Give short answers to the following: (a) (i) Write the equationfor Mohr-Coulomb shear failure criteria for soils. Define thevariables in the equation. Also, show how this equation isrepresented in a graph. Label your graph. (ii) Name two laboratorytests to determine the shear strength of the soils. (b) The soilbelow a concrete dam has a porosity of 0.4 and density of solids of2.7 gm/cm3 . To ensure safety against piping, the specificationsstate that the critical gradient which cause piping should be 6times the exit gradient. What is the allowable exit gradient?(c) Incalculation of consolidation settlement we assume that theconsolidation is onedimensional (in vertical direction only). Isthis a reasonable assumption? Why? (d) Why the permeability of sandincreases with the increase in grain size of the sand? (e) What arethe advantages and disadvantages of a triaxial compression test?(f) Unconfined compression test was conducted on a saturated clay.The vertical stress at failure was 200 kN/m2 . Sketch (not toscale) the Mohr circle and find the shear strength parameters forthis soil.
GEOTECHNICAL COURCE
