A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Hydro-mechanical behavior of undisturbed collapsible loessial soils under different stress state conditions
https://orcid.org/0000-0002-9696-3455
Abstract A conventional triaxial test device was modified to characterize the hydro-mechanical behavior of a loessial soil during isotropic and shear loadings. This device is capable of precise and continuous measurements of water outflow during the application of loading. The tests were performed on “undisturbed” cylindrical specimens, which were taken from loessial deposits in Gorgan, a city in the northeast of Iran. Experimental measurements indicate that the hydro-mechanical behavior of loess is highly affected by the extent of applied mean net stress and the level of suction. During both isotropic and shearing stages of loading, the tested specimens may exhibit collapse, abrupt decrease in volume or sudden positive volumetric strain, upon wetting or applied loading. However, the magnitude and extent of collapse are different depending on the applied state of the stress and the hydro-mechanical loading path. The results of the experiments reveal that the peak shear strength of the soil increases, as the applied mean net stress during isotropic loading or the applied matric suction increases. The shearing test results are also used to investigate the efficiency of suction stress in describing the state of stress for unsaturated loessial soils. The outcome indicated a unique critical state line for unsaturated specimens under different stress paths and loading conditions. Furthermore, considering the effective stress concept, a hardening constitutive law is presented in this study to demonstrate the hardening/softening behavior of the collapsible loessial soils.
Highlights Hydro-mechanical behavior of an undisturbed collapsible loessial soil is studied. A conventional Triaxial test device was modified and used for unsaturated testing. Isotropic consolidation, wetting and shear loadings are applied to the tested soil. The effective stress approach and the suction stress concept are considered. A hardening model is presented to predict the yielding behavior of the tested soil.
Hydro-mechanical behavior of undisturbed collapsible loessial soils under different stress state conditions
https://orcid.org/0000-0002-9696-3455
Abstract A conventional triaxial test device was modified to characterize the hydro-mechanical behavior of a loessial soil during isotropic and shear loadings. This device is capable of precise and continuous measurements of water outflow during the application of loading. The tests were performed on “undisturbed” cylindrical specimens, which were taken from loessial deposits in Gorgan, a city in the northeast of Iran. Experimental measurements indicate that the hydro-mechanical behavior of loess is highly affected by the extent of applied mean net stress and the level of suction. During both isotropic and shearing stages of loading, the tested specimens may exhibit collapse, abrupt decrease in volume or sudden positive volumetric strain, upon wetting or applied loading. However, the magnitude and extent of collapse are different depending on the applied state of the stress and the hydro-mechanical loading path. The results of the experiments reveal that the peak shear strength of the soil increases, as the applied mean net stress during isotropic loading or the applied matric suction increases. The shearing test results are also used to investigate the efficiency of suction stress in describing the state of stress for unsaturated loessial soils. The outcome indicated a unique critical state line for unsaturated specimens under different stress paths and loading conditions. Furthermore, considering the effective stress concept, a hardening constitutive law is presented in this study to demonstrate the hardening/softening behavior of the collapsible loessial soils.
Highlights Hydro-mechanical behavior of an undisturbed collapsible loessial soil is studied. A conventional Triaxial test device was modified and used for unsaturated testing. Isotropic consolidation, wetting and shear loadings are applied to the tested soil. The effective stress approach and the suction stress concept are considered. A hardening model is presented to predict the yielding behavior of the tested soil.
Hydro-mechanical behavior of undisturbed collapsible loessial soils under different stress state conditions
https://orcid.org/0000-0002-9696-3455
Abstract A conventional triaxial test device was modified to characterize the hydro-mechanical behavior of a loessial soil during isotropic and shear loadings. This device is capable of precise and continuous measurements of water outflow during the application of loading. The tests were performed on “undisturbed” cylindrical specimens, which were taken from loessial deposits in Gorgan, a city in the northeast of Iran. Experimental measurements indicate that the hydro-mechanical behavior of loess is highly affected by the extent of applied mean net stress and the level of suction. During both isotropic and shearing stages of loading, the tested specimens may exhibit collapse, abrupt decrease in volume or sudden positive volumetric strain, upon wetting or applied loading. However, the magnitude and extent of collapse are different depending on the applied state of the stress and the hydro-mechanical loading path. The results of the experiments reveal that the peak shear strength of the soil increases, as the applied mean net stress during isotropic loading or the applied matric suction increases. The shearing test results are also used to investigate the efficiency of suction stress in describing the state of stress for unsaturated loessial soils. The outcome indicated a unique critical state line for unsaturated specimens under different stress paths and loading conditions. Furthermore, considering the effective stress concept, a hardening constitutive law is presented in this study to demonstrate the hardening/softening behavior of the collapsible loessial soils.
