Date of Award

Summer 2019

Degree Type


Degree Name

Master of Science (MS)



Committee Chair

Mary MacLaughlin

First Advisor

Larry Smith

Second Advisor

Peter Lucon


Understanding the engineering principles of failure modes in rock formations from seismic activity continues to be a challenging problem for engineers and geologists. The complexity of the geology, geometry, discontinuities, and earthquake ground motions contribute to the difficulty in estimating the stability of rock slopes. In this study, one classic rock slope failure mode is examined: the toppling behavior of a single rigid rectangular block under dynamic loading. An investigation employing experimental and numerical modeling techniques was performed to observe the response of wooden blocks with different aspect (width/height) ratios subjected to loading at the base and compared to established theoretical methods that use pseudostatic loads applied at the centroid. The physical experiments were conducted using a shake table with a data acquisition system consisting of accelerometers and a high-speed video camera. Because the shake table is a newly acquired research tool, a large component of the experimental program involved developing multiple calibration tests validated with mechanical engineering theory to verify the performance of the testing equipment and the experimental data. The link between the two loading scenarios (base and centroid) applied to the toppling block was accomplished using numerical modeling, with the simulations performed using Itasca’s two-dimensional distinct element software UDEC. Results from the shake table and centroid loading scenario using UDEC matched theory. This study demonstrates the significance of understanding the fundamental rocking behavior of rigid blocks to better assess complicated toppling failures due to dynamic forces.


A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geoscience:Geological Engineering Option