Geotechnical · MCQ practice Shallow and Deep Foundation MCQs – Part 3
15 questions. Tap an option to check it instantly, then read the solution.
Part 3 of 4 Question 31 Easy
When the water table rises to the ground surface, the bearing capacity of a soil is reduced to:
A One-fourth B One-half C Two-third D Three-fourth
Answer: B. One-half
The submerged unit weight is about half the bulk unit weight, so bearing capacity drops to about one-half.
Question 32 Easy
Which one of the following has the least bearing capacity?
A Soft rocks B Compact gravel C Loose gravel D Hard rocks
Answer: C. Loose gravel
Loose gravel has the lowest safe bearing capacity of the four (about 245 kN/m² in IS 1904).
Question 33 Easy
In a plate load test, the minimum size of plate to be used is:
A 250 mm × 250 mm B 300 mm × 300 mm C 400 mm × 400 mm D 450 mm × 450 mm
Answer: B. 300 mm × 300 mm
Plates range from 300 mm × 300 mm (minimum) to 750 mm × 750 mm (maximum), at least 25 mm thick.
Question 34 Easy
Black cotton soil is unsuitable for foundations because of its:
A black colour B low bearing capacity C swelling and shrinkage D cohesive particles
Answer: C. swelling and shrinkage
Black cotton soil swells strongly when wet and shrinks and cracks when dry, which lifts and cracks buildings.
Question 35 Medium
For determining the ultimate bearing capacity of soil, the recommended size of square bearing plate in a plate load test is 30–75 cm, with a minimum thickness of:
A 20 mm B 5 mm C 50 mm D None of the above
Answer: D. None of the above
The minimum thickness is 25 mm, which is not among the options, so the answer is ‘None of the above’.
Question 36 Easy
If the footing is in contact with the water table, the reduction in bearing capacity may be as high as:
A 25% B 50% C 65% D 75%
Answer: B. 50%
The submerged unit weight is about half, so the reduction can be as high as about 50%.
Question 37 Easy
The two criteria for determining the allowable bearing capacity of a foundation are:
A Shear failure and settlement B Bond failure and shear failure C Tensile failure and settlement D Tensile failure and compression failure
Answer: A. Shear failure and settlement
Allowable bearing capacity must be safe against shear failure and keep settlement within the permissible limit.
Question 38 Easy
The bearing capacity factors Nc, Nq and Nγ are functions of:
A Cohesion of the soil B Friction angle C Internal friction angle D Both cohesion of the soil and friction angle
Answer: C. Internal friction angle
Nc, Nq and Nγ depend only on the angle of internal friction φ of the soil.
Question 39 Easy
The main observation of the plate load test is:
A Settlement of the test plate B Stability of soil C Stability of the test plate D Settlement of soil
Answer: A. Settlement of the test plate
What is actually measured is the settlement of the test plate under each load increment.
Question 40 Easy
A plate load test is used to determine:
A Bearing capacity of foundations B Settlement of foundations C Both (a) and (b) D None of the above
Answer: C. Both (a) and (b)
The load–settlement curve gives both the bearing capacity and an estimate of settlement.
Question 41 Medium
Which of the following statements is/are true? A. The proportioning of a footing is more often governed by its bearing capacity. B. Friction piles are also called ‘floating piles’.
A Only A B Only B C Both A and B D Neither A nor B
Answer: C. Both A and B
Both statements are true: footing size is usually fixed by bearing capacity, and friction piles are also called floating piles.
Question 42 Easy
Which of the following factor(s) can affect the bearing capacity of soil?
A Grain size of the soil B Shape of footing C Size of footing D All options are correct
Answer: D. All options are correct
Bearing capacity depends on the soil (type, grain size, density, water table) and on the footing (shape, size, depth).
Question 43 Hard
The grouping of piles will not reduce the load-carrying capacity in the case of:
A Friction piles B End bearing piles C Both (a) and (b) D None of the above
Answer: B. End bearing piles
End-bearing piles on rock or a hard stratum carry the same load in a group as individually (group efficiency ≈ 1). Friction piles in clay lose capacity in a group. (The book's printed key gives (c); see the note.)
Question 44 Easy
A shallow foundation is defined as a foundation which:
A has low bearing capacity B has a depth of embedment less than its width C is resting on the ground surface D causes less settlement
Answer: B. has a depth of embedment less than its width
A shallow foundation has depth of embedment less than (or equal to) its width.
Question 45 Medium
Which of the following statements is true?
A A pile is a slender member which transfers the load through its lower end onto a strong stratum B A pile is a slender member which transfers its load to the surrounding soil C A pile is a slender member which transfers its load by friction D A pile is a cylindrical body of concrete which transfers the load at a depth greater than its width
Answer: B. A pile is a slender member which transfers its load to the surrounding soil
The general definition: a pile is a slender member that transfers its load to the surrounding soil (by end bearing, skin friction or both).
Part 3 of 4