Comparison of Equivalent Linear and Nonlinear Site Response Analysis Results and Model to Estimate Maximum Shear Strain

We compared the results of equivalent linear (ELA) and nonlinear site response analyses (NLA) and found that the differences between the values of the peak ground acceleration (PGA), peak ground velocity (PGV), Arias intensity (I-a), significant duration (D5-75), and response spectrum for periods between 0.025 s and 2 s predicted by each method are non-negligible for maximum shear strain values predicted by ELA (gamma(max,ELA)) greater than 0.04% to 1.0%. As gamma(max,ELA) increases, ELA in general predict smaller shear strain and D5-75 values, and larger PGA, PGV, I-a, mean period, and response spectral values for periods less than 0.1 s and periods near the natural site period than NLA. To help researchers and practitioners decide when to use ELA and/or NLA, we developed a model to estimate gamma(max,ELA) before conducting a site response analysis.