Term
| Stability of slopes depends on...? |
|
Definition
-driving forces
-resisting forces such as frictional and cohesive strength |
|
|
Term
| What is effective stress? |
|
Definition
The intergranular stress enabling friction is the effective stress.
High pore pressures may adversely affect the stability of a slope due to a decrease in effective stress |
|
|
Term
| What are some landslide triggers> |
|
Definition
-intense rainfall
-rapid snowmelt
-water-level change
-volcanic eruption
-earthquake shaking
-rapid erosion
** By definition, a trigger is an external stimulus causing a near-immediate response in the form of a landslide by
...rapidly increasing stresses
...reducing the strength |
|
|
Term
| Precipitation & Pore Pressure Response |
|
Definition
| The rapid infiltration of rainfall, causing a temporary rise in pore-water pressures, is the mechanism by which most shallow landslides are generated during storms. |
|
|
Term
|
Definition
| Strong ground shaking during seismic activity is a very common triggering mechanisms for landslides in many different topographic and geologic settings. |
|
|
Term
| Earthquake Triggers – Rockslides |
|
Definition
| Earthquakes can be doubly destructive as they both induce shear stresses and weaken the internal structure of the slope material. |
|
|
Term
| Anthropogenic Triggers – Human Activities |
|
Definition
In addition to the natural occurrence of many landslide triggers, these mechanisms may also be induced through human activities.
... excavation of slope near its toe
... loading of slope at its crest
... drawdown of dam reservoirs
... irrigation
... artificial vibration (e.g. pile driving)
... blasting (mining, construction, etc.)
... jumping up and down on edge of cliff |
|
|
Term
| What are three ways of landslide mitigation? |
|
Definition
-avoid the problem
-prevention
-protection |
|
|
Term
|
Definition
-reduce the mass of soil/rock within the slope or remove the unstable material
-cables anchored in stable rocks to increase normal stress which will increase friction
-drainage of surface and subsurface water |
|
|
Term
|
Definition
-barrier systems
-rockfall nets |
|
|
