Finals 2 - Ground Subsidence Flashcards Preview

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Flashcards in Finals 2 - Ground Subsidence Deck (16)
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1
Q

happens when the ground material is displaced into some sort of underground voids, which can only occur in certain rock types.

A

SUBSIDENCE

2
Q

Subsidence rock types:

A

SALT
PEAT
CLAY
LIMESTONE

3
Q

Types of Subsidence include the following:

A

Shear Failure
Macrovoids
Slope Failure

4
Q

Characterized by heaving at the ground surface accompanied by tilting of foundation in it.

A

Shear Failure

5
Q

Happens in larger cavities, solution caves in limestone, rare natural cavities in other rocks including salt and basalt, mined cavities in any rocks of economic value.

A

Macrovoids

6
Q

A slope collapses abruptly due to weakened self-retainability of the earth under the influence of a rainfall or an earthquake.

A

Slope Failure

7
Q

Some fine soils collapse due to restructuring when saturated for the first time, only occurs in a process known as ____________.

A

Hydrocompaction

8
Q

______ causes subsidence by 15% of the soil thickness.

A

Hydrocompaction

9
Q

is the temporary loss of effective stress of sand during a period of earthquake vibration, where it tends to look like a liquid.

A

Liquefaction

10
Q

Liquefaction is triggered by the following:

A
  • When the sand is uniformly graded, with grain size < 0.70 mm
  • When it is poorly packed with low relative density
  • When it is located below the water table at a shallow depth
11
Q

Consolidation accelerates under a few meters of placed fill and almost stops when surcharge is removed, usually after one year of pre-construction.

A

Surcharge

12
Q

Accelerates water expulsion, so accelerates consolidation.

A

Drainage

13
Q

May allow settlement beneath embankment to be compacted during construction time

A

Drainage

14
Q

Mixing of cement to improve soil strength

A

Grouting

15
Q

Densifying sandy, non-cohesive soils using a crane-supported vibrating poker.

A

Vibrocompaction

16
Q

Permeable fabrics which, when used in association with soil, have the ability to separate, filter, reinforce, protect, or drain.

A

Geotextiles