Estimation of probabilistic seismic sliding displacement and pseudo-static coefficients (k15) for seismic stability assessment of slopes in the southern Lower Mainland, British Columbia

Abstract

Seismic stability of slopes across the Lower Mainland, British Columbia, is investigated based on a probabilistic solution of the Newmark sliding block analogy. The various seismicity sources in the region and the latest updates in sliding displacement prediction models are utilized to determine the probabilistic values for the sliding displacement of slopes at 10 sites across the southern Lower Mainland. The probabilistic displacement (Dprob) values of the considered 10 sites are used to assess the spatial variation of Dprob and the pseudo-static seismic coefficient for Dprob = 15 cm (k15) across the Lower Mainland. Based on spatial variation patterns observed at 7 training sites, regression analysis is employed to develop regional interpolation models to estimate Dprob and k15 values. The accuracy of the regression models to regionally interpolate Dprob and k15 values is confirmed considering model residuals. Calculated probabilistic values at 3 additional test sites confirm that the proposed models estimate Dprob and k15 values with minimal error in Dprob (< 5 cm). The application of the developed Dprob and k15 regional interpolation models is presented with an illustrative example from Coquitlam in the northeastern Lower Mainland.