Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, Egypt
The Thebes Limestone Formation of Lower Eocene age is one of the most extensive rock units in Egypt. It is of importance to the apogee of the ancient Egyptian civilization, particularly in Luxor (South-Central Egypt), where the rock formation hosts the Theban Necropolis, a group of funerary chambers...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-09-01
|
| Series: | Geotechnics |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2673-7094/2/4/40 |
| _version_ | 1797457724641902592 |
|---|---|
| author | Rodrigo Alcaíno-Olivares Martin Ziegler Susanne Bickel Hesham Ismaiel Kerry Leith Matthew Perras |
| author_facet | Rodrigo Alcaíno-Olivares Martin Ziegler Susanne Bickel Hesham Ismaiel Kerry Leith Matthew Perras |
| author_sort | Rodrigo Alcaíno-Olivares |
| collection | DOAJ |
| description | The Thebes Limestone Formation of Lower Eocene age is one of the most extensive rock units in Egypt. It is of importance to the apogee of the ancient Egyptian civilization, particularly in Luxor (South-Central Egypt), where the rock formation hosts the Theban Necropolis, a group of funerary chambers and temples from the New Kingdom Egyptian era (3500–3000 BP). In this work, we investigated the petrophysical and rock mechanical properties (e.g., rock strength, critical crack stress thresholds) through laboratory tests on eleven rock blocks collected from one area within the Theban Necropolis known as the Valley of the Kings (KV). The blocks belong to Member I of the Thebes Limestone Formation, including six blocks of marly limestone, three blocks of micritic limestone, one block of argillaceous limestone from the Upper Esna Shale Formation, and one block of silicified limestone of unknown origin. Special attention was given to the orientation of bedding planes in the samples: tests were conducted in parallel (PA) and perpendicular (PE) configurations with respect to bedding planes. We found that the marly limestone had an average unconfined compressive strength (UCS) of 30 MPa and 39 MPa for the PA and PE tests, respectively. Similarly, the micritic limestone tests showed an average UCS of 24 MPa for the PA orientation and 58 MPa for the PE orientation. The critical crack thresholds were the first ever reported for Member I, as measured with strain gauge readings. The average crack initiation (CI) stress thresholds for the marly limestone (PA: 14 MPa) and the micritic limestone (PA: 11 MPa; PE: 24 MPa) fall within the typical ratio of CI to UCS (0.36–0.52). The micritic limestone had an average Young’s modulus (E) of 19.5 GPa and 10.3 GPa for PA and PE, respectively. The Poisson’s ratios were 0.2 for PA and 0.1 for PE on average. Both marly and micritic limestone can be characterised by a transverse isotropic strength behaviour with respect to bedding planes. The failure strength for intact anisotropic rocks depends on the orientation of the applied force, which must be considered when assessing the stability of tombs and cliffs in the KV and will be used to understand and improve the preservation of this UNESCO World Heritage site. |
| first_indexed | 2024-03-09T16:27:03Z |
| format | Article |
| id | doaj.art-f7339889b8284580b9fb3a3a0b2a825f |
| institution | Directory Open Access Journal |
| issn | 2673-7094 |
| language | English |
| last_indexed | 2024-03-09T16:27:03Z |
| publishDate | 2022-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Geotechnics |
| spelling | doaj.art-f7339889b8284580b9fb3a3a0b2a825f2023-11-24T15:07:29ZengMDPI AGGeotechnics2673-70942022-09-012482585410.3390/geotechnics2040040Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, EgyptRodrigo Alcaíno-Olivares0Martin Ziegler1Susanne Bickel2Hesham Ismaiel3Kerry Leith4Matthew Perras5Department of Civil Engineering, York University, 4700 Keele, Toronto, ON M3J 1P3, CanadaDepartment of Earth Sciences, ETH Zurich, 5 Sonneggstrasse, 8092 Zurich, SwitzerlandDepartment of Ancient Civilizations, University of Basel, 51 Petersgraben, 4051 Basel, SwitzerlandDepartment of Geology, South Valley University, Qena 83523, EgyptGNS Science, 1 Fairway Drive, Avalon, Lower Hutt 5011, New ZealandDepartment of Civil Engineering, York University, 4700 Keele, Toronto, ON