An Infrared Thermography Approach to Evaluate the Strength of a Rock Cliff

0542525 - ÚSMH 2022 RIV CH eng J - Journal Article
Loche, M. - Scaringi, G. - Blahůt, Jan - Melis, M.T. - Funedda, A. - Da Pelo, S. - Erbi, I. - Deiana, G. - Meloni, M.A. - Cocco, F.
An Infrared Thermography Approach to Evaluate the Strength of a Rock Cliff.
Remote Sensing. Roč. 13, č. 7 (2021), č. článku 1265. E-ISSN 2072-4292
Institutional support: RVO:67985891
Keywords : compressive strength * infrared thermography * rebound hammer * cooling rate index
OECD category: Geology
Impact factor: 5.349, year: 2021
Method of publishing: Open access
https://www.mdpi.com/2072-4292/13/7/1265

The mechanical strength is a fundamental characteristic of rock masses that can be empirically related to a number of properties and to the likelihood of instability phenomena. Direct field acquisition of mechanical information on tall cliffs, however, is challenging, particularly in coastal and alpine environments. Here, we propose a method to evaluate the compressive strength of rock blocks by monitoring their thermal behaviour over a 24-h period by infrared thermography. Using a drone-mounted thermal camera and a Schmidt (rebound) hammer, we surveyed granitoid and aphanitic blocks in a coastal cliff in south-east Sardinia, Italy. We observed a strong correlation between a simple cooling index, evaluated in the hours succeeding the temperature peak, and strength values estimated from rebound hammer test results. We also noticed different heating-cooling patterns in relation to the nature and structure of the rock blocks and to the size of the fractures. Although further validation is warranted in different morpho-lithological settings, we believe the proposed method may prove a valid tool for the characterisation of non-directly accessible rock faces, and may serve as a basis for the formulation, calibration, and validation of thermo-hydro-mechanical constitutive models.
Permanent Link: http://hdl.handle.net/11104/0320073