Browsing by Author "Sari, Dursun"

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Citation - WoS: 5
Computer-controlled triaxial test apparatus for measuring swelling characteristics of reconstituted clay-bearing rock
(Amer Soc Testing Materials, 2008) Bilir, M. Erdinc; Sari, Dursun; Muftuoglu, Yadigar V.; Department of Civil Engineering
To avoid problems encountered during and after the construction of engineering projects built within swelling rocks and soils, real data related to swelling stress and strains should be used to model such phenomena. A computer-controlled triaxial swelling test apparatus was developed to determine the swelling potentials for rock and soil specimens. It allows one to measure three-dimensional swelling strains and stress in a cylindrical specimen under variable axial and confinement stress variables. Triaxial swell tests were performed using three different procedures: free swell, strain-controlled, and stress-controlled under different axial and confinement stress conditions. The results of several tests conducted on reconstituted clay-bearing rock samples were statistically analyzed and mathematical models were presented and evaluated.
Citation - WoS: 200
Citation - Scopus: 251
Impact of Cyclic Wetting-Drying on Swelling Behavior of Lime-Stabilized Soil
(Pergamon-elsevier Science Ltd, 2007) Guney, Yucel; Sari, Dursun; Cetin, Murat; Tuncan, Mustafa; Department of Civil Engineering
In this study, the impact of cyclic wetting and drying on swelling behavior of lime-stabilized clayey soils has been investigated. Swelling potential and swelling pressure tests have been carried out on soil mixtures with various amounts of kaolinite-bentonite clays, and on a high plasticity clayey soil sample. The tests have been repeated after the addition of lime to the lime-treated samples in different preparation. In each cycle the tested samples were allowed air dry to their initial water content thus shrinking to their initial height, which is called 'partial shrinkage' method. The results showed that the initial beneficiary effect of lime stabilization was lost after the first cycle and the swelling potential increased at the subsequent cycles. On the other hand, the swelling potential and the swelling pressure of the untreated soil samples started decreasing after the first cycle and they reached equilibrium after the fourth cycle. (c) 2005 Elsevier Ltd. All rights reserved.
Citation - WoS: 7
Citation - Scopus: 8
Rock mass response model for circular openings
(Canadian Science Publishing, 2007) Sari, Dursun; Department of Civil Engineering
The main parameters affecting the failure and deformation state of the rock mass around a circular opening are the level of vertical and horizontal in situ stresses, the characteristics of the rock mass, the diameter of the opening, and the support pressure. The influence of all these parameters on the stress-induced final deformations around circular openings was investigated by a finite difference based two-dimensional numerical simulation for both hydrostatic and nonhydrostatic stress field conditions. From the results of the parametric studies, the variation of tunnel strain versus the ratio of uniaxial compressive strength of the rock mass to in situ vertical stress and the ratio of radial support pressure to in situ vertical stress for fair quality and poor quality rock masses was statistically analysed. As a result of the three-dimensional nonlinear regression analysis and surface curve fitting process by means of a large number of models, a best-fit model with the best correlation with these dimensionless parameters was proposed for calculating tunnel strains and ground response curves. Specific charts were created to highlight the influence of parameters on the deformation response of the openings to various support pressures.