Investigations of anisotropic strength and deformation properties of the basal units of the Niğde massive

ABSTRACTMsc THESISINVESTIGATION OF ANISOTROPIC STRENGTH AND DEFORMATIONPROPERTIES OF THE BASAL UNITS OF THE NIĞDE MASSIVEYusuf Recep BAYRAKDEPARTMENT OF GEOLOGICAL ENGINEERINGINSTITUTE OF NATURAL AND APPLIED SCIENCESUNIVERSITY OF ÇUKUROVASupervisor: Yrd.Doç.Dr.Tolga ÇANYear: 2005, Page: 113Jury : Assist.Prof.Dr. Tolga ÇANProf.Dr. Aziz ERTUNÇAssoc.Prof.Dr. Candan GÖKÇEOĞLURock anisotropy, may be defined as variation of the physical and mechanicalbehavior of the rocks with respect to the direction of the fabric such as foliation,stratification or jointing. Rock anisotropy plays an important role in engineeringapplications and affects the stability of surface and underground excavations andfoundations. In this study, strength, static and dynamic anisotropic properties of the basalunits (amphibole-schist, calc-schist, quartz mica-schist, metagabro) of the Niğde massive,which constitute the core of the Central Anatolian Crystalline Complex, was studied. 224core samples were prepared and 890 laboratory tests were performed with respect to thevarious foliation surfaces as 0, 30, 60, and 90 degrees. Strength anisotropy characteristicswere determined from unconfined compressive and indirect tensile tests. Static anddynamic deformation anisotropy characteristics were determined from elasticity modulusand sonic wave velocity tests, respectively. According to the test results, transversal U-type anisotropic behaviors were observed for all studied rock groups. The strengthanisotropy ratio (Rc) of 5.14, which refer to the high degree anisotropy, were obtained forquartzmica-schists while moderate degree anisotropy with Rc values range between 2.07to 3.81 were obtained for the other lithologies. Finally, relations among the uniaxialcompressive strength, static and dynamic elasticity modulus and p-wave velocities wereobtained with very high coefficients of correlation.Keywords: Transversal anisotropy, anisotropy ratio, uniaxial compressive strength,elasticity modulus, sonic wave velocity.