scholarly journals The Compressibility and Swell of Mixtures for Sand-Clay Liners

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Muawia A. Dafalla
Keyword(s):  
Hydraulic Conductivity ◽  
Expansive Soil ◽  
Clay Content ◽  
Swelling Pressure ◽  
Partial Replacement ◽  
Expansive Clay ◽  
Clay Liners ◽  
Swelling Properties ◽  
Prime Concern ◽  
Swell Percent

Sand-clay liners utilize expansive clay to act as a filler to occupy the voids in the sand and thus reduce the hydraulic conductivity of the mixture. The hydraulic conductivity and transfer of water and other substances through sand-clay mixtures are of prime concern in the design of liners and hydraulic barriers. Many successful research studies have been undertaken to achieve appropriate mixtures that satisfy hydraulic conductivity requirements. This study investigates compressibility and swelling properties of mixtures to ensure that they were acceptable for light structures, roads, and slabs on grade. A range of sand-expansive clay mixtures were investigated for swell and compression properties. The swelling and compressibility indices were found to increase with increasing clay content. The use of highly expansive material can result in large volume changes due to swell and shrinkage. The inclusion of less expansive soil material as partial replacement of bentonite by one-third to two-thirds is found to reduce the compressibility by 60% to 70% for 10% and 15% clay content, respectively. The swelling pressure and swell percent were also found significantly reduced. Adding less expansive natural clay to bentonite can produce liners that are still sufficiently impervious and at the same time less problematic.

scholarly journals Pengaruh Kadar Air Awal Dan Surcharge Pressure Pada Uji Karakteristik Pengembangan Tanah Ekspansif

2017 ◽  
Vol 23 (2) ◽  
pp. 124
Author(s):  
Wilis Diana ◽  
Edi Hartono ◽  
Anita Widianti
Keyword(s):  
Water Content ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Dry Density ◽  
Initial Water Content ◽  
Expansive Clay ◽  
Initial Water ◽  
Swelling Properties ◽  
Swell Percent ◽  
Swell Pressure

Expansive soils experience volumetric changes due to water content changes. These volumetric changes cause swell and shrink movement in soils, which in turn will inflict severe damage to structures built above them. A Proper understanding of how the expansive soil behaves during the wetting/drying process is essential for assessing the mitigation action of expansive soil hazard and design suitable foundation. The structures that build above expansive soil bed are susceptible to heave and to withstand swell pressure, thus the swell pressure must be considered in the design. This study focuses on swelling properties of two expansive clay from Ngawi, East Java and Wates, Yogyakarta. Laboratory test on disturbed samples is used to identified and to measured swelling properties. A series of swelling test was performed under constant soil dry density. The influence of initial water content and surcharge pressure on swelling properties (i.e swell percent and swell pressure) of compacted samples were investigated. The swelling properties test used ASTM standard 4546-03 method B. It was found that the lower initial water content the higher the swell percent, but the swell pressure seems not to be affected by initial water content. At the same initial water content, swell percent decrease with the increase of surcharge pressure, but swell pressure remains unchanged.

Compressibility and hydraulic conductivity of a chemically treated expansive clay

2001 ◽  
Vol 38 (1) ◽  
pp. 154-160 ◽  
Author(s):  
Zalihe Nalbantoglu ◽  
Erdil Riza Tuncer
Keyword(s):  
Fly Ash ◽  
Hydraulic Conductivity ◽  
Expansive Soil ◽  
Dry Weight ◽  
Pozzolanic Reaction ◽  
Exchange Capacity ◽  
Expansive Clay ◽  
Preconsolidation Pressure ◽  
Few Data ◽  
Published Research

The paper presents a series of laboratory tests and evaluates the effect of lime and fly ash on the compressibility and hydraulic characteristics of an expansive soil in Cyprus. The tests were performed at different percentages of lime (0–7%) and fly ash (15 and 25%) by dry weight of soil, and additional tests were also performed on soils treated with 15% fly ash plus 3% lime. Previously published research reveals that few data are available concerning the compressibility and hydraulic conductivity of lime-treated soils. The results of this study indicate an increase in the vertical effective yield stress (apparent preconsolidation pressure) and a decrease in the compressibility characteristics of the treated soils. Moreover, unlike some of the findings in the literature, higher hydraulic conductivity values were obtained with time. This finding has been substantiated by the reduced cation exchange capacity (CEC) values, which indicate that the pozzolanic reaction causes the soils to become more granular in nature, resulting in higher hydraulic conductivity.Key words: cementation, compressibility, fly ash, hydraulic conductivity, lime.

scholarly journals Estimation of Free Swell and Swelling Pressure using Genetic Programming

