# Basic Civil Engineering Questions and Answers – Geotechnical Engineering

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This set of Basic Civil Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Geotechnical Engineering”.

1. Water content is given by:
a) Weight of water/mass of soil
b) Mass of water/mass of solid
c) Mass of water/mass of soil
d) Mass of water/weight of solid

Explanation: In Geotechnical Engineering, water content is an important parameter for analysing the soil. It is expressed as mass of water divided by mass of solids. It is denoted by w and expressed in %.

2. Who is the father of Geotechnical Engineering?
a) Christian Otto Mohr
b) Clausius Cleyperon
c) John Smith
d) Karl Von Terzaghi

Explanation: He was an Austrian civil engineer and geologist. Most of the findings in geotechnical engineering and soil properties are done by him.

3. According to Darcy’s Law:
a) q=iA
b) q=kA
c) q∞iA
d) q∞kA

Explanation: Darcy’s Law states that the rate of flow per unit time is proportional to a hydraulic gradient. q∞iA is the mathematical representation of the law.

4. Triaxial compression test is used to find __________ of soil.
a) Compressive strength
b) Permeability
c) Specific gravity
d) Shear strength

Explanation: There are 4 methods available to measure shear strength of soil – direct shear, triaxial compression, unconfined compression and vane shear test. Triaxial compression test is the most accurate one.

5. ____________ index is used to find settlement of soil.
a) Compression
b) Expansion
c) Recompression

6. Which of the following does not happen when compaction is done?
a) Permeability decreases
b) Water content increases
c) Shear strength decreases
d) Compressibility decreases

Explanation: On compaction of a soil mass, the shear strength is increased. It is tightly and firmly compacted and offers resistance to deformation and flow.

7. ____________ is the measure of loss of strength with remoulding, with water content unchanged.
a) Compressibility
b) Sensitivity
c) Stability
d) Thixotropy

Explanation: Sensitivity values range from 1-16. For an insensitive soil, it is 1. A soil with sensitivity above 16, is termed as quick.

8. In Geotechnical Engineering, soil is considered as a _________ phase material.
a) 3
b) 2
c) 1
d) 4

Explanation: Soil is a 3 phase material. It consists of solids, water and air voids. It is represented in a 3 phase diagram with volume on left side and mass on the right side.

9. Fine particles are those particles with size less than _______ mm diameter.
a) 0.023
b) 0.090
c) 0.075
d) 4.75

Explanation: Fine particles should pass through 75μ IS sieve. Fine particles include clay, silt and organic content in a soil mass.

10. The mass density of water at 4oC is:
a) 1000g/ml
b) 1kg/m3
c) 1000Mg/m3
d) 1000kg/m3

Explanation: Mass density is the ratio of mass of water to volume of water. At 4oC, it is 1g/ml or 1000kg/m3 or 1Mg/m3.

11. Percentage air voids is denoted as:
a) v
b) na
c) s
d) av

Explanation: Percentage air voids is the ratio of volume of air in voids to total volume of soil. It is denoted by na and expressed as a %.

12. Porosity and void ratio are related by:
a) e = n(1-n)
b) n = e(1-e)
c) 1-e = n
d) (1+n)n = e-1 