Engineering Term of the Month – “ Landslides ”
“ The term “ landslide ” describes a wide variety of processes that result in the downward and outward movement of slope-forming materials including rock , soil , artificial fill , or a combination of these . The materials may move by falling , toppling , sliding , spreading , or flowing . Figure 1 below depicts a graphical illustration of a landslide , with the commonly accepted terminology describing its features .” 1
Figure 1 : An idealized slump-earth flow showing commonly used nomenclature for labelling the parts of a landslide . 1
Slope saturation by water is a primary cause of landslides , however many factors need to be taken into consideration such as geological causes , morphological causes , and human causes .
Landslides occur in all 50 states throughout the United States , however the areas that experience the most landslides are the coastal / mountainous areas of California , Washington , Oregon , the mountains in the Midwest , and the hilly regions of the eastern US .
While most common in mountainous regions , landslides can also occur in low-relief areas , and present themselves as cut-and-fill failures , lateral spreading landslides , collapse of mine-waste piles , a wide range of slope failures stemming from quarries and other open-pit mines , etc .
The most common types of landslides , as defined by the USGS , are outlined in the graphic to the right . 1
Sources :
6