2019 ◽  
Vol 8 (12) ◽  
pp. 4718-4720
Keyword(s):  
Genetic Programming ◽  
Regression Models ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Expansive Clay ◽  
Undisturbed Soil ◽  
Geotechnical Parameters ◽  
Theory Of Evolution ◽  
Free Swell ◽  
Problematic Soil

Regression models by genetic programming are useful in establishing relationships among various parameters using Darwin’s theory of evolution. Geotechnical parameters have been used in this model for the dataset obtained from literature. Genetic Programming is the automatic creation of computer programs to perform a selected task using Darwinian natural selection. The datasets for the expansive soil contain all the 3 expansive clay minerals – montmorillonite, illite and kaolinite. The origin for this problematic soil in Tabuk region, Saudi Arabia is due to the presence of Hanadir shale. Consolidometer was used in determining free swell for the undisturbed soil.

Review of Oedometer Method for Predicting Heave on the Expansive Soil

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Willis Diana ◽  
◽  
Agus Setyo Muntohar ◽  
Anita Widianti ◽  
◽  
...  
Keyword(s):  
State Of The Art ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Foundation Design ◽  
Swelling Properties ◽  
One Dimensional ◽  
Testing Procedures ◽  
Frequent Use ◽  
The One ◽  
Heave Prediction

In foundation design on an expansive soil, the most critical step is to quantify accurately the magnitude of heave and swelling pressure due to change in moisture content. The one-dimensional oedometer has been widely accepted method to determine the heave and swelling pressure of expansive soil. Its simplicity, suitability, and the availability were the reasons for the frequent use of oedometer swell testing technique, but many procedures were identified to measure the swelling properties. Each testing procedures were not unique and resulted different swelling properties and heave prediction. Then, this paper provides an overview of various existing heave prediction by oedometer methods and evaluate common practices of this methods. The techniques were reviewed systematically and summarized. The study summarized a state-of-the-art heave prediction based on the oedometer methods. Various equations forms to predict heave based on the oedometer method have been presented, but the fundamental principles were the same to propose the equation of heave prediction. The differences in these methods were related to the procedures in which the heave index parameter were determined. The three main procedures of oedometer test, i.e. consolidation swell (CS), constant volume CV, and swell overburden (SO), have been summarized. Most of the heave prediction uses the parameter from CS and CV methods. Several reports have shown that the closest estimates of field heave were predicted based on CV method.

Measurement of swelling pressure: direct method versus indirect methods

2011 ◽  
Vol 48 (3) ◽  
pp. 354-364 ◽  
Author(s):  
Kamil Kayabali ◽  
Saniye Demir
Keyword(s):  
Expansive Soils ◽  
Direct Method ◽  
Swelling Pressure ◽  
Expansive Clay ◽  
Swelling Properties ◽  
Indirect Methods ◽  
Natural Soils ◽  
Considerable Research ◽  
Free Swell ◽  
Swell Pressure

Light structures including highways and railroads built over potentially expansive clay soils may suffer damage from swelling. Considerable research has been done in an attempt to characterize swelling properties of expansive soils. Although direct measurement of swelling pressure is relatively straightforward, it has not drawn much interest. The present study attempts to measure swelling pressure directly. We call experimental techniques for swelling pressure other than this direct method the indirect methods. Some indirect methods require more than one soil sample and that all samples be identical. However, natural soils may not always provide identical samples. Therefore, reconstructed identical soil samples produced from natural soils were used in the present study. For comparison, the restricted swell, swell-consolidation, double oedometer, and zero swell tests were employed as indirect methods. While the restricted swell test slightly underestimated swell pressure, swell-consolidation and zero swell tests overestimated it. The double oedometer test did not provide swell pressures correlatable with those found using the direct method. Free swell data correlated reasonably well with swell pressure data from the direct method, so an empirical form was established from which swell pressure can be easily estimated.

scholarly journals Factors Affecting the Swelling-Compression Characteristics of Clays in Yichang, China

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Changxi Huang ◽  
Xinghua Wang ◽  
Hao Zhou ◽  
Yan Liang
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Stress Path ◽  
Dry Density ◽  
Initial Water Content ◽  
Initial Water ◽  
Swelling Properties ◽  
Vertical Loading

Expansive soil has been studied for eighty decades because it is prone to cause geotechnical engineering accidents. The results of the moisture content effects on the expansive pressure were not consistent in the literatures. In this paper, swelling deformation and pressure tests were conducted to clarify the effects of the initial water content on the swelling properties. The relation of expansive stress and initial moisture content was accurately described with a Gaussian distribution, unlike in the previously published studies. These results could be explained by the change in the microstructure with diverse moisture contents. In addition, dry density and vertical stress influences on expansive properties were analysed. With an increase in the vertical loading, the soil samples first expanded, and then the samples with a lower dry density collapsed; however, the samples with a higher dry density did not collapse, even under a considerable vertical loading. Furthermore, the relation between stress path and expansive pressure was examined. It was observed that the swelling pressures obtained from the constant volume tests were greater than the results from the swell under load tests. The relationship between the swelling pressure and swelling strain was also analysed.

