Study On The Swelling Behavior Of The Green Clay Of Gzenaya ( Morocco ) Compared With Test Conditions (original) (raw)
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MATEC Web of Conferences, 2014
The swelling phenomenon appears seriously when changing the soil-moisture conditions. The swelling pressure induced by the expansive soil can causes unfavourable problems or instability for the civil structures. So, understanding the soil behavior is considered a valuable work for engineers and consultants in the geotechnical and civil engineering sectors. In reality, the assessment of the swelling pressure of expansive soil depends, first of all, of test conditions related to the change of soil-moisture, as it happens, the influence of the combination "loading-start wetting" and also the unloading process after saturation. To this end, we establish an experimental study on the green clay of Tangier to evaluate the swelling pressure by using oedometer apparatus. Secondly, attention is bore to the combination "initial water content-dry density", another factor related to the change of the soil-moisture, to show the influence of initial state condition on the swelling pressure.
Lecture Notes in Civil Engineering, 2019
This paper aims to describe the dependency of the swelling pressure (Ps) of Tebessa clay soils to the conventional soil properties namely; Plasticity index (PI), dry density (d), initial moisture content (W) and carbonate content (Ca). A statistical model, capable of obtaining an indirect estimation of Ps based on these soil parameters, is provided. High correlation coefficient (R 2) of 0.93 demonstrated predictability of swelling, using multiple regression modeling. Although the above-mentioned parameters play important roles in the swelling behavior of the clayey soils, there is not any universally accepted, simple and quantitative method to classify swelling pressure at present. The equation, proposed in this paper, helps the engineers with evaluating soil pressure in practice. In addition, it can be popularized when environment conditions are satisfied for application in field explorations and design of structures over expansive soils.
2019
This research work aims to study the swelling behavior of clayey soils in Tebessa area (Algeria) using the Design of experiments (DOE) method, based on mechanical, physical and clay mineralogy test results. The effect of different parameters such as dry unit weight, degree of saturation, water content, plasticity index, etc. on the swelling behavior of soil is evaluated and the statistical contribution of each variable in the calculated swelling pressure is also discussed. Besides, relationships between factors affecting the expansion process have been determined. The swelling pressure generated within the soil, which is useful in the design of foundations and civil engineering structures is taken as output process in the screening design methodology. Optimization of the parameters that affect the swelling behavior by Response Surface Method (RSM) allows finding the best set of factor levels to establish the mathematical model. Hence, the efficiency of this model is assessed by comp...
Swelling Clay Parameters Investigation Using Design of Experiments (A Case Study)
Engineering Geology, 2021
The present paper aims to investigate geotechnical parametric effects on the expansion behavior of clayey soils in Tebessa province northeast of Algeria using the Design Of Experiments (DOE) methodology. It has been used as powerful tools based on physical and mechanical properties, data results obtained within laboratory soil mechanics testing. This statistical tool methodology presents the factor screening design to determine the effect of different parameters such as dry unit weight, saturation degree, water content, plasticity index, etc., on the swelling pressure parameter which can be used as expansion behavior of clay indicator. All data previously collected in the studied prone area allows the ability of detailed analysis using design of experiment and parametric optimization process with response surface methodology (RSM). Each variable that present effects on swelling pressure is also discussed. Besides, the obtained models and equations related the factors affecting the e...
International journal of engineering and technology, 2013
The stability of the structures built on expansive soils or crossed expansive layers may be compromised as a result of a change of soil-moisture conditions. Knowledge of the behavior of the soil is considered a valuable data for engineers and practitioners of geotechnical and civil engineering, especially, in the phases of design and structural calculation. This paper is motivated by the extent of damage that should be avoided and can occur in the case of a pressure causing heave foundations, upward movement of flatwork or roadway cracking in spider or x-type pattern. First of all, the assessment of swelling characteristics depends on the conditions of starting wetting and saturation. For this reason, we suggested to establish an experimental study on the tirs or vertisol of Gharb region based on the swell oedometer test methods. A comparative analysis of swelling kinetics, swelling ratio and swelling pressure compared with test conditions is proposed. Our attention was focused, the...
