Please enable JavaScript.
Coggle requires JavaScript to display documents.
GEOTECHNICAL ENGINEERING (Sedimentary rock:
Are formed by the…
GEOTECHNICAL ENGINEERING
Introduction:
The branch of civil engineering concerned with the engineering behaviour of earth materials.
-
-
Rock and Soil Formation:
sedimentary,metamorphic and igneous
-
Sedimentary rock:
Are formed by the lithification of existing rock or the bones,shells and pieces of formerly living things.
Example of:
- sandstone
- limestone
- conglomerate
- shale
Characteristics:
- classified by texture and composition
- often contains fossils
- may react with acid
- has great color variety
- particle size may be the same or vary
Type:
i- sandstone - red or gray - sand grains cemented together
ii- limestone - white to gray - calcite and sometimes fossils
iii- shale - dark gray - compacted mud
Metamorphic rock:
Formed by applying great pressure and temperature(heat) to existing rock converting it rock coverting it into a new distinct type of rock.
Created when they come under extreme pressure such as under many thousands of feet af bedrock or through being crushed at the junction of tectonic plates.
Characteristics:
- rarely has fossils
- may react with acid
- may have layers of visible crystals
- rarely has pores or openings
Type:
i- gneiss -pink/gray - foliated
ii- marble - light colored - unfoliated
iii- slate - dark gray to black - foliated
Disintegration of rock:
- mechanical weathering
- chemical decomposition
- biological decomposition
Mechanical: known as physical disintegration;
- plant root
- frost
- thermal expansion
- abrasion
Chemical: chemical weathering;
- oxidation
- hydration
- carbonation
- hydrolisis
- leaching
Biological: the breakdown of organic matter in soils is done entirely by the misroorganisma;
- organic soils
- residual soils
- transported soils