Studying overturning and large displacement processes of precariously balanced rocks for ground motion estimation

Zhiang Chen, Ramon Arrowsmith, Jnaneshwar Das, Christine Wittich, Christopher M. Madugo, & Albert R. Kottke

Submitted September 10, 2023, SCEC Contribution #12952, 2023 SCEC Annual Meeting Poster #188

Studying the overturning and large-displacement processes of precariously balanced rocks (PBRs) facilitates ground motion estimation. Using a physics engine and robotic tools, we developed a virtual shake robot (VSR) to simulate the dynamics of PBRs for the study of overturning and large-displacement processes. We applied the VSR to investigate a PBR at a study site of Double Rock, located near a critical facility on the central coast of California. Our overturning experiments demonstrated that the ground motion orientation and lateral pedestal support were important factors that affect PBR fragility. Large-displacement experiments estimated rock trajectories (post overturning) for various ground motions. Ground motions positively correlated with large displacement statistics such as mean trajectory length, mean largest velocity, and mean terminal distance. The overturning and large displacement processes of PBRs may provide complimentary constraints to refine ground motion estimation: fragile configurations of existing PBRs indicate an upper-bound ground motion constraint; large displacements of toppled PBRs suggest a lower-bound ground constraint.

Key Words
Fragile geological features, precariously balanced rocks, rock dynamics

Citation
Chen, Z., Arrowsmith, R., Das, J., Wittich, C., Madugo, C. M., & Kottke, A. R. (2023, 09). Studying overturning and large displacement processes of precariously balanced rocks for ground motion estimation. Poster Presentation at 2023 SCEC Annual Meeting.

Related Projects & Working Groups
Ground Motions