Engineering Geology Multiple Choice Questions on “Geological Characters for Investigation”.
1. When a site is said to be sound, which of the following character is not desirable?
a) Strong
b) Impermeable
c) Stable
d) Permeable
Answer: d
Clarification: Technically, the site should be as sound as possible: strong, impermeable and stable strong rocks at the site make the job of the designer much easy: he can evolve best designs.
2. Rocks are inherently which type of materials?
a) Isotropic
b) Anisotropic
c) Homogeneous
d) Non-homogeneous
Answer: b
Clarification: Rocks are inherently anisotropic materials, showing variation in properties in different directions.
3. When is the strength of sound rock always greater?
a) When stresses are normal to bedding planes
b) When stresses are parallel to bedding planes
c) When stresses are inclined at 45° to bedding planes
d) When stresses are inclined at 60° to bedding planes
Answer: a
Clarification: The strength of sound, unfractured stratified rock is always greater when the stresses are acting normal to the bedding planes than if applied in other directions.
4. The most unfavourable strike direction is when the beds?
a) Strike parallel to axis of dam and the dip is upstream
b) Strike parallel to axis of dam and the dip is downstream
c) Strike normal to axis of dam and the dip is downstream
d) Strike normal to axis of dam and the dip is upstream
Answer: b
Clarification: The most unfavourable strike direction is the one in which the beds strike parallel to the axis of the dam and the dip is downstream. It must be avoided as far as possible.
5. Which of the following is not a method for dam construction when a shear zone is encountered?
a) Construct on shear zone
b) Grouting the shear zones
c) Try and avoid the site as much as possible
d) Excavation and back filling
Answer: a
Clarification: Generally small scale fault zones and shear zones can be treated by grouting. But in the case of major shear zones, weak material would be excavated and the space backfilled with hard material like concrete up to the required depth.
6. In synclinal bends, dams placed on which part would run risk of leaking?
a) Upstream limb
b) Downstream limb
c) Core
d) Sloping side
Answer: a
Clarification: In synclinal bends, dams placed on the upstream limbs would run the risk of leakage from beneath the dam.
7. What aspect of the joint has to be thoroughly studied before construction of a dam?
a) Geometry of the joint
b) The depth of the joint
c) Nature of the joint
d) The texture of the rocks
Answer: d
Clarification: The geometry of joints, their intensity, nature and continuity with depth, all must be thoroughly established and their effects on the site rocks evaluated and remedial measures taken in advance.
8. Which joints have to be established with greater care?
a) Sheet joints
b) Mural joints
c) Micro joints
d) Columnar joints
Answer: c
Clarification: Occurrence of micro-joints has to be established with still greater care as such joint systems, if left untreated, could be source of many risks.
9. The fish culture in the stream is not affected by the construction of a dam.
a) True
b) False
Answer: b
Clarification: Environmentally speaking, the fish culture in the stream is the first sector to suffer a major shock due to the construction of a dam.
10. Knowing the lithology of the site is very important in terms of its safety and feasibility.
a) True
b) False
Answer: a
Clarification: The single most important feature that must be known thoroughly at the site and all around and below the valley up to a reasonable depth is the Lithology, i.e., the types of the rocks that make the area.