GTU 3150615 Soil Mechanics Winter 2025 Question Paper & PDF

Normal stress (kPa): 145, 241, 337; and Shear stress at failure (kPa): 103, 117, 132 Plot the failure envelope and analyze the soil’s behavior. Discuss whether the soil exhibits purely cohesive, purely frictional, or c–φ characteristics.

A clay specimen has an unconfined compressive strength of 100 kPa. It is subjected to an unconsolidated–undrained (UU) triaxial test under a cell pressure of 100 kPa. Using the appropriate relation, calculate the axial stress at failure.

A concentrated load of 50 kN acts on the surface of a homogeneous soil mass of large extent. Estimate the stress intensity at a depth of 5 m; (a) Directly under the load, and

Using Boussinesq’s expression, derive the expression for vertical stress at depth h under the centre of a circular area of radius a loaded uniformly with a load q at the surface of the mass of soil.

A standard penetration test is conducted at a depth of 5 m in saturated fine sand having unit weight 20 kN/m³. If observed N value is 25, then estimate the corrected N value.

Describe with a neat sketch how will you carry out the wash boring method of soil exploration.

Compute net safe bearing capacity of a square footing 2.0 m × 2.0 m, located at a depth of 1.5 m below the ground level in a soil of unit weight 19 kN/m³, φ = 20˚, Nc = 17.7, Nq = 7.4, Nγ = 5.0. Assume factor of safety equal to 3. The water table is very deep. If the water table touches the base of the footing, find the reduction in net safe bearing capacity. Use Terzaghi equation. Take unit weight of water 9.8 kN/m³.

A square group of 16 piles was driven into soft clay extending to a large depth. The diameter and length of the piles were 50 cm and 9 m respectively. If the unconfined compression strength of the clay is 60 kN/m², and the pile spacing is 1 m centre to centre, estimate the ultimate capacity of the group. Assume adhesion factor of 0.6. Neglect bearing resistance.