Time rate of swelling of compacted highly plastic clay soil from Sudan

A M Elsharief,Mai Sufian,A Diouri,A Nounah,M Saadi,A Boukhari,N Khachani,J Aride,L Ait Brahim,L Bahi

doi:10.1051/matecconf/201814902032

A M Elsharief, Mai Sufian + Show 8 more

Open Access

https://doi.org/10.1051/matecconf/201814902032

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Abstract

This paper investigates the development of swelling with time for a highly plastic and potentially expansive clay from Sudan. Soil samples were prepared in the laboratory at different moisture content values. The prepared samples were placed in the oedometer ring at three density levels and then placed in an oedometer cell which allows one dimensional swelling. Swelling was observed at different time intervals to 48 hours. The data was analyzed to determine the development of swelling with time. The data analysis clearly demonstrated three stages of swelling, initial, preliminary and secondary for all tested samples except the quasi-saturated ones. The swell percent and primary swelling were very sensitive to the initial moisture content and dry density of the tested samples. Most of the swelling took place during the first 24 hours for all the tested specimens. The hyperbolic model was assessed for prediction of the percent swell. The 12 hours data was found to be very successful in predicting the percentage swell.

Highlights

Swelling takes place when water percolatesinto the pores of a potentially expansive soil
The first two are negligible compared to the matric suction potential which is responsible for driving water into clay soils [2]
The objective was to study the development of swelling with time, the different swelling stages, amounts and times and determine the swell percent for samples compactedat various densities and water contents

Summary

Introduction

Swelling takes place when water percolatesinto the pores of a potentially expansive soil. The potential for a compacted soil to swell is governed by its intrinsic and extrinsic properties. The important intrinsic properties are the soil composition and the mineralogical characteristics of the clay fraction whereas the extrinsic properties are the placement water content, densityand loading [1]. The first two are negligible compared to the matric suction potential which is responsible for driving water into clay soils [2]. Matric suction of a certain clay is governed by its water content and pore size characteristics which are partly controlled by its density. It takes place over relatively long time in three distinct stages: initial, primary and secondary [3].The intrinsic and placement factors affect the magnitude and duration of these swelling stages [4].

Time rate of swelling for compacted clay soils

Soil material and test methods

Data analysis

Findings

Conclusions