Warta Geologi, Vol. 46, No. 2, August 2020, pp. 107–112

Rock slope discontinuity extraction from 3D point clouds:
Application to an open pit limestone quarry

Syaran Suri*, Aisyah Shahirah Juhari, Solihin Yaacob, Nur
Emilia Qistina Anua, Hareyani Zabidi

Mineral Resources Engineering, School of Materials and
Mineral Resources Engineering,

Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang,
Malaysia

* Corresponding author email address: syaransuri@gmail.com

Abstract:
Discontinuities dominantly play a key role in the mechanical, hydraulic,
and deformational behaviors of rock masses, frequently impose significant
influence on the stability of rock slopes. Thus, it is important to have a
profound knowledge on the discontinuity network in rock engineering. This paper
focuses on the identification of plane within 3D point clouds using the
Discontinuity Set Extractor (DSE) program in MATLAB® (The Mathworks Inc.). The
3D point clouds were generated using the Agisoft PhotoScan Professional digital
photogrammetry software (version 1.1.6) from photos captured via UAV method. To
verify the plane identification, the photogrammetric results were compared with
the manual mapping generated using the scanline method. Rosette plot for both
methods revealed discontinuities set of similar direction but different in
quantity. The most dominant discontinuities orientation was in the NNW-SSE
direction at N330° – N340°, while the least dominant orientation took place in
the E-W direction at N080° – N090°. The reliability of the discontinuity models
was enhanced using the Structure from Motion (SfM) technique.

Keywords:
Open pit quarry, discontinuity, Point clouds, UAV

DOI :
https://doi.org/10.7186/wg462202011

ISSN
0126–5539; e-ISSN 2682-7549