Construction Materials Questions and Answers - Plinth

1. The part of a building constructed below ground level is known as _________
a) Plinth
b) Superstructure
c) Basement
d) Foundation

  Discussion

Answer: d
Explanation: Foundation is laid below the ground level and it is in direct contact with sub-strata and transmits all the loads to the sub-soil. The structure below the ground level is also known as Substructure or Foundation (excluding plinth).

2. The load of the structure distributed by the foundation is __________
a) Concentrated
b) Varying
c) Uniform
d) Eccentric

  Discussion

Answer: c
Explanation: The foundation is laid below the ground in such a way that a load of the structure is uniformly distributed to the ground to make the structure stable.

3. For loose soil, the formula used to find the minimum depth of foundation is given by _______
a) Rankine’s formula
b) Hiley formula
c) Bernoulli’s formula
d) Newtonian formula

  Discussion

Answer: a
Explanation: The depth of foundations can also be obtained by drawing the lines of angles 45 degrees and 60 degrees from the base of the foundation towards ground level. Hence to simplify the method, Rankine formula is used.

4. The foundation in which the loading on the soil remains practically the same after the construction of the building is known as _______
a) Step foundation
b) Grillage foundation
c) Raft foundation
d) Inverted arch foundation

  Discussion

Answer: b
Explanation: Grillage foundation or Floating foundation is so adjusted that the weight of the excavated earth is just equal to the total load of the building. In such a case, the settlement is reduced to a minimum extent.

5. _________ method of increasing the bearing power of soil becomes very useful when the load coming on the soil is practically uniform.
a) Raft foundation
b) Grillage foundation
c) Mat foundation
d) Inverted arch foundation

  Discussion

Answer: a
Explanation: Raft foundations are very useful in the soil which is of yielding nature that is soft clay or reclaimed soil. The raft is designed as an inverted RCC roof with uniformly distributed load of the soil pressure and supported by walls, beams and columns.

6. When the ground is sloping _____________ foundations are used to correct the levels of the sloping ground on which the building is to be constructed.
a) Shallow foundation
b) Combined foundation
c) Cantilever foundation
d) Steeped foundation

  Discussion

Answer: d
Explanation: Stepped foundation is adopted when the construction becomes uneconomical to provide foundations at the same level. In this, minimum depth of 800 mm should be provided at all the points.

7. Which type of foundation is used for the construction of building on black cotton soil?
a) Inverted arch foundation
b) Floating foundation
c) Mat foundation
d) Grillage foundation

  Discussion

Answer: c
Explanation: Black cotton soil is clay or loose type of soil and is considerably swells and shrinks by variation in moisture content. The variation in the volume of the soil is to the extent of 20 to 30% of the original volume. Hence, Raft Foundation or Mat Foundation plays important role in uniform distribution of a load of structure over black cotton soil.

8. ________ is applied to the process of laying down certain lines and marks on the ground before the excavation of foundation trenches.
a) Ground tracing
b) Surveying
c) Dumpy level
d) Digging

  Discussion

Answer: a
Explanation: The sitting out or Ground tracing is mainly done for two purposes- firstly, the excavation of foundation trenches can be started immediately after this process is completed and secondly, the lines and marks established by this process serve as a guide.

9. If the foundation of the structure is to be divided into two or more independent units ________ are provided to take care of unequal settlement.
a) Construction joints
b) Mechanical joints
c) Slip joints
d) Connecting joints

  Discussion

Answer: c
Explanation: Slip joints are situated on the boundary of independent units and they help in localising the effect of unequal settlement in affected portion of the structure only.

10. A common footing provided for two or more columns is known as _________
a) Continues footing
b) Combined footing
c) Cantilever footing
d) Eccentric footing

  Discussion

Answer: b
Explanation: Combined footing becomes useful when an exterior column is situated near the boundary line of the plot and it is not possible to project its footing symmetrically on both sides.