Engineering Geology Multiple Choice Questions on “Types of Mass Movements”.
1. What is the downgrade movement of mass along no definite surface called?
a) Flowage
b) Sliding
c) Subsidence
d) Earthquake
Answer: a
Clarification: By flowage is understood a downgrade movement of mass along no definite surface of failure. Mass involved in this type of failure is primarily unconsolidated or loosely packed or rendered so by natural processes.
2. In which type of flowage, failure is not easily perceptible?
a) Rapid failure
b) Quick failure
c) Slow failure
d) Moderate failure
Answer: c
Clarification: Flowage is further distinguished into slow and rapid flowage. In the slow flowage, failure is not easily perceptible. The ground may be moving downslope at such low rates as few centimeters a year or even less.
3. In which type of flowage, failure is easily visible?
a) Rapid failure
b) Quick failure
c) Slow failure
d) Moderate failure
Answer: a
Clarification: In rapid flowage, however, the movement of failing mass may be easily visible and the mass may travel a few metres or more a day. The conditions causing flowage in the two classes may be closely related or entirely different.
4. What is a type of mass failure in which a superficial mass fails by moving as a whole along a definite surface of failure called?
a) Flowage
b) Sliding
c) Subsidence
d) Earthquake
Answer: b
Clarification: A true landslide is a type of mass failure in which a superficial mass fails by moving as a whole along a definite surface of failure. The surface of failure may be planar or semi-circular in outline.
5. What is the characteristic of the mass above and below a landslide respectively?
a) Both stable
b) Both unstable
c) Unstable and stable
d) Stable and unstable
Answer: c
Clarification: It is often characteristic of a landslide that the mass above the failure surface is unstable whereas the material lying below this surface is generally stable.
6. What type of landslide may undergo landslide?
a) Rock fragments
b) Loose soil
c) Whole blocks
d) Any type of mass
Answer: d
Clarification: Sliding may involve material of any composition, shape and of varying degree of consolidation: Loose soil, rock fragments and whole blocks or slabs of rock.
7. What is the character of the surface of shear in hard, brittle and coherent mass?
a) Curved
b) Planar
c) Circular
d) Undulated
Answer: b
Clarification: When the mass involved is hard, brittle and coherent, such as massive igneous, sedimentary and metamorphic rocks, shear surfaces are broadly planar in character.
8. What is the character of the surface of shear in loose, inherently weak rocks?
a) Curved
b) Planar
c) Circular
d) Undulated
Answer: a
Clarification: In unconsolidated deposits, loose, inherently weak rock masses and weathered top surface, sliding commonly takes place along curved shear surfaces.
9. Type of landslide where surface of failure is planar is __________
a) Translational
b) Rotational
c) Rock toppling
d) Longitudinal
Answer: a
Clarification: The surface of failure is generally planar in character, speed of failure is quite rapid and the nature of mass involved in failing may be rock mass, rock slabs, debris and soil cover or even a mixture of all of them.
10. What is the characteristic sloping surface in rotational slides?
a) Curved
b) Planar
c) Circular
d) Undulated
Answer: a
Clarification: In rotational slides, the failing surface is generally curved in character and the speed of failure is also quite rapid. Because of the nature of the failing surface, the movement of the mass takes the form of a sort of rotation, rather than translation.
11. Type in which falls are involved rather than sliding is __________
a) Translational sliding
b) Rotational sliding
c) Rock toppling and falls
d) Subsidence
Answer: c
Clarification: Rock toppling and falls are grouped along with slides although there may be little or no sliding involved in their failure.
12. Sinking or settling of the ground in almost vertical direction naturally is called __________
a) Flowage
b) Sliding
c) Avalanche
d) Subsidence
Answer: d
Clarification: Subsidence is defined as sinking or settling of the ground in almost vertically downward direction which may occur because of the removal of natural support from the underground or due to compaction of the weaker rocks under the load from overlying mass.
13. What movements is observed in all cases of subsidence?
a) Horizontal
b) Shearing
c) Vertical
d) Inclined movement
Answer: c
Clarification: The net result in each case is that the surface material is natural ground or artificial fill- suffers a sinking downward movement.
14. In which type of slide, weather conditions play a very important role?
a) Translational sliding
b) Rotational sliding
c) Rock toppling and falls
d) Subsidence
Answer: c
Clarification: In rock toppling and falls, the weather conditions play a very important role compared to other types of sliding. The precipitation, frost action leads to changes in the rocks and lead to rock toppling and falling.
15. Translational sliding is quite common in slopes made up of __________
a) Rocks
b) Cohesive soils
c) Rocks and non-cohesive soils
d) Rocks and cohesive soils
Answer: d
Clarification: In translational slides, the sliding is quite rapid and the nature of mass involved in failing may be a rock, rock slabs, debris etc. These slides are quite frequent on slopes made up of rocks and cohesive soils.