An Experimental Study on Swelling Properties of Expansive Soil Treated with Iron Furnace Slag

2020 ◽  
Vol 27 (3) ◽  
pp. 61-66
Author(s):  
Yaseen Yaseen ◽  
Jawdat Abbas
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Industrial Wastes ◽  
Engineering Properties ◽  
Swelling Properties ◽  
Waste Products ◽  
Iron Slag ◽  
Furnace Slag

Using industrial waste materials in the treatment of problematic soils is an environmentally friendly and cost-effective technique. It helps in decreasing disposal issues induced by various industrial wastes. Also, it is crucial to understand the behaviour of these waste products before use. This paper presents experimental research in the treatment of expansive soil by the utilization of iron furnace slag. Laboratory program was performed to examine the effect of iron furnace slag on enhancing the engineering properties of expansive soil. Several tests included liquid limits, plastic limits, free swell percentage, swelling pressure, and unconfined compressive strength were conducted on untreated and treated soils. The efficiency of adding 0, 2, 4, and 6 percentages of iron slag to the soil was investigated. The results of the natural and iron slag stabilized soils showed that iron slag has a notable effect on strength parameters and considerable improvement in plasticity and swelling properties. The addition of iron slag to the soil increased the unconfined compressive strength while reduced the swelling potential of soil. It is concluded that the utilization of iron slag to improve the properties of expansive soil is successful and useful

scholarly journals MICROSTRUCTURE AND GEOTECHNICAL CHARACTERISTICS ‎OF A HIGHLY PLASTIC ‎CLAY TREATED BY MAGNESIUM ‎CHLORIDE

Mining Scince ◽  
2019 ◽  
Vol 26 ◽  
Author(s):  
Ouassila Bahloul ◽  
Khelifa Abbeche ◽  
Azzedine Bahloul
Keyword(s):  
Magnesium Chloride ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Friction Angle ◽  
Liquid Limit ◽  
Expansive Clay ◽  
Geotechnical Characterization ◽  
Geotechnical Characteristics ◽  
Strength Tests ◽  
Physical And Mechanical Characteristics

Chemical stabilization of soil is an effective improvement technique because it reduces the ability of ‎the soil ‎to swell. We added different proportions of magnesium chloride to an expansive clay and ‎performed ‎swelling, geotechnical characterization, and mechanical strength tests. The results show ‎that the swelling ‎potential and swelling pressure of the expansive soil were significantly decreased ‎by the addition of ‎magnesium chloride (MgCl2). This treatment also improved the physical and ‎mechanical characteristics and ‎microstructure of the soil. The soil’s plastic limit, shrinkage limit, ‎cohesion, and internal friction angle all ‎increased linearly with the addition of the MgCl2 stabilizer. ‎However, we observed that the liquid limit of the ‎soil decreased as the level of magnesium chloride ‎was increased.‎

scholarly journals Effects of the initial granular structure of clay sealing materials on their swelling properties: experiments and DEM simulations

2020 ◽  
Vol 6 ◽  
pp. 1
Author(s):  
Benjamin Darde ◽  
Anh Minh Tang ◽  
Jean-Noël Roux ◽  
Patrick Dangla ◽  
Jean-Michel Pereira ◽  
...  
Keyword(s):  
Swelling Pressure ◽  
Granular Structure ◽  
Radioactive Waste Disposal ◽  
Expansive Clay ◽  
Material Behaviour ◽  
Swelling Properties ◽  
Measurement Variability ◽  
Sealing Material ◽  
Single Pellet ◽  
Two Phases

Pellet-based expansive clay materials are considered as a sealing material for closing the galleries in radioactive waste disposal concepts. In repository conditions, the granular mixture progressively homogenises upon hydration by the host rock pore water. The present study focuses on the material behaviour before homogenisation. A grain-scale experimental characterisation is first performed in the laboratory. A model describing the hydromechanical behaviour of a pellet is proposed based on the experimental results. Then, suction-controlled swelling pressure tests are performed in the laboratory. Using Discrete Element Method (DEM) and the model proposed for a single pellet, the tests are successfully simulated. It is highlighted that (i) the swelling pressure evolves in two phases in the investigated suction range, controlled by the granular structure of the mixture; (ii) wall effects at the laboratory scale affects the material response; (iii) measurement variability associated to the sensor diameter is non-negligible; (iv) DEM is a valuable tool able to provide insight into the material behaviour.

Sign in / Sign up

Export Citation Format

Share Document