VEDA DIPLOMA/BTECH WEEKLY EXAM (16/06/2025)

The term is used to indicate the depth up to which the increase in pressure due to structural loading is likely to cause perceptible settlement or shear failure of foundation

• Significant depth

• Ultimate depth

• Limiting depth

• None of these

Answer explanation

Exploration in general should be carried out to a depth up to which the increase in pressure due to structural loading is likely to cause perceptible settlement or shear failure. 

Such a depth is known as significant depth.

Wash boring is used up to a depth of

• 30 to 45 m

• 15 to 25 m

• 40 to 50 m

• 10 to 15 m

Answer explanation

Wash boring:

This method gives a reliable result about a depth of 30m to 45m. 

The process of wash boring consists driving a casing into the ground and the material inside the casing is washed out and collected in a tank. 

The material collected in the tank is then inspected. 

Auger boring may be useful even up to a depth of ____ m for loose soil

• 3 m
• 6 m
• 8 m
• 15 m

Answer explanation

Auger boring is generally useful for 6–8 m in normal soils, and up to 15 m in loose soils. The auger acts like a screw, driven into the ground and withdrawn with soil.

Type of sampler used in Standard Penetration Test

• Thin walled Sampler
• Piston sampler
• Rotary sampler
• Split spoon sampler

Answer explanation

Standard Penetration Test uses a split spoon sampler driven into the soil to measure N-value. It's essential in soil consistency evaluation.

The distance between electrodes in Electrical Resistivity Method indicates

• Depth of exploration
• Depth up to which ground resistance is to be measured
• Both a and b
• None of these

Answer explanation

In electrical resistivity, the spacing between electrodes determines how deep the current penetrates — indicating both depth of exploration and resistance measurement.

Which of the following statement is false about Site Investigation of soil?

• Open Excavation is also called Trial pit method
• Geophysical methods include seismic reflection method
• Percussion Boring machine is useful for hard material like rock
• None of these

Answer explanation

All statements are correct: Trial pits allow visual inspection, seismic methods are part of geophysics, and percussion boring suits hard strata.

Minimum gross pressure intensity at the base of the foundation at which the soil fails in shear

• Net pressure intensity
• Gross pressure intensity
• Ultimate bearing capacity
• Net ultimate bearing capacity

Answer explanation

Ultimate bearing capacity is the minimum gross pressure intensity at which the soil at the base of foundation fails in shear.

The ultimate bearing capacity of a surface strip footing on clay, according to Terzaghi's theory

• 5.7 C

• 5.14 C

• q_uB

• 9 C

Answer explanation

For φ = 0°, Terzaghi’s theory gives ultimate bearing capacity as q_u = cNc = 5.7 C.

For determining the ultimate bearing capacity of soil, the recommended size of plate to be used in plate load test should have a minimum thickness of

• 45 mm

• 75 mm

• 30 mm

• 25 mm

Answer explanation

As per guidelines, minimum thickness of the plate used in a plate load test should be not less than 25 mm to ensure rigidity.

The net ultimate bearing capacity of a purely cohesive soil

• Depends on the depth, but is independent of the width, of the footing
• Depends on the width as well as the depth of the footing
• Depends on the width of the footing and is independent of the depth of the footing
• Is independent of both the width and the depth of the footing

Answer explanation

For φ = 0 soils, net ultimate bearing capacity depends only on cohesion (c) and Nc, not footing width or depth.