Geotechnical · MCQ practice Shallow and Deep Foundation MCQs – Part 2
15 questions. Tap an option to check it instantly, then read the solution.
Part 2 of 4 Question 16 Easy
Identify whether the given statements about the plate load test, used to find the ultimate bearing capacity of soil, are correct or incorrect. (A) The plate load test is a laboratory test used to find the ultimate bearing capacity of soil. (B) The bearing plate is either circular or square, made of steel not less than 25 mm in thickness.
A Statement B is correct and A is incorrect B Both statements are incorrect C Both statements are correct D Statement A is correct and B is incorrect
Answer: A. Statement B is correct and A is incorrect
The plate load test is a field (in-situ) test, so A is wrong. The plate is square or circular steel at least 25 mm thick, so B is right.
Question 17 Medium
Identify the correct pair(s) of penetration depth and standard load in the California Bearing Ratio test on soil: 1. 2.5 mm – 1370 kg; 2. 5 mm – 2080 kg; 3. 7.5 mm – 2780 kg.
A Only 1 B Only 3 C Only 2 and 3 D Only 1 and 2
Answer: A. Only 1
Standard loads are 1370 kg at 2.5 mm, 2055 kg at 5.0 mm and 2630 kg at 7.5 mm. Only pair 1 is correct. (The official key accepted (d); see the note.)
Question 18 Medium
______ is the maximum net intensity of loading that can be allowed on the soil without the settlement exceeding the permissible value.
A Gross safe bearing capacity B Ultimate bearing capacity C Safe bearing pressure D Net pressure
Answer: C. Safe bearing pressure
That is the safe bearing pressure (net soil pressure for a specified settlement).
Question 19 Easy
The type of footing in which load-bearing members share a common rectangular or trapezoidal footing is called:
A stepped footing B eccentric footing C combined footing D isolated footing
Answer: C. combined footing
A footing common to two or more columns is a combined footing — rectangular for equal loads, trapezoidal for unequal loads.
Question 20 Easy
When the water table is close to the ground surface, the bearing capacity of a soil is reduced to ______.
A three-seventh B one-third C one-half D one-fifth
Answer: C. one-half
Submerged unit weight is about half the bulk unit weight, so the bearing capacity of a cohesionless soil falls to about one-half.
Question 21 Medium
Under a rigid footing on cohesive soil, the contact pressure distribution is:
A uniform B non-uniform, with maximum at the ends and minimum at the centre C linear D non-uniform, with maximum at the centre and minimum at the ends
Answer: B. non-uniform, with maximum at the ends and minimum at the centre
A rigid footing on clay settles uniformly, and the pressure is highest at the edges and lowest at the centre.
Question 22 Medium
When compared with open caissons, floating caissons generally ______.
A have a greater depth below the ground surface B have a slow and inconvenient installation C are less expensive D have a higher load-carrying capacity
Answer: C. are less expensive
Floating (box) caissons are used for shallow depths and moderate loads and are cheaper than open caissons.
Question 23 Medium
On piles, the drop of the hammer must be at least:
A 80 cm B 100 cm C 120 cm D 140 cm
Answer: C. 120 cm
The answer given for this question is 120 cm (1.2 m) as the minimum free fall of a drop hammer.
Question 24 Easy
For a number of columns constructed in a row, the type of foundation provided is:
A Footing B Raft C Strap D Strip
Answer: D. Strip
A continuous strip footing is provided under a row of columns.
Question 25 Easy
Piles are usually driven by:
A diesel operated hammer B drop hammer C single acting steam hammer D All options are correct
Answer: D. All options are correct
All three hammers are commonly used to drive piles.
Question 26 Medium
A foundation is called shallow if its depth is:
A one-fourth of its width B half of its width C three-fourth of its width D equal to its width
Answer: D. equal to its width
A shallow foundation has depth less than or equal to its width (D ≤ B). The limiting case is depth equal to width. (In the revised key no single option was treated as exclusively correct — see the note.)
Question 27 Easy
The advantage of a concrete pile over a timber pile is:
A no decay due to termites B no restriction on length C higher bearing capacity D All options are correct
Answer: D. All options are correct
Concrete piles do not decay, can be made to any length and carry more load, so all options are correct.
Question 28 Easy
A raft foundation is provided if the area required for footings exceeds the plan area of the building by:
A 10% B 20% C 30% D 50%
Answer: D. 50%
When individual footings would cover more than about 50% of the plan area, a single raft is more economical.
Question 29 Medium
Which of the following statements is true?
A To ensure uniform pressure distribution, the thickness of the foundation is kept uniform throughout B To ensure uniform pressure distribution, the thickness of the foundation is increased gradually towards the edge C To ensure uniform pressure distribution, the thickness of the foundation is decreased gradually towards the edge D To ensure uniform pressure distribution, the thickness of the foundation is kept zero at the edge
Answer: C. To ensure uniform pressure distribution, the thickness of the foundation is decreased gradually towards the edge
Footings are made thickest under the column and taper (or step down) towards the edges.
Question 30 Easy
A foundation rests on which of the following?
A base of the foundation B sub grade C foundation soil D both sub grade and foundation soil
Answer: D. both sub grade and foundation soil
The soil (or rock) directly below a foundation is called the subgrade or foundation soil; both terms describe what the foundation rests on.
Part 2 of 4