The document discusses landslides, defining them as the downward movement of land masses composed of rocks and soil, and categorizes various types such as soil creep, solifuction, and rapid flows. It highlights causes of landslides, including geological factors, human influence, and environmental conditions like rainfall, along with their significant effects on infrastructure, loss of life, and changes to the landscape. Preventive measures are suggested to mitigate the risks associated with landslides, such as proper drainage and stabilization of slopes.

1. By- AkhtarKamalBy- AkhtarKamal

2. LandslideLandslide
 It is refers to the downward sliding of huge quantities of land
mass
 Downward movement of slope forming material composed of
rocks and soil or combination of all these material along
surfaces of separation by FALLING, SLIDING AND FLOWING
either sudden or slow from one place to another place.
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3. Classification of Earth MovementsClassification of Earth Movements
 All movement of land masses are referred as landslides, but differin many respects,
therefore all types of landslides are categorized as Earth Movements.
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4. SolifuctionSolifuction
 Solifuction is a downward movement of wet soil along the slopes
under the influence of gravity.
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5. Soil CreepSoil Creep
 Creep is extremely slow
downward movement of dry
surfacial matter.
 Movement of the soil occurs in
regions which are subjected to
freeze-thaw conditions. The
freeze lifts the particles of soil
and rocks and when there is a
thaw, the particles are set back
down, but not in the same
place as before.
 It is very important for CEs to
know the rate of movement
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6. Rapid FlowsRapid Flows
 Rapid flow is similar to the creep, but differ in terms of speed
and depth. It is faster.
 Creep is involved up to shallow depth (app. 1-2 m), whereas
the rapid flow is involved to greater depth (app. up to 5 m or
more)
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7. LandslidesLandslides
 If a mass of earth moves along a
surface the failure is termed as
Landslide
 Large block known as a slump block
moves during the landslide.
 The scar above a landslide is easily
visible.
 They can occur along a slope where
the internal resistance of the rocks
are reduced or they loose their
holding capacity.
 Common after earthquakes or after
removal of part of the slope due to
construction, particularly for
construction of roads.
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8.  During the movement landslide
can result into the Debris slides -
are failure of unconsolidated
material on a surface; Rock slide
or Rock Fall – where movement
of large rock block rolls
 They are also common along the
steep banks of rivers, lakes etc.
 Pore Water Pressure is the key
to monitoring landslides. Shear
strength (a resisting force)
decreases and the weight (a
driving force increases).
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9.  Talus – accumulationTalus – accumulation
formed by the coarser rockformed by the coarser rock
fragments resulted from thefragments resulted from the
mechanical weatheringmechanical weathering
along a slope underalong a slope under
influence of gravityinfluence of gravity
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10. SubsidenceSubsidence
 It represents the downward movement of the surface
 It may occur due to plastic outflow of the underlying
strata or due to the compaction of the underlying material
1) Subsidence due to Plastic outflow:
 It may occur when a plastic layer like clay bed is squeezed outward
due to overlying heavy load
1) Subsidence due to collapse
 It occur due to extensive pull out of large volume of underground
water or due to subsurface solution activity in limestone terrain.
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11. SubsidenceSubsidence
 The Leaning Tower of Pisa, Italy, the tilting of which
accelerated as groundwater was withdrawn from aquifers to
supply the growing city.
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12. Causes of LandslidesCauses of Landslides
 LANDSLIDES OCCURDUE OF VARIOUS REASONSLANDSLIDES OCCURDUE OF VARIOUS REASONS
 Internal Causes:Internal Causes:
 Geological Weak Material
 Weakness in the composition and structure of rock or soil may also cause landslide.
 Erosion
 Erosion of slope due to cutting down of vegetation, construction of road might increase
the vulnerability of terrain to slide down.
 Intense rainfall
 Storm that produce intense rainfall periods as short as several hour also result in land
slide. heavy melting of snow in the hilly terrains also result in landslide.
 Influence of slope
 Provides favourable condition for landslides; steeper slope are prone to slippage of land.
It is known that most of the materials are stable up to certain angle- “Critical angle” or
“angle of repose” – it varies from 300 for unconsolidated sediments to 900 for massive
rocks and 600-900 for partially jointed rocks.
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13.  Geological structures
 Occurrence of inclined bedding planes, joints, fault or shear zone are the planes of
weakness, which create conditions of instability.
 Human Influence
 Undercutting along the hill slopes for laying roads or rail tracks can result into instability.
 Deforestation in the uplands, result into more erosion during the rainy season.
 Ground waterorassociated water
 Main factor responsible for slippage. Suppose the hard or massive rocks are underlined
by softer rocks (shale or clay bed)
 When rain water percolates through some fractures or joints the clayey beds becomes
very plastic and acts as slippery base, which enhance the chances of loose overburden
to slip downward.
