Foundation Engineering (CE-802 (B)) - Important Questions

Explain the Standard Penetration Test (SPT), the meaning of N value, why corrections are needed, and the overburden and dilatancy corrections applied to observed N.

Explain the various types of foundations/footings with sketches, their applications and basic criteria for satisfactory performance.

Explain boring methods for subsurface exploration including rotary drilling technique with sketch and its advantages over other methods

Apply overburden and dilatancy corrections to observed SPT N-values at given depths to obtain corrected N-values.

Interpret soil density from Dynamic Cone Penetration Test (DCPT) blow counts and suggest a suitable foundation type.

Discuss IS criteria for depth of boreholes in subsurface investigation.

Compute inside clearance, outside clearance, and area ratio for a sampling tube and comment on sample quality.

Enlist and describe the components of a well foundation with a neat sketch.

Discuss the different methods used for boring holes and explain the CPT test

What are the factors affecting the selection of type of foundations?

What do you understand by Geophysical method of soil exploration?

Explain disturbed vs undisturbed samples and CNS layer.

Describe the different modes of shear failure in soils beneath shallow foundations with neat sketches.

Using Terzaghi's theory, calculate the ultimate bearing capacity (or total allowable load) for a shallow footing on sand.

Calculate the immediate elastic settlement of a $2\,m \times 3\,m$ rectangular footing carrying $600\,kN$ at $1\,m$ depth on a soil stratum with given Poisson's ratio and Young's modulus.

Calculate allowable bearing pressure and safe load from ultimate bearing capacity, factor of safety and footing area.

Determine settlement of a square footing in clay from plate load test settlement under same load intensity.

Explain the different components of settlement of shallow foundations and give the equation for immediate settlement of cohesive soils.

Determine the short-term (immediately after construction, undrained) and long-term (few years after, drained) ultimate bearing capacity of a square footing on clay.

Using Terzaghi's theory, determine the net ultimate bearing capacity of a circular footing on pure clay for different water table positions.

Explain the factors affecting the bearing capacity of soil.

Determine ultimate bearing capacity of a square footing in clay from plate load test ultimate load per unit area.

Define net pressure, ultimate bearing capacity, net ultimate bearing capacity, net safe bearing capacity and allowable bearing pressure.

Explain the concept of general shear failure.

Determine ultimate load carrying capacity of a pile in uniform clay using static formula with cohesion and adhesion factor, considering skin friction and end bearing.

Calculate the ultimate / safe load capacity of a friction pile group in soft clay neglecting end bearing using adhesion factor (and block failure check).

What is negative skin friction in piles, its causes and effects?

Determine the safe load capacity of a pile group from given single pile capacity and group efficiency.

What is negative skin friction and how to calculate it for a single pile?

Classification / types of pile foundations based on function or action

Explain the various approaches to estimate load carrying capacity of a single pile and discuss the static formulae.

A drop hammer weighing 60 kN and having an effective fall of 0.75 m drives an RCC pile weighing 30 kN. The average settlement per blow is 1.4 cm. The total elastic compression is 1.8 cm. Assume the coefficient of restitution as 0.3 and a factor of safety is 3, determine the allowable load on pile.

Calculate safe load capacity of a single pile driven in sand using static formula with given $N_q$.

Explain the geometrical properties / considerations for proper spacing of piles in a pile group.

Design a friction pile group in clay to carry a given load with factor of safety.

Determine required length of bored pile in two-layered cohesive soil to carry a given safe load with factor of safety.

Problems and preventive measures for foundations/construction on expansive and collapsible soils

Explain the types, functions and various uses of geosynthetics for soil improvement.

Design an under-reamed pile for a given compressive column load and allowable bearing capacity, determining the required bulb diameter for a given stem diameter.

Explain the different types of geosynthetic materials and discuss their engineering properties and applications.

Explain the characteristics of expansive and collapsible soils.

Discuss characteristics of expansive soil and write short note on under-reamed pile.

Estimate the ultimate tensile (uplift) capacity of a singly under-reamed pile in expansive clay given pile dimensions, weight, undrained shear strength, adhesion factor and bearing capacity factor.

Explain in detail about the concept of Under-reamed pile foundation and suitability criteria?

Explain in detail about the geosynthetics-materials and types.

Determine the total Rankine active earth thrust (magnitude and point of application) on a retaining wall retaining layered/stratified cohesionless backfill.

Explain the classification, functions and modes of failure of retaining walls and the design checks for stability against overturning, sliding and bearing capacity failure.

Write short notes on a) Coulomb's earth pressure theory, b) static and dynamic pile formulae, and c) corrections for plate load test results.

Differentiate between a sheet pile and a retaining wall. List the uses of sheet piles.

Calculate the total lateral earth pressure on a trapezoidal masonry retaining wall and the maximum and minimum base pressure intensities.

Compare Rankine's and Coulomb's earth pressure theories, including merits of Coulomb's theory over Rankine's theory.

Determine Rankine active earth pressure distribution, resultant thrust magnitude and its point of application for a vertical wall retaining dry cohesionless backfill.

Explain about the Culmann's graphical method.

Determine magnitude and line of action of passive earth pressure for a wall supporting c-phi backfill with surcharge and water table.

What are various types of lateral earth pressure? Derive the expression for calculating earth pressure at rest.

Calculate total active thrust on a wall retaining cohesive backfill allowing tension cracks to full theoretical depth.

Construct active earth pressure diagram and find total thrust per unit length of wall for the given retaining structure.

List the various equipments used for field compaction. Also differentiate between light weight and heavy weight proctor test.

Why and in which situations soil stabilization techniques are required in field? Describe the electrical stabilization technique for improvement of soil.

Derive Boussinesq equation for a point load.

What are the different methods of soil stabilization? Explain with neat sketches.

Discuss essential difference between Boussinesq's and Westergaard's theories.