SOIL IMPROVEMENT USING COIR FIBER: A CASE STUDY

A good transportation system is an essential requirement of any nation. It not only makes the life of the people more convenient but also results in the development of the nation as a whole. Construction and maintenance of roads require proper engineering studies and large capital investment. However, poorly constructed roads not only have lesser durability but also makes riding on the road uncomfortable increasing the operation and maintenance cost of vehicles. Suitable subgrade availability is one of the prime factors while finalizing the road alignment after engineering surveys for road alignment. But sometimes while finalizing the road alignment tradeoff is inevitable between economy and availability of suitable subgrade. Changing the alignment to avoid a weak and unstable subgrade may lead to more construction and/or vehicle operation cost. This is truer especially when a non-suitable subgrade exists for a shorter length along the alignment. In such a situation, the best remedy is to adopt soil stabilization techniques for the non-suitable soil to improve its engineering properties hence make it suitable as the subgrade material. Soil such as clayey soil is an unsuitable subgrade soil mainly because of its large swelling and shrinkage properties. Hence it needs to be stabilized before adopting it as subgrade soil. Present research work deals with the stabilization of clayey soil using coir fiber. Light compaction test and California Bearing Ratio (CBR) test are conducted on the mixture of clayey soil and coir fiber to know the effect of coir fiber in improving the engineering properties of clayey soil. The clayey soil is collected from the Bilasipara region of Dhubri district, Assam state, India. Hence this research work is helpful for infrastructure development activities in the northeastern region of India.