Assessment of Geotechnical Properties of Al-Fatha Formation in Zurbatiyah Region Eastern Iraq

A series of experimental tests were carried out to study and assessment of the geotechnical properties of the Fatha formation rocks in the Zurbatiyah region in eastern Iraq, the physical and mechanical characteristics have been studied in the study area of two types of rocks are represented by gypsum and limestone rocks. The physical results and tests helped to explain the mechanical behavior of the rock specimens that were studied. Several destructive and non-destructive tests were conducted on rock samples collected from various zones. Uniaxial compressive strength, point load, and Brazilian tests were tested on 60 intact rock specimens. The results of uniaxial compressive strength show that the maximum value of the compressive strength of the gypsum specimens was 35.08 MPa, while the maximum value in limestone specimens, was 38.095 MPa. In the indirect point load test, the maximum point load strength index I_S(50) was 2.810 and 6.428 MPa for gypsum and limestone rock specimens respectively. In the indirect Brazilian test, the maximum tensile strength (σ_t) values were 4.66 and 7.36 MPa for gypsum and limestone rock specimens respectively. A new correlation with a high value of the regression coefficient R² is presented, linking the uniaxial compressive strength (UCS) versus the rebound number of the Schmidt hammer (N).