Rotation along shear planes in cohesive soils

ABSTRACTMSc THESISROTATION ALONG SHEAR PLANES IN COHESIVESOILSBülent DERİNDEPARTMENT OF GOELOGICAL ENGINEERINGINSTITUTE OF NATURAL AND APPLIED SCIENCESUNIVERSITY OF ÇUKUROVASupervisor : Assoc. Prof. Dr. Hasan ÇETİNYear: 2005, Pages: 58Jury : Assoc. Prof. Dr. Hasan ÇETİNProf. Dr. Aziz ERTUNÇAssoc. Prof. Dr. Mustafa LAMANIn this study, soil thin sections of artificially prepared clayey soil sampleswere used. Orientations of particle, pore and other constituens were measured andthe relationship between the soil structure and maximum principal stress was studiedusing various computer programs. The results were plotted as rose diagrams and theeffects of rotation on the orientation and maximum principal stress were investigated.Engineering properties of soils in soil mechanics are controlled mainly bythe charecteristics and orientations of the particles as well as forces acting on theseparticles. About 600-1100 particle, pore and clay domain orientations in CU (fast)and CD (slow) direct shear tests were measured on each thin section. UsingCorelDRAW program, angles between long axes of the particles, pores and claydomains and verticle and horizontal planes were measured. Then, using Dipsprogram rose diagrams of the measurements were prepared. Photographs were takenfrom representative structures of each thin sections.Orientations between 0-10 degrees and average angles with the verticalplanes were found to corelate well in both CU (fast) and CD (slow) direct shear testsindicating that the roration has taken place in both tests. Effects of rotation on bothorientation and maximum principal stress were determined.Key words : Rotaion, Orientation, Principal Stress, Thin-section