From 3-phase diagram of soil, derive the expression S.e =w.G.

An imaginary soil mass is contained in a cubical container measuring 100 mm sides. The soil consists of spherical.grains of size 10 mm in diameter. Determine the maximum possible void ratio and porosity.

Explain consistency limits of soil and discuss their significance.

A grading curve of a soil gives effective size as 0·15 mm, 30 percent finer size as 0·4 mm and 60 percent finer as 0·9 mm. Find the uniformity coefficient and coefficient of curvature.

Describe the procedure to determine coefficient of permeability using Variable Head Test.

A 6 m thick layer of saturated clay is overlain by sand 5 m deep. The water table is 4 m below the ground surface. The saturated unit weight of clay and sand are 21 kN/m^3 and 19 kN/m^3 respectively. The unit weight of sand above the water table is 16 kN/m^3 . Find the total and effective vertical stresses at the top and middle of clay layer.

Discuss how shear strength is determined using unconfined compression test.

In a consolidated undrained triaxial test on a normally consolidated clay c deviatoric stress and pore pressure at failure are 120 kPa and 100 kPa respectively. The sample was consolidated under cell pressure of 180 kPa. Find cr1, cr3 and ar

Discuss the comparison between Standard and Modified Proctor tests for compaction with their applicability in the field.

The following results were obtained from a standard compaction test on a soil sample. Determine optimum moisture content and maximum dry density.

Water content Wet weight
8·0 1450
11·2 1690
14·0 1910
17·0 1930
18·5 1845
20·4 1736

Describe how SPr is performed and discuss corrections to observed N-values.

Describe the various samplers with their appropriate usage.

Explain effect of water table on the bearing capacity as per IS 6403 -1981.

A 500 mm square bearing plate settles by 10 mm in the plate load test on cohesionless soil, when the intensity of loading is 200 kN/m^2. Estimate the settlement of a shallow foundation of size 2 m x 2 m under the same intensity.

Describe under-reamed piles with their applicability. Also draw its sectional elevation with dimension proportioning.

A circular pile of diameter 600 mm and 11 m length penetrates a deposit of clay with c 38 kN/m^2 . Assuming m 0.65, determine the load carried by the pile with skin friction.