Consolidated undrained shearing response of hydrophobic sands

Download
2018
Tatar, Hüseyin Melih
The geotechnical properties of hydrophilic (wettable) sands have been widely discussed in the literature. However, sands may gain hydrophobic (non-wettable) property after certain processes. Available studies regarding the response of hydrophobic sands mostly focused on its environmental and hydrological aspects. The current state of knowledge about the geotechnical aspects of hydrophobic sands is quite limited and consists of the results of a limited number of direct shear tests. To close this gap, a comparative laboratory testing program consisting of 18 static strain-controlled consolidated undrained triaxial shear tests was designed. Tests were performed on fully saturated hydrophilic and hydrophobic reconstituted Kızılırmak sand samples of different relative densities with pore water measurements. Additionally, soil classification tests including specific gravity , minimum void ratio and maximum void ratio determination and sieve analysis were performed. Hydrophobic samples were prepared by using varying amounts of WD-40 lubricant. The effects of hydrophobic agent was examined by comparing the stress – excess pore water pressure - strain responses of hydrophobic sand samples with those of conventional (hydrophilic) sand samples. Test results revealed that addition of hydrophobic agent increases the dilatancy of sands at low confining stresses (~100kPa) by decreasing the excess pore water pressure generation. At higher confining stresses (~400kPa) this effect is less pronounced. Moreover, the addition of hydrophobic agent does not significantly and systematically change the shear strength of sand samples independent of their initial relative density and confining stress levels.

Suggestions

Consolidated Undrained Monotonic Shearing Response of Hydrophobic Kizilirmak Sand
Tatar, Huseyin Melih; Çetin, Kemal Önder (2021-03-01)
Geotechnical properties of hydrophilic (wettable) sands have been widely discussed in the literature. However, sands may gain hydrophobic (non-wettable) properties after being exposed to a hydrophobic agent in the nature. The number of available studies regarding the response of hydrophobic sands is very limited, and mostly focus on their environmental and hydrological aspects. To close this gap, a controlled laboratory testing program, consisting of 18 monotonic strain-controlled consolidated undrained tri...
Forced vibrations of functionally graded annular and circular plates by domain-boundary element method
Eshraghi, Iman; Dağ, Serkan (Wiley, 2020-08-01)
Axi-symmetric dynamic response of functionally graded circular and annular Mindlin plates with through-the-thickness variations of physical properties is investigated by a new domain-boundary element formulation. Three governing partial differential equations of motion of the inhomogeneous plate are converted to integral equations by utilizing the static fundamental solutions of the displacement components. These integral equations are then spatially discretized by dividing the entire domain into a number o...
Inelastic axial-flexure-shear coupling in a mixed formulation beam finite element
Sarıtaş, Afşin (2009-10-01)
In this paper a beam element that accounts for inelastic axial-flexure-shear coupling is presented. The mathematical model is derived from a three-field variational form. The finite element approximation for the beam uses shape functions for section forces that satisfy equilibrium and discontinuous section deformations along the beam. No approximation for the beam displacement field is necessary in the formulation. The coupling of the section forces is achieved through the numerical integration of an inelas...
Cyclic behavior of Adapazarı silt and clay mixtures
Pekcan, Onur; Çetin, Kemal Önder; Bakır, Bahadır Sadık (null; 2004-01-07)
Within the confines of this paper, it is intended to understand cyclic behavior of clayey silt and silty clay mixtures, sampled from Adapazarı–Turkey. For this purpose, series of cyclic triaxial tests were performed on the samples retrieved from five selected soil sites, where buildings founded on these soils exhibited significant foundation displacements. After consolidating samples to 0.50 atm. cyclic loads were applied to simulate 1999 Kocaeli-Turkey earthquake shaking. Volumetric strains were recorded b...
Enhanced vaterite and aragonite crystallization at controlled ethylene glycol concentrations
Oral, Çağatay Mert; Kapusuz, Derya; Ercan, Batur (Sakarya Üniversitesi, 2019-04-01)
Calcium carbonate (CaCO3) has three distinct anhydrous polymorphs, namely vaterite, aragonite and calcite. Although there is a high demand for aragonite and vaterite polymorphs for biomedical use, their unstable nature makes it challenging to synthesize them compared to calcite, which is the most stable form of CaCO3. Despite the remarkable effort on stabilizing vaterite and aragonite polymorphs in aqueous solutions, phase-pure vaterite and aragonite polymorphs have not been synthesized yet, without referri...
Citation Formats
H. M. Tatar, “Consolidated undrained shearing response of hydrophobic sands,” M.S. - Master of Science, Middle East Technical University, 2018.