29-12-2012, 01:27 PM
LANDSLIDES ASSOCIATED WITH MULTIPURPOSE PROJECTS
LANDSLIDES.pptx (Size: 3.11 MB / Downloads: 73)
LANDSLIDE
A wide range of ground movement
Occur in offshore, coastal and onshore environments
Primary driving force - action of gravity
Landslide mitigation - lessening the effect of landslides by man made projects, at slopes vulnerable to landslides
TYPES OF LAND SLIDES
DEBRIS FLOW
Slope material becomes
saturated with water
Often mistaken for flash
flood
The solid-liquid mixture - densities up to 2 tons/m3 and velocities up to 14 m/s
Severe damage to structures and infrastructure
EARTH FLOW
Down slope, viscous flows
of saturated, fine-grained
materials
Move at speeds from 0.17 to 20 km/h
Occur much more during periods of high precipitation
DEBRIS AVALANCHE
Chaotic movement of rocks,
Soil and debris mixed with
Water or ice
Triggered by the saturation of thickly vegetated slopes
Highly rapid
LANDSLIDE MITIGATION TYPES
CONCRETE SLURRY WALLS
Contain the soil,
Support great axial loads,
Containment of water flows
Excavated from the surface
by means of an excavation
clamshell
Thickness - 0.50 m to 1.50 m.
CONCLUSION
Proper planning and designing of multipurpose project
Physical geography and socio – economic factor are to be considered
Besides gravity, human activities induce land slides