Introduction - Semi-quantitative Approaches for Landslide Assessment and Prediction - page 32

A. Slope movements of super cial deposits (slope detritus, weathering material),

produced mainly by subareal agents.

i. Talus creep that creates the terminal bending of strata
ii. Sheet Slides
iii. Earth Flows
iv. Debris Flows and liquefaction of sand.

B. Slides in Clays, Marls, Claystone, Clayey shales etc.

i. Along cylindrical surfaces
ii. Along composite sliding surfaces
iii. Caused by squeezing out of soft underlying rocks.

C. Slope Movements of solid rocks:

i. Rockslides on predisposed surfaces (bedding, schistosity, jointing and fault
planes)
ii. Long term deformation of slopes
iii. Rock falls.

D. Slope Movements include geological phenomena:
i. Solifluction
ii. Slides in sensitive clays
iii. Subaqueous slide.

cation of mass wasting-
mass movement phenomena (landslides) based on direction and type of movement:

Chorley et al. ( 1985 ) presented a very simpli ed classi

i. Vertical movement:

(a) Fall rock fall, earth fall and topple

(b) Subsidence

—

— collapse and settlement.

ii. Lateral Movement:

(a) Slides block slide

(b) Spreading

—

cambering (draping of sedimentary units) and Sackung
(lateral spreading away from the anticlinal crest).

—

iii. Diagonal Movement:

(a) Creeping — soil creep, rock creep and talus creep

(b) Slide — rock slide, debris slide, slumping

(c) Flows — earth flow, debris flow and mud flow.

ed mass movements into three major types such as:
i. creep, ii. Frozen ground phenomena and iii. Landslides. His classi

Hutchinson in 1968 classi

cation was
based on the rate of movement and the type of materials involved in failure. He
divided landslides into translational slide, rotational slips, falls, and subaqueous
slides. In 1988 Hutchinson classi ed landslides in the following manner based on