M3J 1P3, CanadaThe Thebes Limestone Formation of Lower Eocene age is one of the most extensive rock units in Egypt. It is of importance to the apogee of the ancient Egyptian civilization, particularly in Luxor (South-Central Egypt), where the rock formation hosts the Theban Necropolis, a group of funerary chambers and temples from the New Kingdom Egyptian era (3500–3000 BP). In this work, we investigated the petrophysical and rock mechanical properties (e.g., rock strength, critical crack stress thresholds) through laboratory tests on eleven rock blocks collected from one area within the Theban Necropolis known as the Valley of the Kings (KV). The blocks belong to Member I of the Thebes Limestone Formation, including six blocks of marly limestone, three blocks of micritic limestone, one block of argillaceous limestone from the Upper Esna Shale Formation, and one block of silicified limestone of unknown origin. Special attention was given to the orientation of bedding planes in the samples: tests were conducted in parallel (PA) and perpendicular (PE) configurations with respect to bedding planes. We found that the marly limestone had an average unconfined compressive strength (UCS) of 30 MPa and 39 MPa for the PA and PE tests, respectively. Similarly, the micritic limestone tests showed an average UCS of 24 MPa for the PA orientation and 58 MPa for the PE orientation. The critical crack thresholds were the first ever reported for Member I, as measured with strain gauge readings. The average crack initiation (CI) stress thresholds for the marly limestone (PA: 14 MPa) and the micritic limestone (PA: 11 MPa; PE: 24 MPa) fall within the typical ratio of CI to UCS (0.36–0.52). The micritic limestone had an average Young’s modulus (E) of 19.5 GPa and 10.3 GPa for PA and PE, respectively. The Poisson’s ratios were 0.2 for PA and 0.1 for PE on average. Both marly and micritic limestone can be characterised by a transverse isotropic strength behaviour with respect to bedding planes. The failure strength for intact anisotropic rocks depends on the orientation of the applied force, which must be considered when assessing the stability of tombs and cliffs in the KV and will be used to understand and improve the preservation of this UNESCO World Heritage site.https://www.mdpi.com/2673-7094/2/4/40physical rock propertiesstrength anisotropyThebes Limestone Formationengineering geologycrack initiationunconfined compressive strength (UCS) |
| spellingShingle | Rodrigo Alcaíno-Olivares Martin Ziegler Susanne Bickel Hesham Ismaiel Kerry Leith Matthew Perras Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, Egypt Geotechnics physical rock properties strength anisotropy Thebes Limestone Formation engineering geology crack initiation unconfined compressive strength (UCS) |
| title | Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, Egypt |
| title_full | Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, Egypt |
| title_fullStr | Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, Egypt |
| title_full_unstemmed | Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, Egypt |
| title_short | Rock Mechanical Laboratory Testing of Thebes Limestone Formation (Member I), Valley of the Kings, Luxor, Egypt |
| title_sort | rock mechanical laboratory testing of thebes limestone formation member i valley of the kings luxor egypt |
| topic | physical rock properties strength anisotropy Thebes Limestone Formation engineering geology crack initiation unconfined compressive strength (UCS) |
| url | https://www.mdpi.com/2673-7094/2/4/40 |
| work_keys_str_mv | AT rodrigoalcainoolivares rockmechanicallaboratorytestingofthebeslimestoneformationmemberivalleyofthekingsluxoregypt AT martinziegler rockmechanicallaboratorytestingofthebeslimestoneformationmemberivalleyofthekingsluxoregypt AT susannebickel rockmechanicallaboratorytestingofthebeslimestoneformationmemberivalleyofthekingsluxoregypt AT heshamismaiel rockmechanicallaboratorytestingofthebeslimestoneformationmemberivalleyofthekingsluxoregypt AT kerryleith rockmechanicallaboratorytestingofthebeslimestoneformationmemberivalleyofthekingsluxoregypt AT matthewperras rockmechanicallaboratorytestingofthebeslimestoneformationmemberivalleyofthekingsluxoregypt |