 Water is the most powerful solvent, which not only causes decomposition of minerals but
also leaches out the soluble matter of the rock and reduces the strength.08/14/16Prepared by AKHTAR KAMAL
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14. External factorsExternal factors
 Most common is the vibration resulted due to earthquakes; blasting to
explosives; volcanic eruption etc.
 Earthquakes often initiate mass failures on large scale eg. 1897 Assam
quake produced gigantic landslide ever recorded in the region.
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15. Effects of LandslidesEffects of Landslides
 Landslides are a major catastrophe the world as it is widespread and
significant impact. The effects of landslides is dangerous to humans and
to other living things
 For example, the slope of the saturated with water to form debris flows or
mudflows. Concentrated mixture of rock and mud may destroy the trees,
houses, and cars and blocking the bridge. Mud mixed with river flow can
cause devastating flooding along the route.
 Similarly, the ice floes formed in the river caused by ice clogging the
rivers and flows more slowly. However, it can produce enough energy to
destroy the bridge. Ice may accumulate on the edge or on top of weak
layers of snow or unstable causes crash occurred.
 Pyroclastic flows (pyroclastic) arising from dust debris of ash, poisonous
gas and hot rock from volcanic eruptions that spread quickly to eat
anything that travelled to the effects of destruction and death. Among the
social effects that can be described as… 08/14/16Prepared by AKHTAR KAMAL
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16. 1. Economic Decline 1. Economic Decline
 Landslides are certainly cause damage to property.
 This brings losses to the economy of a country. Economic
rehabilitation is also needed in the area that has experienced
a landslide.
 This would cost a lot and some of the offending country
economy.
 Example:
 A average, these landslides caused loss of $ 1-2 billion U.S.
dollars and 25disaster in the United States each year.
 At Utah, U.S., in 1983, the total cost to repair the landslide area
of 500 million dollars and it is financing the cost of the most
expensive landslide in U.S. history
 Loss due to landslides in the United States is estimated at 1.5
billion dollars annually.
 Earthquake the earth Loma Prieto in October
1989 caused thousands of landslides covering an area of 5400
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17. 2. Damage To Infrastructure.2. Damage To Infrastructure.
 Landslides can lead to damage to property resulting
from the force flow or mud.
 Infrastructure land such as buildings, roads, places of
leisure and so on can be destroyed by the landslide
occurred.
 Example:
A. Destruction a building and placement.
B. Land massive collapse can cause the destruction of a city.
C. Damage to roads
D. Affect
communication system of roads and communication syste
ms.
E. Earthquake the earth in October 1989 resulted in tens
of thousands of experienced landslides with an area up to
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18. 3. Loss Of Life.3. Loss Of Life.
 Loss of life is a dangerous effect
upon the occurrence of a
landslide and it is difficult to
avoid.
 Many lives will be lost upon the
occurrence of landslides.
 Example:
 Landslide Estate Park Hill
View occur on 20 November
2002 destroyed a house killing
eight bungalows and family life.
 Landslide in Highland Tower, Ulu
Kelang cause of 48 people
were killed and many injured.
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19. 4. Changes In The Surface Landscape.4. Changes In The Surface Landscape.
 Landslide causes significant changes in
the landscape of the earth's surface.
 Pile of soil and mud from the landslide
activity caused the high ground may be flat
and settling sediment can become thick
very quickly.
 Consequently, dam rivers or lakes become
more shallow to hold a lot of water. Water
level becomes higher and the ground
becomes waterlogged areas.
 Landslides can also cause soil or rock
slope becomes increasingly steep and 08/14/16Prepared by AKHTAR KAMAL
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20. Preventive MeasuresPreventive Measures
 The main factors which contribute to landslides are Slope, water
content, geological structure, unconsolidated or loose
sediments, lithology and human interference.
 Slope
 Retaining wall may be constructed against the slopes, which can
prevents rolling down of material. Terracing of the slope is an
effective measure.
 Effect of water
 Make proper drainage network for quick removal of percolating
moisture or rain water by constructing ditches and water ways along
the slope
 Geological structures
 Weak planes or zones may covered or grouted to prevent
percolation of water, this increases the compaction of loose
material.
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21. Landslides And MudflowsLandslides And Mudflows
 Plant ground cover on slopes and build retaining walls.
 In mudflow areas, build channels or deflection walls to direct
the flow around buildings.
 Install flexible pipe fittings to avoid gas or water leaks.
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22. MajorLandslide HazardMajorLandslide Hazard
 ALASKA:ALASKA:
 The 1964 prince William
sound earthquake triggered
a large volume landslide at
turn again heights.
 Millions of cubic meters of
soil and rock moved down
slope.
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23. ALASKAALASKA
 Slope failure was induced
by ground shaking of “Quick
Clay.”
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26. JAPANJAPAN
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27. A view of the landslide site in Aizawl, Mizoramon May 12,A view of the landslide site in Aizawl, Mizoramon May 12,
2013.2013.
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28. ThankyouThankyou
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