Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, Egypt

Research reveals that the Thebes Limestone Formation, crucial to ancient Egyptian civilization and home to the Valley of the Kings, exhibits distinct mechanical properties depending on the orientation of bedding planes. Marly limestone shows an average unconfined compressive strength (UCS) of 30 MPa when tested parallel to bedding (PA) and 39 MPa perpendicular (PE), while micritic limestone displays a UCS of 24 MPa (PA) and 58 MPa (PE). The study, the first to report critical crack thresholds for Member I, found these values within expected ratios relative to UCS. Additionally, micritic limestone's Young’s modulus varies significantly with orientation (19.5 GPa PA vs. 10.3 GPa PE), and Poisson’s ratio also differs (0.2 PA vs. 0.1 PE). The findings highlight the transverse isotropic strength behavior of these limestones, emphasizing the importance of considering force orientation for stability assessments in tombs and cliffs within the Valley of the Kings. This research contributes to the preservation efforts of this UNESCO World Heritage site.

Alcaíno-Olivares, R., Ziegler, M., Bickel, S., Ismaiel, H., Leith, K., & Perras, M. (2022). Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, Egypt. Geotechnics, 2(4), 825–854. https://doi.org/10.3390/geotechnics2040040