Geoscience Reference
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Almagia (1910), Terzaghi (1925), Ladd (1935), Sharpe ( 1938 ), Savarenski (1939),
Emelyanova (1953), Varnes ( 1958 ), Hutchinson, developed varied schemes of
landslide classi
ed landslide based on the physical
properties involved in downward movement of materials. Sharpe ( 1938 ) classi
cation. Terzaghi classi
ed
slide, on the basis of the materials displaced and the type and rate of movement.
Savarenski (1939) divided landslide into asequent, consequent and insequent
considering the shape of landslide surface. Asequent landslides develop in homo-
geneous cohesive soils along curved and approximately cylindrical surfaces.
Consequent landslides move along the bedding planes, joints or plane of schistosity
dipping downslope. Insequent landslides run transversely to bedding plane and are
generally of large dimensions.
Karson and Kirkby (1972) classi
ed mass movement processes into three major
types such as, slide,
flow and heave on the basis of type of movement. Slides take
place along clear-cut shear planes and are ten times longer than they are wide. Two
main types are translational slides and rotational slides. Translational slides occur
along planar shear planes and include debris slides, earth slides, earth block slides,
rock slides and rock block slides. Rotational slides are called as slumps which occur
along concave shear planes. This type of movement includes rock slumps, debris
slumps and earth slumps. Flow is the gravity induced mass movement (Selby
2005 ). It is one of the most destructive natural processes, causing hundreds of
deaths and losses of millions of dollars worth of property each year (Costa 1984 ).
Flows are generally categorized ad avalanches, debris flows, earth flows or mud
flows (Varnes 1978 ). Hsu ( 1975 ) suggested the term
fl
to explain high
velocity mass movement that shows clear flowage behaviour. The very slowest type
of flow is termed as
' sturzstroms '
which involves the oversaturation of earth
materials and their downward movement. Heave is caused by alternating phases of
expansion and contraction as a result of heating and cooling, wetting and drying
and burrowing activities of animals. Heave is classed as soil creep and frost creep.
Varnes ( 1978 ) proposed for
'
soli
fl
uction
'
five principal types of mass movements.
1. Falls: the free fall of loosened rock mass for the greater part of distance of
movement.
2. Topples: overturning of rock mass about a point below its centre of gravity.
3. Slides: the rock mass moves about a point above its center of gravity, known as
rotational slide. The rock mass when moves along more or less planar or gently
undulating surfaces, known as translational slide.
4. Lateral spreads: when the lateral extension movements occur in a fractured rock
mass.
5. Flows: it includes continuous deformation of the rocks and gradual downward
movement of the materials. In soil it represents flow like viscous fluid.
6. Complex Slides: a combination of two or more of the above stated types.
ed slope movements considering the character of the rocks
and the type of movements:
Zaruba ( 1969 ) classi
 
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