Highly compressible clays are always prone to settlement and subsequent failures. Hence such type of clay deposits needs to be stabilized before commencing any type of construction over it. In the present scenario, accumulation of pozzolanic wastes poses a great threat to environment and human health. Hence their use as stabilizers will not only sort out the problem of their disposal but also enhance their utility in geotechnical engineering works where possible. Locally available highly compressible soil was stabilized by adding 5, 10, 15, 20, 25% of fly ash and rice husk ash as an additive.

Effects of stabilization on index properties like shrinkage and compaction and on engineering properties like shear strength and stiffness characteristics were observed and analysed. A general decrease in shrinkage limit of soil was observed when clay was treated with fly ash and rice husk ash. It was observed that OMC increases and MDD decreases when clayey soil

was stabilized with rice husk ash. On the other hand, an increase in MDD and decrease in OMC was observed when soil was stabilized with fly ash. No significant trend was observed in shear strength characteristics of stabilized soil. However, a general increase in shear strength was observed when soil was stabilized with fly ash and rice husk ash. A large reduction in compression index and subsequent increase in stiffness was observed with increase in percentage of fly ash and rice husk ash stabilizer.