Karstic cavities underground investigation: GPR and geotechnical data correlation

Mehrez Jamei, Northern Border University, College of Engineering, Civil Engineering Department, Arar, Saudi ArabiaFollow
Mabrouk Abdelkader, Northern Border University, College of Engineering, Civil Engineering Department, Arar, Saudi Arabia
Anwar Ahmed, Northern Border University, College of Engineering, Civil Engineering Department, Arar, Saudi Arabia
Yahya Alassaf, Northern Border University, College of Engineering, Civil Engineering Department, Arar, Saudi Arabia

Author ORCID Identifier

Abstract

This paper focuses on the methodology involving ground penetration radar (GPR) for detecting and localizing random cavities in underground limestone soil, in conjunction with geotechnical data. A GPR survey was conducted alongside field and laboratory geotechnical tests at a field where mining activities are now promoted (Saudi Arabia Northern Borders Province). The paper presents correlations between the instantaneous amplitude of the reflected electromagnetic (EM) waves and rock quantification distributed (RQD), recovery rock parameter (REC), and uniaxial compressive strength (UCS). The GPR investigation proved to be an efficient nondestructive geophysical method for determining: 1) the 3D location of cavities, 2) their random distribution, and 3) an approximate assessment of their shapes and dimensions. These correlations serve as guideline-relations linking GPR, as a geophysical method, with common geotechnical results (including drilling issues and Standard Penetration Tests/SPT). In the context of constructing foundations in limestone with underground cavities, these correlations between GPR and geotechnical tests have been instrumental in guiding soil improvement through the cement injection technique. The proposed correlation between RQD and instantaneous amplitude can serve as a mathematical relationship to streamline future project construction decisions in karstic sites, particularly in the initial phases of construction planning and facility management.

Recommended Citation

Jamei, Mehrez; Abdelkader, Mabrouk; Ahmed, Anwar; and Alassaf, Yahya (2026) "Karstic cavities underground investigation: GPR and geotechnical data correlation," Journal of Sustainable Mining: Vol. 25 : Iss. 2 , Article 7.
Available at: https://doi.org/10.46873/2300-3960.1499