What feature of water is an internal cause of slope failure?
The Role of Water
Since water is heavier than air, this increases the weight of the soil. Weight is force, and force is stress divided by area, so the stress increases and this can lead to slope instability. Water has the ability to change the angle of repose (the slope angle which is the stable angle for the slope).
How does steepness of slope affect mass wasting?
The steeper the slope, the greater potential for gravity to pull objects down. The shallower the slope, the less effect gravity has on pulling objects down. There are several factors that influence mass wasting, but ultimately it is a battle between friction and gravity. But if gravity is stronger, the slope will fail.
How does water affect mass movement?
Although water is not always directly involved as the transporting medium in mass movement processes, it does play an important role. Addition of water from rainfall or snow melt adds weight to the slope. Water can seep into the soil or rock and replace the air in the pore space or fractures.
Why are landslides more common on steep slopes?
Why are landslides more common on steep slopes? Slope angle determines the relative magnitude of driving forces. Why might infiltration of water deep into a slide mass increase landslide hazards? The water increases the pore water pressure, effectively lifting the slide mass from stable ground beneath.
What is the slowest but most widespread form of slope failure?
❖The slowest and most widespread type of mass wasting is called creep. This involves the imperceptible downslope movement of soil and rock.
What are the types of slope failure?
Types of Slope Failures
- Translational Failure.
- Rotational Failure.
- Wedge Failure.
- Compound Failure.
What are three possible causes of Oversteepened slopes?
erosion by rivers, glaciers, or ocean waves create oversteepened slopes. rock and soil slopes are weakened through saturation by snowmelt or heavy rains. earthquakes create stresses that make weak slopes fail. earthquakes of magnitude 4.0 and greater have been known to trigger landslides.
What are the 4 types of mass movement?
There are four different types of mass movement:
- Rockfall. Bits of rock fall off the cliff face, usually due to freeze-thaw weathering.
- Mudflow. Saturated soil (soil filled with water) flows down a slope.
- Landslide. Large blocks of rock slide downhill.
- Rotational slip. Saturated soil slumps down a curved surface.
Can we prevent mass wasting How?
Engineering solutions include barriers and retaining walls, drainage pipes, terracing the slope to reduce the steepness of the cuts, and immediate revegetation. Rockfalls can be controlled or eliminated by the use of rock bolts, cables, and screens and by cutting back slopes to lesser gradients.
Which factors can lead to a mass movement?
The factors that cause most mass movement events are the undercutting of steep slopes, the removal of vegetation, earthquakes, and heavy prolonged rainfall. Many mass movement disasters are preceded by development, deforestation, and slope steepening, which weakens the slopes.
What are 4 causes of mass movement?
The causes of mass wasting include an increased slope steepness, increased water, decreased vegetation and earthquakes. One of the types of mass wasting that is an example of the slope failing is a slump. This is the sliding of coherent rock material along a curved surface.
What is the slowest type of mass movement?
Solifluction and creep are the slowest types of mass movement. Creep is the slowest of all the mass movements and moves the most soil out of all the mass movements. The only way to detect soil creep is to observe the fences, buildings, and other surface objects that may be in that area.
How does vegetation affect slope stability?
Vegetation influences slope stability by removing water through transpiration. The major effect of transpiration is the reduction of soil pore water pressures which counteracts the loss of strength which occurs through wetting, this is most readily seen as a loss of moisture around trees.
Which areas are the most susceptible to slope failure?
html) shows areas with greatest potential for landslides and other slope failure events (in red and pink colors). The areas at greatest risk are in mountainous regions (Fig. 2) with relatively steep slopes such as the Appalachians, Rockies, and mountain ranges of California.
What aspect of hillside development has contributed to the frequency of landslides in Southern California?
1. What aspect of hillside development has contributed to the frequency of landslides in southern California? Water flows much faster on steep slopes. The steeper the slope, the less vegetation plays a role in anchoring the slope.