Site characterization using drone based photogrammetry

An emerging topic in geotechnical site characterization is using drones for rock mass characterization through Structure from Motion (SfM) photogrammetry. This study highlights a series of surveys utilizing a DJI Mavic II drone performed between July and August 2022 at an abandoned quarry in Clear Creek Canyon Park, located 0.25 miles west of Golden, Colorado. The purpose of these surveys was for failure surface identification of a historic wedge failure, structural domain segregation of the remaining rock slope, and rock mass characterization of the segregated structural domains. The study site is composed of a heavily jointed interlayered gneiss rock mass with distinct planar discontinuities. However, structural discontinuity orientations may only be homogenous across some sections of the rock mass. This research highlights an improved contour density-based methodology drawing upon existing methods of structural domain identification to locally divide the rock mass into domains of similar structural orientation. Equal angle stereographic comparisons between domains are considered utilizing an exponential Kamb density method. The results of this study reveal that both blasting effects and tectonic features likely induced the historic wedge failure. In addition, this study reveals that the remaining rock mass of uniform lithology may have profound differences in structural orientations, requiring appropriate domaining for rock mass characterization. Finally, rock mass characterization was assessed to remotely gauge fracture frequency and rock quality metrics by revealing probabilistic variations in spacing, volumetric joint count, Rock Quality Designation (RQD), rock block volume, and Geological Strength Index (GSI) in each structural domain.

Name thesis:degree_name

Master of Science (M.S.)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Civil and Environmental Engineering

Grantor dc:publisher

Colorado School of Mines. Arthur Lakes Library

Year dc:date.issued

2023

Author dc:creator

• Benfield, Steven L.

Advisors dc:contributor.advisor

• Gutierrez, Marte S.
• Zhou, Wendy

Committee members dc:contributor.committeemember

• Lu, Ning
• Roth, Danica

Statement dc:rights

• Copyright of the original work is retained by the author.

Language dc:language.iso

eng, English

Identifier

T 9530

OAI identifier oai:identifier

oai:repository.mines.edu:11124/178469