Landslides Flashcards
Describe geologial feature
Faults Joints, bedding a shear zones Stress relief joints Tension cracks Sheared planes Weak layers Weathered zones Permeable layers Colluvium deposits
Define landslides
The downward movements of rock and soil debris that have become separated from the underlying, stable part of the slope by a shear zone or slip surface (smith, 1997)
Describe mode of failure of a slope
Weak and homogenous materials Horizontally layered subsoil Inclined layered subsoil Complex situations Rock falls
List the main landslip types
Fall
Topple
Slide
Flow
Define Fall
A free movement of material away from steep slopes such as cliffs
Rock falls move coherent rocks, debris falls arose from unconsolidated or barely consolidated detritic rocks, and soil falls are composed of fine material from soul
Primary fall
Movement uninterupted throughout, any interruption of movement makes the fall of a secondary fall
What do direction, length and the shape of trajectories o blocks bouncing from a slope depend on?
1
Define topple
Consists of a forward rotation of a mass of rock, debris or soil about a pivot or hinge on a hillslope
Toppig may culminate in an abrupt fallig or sliding, but the form of movement is titling without collapse
Define slide
A movement o material along a recognisable shear surface
List types of slide
Rotational
Translational
Define rotational
Slump, rotational slip, rotational slide
Multiple rotational landslide, multiple slump
Define translational
Block slide(planar rock slide) Slab slide ( debris block slide, soil block slide, earth block slide, sheet slide, flake slide)
List the main landslip types
Fall
Topple
Slide
Flow
Define Fall
A free movement of material away from steep slopes such as cliffs
Rock falls move coherent rocks, debris falls arose from unconsolidated or barely consolidated detritic rocks, and soil falls are composed of fine material from soul
Primary fall
Movement uninterupted throughout, any interruption of movement makes the fall of a secondary fall
