Admission: $20, $10 for Students, (Includes Buffet Lunch)
The Regina Geotechnical Group is pleased to host the Cross Canada Lecture Series. This fall's speaker is Dr. Ross Boulanger of the University of California, Davis. Dr. Boulanger will present the following topic:
Evaluating liquefaction in finely interbedded sand, silt and clay deposits
Current liquefaction evaluation procedures have a tendency to over-predict liquefaction effects in
finely inter-bedded sand, silt and clay deposits. The nature and extent of this apparent bias are
illustrated using case histories, and the potential reasons discussed. Three related research projects
are then described.
The performance of the Cark Canal in the 1999 Kocaeli earthquake is re-examined using one-dimensional CPT-based liquefaction vulnerability indices and nonlinear deformation analyses with spatially correlated stochastic models; the results illustrate the importance of spatial variability to field performance and the inherent limitations in 1D LVI methods. The relationship between cyclic strength and cone penetration resistance in low-plasticity fine-grained soils is examined using laboratory testing and simulated cone penetration resistances; the results provide insights on potential biases in existing liquefaction triggering models. An axisymmetric direct cone penetration model is developed for use with the MIT-S1 constitutive model and its capabilities illustrated by simulating penetration resistance in anisotropic clay. Future research needs and recommended practices for evaluating liquefaction effects in finely interbedded sand, silt and clay deposits are discussed.