Date of Completion

8-18-2014

Embargo Period

8-12-2014

Major Advisor

Amvrossios C. Bagtzoglou

Associate Advisor

Emmanouil N. Anagnostou

Associate Advisor

Lanbo Liu

Associate Advisor

Ramesh B. Malla

Associate Advisor

Jafar Razmi

Field of Study

Environmental Engineering

Degree

Doctor of Philosophy

Open Access

Open Access

Abstract

Landslides are one of the major geological hazards in the world due to the resulting loss of life and overwhelming costs to the neighboring communities and damage to the environment. The main triggering events for landslides are earthquakes and rainfall events. In this dissertation, the disk-based Discontinuous Deformation Analysis (DDA) method is used to model landslides triggered by earthquakes. The DDA method is applied to model particulate media with the application to landslide behavior. For this purpose, stiffness and force matrices due to body forces, point loading, inertia forces, and displacement and directional constraints are derived in detail for disk blocks. Next, an efficient model for particle contacts is presented. Normal and shear contact forces as well as friction forces for all contact types are derived by vector analysis. Furthermore, the validity and capability of the model are demonstrated by numerical results obtained for several illustrative examples. Moreover, to investigate the applicability of disk-based DDA to dynamic problems (like earthquake-triggered landslides) the accuracy of the method under dynamic conditions is evaluated by a comprehensive sensitivity analysis and comparison of results with existing analytical solutions. Also, for the first time, the disk-based DDA method is applied to simulate a real landslide triggered by an earthquake. For this purpose, the kinematic behavior of the Donghekou landslide triggered by the Wenchuan earthquake is simulated and results obtained using disk-based DDA are compared favorably with actual data. This study shows that disk-based DDA, as a practical numerical tool, can be used to simulate the post-failure behavior of landslides triggered by an earthquake. Finally, a new combined hydrology and slope stability method is developed to model landslides triggered by rainfall and earthquake events. In order to verify the method, two case studies are considered and the results obtained by the developed model are compared successfully with actual data. Moreover, this model is used to study the impact of rainfall and several soil and slope parameters on instability of landslides triggered by earthquakes.

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