Characterization of the High Swelling Green Clay in the Vicinity of Amman Area
The Open Civil Engineering Journal, 2021
Introduction: Jordan is awarded huge areas in the north and western part of the country in which brown and green clay is dominant. This research focuses on the problems and behaviour of the green clay only. The main problem of the green clay is its high swelling pressure which is the main cause of excessive settlement and wall cracks in buildings, especially during the wet season. Methods: This study aims to investigate the engineering properties and behaviour of the green clay deposits in the Amman area, which will serve as a guide for both geotechnical and structural engineers when preparing the foundation design. Results: Based on the consolidation test, the investigated green clay showed high swelling pressure of 3.11 kg/cm2, liquid limit (LL) of 73%, plasticity index (PI) of 40%, the shrinkage limit (SL) of 12%, and liquidity index (LI) of 0.125. The moisture content at saturation is 35.14%, while the natural moisture content is 28%, dry density is 1407 kg/m3, cohesion (C) is 0...
A Semi-empirical Approach-Based Model for Swell Characterization of Expansive Clays
Geotechnical and Geological Engineering, 2019
Expansive soils often pose as a potential geo-hazard for structures built on them due to the volumetric changes associated with moisture variation. Soil water characteristic curve (SWCC) is a direct representation of the pore and grain distribution of clays while the variation of in situ soil matric suction governs the hydration processes. In the present research, five natural expansive clays were studied at their 95% of maximum dry unit weight. Swell behavioral evaluations are conducted using standard test procedures. Both desorption and adsorption SWCC's were determined using pressure cell apparatus and filter paper method. Adsorption paths are utilized for analysis study as swelling behavior is the main scope of the research. A novel path traversed by the soil specimen on the void ratio-moisture content-log (soil suction) plot, and the corresponding slope, namely the modified specific moisture capacity, 'a', is identified as the main influential parameter. This modified specific moisture capacity exhibited direct relationship to swelling strains and swelling pressure of all five natural clays. A simple model for predicting one dimensional swell strain and swell pressure was established based on reliable predictions obtained using the modified specific moisture capacity of clays. Keywords Expansive clays Á Soil water characteristic curves Á 1-D swelling strain Á Swelling pressure Á Modified specific moisture capacity
Predicting the Strength Properties of Swelling Clay
This paper studies empirical correlation between expansive soil index properties and soil strength.Disturb soil samples from different areas in Sudan were collected to represent the most expansively soils in the country. The samples were collected from Al-Qadarif (S1), Wad Medani (S2) and Al-Giraif East in Khartoum (S3). The basic properties of the soil samples were measured. The three soils give high plasticity and very weak strength. The chemical analysis shown that S1 has the highest montmorillonite mineral than the other two soils. Therefore S1 is considered as the most expansively soil compared with the other soils. The consistency factor which was developed can be used to correlate the basic properties of the soil with the soilstrength. The consistency factor is a combination of the moisture content, dry density, void ratio, liquid limit and plasticity index. These parameters are combined in a way reflecting the influence of each of them on the soil property. The strength properties (CBR and UCS) were measured for the soil samples compacted at different moisture content and different dry densities.Very good linear relationships were developed between the consistency factor and the strength properties. The correlations developed were verified by using the data of this study and the data reported by some previous researchers. The developed correlation was plotted on Nomograph.
Estimation of swelling characteristics of expansive soils with influence of clay mineralogy
Acta Agriculturae Scandinavica, Section B — Soil & Plant Science, 2021
ABSTRACT In the present study, characterisation and quantitative microanalysis were identified for six expansive soils of which one is natural soil, i.e. black cotton (BC) soil and remaining soils were prepared by mixing of BC soil with different percentage of bentonite. The BC soil and prepared soil samples were characterised by the X-ray diffraction (XRD) and scanning electron microscope (SEM). The regular or irregular mixed layers of soils justified by SEM images. There are superstructures whose spacing can simply be described as the ratio of BC soil and prepared soil. d-Spacing was calculated by Bragg’s formula (XRD) which was observed by joint committee on powder diffraction standards card and calculated by Bragg’s equation for h-k-l plane for expansive soils and it was observed that d-spacing decreased with increasing prepared soil combination. Moisture content was taken below optimum moisture content, i.e. 15%, 17% and 20% to determine swelling and swelling pressure and found that montmorillonite mineral affects the swelling characteristics of expansive soils.