Important Question And Answer: Civil - Engineering Geology - Application Of Geological Investigations

1. Define remote sensing.

Every object on earth emits its own internal energy according to its molecular and atomic structure, in addition to reflecting sun light during the day time. This radiations being registered by sensors in several wavelengths, including those in the infrared and microwave regions of the

spectrum. When such sensors are installed on aircrafts or on satellites they can record the earth's objects from for off distances.

Such distant (acquisition of information about the objects on the earth's surface is known as remote sensing )

2. What is meant by aerial photography & Imageries.

The photographs of the earth taken from aircrafts are called the aerial photographs; the pictures taken from the satellites are called the imageries.

3. Define aerial photographs.

Aerial photographs of the region are taken by cameras placed in the aircrafts. Aerial photos give three dimension of the photographed area. These photos contain a detailed cord of the ground at the time exposure.

4. Define satellite imageries.

The satellite imageries can either be read manually like aerial photographs, or with the help of computers.

5. What is meant by geographic information system?

The modern computers can process maps and data with suitable computer programmer. The process of integrating and analyzing various types of data with the help of computer is known as geographic information system.

6. What are applications of remote sensing?

General geological mapping, mineral prospecting, petroleum exploration, ground water exploration, engineering .uses of site rocks, disaster studies, coastal geological studies.

7. What are geological considerations involved in the construction of buildings.

Basic requirements of a building foundation, building foundation on soils, building foundation carried to the deep hard rocks, building founded on surface bed rocks, types of settlement in buildings.

8. What are the characteristics of air photos? Shape, size, flight, photo data and scale.

9. What are the kinds of air photos?

Vertical air photos, oblique air photos, anusaics ,hotostrips, stereoprain.

10. Define stereo meter

The instrument is used under a mirror stereoscope for measuring heights and areas of objects from air photos.

11. What is mean by measuring dots?

A stereo meter consists of two small Tran's parent glass or platic plates attached to a long metallic bar. A clear dot is etched on earth of the paltes called 'measuring dots'.

12. Define land slide.

A land slide is a slow or sudden down hill movement of slope forming rock and soil materials under the force of gravity.

13. Places in which land slide occur.

They occur in hill valley slopes, sea coasts, river banks and bends, on the slopes of volcanic cones and in earth quake prone areas. They also occur under water as on lake or sea floor.

14.  What are the classifications of land slides?

Presence or absence of a definite slip plane, materials involved and their water content, kind and rate of movement.

15. What are the parts of atypical slides

Crown, scrap, head, slip plane, flanks, transverse ridges, fool, toe, length, width,  height, depth.

16.            What are the types of land slides?

(1) Slides: Translational, Rotational

(2) Falls

(3) Flows

Slow, Soil creep, Rock creep

(4) Complex slides.

17.            What are the characteristics of land slide?

1, Steep scraps in their upper parts and irregular ridges and furrows at lower parts.

2, Land slides vary in extent from several square meters to several kilometers. It is thickness may several meters.

3, Land slide velocities ranges from very small movement to more than 100 km/h.

18.          What are the causes of land sides?

a) Natural causes.

1, Internal factors. 2, External factors.

b) Man induced causes.

19. What are the Geological considerations involved in Road cutting?

a. Topography

b. Lithological characters

c. Structural features of the rocks

Ground water conditions

20. What are the structural features of tunnel sites?

a. Dip and strike

b. Folds

c. Faults

d. Joints.