EARTHSC 2GG3 Lecture Notes - Lecture 9: Saguenay River, Spoil Tip, Frank Slide
17 Dec 2019
School
Department
Course
Professor
L A N D S L I D E S
04-FEB-2019
INT R O DUC TIO N
• Landslide and mass wasting
o Terms used to describe the downslope movement of rock or sediment due to gravity
• Types of landslides are determined by:
o Mechanism of movement
o Type of material
o Amount of water present
o Rate of movement
197 1 – SAG UENA Y R I V ER , Q U EB E C
• 27-hectare landslide
• 26 homes lost
• 31 killed
190 3 – FR A N K S L ID E , A L B E R T A
• buried town of Frank
• killed 70 people
• lasted 90 seconds
196 0 – ABE R FA N , W AL E S
• coal spoil heap failed
• killed 144, predominantly school children
• Landslides kill thousands each year – often related to heavy rains
TYP E S O F LA ND SL ID E S
• Fall: bounding of rock or blocks of sediment from the face of a cliff
• Slide: downslope movement of a coherent block of rock or sediment along a discrete failure plane
• Slump: failure plane is curved upward
• Flow: downslope movement of sediment in which particles move semi-independently of one another, often with the aid of
water
• Debris flows: typically move rapidly; mixtures of mud, debris, and water
• Creep
o Very slow flow of rock or sediment
o Sackung: slow movement of large masses of rock
o Topple – a rock mass pivots about a point
• Know Frank slide.
FORC ES O N S L O P ES
• Driving forces move rock or sediment down a slope
o The weight of slope material is the largest driving force
▪ Can include fill material and buildings
• Resisting forces oppose down slope movement
o Shear strength of the material
o Resistance of material to sliding or flowing along slip planes
• Factor of Safety (SF) is the ratio of the resisting forces to the driving forces.
o Stable when greater than 1; unstable when less than 1
• Driving and resisting forces are not static
Document Summary
Landslide and mass wasting: terms used to describe the downslope movement of rock or sediment due to gravity. Types of landslides are determined by: mechanism of movement, type of material, amount of water present, rate of movement. 1 9 7 1 s a g u e n a y r i v e r , q u e b e c. 1 9 0 3 f r a n k s l i d e , a l b e r t a buried town of frank killed 70 people lasted 90 seconds. 1 9 6 0 a b e r f a n , w a l e s coal spoil heap failed killed 144, predominantly school children. Landslides kill thousands each year often related to heavy rains. Fall: bounding of rock or blocks of sediment from the face of a cliff. Slide: downslope movement of a coherent block of rock or sediment along a discrete failure plane.
