Evaluation of One-Dimensional Site Response Techniques Using Borehole Arrays

Abstract

AbstractNumerical techniques commonly used to compute the dynamic response of soil deposits under earthquake shaking are investigated by analyzing data from instrumented borehole arrays. Eleven instrumented vertical arrays are investigated using over 650 recorded ground motions that span a range of shaking intensities. Based on data from the selected borehole arrays, site response predictions using one-dimensional equivalent linear (EQL) analysis, equivalent linear analysis with frequency-dependent soil properties (EQL-FD), and fully nonlinear (NL) analysis are compared with the borehole observations. The results across all sites indicate that at peak shear strains less than about 0.1%, all three site response techniques predict, on average, site amplification within ±20% of observed. At peak shear strains larger than 0.1% and at periods less than about 0.4 s, EQL and NL analyses underpredict site amplification and EQL-FD analyses overpredict site amplification. The underprediction for the EQL and NL tech...