Authors
1
M.Sc. of Geotechnical Engineering, Department of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran.
2
Assistant Professor, Department of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran
3
Associate Professor, Department of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran
Abstract
One of the challenging subjects in geological and geotechnical engineering is the effects of soil specimen disturbance in order to determine several physical and strenght characteristics. Disturbance occurs in all stages, including drilling the borehole, preparing, transporting and conducting tests in the laboratory. Practically, it is impossible to prepare an ideal undisturbed sample. Due to the difficulties of preparing undisturbed samples, especially in soil layers, the tests are mostly performed on the remolded samples. Several studies have been conducted on the methods of evaluating sample disturbance. The target of this study was to evaluate the effects of disturbance on the strenght properties of clay soils as case study of Tabriz city. By conducting uniaxial compressive and direct shear tests on undisturbed and remolded samples, the effects of disturbance and sensitivity of the samples were investigated. Generally, the compressive strength of remolded samples decreases due to disturbance. In addition to determining Spearman's correlation coefficient, linear and non-linear regression analysis were performed in order to estimate the compressive strength of the undisturbed sample. By determining the sensitivity ratio, the sensitivity of samples is low. Correlation between the strength of undisturbed and remolded samples in direct shear test, including cohesion and internal friction angle, was studied by performing regression analysis.
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