List the two physical factors that cause slopes to form and then change with time , circle the one that is thought to be the first to act
Gravity
(water in streams)
What are the 3 different human activities that have resulted in causing major landslides
groudnwater usage
steepening slope
blocking hillside drainage
It is more likely for limestone to be eroded by infiltrating precipitation water when the limestone is nearly pure calcium carbonate than when the limstone conains a lot of impurities , such as clay and iron oxide(true or false)
False
In reference to groudn subsidence , hydro-compaction occurs when water pressure reduction is caused by pumping water from a soil aquifer, and a soft clay layer then settles due to increased effecitive stress ( true or false)
False
What are the two types of bedrocks hat can span long distances in underground openings
limestone and salt
Explain the major difference between a rock topple and a rock fall , and draw a sketch
topple - rocks falls
topple - rocks get airborne
briefly explai nwhat is the fundamental purpose for drilling horizontal driain holes back into a rock formation at side of a rock cut made for a new highway allignment
relieves groudnwater pressure so sigma n goes up , n goes up
What type of curve is used to model the surface settlment trough shape that can occur as a consequence of tunnel construction through soil
gaussium cuve
List the 6 out of 7 categories of mass movement of slopes as delineated by TRB
rock topple , rock block , soil creep , earth slump , debris avalanche , earth lateral spread
for the rock block on the inclined bedding plane shown below draw the two force mechanisms that are acting to A. cause instability , b to resist instability
...
What are the three destabilizing effects that precipitation water has on earth slope masses and which often trigger major instability o slopes in rainy winters in california
fills cracks , presence of water increases bulk unit mass , sheer strength gets reduced
What are 4 of the 8 different types of soil slope failures hat occur by flow
mudslides , earthflow , talus creep , debris flow
What is the ame of the coal mining method tha uses a 1-2 mile long machine to excavate continuous swaths of thick undergroudn coal and then lets the rock and groudn above collapse , causing many feet of surface subsidence
longwall
Irregularities , such as bedding plane undulations or wavy foliations in schist or gneiss , can cause the friction resistance along a bedding plane or foliations to be substantially increased about the friction resistance that would be present if the bedd
true
A mudflow is dfferent from an earthflow because the rate of mass movement of the earthflow is usually very fast, and the rate of movement of a mudflow is typically more of a slow creep rate ( True or false)
False
Sinkholes often form in areas of limestone where the regional groundwater table has fallen and exposed previously flooded caverns in the rock making it easier for rock to weather and soil to flow down into the voids in the limestone bedrock ( true or fals
TRue
What type of geological formation is paticularly susceptible to consolidation subsidence by withdrawal of groundwater from a deep aquifer , such as what happened in MExico City
Thick base of clay
The width ground surface that settles because a mine collapsese or a tunnel excavation draws in too much soil is usually mucher wider at ground surface than the width of the zone of the underground collapse ( true or false)
True
WHen earthquakes occur , there are often many slope failures. List two of the 3 primary mechanisms by which earthquakes trigger large earth slope failures
Adds heighted force
causes pore water pressure increase
On the simple cross-setion below of a slow that has caused by massive deep slump , indicate the scarp , crown , surface of rupture , zone of accumulation , foot , toe
...
What is the name of the spire that grows up from the floor of a cave in limestone and forms from the chemical-rich dripping water
stagalmite