A STUDY TO MAKE SURPLUS LYING CLAYEY SOIL SUITABLE FOR EMBANKMENT FILLS BY BLENDING IT WITH LOCAL SANDY SOIL by Pardeep Puri
Abstract
India is a developing country and lot of infrastructural works are announced by Government of India/ State Governments every year like Highways, Railways, Airports, Express Ways, Bridges, Tunnels and Buildings etc. Properties of soil changes frequently w.r.t. distance as well as depth. In certain locations the soil is soft and weak and does not possess the required engineering properties. Therefore before placing these structures on natural soil or using locally available natural soil for the above works, detailed soil investigation to know the properties of virgin soil needs to be done. To build the structures on allotted site or make use of locally available soil for overall economy of the project, stabilization of clayey or clayey silty soil needs to be done. Soil stabilization is done by various methods like mechanical stabilization cement stabilization, lime stabilization, chemical stabilization, thermal stabilization, electrical stabilization & consolidation stabilization etc. Chemical stabilization is done by making use of material like lime, fly ash, cement, sodium chloride, calcium chloride, magnesium chloride etc. Soil stabilization of clayey soil is also done by using lime kiln dust, cement kiln dust, brick kiln dust, stone quarry dust etc. A Thermal Plant namely Nabha Thermal Plant has been installed and made operational in the year 2014 by Punjab State in Village Nalash, Tehsil Rajpura District Patiala. While constructing Thermal Plant, earth to the tune of 6 lac cum had been excavated for making lake and had been dumped near the plant in the form of heaps which has occupied about 100 acres of land. Consequently this heavy chunk of land has turned into desert like situation and cannot be used for cultivation or other purposes till the dumped material is disposed off. Many infrastructure projects like Special Railway Project from Ludhiana to Kolkata called Eastern Dedicated Freight Corridor, Rajpura –chandigarh line and doubling of Rajpura-Bathinda lines have been announced by Govt, of India and construction works of two out of three have already been commenced recently. These projects require heavy quantum of earth for making embankments. There is scarcity of earth in this area due to high fertility of land. An effort has been made by the researcher to utilise this surplus lying earth for above civil engg. projects involving earth work in embankment by blending it with locally available sandy soil . This may save cost and create environment friendly area by converting the land again into green belt after utilisation of this surplus earth. Effect of mixing local sandy soil with clayey soil on index properties, heavy compaction and California bearing ratios, shear strength and Strain modulus (EV2) have been studied in this report. Field testing to study strain modulus (load deformation characteristics of soil at second loading cycle between 30% & 70% of maximum normal stress) on trail bed of varying thicknesses has also been done. Results show that plasticity of improved soil has decreased a lot, MDD’s & CBR’s have increased, classification of soil has changed from CH to CL, shear strength and strain modulus properties have increased. Relations between soaked CBR v/s un soaked CBR and soaked CBR v/s contents of sandy soil have also been developed to help field engineer predict the values of soaked CBR towards reduction in construction time.
