Prediction of nonlinear soil effects

摘要: Mathematical models of soil nonlinearity in common use and recently developed nonlinear codes are compared to investigate the range their predictions. We consider equivalent linear formulations with without frequency-dependent moduli damping ratios for total effective stress. Average velocity profiles 150 m depth midrange National Earthquake Hazards Reduction Program site classifications (B, BC, C, D, E) top 30 used compare response a wide conditions from rock soft soil. Nonlinear using amplification spectrum, calculated as ratio surface ground motion input at base profile. Peak motions 0.1 g 0.9 considered. For class B, no significant differences exist between considered this article. classes BC small low (0.1 0.2 ), but become higher levels. D E overdamping frequencies above about 4 Hz by solution frequency-independent parameters is apparent entire The formulation under damps relative C larger most levels E. At underdamping not severe formulation, there still time domain. A recommended greater than few tenths acceleration gravity. type driven considerations importance water content availability laboratory soils data. Our average curves stress favorably observed spectral sites Seattle area 2001 Nisqually earthquake. Manuscript received 18 June 2004.