Middle Channel Bridge. The FE model and nonlinear solution strategy are built in the open-source software platform OpenSees of the Pacific Earthquake Engineering Research Center. Based on the simulation results, the overall system seismic response behavior is examined, as well as local deformations/stresses at selected critical locations. It is shown that permanent ground deformation may induce settlement and longitudinal/transversal displacements of the abutments and deep foundations. The relatively massive approach ramps may also contribute to this simulated damage condition, which imposes large stresses on the bridge foundations, supporting piers, and superstructure. [ABSTRACT FROM AUTHOR]

The article offers the authors' insights on a feedback to their article "Mechanisms of Seismically Induced Settlement of Buildings with Shallow Foundations on Liquefiable soil," and on the performance of the two buildings of International Teleport Plaza (ITP) during the Loma Prieta earthquake in 1989. The authors says that the liquefiable layer's depth significantly influence the deviatoric-induced settlements. They add that the ground loss phenomenon can result to big differential sediments.

Describes the damages to the anchor bolt connection between the concrete foundation and the wood sill plate caused by the 1992 earthquake at Big Bear Lake in San Bernardino County, California. Cause of depletion of shear capacity of the connection; Persons who are responsible for installation; Observations about tie-down anchors.