Reconstruction of three-dimensional rockfall trajectories using remote sensing and rock-based accelerometers and gyroscopes

Abstract

Abstract. A comprehensive understanding of rockfall trajectories holds the promise to enhance the application of numericalmodels for engineering hazard analysis. Here, we present a full three-dimensional trajectory reconstruction of the Chant Sura EOTA221 rockfall experiment. The data analysis allows a complete kinematic description of a rock’s trajectory in real terrain and underscores the physical complexity of rock-ground interactions. In-situ accelerometer and gyroscope data are combined with videogrammetric and unmanned aerial systems mapping techniques to understand the role of rock rotations, ground penetration and translational scarring in rockfall motion. The exhaustive trajectory reconstruction provides information over the complete flight path such as translational velocity vectors, angular velocities, impact duration and forces, ballistic jump heights and lengths. The experimental data provides insight into the basic physical processes detailing how rotating rocks of general shape penetrate, rebound and scar ground terrain. The data serves in future as a calibration basement to enhance numericalrockfall modelling.

The Implications of M3C2 Projection Diameter on 3D Semi-Automated Rockfall Extraction from Sequential Terrestrial Laser Scanning Point Clouds

“…The shape of a rockfall is known to have a significant effect on its passage down the slope and its runout [18,19]. Detailed 3D rockfall shape has been carried forward into a new generation of rockfall models, which have incorporated custom rockfall objects and detailed terrain models [20][21][22].…”

“…The shape of a rockfall can provide insight into the structure of the sourcing rock and the failure mechanics. With a new generation of 3D rockfall modeling software, the shape of a rockfall and the quality of the rock can also give insight into its chaotic interaction with terrain and the potential runout of the fragment(s) [20][21][22]. Blott and Pye [68] described shape using four important characteristics; form, roundness, irregularity, and sphericity.…”

Shape still matters: rockfall interactions with trees and deadwood in a mountain forest uncover a new facet of rock shape dependency

“…The observation and reconstruction of rockfall trajectories in forests is a demanding task (Bourrier et al, 2012). In a previous open-land study (Caviezel et al, 2019), two different trajectory reconstruction methods were described, namely the labor-intense a posteriori impact mapping (AIM) method and the (semi-)automatic dense cloud reconstruction (DCR) method. For the latter, synchronous stereo video image pairs were photogrammetrically analyzed.…”

Mitigation effects of trees on rockfall hazards: does rock shape matter?

“…Here the eota rock has a geometry following the regulations issued by the official European Technical Assessment Approval Guidelines (Caviezel et al 2019). For the second sub-group simulations three box-shaped rocks are investigated, where ξ remains the same, i.e.…”