Investigation of anisotropy and stress distribution for unsaturated clayey soils

ABSTRACTPh. D. DissertationINVESTIGATION OF ANISOTROPY AND STRESS DISTRIBUTION FORUNSATURATED CLAYEY SOILSTaha TAŞKIRANDEPARTMENT OF CIVIL ENGINEERINGINSTITUTE OF NATURAL AND APPLIED SCIENCESÇUKUROVA UNIVERSITYSupervisor : Prof. Dr. M.Arslan TEK NSOYYear: 2006, Pages 151Jury : Prof. Dr. M.Arslan TEK NSOY (Head): Prof. Dr. Mustafa LAMAN (Member): Prof. Dr. Hasan ÇET N (Member): Asst. Prof. Hanifi ÇANAKÇI (Member): Asst. Prof. A.Azim YILDIZ (Member)The purpose of this study is to investigate anisotropy of residual clayey soils.At the beginning, existing descriptions of anisotropy were presented and a newdefinition for anisotropy, which is not contradictory to previous descriptions andappropriate to soil structure, was introduced. For this purpose, first of all,anisotropic-elastic parameters of a saturated and non-residual soil was tried to bemeasured. A new test equipment was designed because the preliminary tests showedthat these parameters can not be measured using conventional test equipments.Anisotropic elastic parameters of a clayey soil were measured by means of this newequipment.Considering the soils as elastic-anisotropic medium, a stress distributionexpression which includes new description of anisotropy, was presented. Also, to beable to see the influence of anisotropy on stress distribution, finite element method(FEM) based on anisotropic elasticity, Boussinesq and Westergaard stressdistribution calculations were carried out and results were compared. It is found thatthe stresses obtained by the proposed method are well agreed with that of FEManalysis. Besides, the compacity were found as an effective parameter on stresses.Consequently, relative water content, matric suction, soil history, effectivestress level were found to be factors affecting anisotropy ratio.Key Words: Anisotropy, stress distribution, unsaturated soilII