Deck 12: Below-Grade Construction Foundation Systems and Basements

Question 1

Pile foundations are commonly used in coastal areas.

Answer 1

True

Question 2

Drilled piers used as foundation elements consist of

A)wood.
B)cast- in- place unreinforced concrete.
C)structural steel.
D)precast concrete.
E)cast- in- place reinforced concrete.

Answer 2

E

Question 3

In a deep foundation system, foundation settlement is generally larger than in a shallow foundation system.

Answer 3

False

Question 4

A foundation system consisting of perimeter foundation walls and an elevated ground floor with an underlying crawl space is commonly used

A)for low- rise buildings in cold climates.
B)where the water table is high.
C)for low- rise buildings in warm climates.
D)where the soil is expansive.
E)where the soil- bearing capacity is low.

Question 5

Drilled piers transfer building loads mainly by end bearing, while piles do so by both end bearing and skin friction.

Question 6

Where a tremmie is used in a pier, casing is unnecessary.

Question 7

A deep foundation system consists of a

A)pier or pile foundation.
B)raft foundation.
C)mat foundation.
D)slab- on- ground foundation.
E)all of the above.

Question 8

Which of the following foundation systems has large voids?

A)Mat foundation
B)Strip footing
C)Concrete slab- on- ground
D)Raft foundation
E)None of the above

Question 9

In expansive soils, drilled piers are subjected to

A)an uplift force in the expansive region of the soil, which generally occurs in the upper soil layer.
B)an uplift force in the expansive region of the soil, which generally occurs well below the ground surface.
C)a downward force in the expansive region of the soil, which generally occurs well below the ground surface.
D)any one of the above, depending on the local geology.
E)none of the above.

Question 10

Settlement of foundations causes stresses in the structural frame of the building when the settlement is

A)nonuniform over the foundation area.
B)caused by live loads.
C)caused by dead loads.
D)large and uniform over the entire foundation area.
E)caused by lateral loads.

Question 11

A strap footing is generally used where

A)the soil has low bearing capacity.
B)the columns in the building abut the property line.
C)the soil is expansive.
D)the columns in the buildings are closely spaced.
E)none of the above.

Question 12

Which of the following foundation items must be integrated under a concrete cap?

A)Driven piles
B)Drilled piers
C)Isolated column footings
D)Wall footings
E)All of the above

Question 13

A strip footing is generally used under a

A)wall.
B)drilled pier.
C)column.
D)pile.
E)all of the above.

Question 14

A raft foundation is a shallow foundation system.

Question 15

A commonly used foundation drainage system consists of

A)a perforated drain pipe.
B)a perforated drain pipe wrapped with filter fabric and set within a layer of crushed stone or gravel.
C)a perforated drain pipe set within a layer of crushed stone or gravel.
D)a perforated drain pipe set within a layer of crushed stone or gravel, the layer wrapped with a filter fabric.
E)any one of the above.

Question 16

Which of the following foundation systems does not extend, generally uninterrupted, for the entire footprint of the building?

A)Mat foundation
B)Pier or pile foundation
C)Slab- on- grade foundation
D)Raft foundation

Question 17

A tremmie is used during the drilling of a pier to

A)bring the cut soil out of the hole.
B)seal the pier hole against percolation of water.
C)bring up the groundwater that collects at the bottom of the pier.
D)prevent the caving in of the soil.
E)none of the above.

Question 18

A reinforced concrete slab- on- ground foundation is suitable for

A)all types of buildings on stable soils, provided that it is at least 12 in. thick.
B)lightly loaded low- rise buildings on expansive soils.
C)all types of buildings on stable soils, provided that it comprises perimeter and intermediate beams in both directions.
D)lightly loaded low- rise buildings on both stable and expansive soils.
E)lightly loaded low- rise buildings on stable soils.

Question 19

A ribbed reinforced concrete slab- on- ground foundation is preferred over a constant- thickness slab foundation because

A)it does not require control joints.
B)its formwork is simpler.
C)it can be constructed more quickly.
D)it provides the same strength and stiffness at a lower cost.
E)all of the above.

Question 20

The augers used for boring pier holes generally use

A)a hammering operation.
B)a rotary operation followed by a hammering operation.
C)a rotary operation with a helix- type blade cutter.
D)a vibratory operation followed by a hammering operation.
E)none of the above.

