摘要：Abstract
In modern time, due to scarcity of land space in the urban area tall building became essential to cater the housing requirement, which interns causes tremendous increase in the load in the foundation soil for which pile foundation with larger diameter and length becomes more effective solutions in terms of both increased load carrying capacity and settlement reducer. Stabilization of the bore holes with larger diameter and length is a biggest challenge. The stabilization of the excavated borehole can be done using bentonite as well as polymers where the former consists of clay particles which form a low permeable layer around the excavated soil and the later consists of chemicals providing more effective means in the stabilizations. A particular concentration of bentonite and polymer in water is required to achieve the desired property of the fluid so that sides of bore hole can be stabilized, which interns modify the frictional resistance of the pile. In the present study the concentration of bentonite and polymer is varied in water to achieve optimum concentration so that desired property to stabilize the bore is achieved. A series of direct shear test is performed by spreading the bentonite and polymer slurry on shearing plane to study the effect of these fluids on frictional resistance of the pile. The test results reflect that the effect of both the slurry is to reduce the frictional resistance of the pile but reduction is more in case of bentonite than polymer. Based on the experimental results pull-out strength of a pile of given diameter and length is calculated by method suggested by the IS code for both slurry and the result is compared with result of pull out test performed on physically modelled pile on the fabricated experimental setup. The two results are compared and it is observed that IS code method under predict the pull out strength and hence a modification factor is proposed.
