BRAHMAPUTRA SILT AS STABILIZER OF EXPANSIVE CLAY
The mighty Brahmaputra is the largest river in Assam. It is known for the problem of excess siltation and hence its river bed has risen from time to time. It causes devastating flood on both the banks of the river and huge amount of losses has been occurred in terms of cultivation, livestock and human lives. Due to excess siltation problem the flood control embankments constructed for mitigation of flood hazard are to be risen from time to time to serve its primary needs. The problem of siltation were tried to mitigate in the past with the help of dredging of its river bed but it was observed that the amount of silt deposition were large as compared to the quantity of dredged materials. So, the only way to solve the problem is to use the Brahmaputra silt for some useful work like landfill engineering, stabilization of expansive clay etc. To have a remedial action to these problem, comprehensive experimental investigations were carried out in the laboratory to assess its suitability to stabilize expansive clay. Bentonite was used as expansive clay and silt was used as a stabilization agent. Series of investigations were carried out to determine the influence of silt on the Liquid limit, Plastic limit and Plasticity Index of the Bentonite. The amount of slit added to the Bentonite is initially 10% and in multiples of it. The index and other properties like consolidation and swelling of Bentonite-silt mixture was determined. It is observed that a linear relationship is exists between the liquid limit, plastic limit and the percentage of silt added to the Bentonite. The coefficient of regression was found to be 0.99. So it can be concluded that the Brahmaputra silt can be versatile stabilizing agent for the expansive clay.