EXPERIMENTAL AND THEORETICAL SEISMIC MODELING OF A SURFACE FOUNDATION IN FINITE-DOMAIN SIMULATIONS

摘要

A fundamental experimental study to explore the vertical, horizontal, and rocking responses of a plate footing resting on a horizontal sand stratum under seismic excitations is reported in this paper. By means of centrifuge modeling, multiple series of tests were performed using an absorbing boundary container and a shake table which delivered simultaneous vertical-horizontal-rocking motions to the soil. To evaluate the applicability of the elastodynamic theory to a stratum configuration, relevant sets of complex-valued foundation impedance functions and foundation input motion functions were computed for a square rigid footing bonded to the surface of an infinite horizontal stratum as well as the employed finite-size centrifuge model, both with a square-root depth-dependent shear modulus profile. Through a comparison of the experimental data with the classical 1-D stratum and 3-D finite-domain solutions, it is shown that boundary effects in geotechnical centrifuge models need to be accounted for generally to ensure a proper interpretation and synthesis of the data.