Effect of Suction on Volumetric Yielding Behavior under Different Initial Conditions for Fine-Grained Soils

The unsaturated soils are difficult to consider within the framework of classical (saturated) soil mechanics. In general, the unsaturated soil is stiffer than the saturated one (hardening), so the location and slope of normal consolidated line (NCL) or the volumetric yielding behavior of unsaturated...

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Main Authors: Yasir Al-Badran, Tom Schanz
Format: Article
Language:English
Published: Unviversity of Technology- Iraq 2013-11-01
Series:Engineering and Technology Journal
Subjects:
Online Access:https://etj.uotechnology.edu.iq/article_83848_1108060d5d45f77fc229bc3d75a5343a.pdf
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author Yasir Al-Badran
Tom Schanz
author_facet Yasir Al-Badran
Tom Schanz
author_sort Yasir Al-Badran
collection DOAJ
description The unsaturated soils are difficult to consider within the framework of classical (saturated) soil mechanics. In general, the unsaturated soil is stiffer than the saturated one (hardening), so the location and slope of normal consolidated line (NCL) or the volumetric yielding behavior of unsaturated soil is different from the saturated behavior. This work investigates the volumetric yielding behavior of unsaturated soil; by determine the One-dimensional normal consolidated lines (NCL’s) under different suctions. Two materials namely pure Calcigel bentonite (100B) and a mixture of 30% Calcigel bentonite and 70 % Haider sand (30B) were prepared at two initial conditions (i.e. slurry and loose states). In this type of test, after reaching to the designed suction, the net stress is increased through the test while the suction is kept constant. Thirteen 30B specimens and two 100B specimens were tested under constant suction condition. The constant applied suction in this study was varied from 0 kPa till 39000 kPa because of the possibility to increase the preconsolidation pressure (yield stress) more than 24000 kPa (the maximum limit of the used one-dimensional high stress consolidation equipments). Two techniques (i.e. axis translation technique and vapor equilibrium technique) were used to apply and control suction on tests. The controlled-suction one-dimensional high stress consolidation tests results show that the position and the slope of NCL’s depend on both net stress and suction. The NCL’s either, for low suction value, has void ratio lower than the saturated NCL (associated with slope lower than the saturated NCL), or the NCL has void ratio higher than the saturated NCL (associated with slope higher than the saturated NCL) for higher suction value.
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spelling doaj.art-1136b4300a194308a6f813ca7e3c936a2024-02-04T17:37:05ZengUnviversity of Technology- IraqEngineering and Technology Journal1681-69002412-07582013-11-01312033935810.30684/etj.2013.8384883848Effect of Suction on Volumetric Yielding Behavior under Different Initial Conditions for Fine-Grained SoilsYasir Al-BadranTom SchanzThe unsaturated soils are difficult to consider within the framework of classical (saturated) soil mechanics. In general, the unsaturated soil is stiffer than the saturated one (hardening), so the location and slope of normal consolidated line (NCL) or the volumetric yielding behavior of unsaturated soil is different from the saturated behavior. This work investigates the volumetric yielding behavior of unsaturated soil; by determine the One-dimensional normal consolidated lines (NCL’s) under different suctions. Two materials namely pure Calcigel bentonite (100B) and a mixture of 30% Calcigel bentonite and 70 % Haider sand (30B) were prepared at two initial conditions (i.e. slurry and loose states). In this type of test, after reaching to the designed suction, the net stress is increased through the test while the suction is kept constant. Thirteen 30B specimens and two 100B specimens were tested under constant suction condition. The constant applied suction in this study was varied from 0 kPa till 39000 kPa because of the possibility to increase the preconsolidation pressure (yield stress) more than 24000 kPa (the maximum limit of the used one-dimensional high stress consolidation equipments). Two techniques (i.e. axis translation technique and vapor equilibrium technique) were used to apply and control suction on tests. The controlled-suction one-dimensional high stress consolidation tests results show that the position and the slope of NCL’s depend on both net stress and suction. The NCL’s either, for low suction value, has void ratio lower than the saturated NCL (associated with slope lower than the saturated NCL), or the NCL has void ratio higher than the saturated NCL (associated with slope higher than the saturated NCL) for higher suction value.https://etj.uotechnology.edu.iq/article_83848_1108060d5d45f77fc229bc3d75a5343a.pdfinitial statebentoniteunsaturated soilvolume changeyield stressncland suction
spellingShingle Yasir Al-Badran
Tom Schanz
Effect of Suction on Volumetric Yielding Behavior under Different Initial Conditions for Fine-Grained Soils
Engineering and Technology Journal
initial state
bentonite
unsaturated soil
volume change
yield stress
ncl
and suction
title Effect of Suction on Volumetric Yielding Behavior under Different Initial Conditions for Fine-Grained Soils
title_full Effect of Suction on Volumetric Yielding Behavior under Different Initial Conditions for Fine-Grained Soils
title_fullStr Effect of Suction on Volumetric Yielding Behavior under Different Initial Conditions for Fine-Grained Soils
title_full_unstemmed Effect of Suction on Volumetric Yielding Behavior under Different Initial Conditions for Fine-Grained Soils
title_short Effect of Suction on Volumetric Yielding Behavior under Different Initial Conditions for Fine-Grained Soils
title_sort effect of suction on volumetric yielding behavior under different initial conditions for fine grained soils
topic initial state
bentonite
unsaturated soil
volume change
yield stress
ncl
and suction
url https://etj.uotechnology.edu.iq/article_83848_1108060d5d45f77fc229bc3d75a5343a.pdf
work_keys_str_mv AT yasiralbadran effectofsuctiononvolumetricyieldingbehaviorunderdifferentinitialconditionsforfinegrainedsoils
AT tomschanz effectofsuctiononvolumetricyieldingbehaviorunderdifferentinitialconditionsforfinegrainedsoils