1. LANDSLIDES Engr. Imran Mehmood Civil Engineering Department
Swedish College of Engineering & Technology, Wah Cantt
Date # 03 February, 2012

2. landslides
“Sliding of a land, movement of a certain rock-mass from place to another, movement of a rock mass from higher level to lower one by the action of the force of gravity” The Rate Of Movement Of Such A Mass Is Never Constant It may be so slow that even the most sensitive instrument may fail to record it. The effect of such a landslide can be seen after a number of years. It is most common type of phenomenon. It may be so abrupt that it may endanger the surrounding masses. This is a rare phenomenon.

3. CAUSES OF LANDSLIDES
The landslides may be caused due to either of the following:
Water Content – Presence of water in a rock material is considered to be the main source of landslides. The water increases the weight of rock material but also decreases the binding capacity of rock particles. This is the fact that why landslides generally occur after rainfall.
Overloading – Landslides may also be caused due to overloading the surface, which may be natural or artificial. Natural loading may be sue to heavy rainfall or due to rise in the water level in a reservoir. Artificial loading may be due to the construction of a heavy building or heavy traffic.

4. CAUSES OF LANDSLIDES
The landslides may be caused due to either of the following:
Excavation of the Adjoining Area – It has been observed that if a deep excavation is made, it takes away the lateral support of the adjoining area which facilitates the landslides.
Sudden Disturbance – Sometimes, a sudden disturbance takes place due to an earthquake. It has been observed that if such a disturbance is of severe intensity, it also causes the landslides to occur.

5. classification OF LANDSLIDES
The landslides may be caused due to either of the following:
Flowage – it is a movement in which the top surface of a mass flows from one place to another through a small distance. There is no definite line of flow. Rate of flowage is very small.
Sliding – is a movement in which a certain mass actually slides from one place to another under the force of gravity.
Subsidence – is a movement in which a certain mass actually subsides, sinks or settles down due to the force of gravity. This type of movement may be caused either due to overloading of the surface.

6. TYPES OF LANDSLIDES
The landslides may be caused due to either of the following:
Rock Fall – A rock fall is a sudden movement of rock, separated along fractures or bedding planes. There is no fluidity in the motion, only bouncing, rolling and free fall.

7. TYPES OF LANDSLIDES
The landslides may be caused due to either of the following:
Translational Landslide – move more or less straight downhill on a flat zone of weakness

8. TYPES OF LANDSLIDES
The landslides may be caused due to either of the following:
Debris Flow – Debris is mixed rock and soil (but not dominantly fine material), with more or less water and air included. A debris flow acts as a fluid and moves rapidly.

9. TYPES OF LANDSLIDES
The landslides may be caused due to either of the following:
Earth Flow – Earth flows involve fine-grained material that forms a thick slurry and has a fluid motion

10. Mitigation techniques for LANDSLIDES
Draining a Landslide
Draining water is a common mitigation technique to help stabilize slides, although this one still moves.

11. Mitigation techniques for LANDSLIDES
Gabion Wall
Gabions, blocks of rocks wrapped in steel mesh, are commonly used to fortify vulnerable slopes. Unlike concrete walls, gabions allow free drainage through themselves, benefiting the slope from both sides.