Nonlinear site response of deep stiff granular soil deposits in the Caracas Basin

摘要

Site response analyses of relatively deep deposits of stiff granular material have suggested the possibility of significant ground amplification. Since most site response analyses seldom use depths exceeding 50-100m, these problems have not receivedsignificant attention. In this study, an enhanced hysteretic model for cohesionless soils was used to describe the effect of confining stress on measured soil nonlinearity and implemented in a nonlinear computer code for site response analyses. For moderate to significant shaking, preliminary analyses suggest that the equivalent linear procedure significantly underestimates spectral accelerations for deep soil profiles when compared with the nonlinear analyses using the new hysteretic model.