Assessment of Rheological Models for Run-out Distance Modeling of Sensitive Clay Slides, Focusing on Voellmy Rheology
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Sensitive clay landslides especially that of quick clay are the major natural hazards in Canada and Scandinavian countries. Fair estimation of post-failure movement (retrogression and run-out distances) is very important in taking remedial measures like hazard mapping and mitigation strategies to protect loss of human lives and properties as well as damage of infrastructures. To do these estimations, some empirical approaches have been used so far. However most fell short to give close prediction of the run-out distances. This situation gives rise to implement some of the existing mass flow numerical modeling tools to simulate post-failure movements of sensitive clays. Some preliminary studies were conducted to evaluate the extent to which the available flow (rheological) models are able to simulate run-out of sensitive clay slides.This study continued the search and found the Voellmy rheological model implemented in RAMMS::Debris Flow and DAN3D. The model is tested by back calculating a small scale run-out laboratory model test and the 2012 Byneset, Norway, quick clay landslide cases. Preliminary attempt to numerically simulate quickness test of sensitive clays was also made.Even though the same rheological model is implemented in RAMMS and DAN3D, some differences in the analysis results were observed. This rheological model was able to simulate the run-out distances of the given cases. However, its two governing friction parameters are found more sensitive to the flow conditions than the usual strength parameters of sensitive clays.Some recommendations and future works are also given depending on the simulation results.