Stabilization by Modification of Lithomargic Clay(Shedi Soil) Using GGBS,Lime and Other Additives

Abstract

- Shedi soil (lithomargic clay) is very sensitive to water and loses its strength when it is saturated. Generally this
soil is classified as silty sand or sandy silt with higher percentage silt content. The lithomargic soilstratum exists at
considerable depth below ground level and is formed from lateritic soil by some chemical action of ground water. It does not
possess any desirable engineering property and its behaviour is unpredictable. This type of soil is abundantly available in the
coast belt of south-western India, starting from Cochin to Goa. In thispaper an attempt is made to study the behaviour of the
shedi soil before and after stabilization. The experimental work involves the study on engineering behaviour of lithomargic
soil of western coast of India in Mudipu area with field and laboratory investigation to find classification of soil and to test
the engineering property along withAtterberg limits which indicates the strength of soil to some extent. In this work the
objective is also to improve the engineering property by stabilizing the soil by additives such as lime, GGBS and chemical
admixtures such as NaCl, NaOH, Na2SO4. It is observed that the unconfined strength of the shedi soil can be improved with
certain % of lime, GGBS and chemical admixtures, separately in combination with soil and the results obtained are
promising so as to practice in ground improvement for foundation and pavement formation. It has been observed that 5%
lime and 30% GGBS by weight separately added to shedi soil is found to be optimum dosage for obtaining maximum UCS
values after 0,7 and 30 days of curing. Combination of mixtures such asshedi soil+ GGBS, shedi soil+ GGBS and lime,
shedi soil+ GGBS and 1% of NaCl, NaOH, Na2SO4 are also tried to obtain maximum strength of stabilized shedi soil.