Unified Multi-phase Numerical Framework for Understanding Co-Seismic Slope Failures in Complex Sites

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

This research project will focus on advancing the fundamental understanding of the mechanics of slope failures triggered by earthquakes and will help to predict, reduce, and mitigate their destructive consequences. Earthquake-triggered slope failures cause significant economic and life losses in seismically active regions. However, state-of-the-art procedures that address triggering and runout of co-seismic slope failures are highly idealized and do not incorporate the complexities of soil behavior subjected to cyclic loading. This research will develop a validated numerical framework to analyze the overall failure process, from the ground shaking and failure initiation to the post-failure processes. The numerical tool will accommodate large deformations and hydro-mechanical coupling and will be compatible with existing continuum-based constitutive models for the simulation of liquefaction triggering and cyclic mobility. The developed numerical tool and a tutorial manual will be shared through an open-source platform. The research will also be complemented by outreach activities, including lectures for graduate students and training sessions for practitioners. The outcomes of this research can be provide a more comprehensive understanding of the risk associated with earthquake hazards. The goal of this research is to better capture and understand the connection between ground motion characteristics, pore pressure evolution and final mobility of slope failures. Thus, the research objectives of this project include: (i) to establish and validate a generalized numerical framework capable of simulating earthquake loading, site response, and large deformations of complex sites, all within a unified computational framework; (ii) to quantify pore water pressure evolution during the entire instability process; and (iii) to correlate the intensity of the ground motions with the failure initiation, post-failure behavior, and hydro-mechanical response. To accomplish these objectives, the existing Material Point Method framework will be further developed to accurately simulate ground shaking, site response, and large deformations. State-of-practice constitutive models accounting for material damping and cyclic mobility will be considered in the same framework, and their performance will be evaluated. The developments will be validated using existing data from centrifuge testing and field case studies. This project will allow the PI to inform, advance, and transform the way co-seismic slope stability analyses are approached, especially for complex geometries and when critical infrastructure is at risk. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.