JNTU B.Tech III GEOTECHNICAL ENGINEERING Previous Question Paper (August/September - 2024 - R13)

Explain the following structures of soil: single grained, flocculated and honey combed.

Derive the relationship between bulk density, degree of saturation and void ratio of a soil.

Write the usefulness of grain size distribution and consistency limits in geotechnical engineering.

From the data given below, determine LL of soil and also determine PI, if PL of soil is 25%.

Explain the following: i) Effective stress principle, ii) Darcy’s law and iii) Capillary rise.

A falling head permeability test is to be performed on a soil sample whose permeability is estimated to be about 1×10^-5 cm/s. What diameter of the standpipe should be used if the head is to drop from 60 cm to 35 cm in 250 seconds and if the cross-sectional area and length of the sample are respectively 18 cm² and 10 cm?

Define Quick sand condition and derive the expression for critical hydraulic gradient.

In order to compute the seepage loss through the foundation of a cofferdam, flow nets were constructed. The result of the flow net study gave number of flow lines = 6 and number of potential drops = 16. The head of water lost during seepage was 18.95 m. If the hydraulic conductivity of the soil is 10.15 × 10^-5 m/s, compute the seepage loss per metre length of dam per day.

Write usefulness and construction procedure of Newmark’s influence chart.

Differentiate compaction over consolidation and write the objectives of compaction.

Explain the Spring Analogy concept of consolidation, with neat sketches.

Discuss the square root time method for coefficient of consolidation of soil.

Explain the limitations of Terzaghi’s 1-D consolidation theory.

The void ratio of clay A decreased from 0.572 to 0.505 under a change in pressure from 150 kPa to 200 kPa. The void ratio of clay B decreased from 0.612 to 0.597 under the same increment of pressure. The thickness of sample A was 2 times that of B. Nevertheless, the time required for 50% consolidation was three times longer for sample B than for sample A. What is the ratio of the coefficient of permeability of A to that of B?

What is preconsolidation pressure? Explain how do you estimate it graphically?

A consolidation test is performed on a 20 mm thick clay sample. After 360 seconds, 50% consolidation is reached. After how long time would the same degree of consolidation is achieved in the field where the clay layer is 4.0 m thick? Assume the sample and the clay layers have the same drainage boundary conditions (single drainage).

Explain when do you prefer UU, CU and CD test results in geotechnical analysis.

A triaxial compression test on a cohesive soil sample of cylindrical shape yielded the following results: Major principal stress = 100 kPa and Minor principal stress = 250 kPa. If the angle of inclination of the rupture plane to the horizontal is 60°, determine the cohesion and angle of internal friction by analytically.

Discuss the demerits of direct shear test and merits of triaxial compression stress test.

Determine the shear strength parameters in terms of effective stress from analytical procedure using the following data.