Publication: Preliminary evaluation of rock mass weathering grade for granitic rock Using image analysis of cielab color space
Loading...
Date
2024-07-01
Authors
Andrew, Lee Kwan Yee
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
In tropical regions, intense weathering processes lead to the instability and failure of
rock slopes. In addition to the various advanced numerical rock slope stability
assessment techniques that have been developed to date, simple evaluation techniques
that characterize the rock slope weathering degree based on color changes of the rock
surface continue to be one of the primary methods utilized by the majority of geologists
for rock slope stability assessment. This study proposed a new evaluation method for
weathering assessment of the granite rock slope using digital image processing
technologies to reduce human-induced errors based on a manual characterization
procedure. The color variations of the limestone rock with respect to the CIELAB color
space, which inferred differential weathering of the rock mass, were measured in situ
using a 40 mm FRU colorimeter. For verification purpose, the Schmidt hammer was
employed to ascertain the intact rock strength and the color changes of the granite rock
in accordance with the International Society For Rock Mechanics (ISRM) weathering
grade standard. Results indicated that a* and b* were highly correlated with R² =
0.7519 and R² = 0.5421 for Slope B and C of Baling-Gerik Route, respectively and R²
= 0.9027 for the Slope of Lebuhraya Kubu Bharu – Teranum – Raub. This is
highlighting the consistency of the in situ CIELAB color space data. The results were
verified with the weathering grades analyzed using image analysis technique of
JudGeo Software developed by the Kajima Corporation. Conclusively, in the preliminary assessment of rock mass weathering, the CIELAB color space together
with image analysis is an effective tool particularly for slightly vegetated rock slope
outcrops.