Intro To Mining and Engineering Geology
Intro To Mining and Engineering Geology
Intro To Mining and Engineering Geology
Lecture2-Type of soil ,Soil stabilization and site investigation Lecture 9-Application of Engineering geology
combined with practices and experience to assist the engineer in the solution of
Or, it’s the branch of geology which studies the dynamics of the upper horizon
1. Soil engineering
2. Engineering geodynamics
which include the engineering geological processes e.g.
Landslides, carstification, earthquakes, action of surface
and subsurface waters, action of marine waters and
etc..
Soil
In general sense of engineering, soil is
defined as the uncemented aggregate of
mineral grains and decayed organic matter.
Soil is a mixture of minerals, organic matter,
gases, liquids and countless organisms the
together support life on earth.
The main physical properties of soil are
dictated by the size, shape and chemical
composition of the grains.
Soil Engineering
Soil Mechanics
Is the branch of science that deals with the study of
physical properties of soil and the behavior of soil
masses subjected to various types of forces.
Soil engineering
It is the application of the principles of soil mechanics
to practical problems.
Soil horizons
Soil Fraction
Soil Texture
Coarse- textured soils have a high sand content. They consist of large particles
with uneven surfaces and because of this, have large pores paces.
Fine- Textured , soils range from silty clay to heavy clay, heavy clays are like
soft plastic when wet and are hard when dry
Factor affecting Soil types
Physical weathering
Action of frost, water, wind, glaciers, plant/animals, etc.
breaking particles away from original bedrocks.
Particles transported by wind, water, ice
Soil formed are called granular soil type
Grains are similar to original bedrock
Soil types
Chemical weathering
Occurs when water flows through rocks and leaches out some
of the mineral components of the rock.
Soils formed are called clays
Clay particles are mineral crystals that have very different
properties from those of the original bedrock.
Clay Minerals
The term clay is used as mineral name or textural name (-1 or -2
µm).
“Phyllosillicates ’’.
The different clay minerals groups are characterized by stacking arrangements of
sheets in which two or three sheet layers are hold together.
The two basic units in clay minerals structures are the Silica tetrahedron and the
Aluminum or Magnesium octahedron.
Silica sheet composition (Si4O10)4 .
Octahedron sheet composition either,
1. Gibbsite sheet, Gibbsite mineral [Al2 (OH) 6], Di-octahedral.
Or
2. Brucite sheet, Brucite mineral [Mg3 (OH) 6], Tri-octahedral.
Basic Structural Units
Clay minerals are made of two distinct structural
units. hydroxyl or
oxygen
oxygen
aluminium or
magnesium
Silicon
0.29 nm
1:1 Minerals-Kaolinite
•Si4Al4O10(OH)8. Platy shape
•The bonding between layers are vander Waals forces
and hydrogen bonds (strong bonding).
•There is no interlayer swelling (Nonexpandable)
•The charge deficiency is balanced by the potassium ion Trovey, 1971 ( from
Mitchell, 1993)
between layers..