Question 21

A foundation system consisting of grade beams bearing on drilled piers and an elevated ground floor with an underlying crawl space is

A)suitable for lightly loaded low- rise buildings on stable or high- bearing- capacity soils.
B)suitable for all types of buildings on expansive or low- bearing- capacity soils.
C)suitable for lightly loaded low- rise buildings on expansive or low- bearing- capacity soils.
D)suitable for all types of buildings on all types of soils.
E)suitable for all types of buildings on stable or high- bearing- capacity soils.

Question 22

Of the two types of foundation members-piers and piles-which is driven (pushed)into the ground and which is made by drilling a hole into the ground?

Question 23

Which of the two deep foundation members (piles or piers)must be closely spaced and three or more of them joined together with a cap over them? Give reason for your answer.

Question 24

Void boxes used for concrete formwork in foundation systems are made of

A)wood.
B)steel.
C)plastic.
D)fiberglass.
E)none of the above.

Question 25

In a building with a foundation system consisting of grade beams bearing on drilled piers and an elevated ground floor with an underlying crawl space, the ground floor is generally constructed of

A)precast concrete.
B)steel frame.
C)wood frame.
D)any one of the above.
E)none of the above.

Question 26

In a basement excavation with walls supported by an excavation retention structure, waterproofing is applied to the excavation retention structure.

Question 27

Waterproofing that is applied to the outside of basement walls is called

A)positive- side waterproofing.
B)blind- side waterproofing.
C)negative- side waterproofing.
D)either positive- side or negative- side waterproofing.
E)either positive- side or blind- side waterproofing.

Question 28

In placing concrete into the drilled hole for a pier, special equipment is used. What is that equipment and what function does it serve?

Question 29

A PT concrete slab- on- grade foundation is commonly used

A)on expansive soils.
B)on soils with a high water table.
C)on stable soils.
D)all of the above.

Question 30

How are foundation piers constructed?

Question 31

What is a mat foundation?

Question 32

What is a foundation pile and the material(s)used for it?

Question 33

Driven piles and bored piers are both deep foundation elements. In which situations are piles used and in which situations are piers used?

Question 34

How would you describe a foundation called footing? Is it a deep foundation or shallow foundation?

Question 35

A PT concrete slab- on- ground foundation does not require control joints.

Question 36

What is a deep foundation?

Question 37

A foundation system consisting of perimeter grade beams and a reinforced concrete slab thickened over drilled piers is suitable

A)where the water table is high.
B)where the soil- bearing capacity is high.
C)for low- rise buildings in cold climates.
D)for buildings with unconditioned interiors.
E)where the soil is expansive.

Question 38

Give an example of a commonly used mat foundation.

Question 39

Building foundations are divided under two broad categories depending on their depths below ground. Name them.

Question 40

A posttensioned (PT)concrete slab- on- ground foundation generally consists of

A)a PT slab, perimeter beams, and intermediate beams.
B)a PT slab only.
C)a PT slab and perimeter beams.
D)any one of the above, depending on the superimposed loads.
E)none of the above.

Question 41

With the help of sketches and notes, describe various foundation systems that cover the entire footprint of the building.

Question 42

Explain why the buildup of moisture in a crawl space must be controlled and what measures are commonly employed to achieve this goal.

Question 43

In which situation is a post- tensioned (PT)concrete slab- on- ground commonly used?

Question 44

What is a French drain?

Question 45

Explain what a rat slab is and where it is likely to be used.

Question 46

What is the difference between shallow foundations and deep foundations? Where would you recommend the use of deep foundations? Explain.

Question 47

Using sketches and notes, describe at least one type of foundation system used for low- rise buildings on stable soils.

Question 48

Using sketches and notes, describe at least one type of foundation system used for low- rise buildings on unstable soils.

Question 49

In terms of waterproofing a basement wall, what is blind- side waterproofing?

Question 50

What is a concrete slab- on- ground?

Question 51

Using sketches and notes, describe the anatomy of a reinforced concrete slab- on- ground foundation.

Question 52

What is a casing, and where is it commonly used? Explain.

Question 53

In terms of waterproofing a basement wall, what is positive- side waterproofing and what is negative- side waterproofing?

Question 54

On an expansive soil, the first floor concrete slab is often designed as an elevated slab, i.e., like an upper- level slab. List one of the ways of constructing such a slab.

Question 55

What is a ribbed concrete slab- on- ground and its advantages over a constant- thickness slab?