Geohazards

Question 1

Define technogical failures

Answer 1

Includes

Dam failures, nuclear accidents, fires

Question 2

What are the five steps to combat risk?

Answer 2

Before :Assess, mitigate, prepare

After : respond and recover

Question 3

What are some important tools to use during a ego hazards assessment program?

Answer 3

Hazard maps
Remote sensing
Aerial photos
Land use planning. Geological information to characterize site materials and selection
Engineering geologist role is to assess the hazards of sites and to support planners

Question 4

Earthquake intensity is determined by what factors?

Answer 4

Magnitude
Distance
Geology 
Building style
Duration of shaking

Question 5

Seismic amplitude is strongly dependant on what?

Answer 5

Consolidation of the rock or soil material

Question 6

How often to mega thrust earthquakes occur?

Answer 6

500-600 years

Question 7

How to ghost forests occurs?

Answer 7

Coastal areas subside due to seismic shaking, inter tidal water is than able to flood the new low lying area. The salt water than begins to kill the trees

Question 8

What types of soils are subject to liquefaction?

Answer 8

Typically fine grained soils of low density ( N value of 20 -30)
Coastal deposits, lake deposits and low lying areas with high water table
These areas have low soil strength, bearing capacity and slope stability

Question 9

What are three types of liquefaction failures?

Answer 9

Cyclic mobility
Overturning
Sand boiling

Question 10

What are the main points for mitigating debris flows?

Answer 10

Slow the flow
Contain sediment
Control the flow
Protect channel to limit erosion
Store sediment

Question 11

What are some hazards associated with mine subsidence?

Answer 11

Sinkholes
Coal ignition
ARD
Noxious gas escape

Question 12

What are the two types of mine induced subsidence?

Answer 12

Sag subsidence primarily caused by long wall mining

Sinkholes caused by pillar breakdown

Question 13

What are the three mechanism for mine shaft deterioration?

Answer 13

Floor heave
Pillar crashing
Roof collapse

Question 14

Define floor heave?

Answer 14

Occurs when the seat earth absorb ground water and swells causing tilt at the surface

Question 15

Review bulking ratios and collapse calculations

Answer 15

Ok

Question 16

What is the purpose of a subsidence investigation?

Answer 16

Determine if relocation of a structure is needed
How to stabilize the ground
Design to accommodate movements

Question 17

Define geologic hazards

Answer 17

Geological state that has the potential for widespread damage
Includes: earthquakes 
Volcanoes
Landslides
Floods
Landslides
Tsunamis