ERTH 2415 Lecture Notes - Lecture 16: Friction, Microscopic Scale, Silt
23 Nov 2016
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Document Summary
Erth 2415 lecture 16: mass movements i. Mass movements: collective name for a variety of processes for the downslope movement of earth materials under the direct influence of gravity. When driving forces > resisting forces, mass movement occurs. Driving force is the component of gravity parallel to the slope. Resisting force is the proportional to inertia and friction, and counteracts the driving force. Conditions decreasing stability : adding mass high on a slope, steepening of slope, removing support at the base of the slope. Conditions decreasing stability : presence of weak material. Material that deforms plastically under stress and loses strength. Friction: force that resists motion between two surface in contact. Controlling factors are: roughness of the surfaces and presence of lubricants. The smaller the friction coefficient (u), the less stable it is: fractures in rock fractures oriented in the slope direction are particularly unstable. Microscopic scale: internal roles of water water has an effect on several things:
