Hydro-mechanical behavior of unsaturated specimens isotropically reconstituted from slurry and compacted specimens

Ahmadi Naghadeh, Reza
Response of unsaturated soils constitutes an important consideration for many problems in geotechnical engineering. The main objective of this study is to understand coupling hydro-mechanical behavior of the unsaturated reconstituted specimens from slurry and moist-tamped compacted specimen, and to develop practical and cost-effective testing equipment and procedure. The innovations that will be put forth by this study will make the unsaturated soil mechanics more accessible and appealing to those practical engineers working. A prediction type exponential equation is introduced to predict the shear strength of the unsaturated soil. Equation involves three constant parameters. Two of which are effective shear strength parameters (i.e. ϕ́ and ć can be determined through conventional saturated shear strength tests). The third parameter is ultimate shear strength.


Prediction of swelling behavior of expansive soils using modified free swell index, methylene blue and swell oedometer tests
Jaleh Forouzan, Amir; Çokça, Erdal; Department of Civil Engineering (2016)
Expansive soils are recognized as problematic soils that impose several challenges for civil engineers. Such soils undergo significant volume change in case water penetrates into them, and they shrink as they lose moisture. Lightly-loaded engineering structures such as pavements, single story buildings, railways and walkways may experience severe damages when they are founded on such soils. Determination of expansive soils and quantifying their swelling potential and pressure caused by their expansion are e...
Comparative study of soil water characteristic curve prediction methods
Ahmadiadli, Mohammad; Huvaj Sarıhan, Nejan; Toker, Nabi Kartal; Kürkçü, Mefküre Gamze (2012-06-30)
The soil-water characteristic curve (SWCC), which defines the relation between soil suction and water content, plays a key role in geotechnical studies of the unsaturated soils. Some researchers such as Brooks & Corey (1968), Van Genuchten (1982) and Fredlund& Xing (1994) have proposed curve fitting equations for SWCC. Fitting equations to the laboratory test data obtained from direct measurement of water content versus changes in matric suction is the most reliable method, but it is expensive and time cons...
Effective Stress and Shear Strength of Moist Uniform Spheres
Toker, Nabi Kartal; Culligan, Patricia J. (Wiley, 2014-05-01)
In continuum soil mechanics, the mechanical behavior of an element of soil is related to the effective stress, which is a measure of the average stress transmitted through the solid matrix in the form of contact stresses. In unsaturated soils, the coexistence of water and air within the soil pore space complicates this concept because the microscopic distribution of each fluid phase in soil pores cannot be known. Because it is thus not possible to physically measure effective stress in unsaturated soils, it...
Swell pressure prediction by suction methods
Kandemir, A; Erol, O; Erzin, Y (1997-09-12)
Soil suction is the most relevant soil parameter for characterization of the swell behaviour. An attempt has been made to predict the swell pressures from soil suction measurements. Bentonite-Kaolinite clay mixtures were prepared to obtain soils in a wide range of plasticity indices. Suction measurements using thermocouple physchrometer technique and constant volume swell tests in oedometers were made on statically compacted specimens. Soil suction is correlated to plasticty index, water content and dry den...
Exponential Equation for Predicting Shear Strength Envelope of Unsaturated Soils
Ahmadi Naghadeh, Reza; Toker, Nabi Kartal (2019-07-01)
An exponential equation is introduced to predict the nonlinear variation of shear strength with matric suction for unsaturated soils. The proposed equation involves three constant parameters, two of which are effective shear strength parameters (i.e., phi ' and c '). The third parameter is the maximum capillary cohesion, c '' max, which is the maximum possible increase in shear strength due to matric suction. A procedure for the determination of c '' max from the soil-water characteristic curve (SWCC) is de...
Citation Formats
R. Ahmadi Naghadeh, “Hydro-mechanical behavior of unsaturated specimens isotropically reconstituted from slurry and compacted specimens,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.