Nonlinear Dynamic Analyses of Perris Dam Using Transition Probability to Model Interbedded Alluvial Strata

This case study presents an application of a conditional transition probability method for interpreting subsurface stratigraphy the interbedded alluvium underlying Perris Dam, and evaluating effects stratigraphic uncertainty on nonlinear dynamic analysis (NDA) results design earthquake loading. The challenges involved in synthesizing information from different sources (i.e., geologic conditions, site investigation tools, lab data, field classifications) into soil categories were examined. methods developing three-dimensional (3D) realizations upper Holocene lower Pleistocene alluvial strata over 305-m-wide interval along dam alignment is described, including with insufficient data limitations utilizing stationary, geostatistical approximating nonstationary conditions. Two-dimensional (2D) NDA models Dam created by slicing 3D five 2D cross sections. constitutive PM4Sand PM4Silt used to model sand clay strata, as well zones embankment. deformations variability each section compared, sensitivity studies completed examine impact several factors, impacts small-strain shear modulus alluvium, mean lengths sills categories, strengths category, ground motions. sections uniformly (noncategorical) distributed properties performed without additional deterministic embedded lenses, compared others. use NDAs implications lessons practice, are discussed.