Highlights Hydro-mechanical behavior of an undisturbed collapsible loessial soil is studied. A conventional Triaxial test device was modified and used for unsaturated testing. Isotropic consolidation, wetting and shear loadings are applied to the tested soil. The effective stress approach and the suction stress concept are considered. A hardening model is presented to predict the yielding behavior of the tested soil.
Hydro-mechanical behavior of undisturbed collapsible loessial soils under different stress state conditions
Garakani, Amir Akbari (author) / Haeri, S. Mohsen (author) / Khosravi, Ali (author) / Habibagahi, Ghassem (author)
Engineering Geology ; 195 ; 28-41
2015-05-23
14 pages
Article (Journal)
Electronic Resource
English
<italic>b</italic> , Double-hardening parameter , <italic>b</italic> <inf>1</inf> and <italic>b</italic> <inf>2</inf> , Fitting parameters of the hardening model , <italic>d</italic> <inf>200</inf> , Percent passing sieve No. 200 , <italic>d</italic> <inf>4</inf> , Percent passing sieve No. 4 , <italic>d<inf>c</inf></italic> , Percentage of clay fraction , <italic>de<sup>p</sup></italic> , Increment of plastic change in void ratio , <italic>dS<inf>e</inf></italic> , Increment of change of effective saturation , <italic>e</italic> , Void ratio , <italic>e<inf>o</inf></italic> , Initial void ratio , <italic>M</italic> , Slope of critical state line , <italic>p</italic>′ , Mean effective stress , <italic>p<inf>o</inf></italic>′ , Initial mean effective stress , <italic>p<inf>c</inf></italic>′ , Mean apparent pre-consolidation stress , <italic>p<inf>n</inf></italic> , Mean net stress , <italic>p<inf>no</inf></italic> , Initial mean net stress , <italic>p<inf>s</inf></italic> , Suction-stress , <italic>q</italic> , Deviator stress , <italic>S<inf>e</inf></italic> , Effective saturation , <italic>S</italic> <inf><italic>e</italic>,<italic>sat</italic></inf> , Effective saturation at the matric suction of zero , <italic>S<inf>r</inf></italic> , Degree of saturation , <italic>S</italic> <inf><italic>r</italic>,<italic>res</italic></inf> , Residual degree of saturation , <italic>S<inf>ro</inf></italic> , Initial degree of saturation , <italic>u<inf>a</inf></italic> , Pore air pressure , <italic>u<inf>w</inf></italic> , Pore water pressure , <italic>w<inf>o</inf></italic> , Initial water content , <italic>w<inf>L</inf></italic> , Liquid limit of the soil , <italic>w<inf>P</inf></italic> , Plastic limit of the soil , <italic>χ</italic> , Effective stress parameter , <italic>ε<inf>v</inf></italic> , Volumetric strain , <italic>ε<inf>a</inf></italic> , Axial strain , <italic>γ<inf>do</inf></italic> , Initial dry density , <italic>κ</italic> , Slope of the elastic rebound curve , <italic>λ</italic> , Slope of the virgin compression curve , <italic>ψ</italic> , Matric suction , <italic>ψ<inf>e</inf></italic> , Transition matric suction , Unsaturated soil , Hydro-mechanical behavior , Collapsible loess , Undisturbed sampling , Shear strength , Suction stress
Some Civil Engineering Aspects Concerning Loessial Collapsible Soils in Romania
| British Library Conference Proceedings | 1995
Effect of Soil Structure and Disturbance on Hydromechanical Behavior of Collapsible Loessial Soils
| Online Contents | 2017
Effect of Soil Structure and Disturbance on Hydromechanical Behavior of Collapsible Loessial Soils
| Online Contents | 2016