HR: 0800h
AN: H41B-0301    [Abstracts]
TI: Dynamic Triggering of Landslides
AU: * Gipprich, T
EM: tgippric@Mines.EDU
AF: Center for Wave Phenomena Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401 United States
AU: Snieder, R
EM: rsnieder@mines.edu
AF: Center for Wave Phenomena Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401 United States
AB: Dynamic stress generated by earthquakes is one of the major causes for triggering landslides. There are several techniques available to simulate the ground motion associated with these earthquakes and how it generates failure. These methods, however, are primarily based on triggering by shear failure; the role of tensile failure in earthquake triggered landslides is not clear. We have developed a method to investigate the dynamic stress associated with ground motion and show how this can be used to asses the role of generating shear and tensile failure in the initiation of slope instability. In this project, a 1D elastic finite element model is used to produce the dynamic stress generated by a given ground motion for a 2D infinite slope. This model allows us to test increasingly complex scenarios of an incoming wave with arbitrary time dependence. From the total stress tensor, the principal stress components are computed and displayed on the traditional Mohr circle. At the point of intersection with a failure envelope, stress has exceeded strength, causing the slope to fail. The location of intersection of the Mohr circle provides the orientation of the failure plane on the slope, as well as the failure mechanism (shear versus tensile). The Mohr-Coulomb failure envelope is utilized to determine shear failure situations. The Griffith failure criterion is a modified extension of the Mohr-Coulomb envelope and allows us to model for either shear or tensile failure. This resulting information is graphed pictorially giving us a view of how the incoming wave generates shear or tensile failure as it hits the failure plane. This project provides valuable insight into the generation of slope failure and the behavior over time that is important in the dynamic triggering of landslides.
DE: 8020 Mechanics
DE: 7212 Earthquake ground motions and engineering
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting