In: Civil Engineering
4. What are the conditions that exacerbate or mitigate the effects of landslides?
5. What are the four types of landslides?
01.What are the conditions that exacerbate or mitigate the effects of landslides?
Landslides can cause seismic disturbances; landslides can also result from seismic disturbances, and earthquake-induced slides have caused loss of life in many countries. Slides can cause disastrous flooding, particularly when landslide dams across streams are breached, and flooding may trigger slides. Slope movement in general is a major process of the geologic environment that places constraints on engineering development. In order to understand and foresee both the causes and effects of slope movement, studies must be made on a regional scale, at individual sites, and in the laboratory. Areal studies - some embracing entire countries - have shown that certain geologic conditions on slopes facilitate land sliding; these conditions include intensely sheared rocks; poorly consolidated, fine-grained clastic rocks; hard fractured rocks underlain by less resistant rocks; or loose accumulations of fine-grained surface debris. Field investigations as well as mathematical- and physical-model studies are increasing our understanding of the mechanism of slope movement in fractured rock, and assist in arriving at practical solutions to landslide problems related to all kinds of land development for human use. Progressive failure of slopes has been studied in both soil and rock mechanics. New procedures have been developed to evaluate earthquake response of embankments and slopes.
02.What are the four types of landslides?
1.transitional
2.Rotational
3.Block and
4.Lateral landslides
A slide, in the strictest sense, is characterized by failure of material at depth and then movement by sliding along a rupture or slip surface. If sliding is on a predominantly planar slip surface, then the slide is called a block slide. If movement is on a curved slip surface, then the slide is called a rotational slide. A lot of rotational slide end up as a mud flow leaving a gaping hole in the ground where the slide began. Debris from the slide is strewn down a torrent track along which the mud flow travelled to the base of the slope or where the flow path widens and dissipates. A rotational slide with one or more curved slip surfaces where the movement of material is incomplete, leaving individual slumped blocks, is referred to as a slump.