An attempt is made to develop a spatially distributed shear strength based sub-soil information model of Guwahati city
on a regional scale. The study involves undisturbed sampling up to a depth of 15.0m from E.G.L. and laboratory testing on 2500
soil samples collected from 520 numbers of boreholes across Guwahati city. The shear strength parameters are obtained by
performing consolidated drained triaxial test, direct shear test and unconfined compression tests under laboratory controlled test
conditions. Guwahati sub-soil is found to be predominantly alluvial, and excluding the hilly areas, it is found that 80% of the
soil are find grained CL or CI type i.e. inorganic clays with low or intermediate compressibility. These soil types exhibit a wide
range of unit cohesion, ‘C’ with small values of angle of internal friction ‘φ’ and significant contribution to the shear strength
comes from unit cohesion component only.
