Question 1

Pile foundations are commonly used in coastal areas.

Accepted Answer

Pile foundations are commonly used in coastal areas due to the presence of soft soils, variable soil conditions and high water tables.

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.

Accepted Answer

Drilled piers used as foundation elements typically consist of cast-in-place reinforced concrete, as this provides the necessary strength and durability for the foundation. Wood, cast-in-place unreinforced concrete, and structural steel are not typically used for drilled piers due to their insufficient strength and durability. Precast concrete may be used in some cases, but cast-in-place reinforced concrete is generally preferred.

Question 3

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

Accepted Answer

Deep foundation systems are typically used to transfer the load to a deeper, more stable layer of soil or rock where there is less movement, thus generally resulting in smaller settlements compared to shallow foundations which are more affected by surface soil conditions.

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.

Accepted Answer

A foundation system consisting of perimeter foundation walls and an elevated ground floor with an underlying crawl space is commonly used for low-rise buildings in cold climates to protect against frost heave.

Question 5

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

Accepted Answer

Drilled piers transfer loads primarily through skin friction and end bearing, similar to piles, which also use both mechanisms.

Question 6

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

Accepted Answer

A tremmie is used to place concrete underwater or in deep foundations, and casing might still be necessary to prevent soil collapse during excavation or to maintain the integrity of the borehole before concrete placement.

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.

Accepted Answer

A pier or pile foundation is typically used in situations where the soil is too weak to support a shallow foundation or where the load needs to be transferred to a lower, more stable layer of soil or rock. Raft, mat, and slab-on-ground foundations are all types of shallow foundations and are typically used for lighter loads on stronger soils. Therefore, A is the best choice for a deep foundation system.

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

Accepted Answer

Raft foundations have large voids to reduce the overall weight of the foundation.

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.

Accepted Answer

In expansive soils, drilled piers are subjected to an uplift force in the expansive region of the soil, which generally occurs in the upper soil layer. This uplift force can occur due to the swelling of the soil caused by moisture changes, leading to a decrease in bearing capacity and potential foundation failure.

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.

Accepted Answer

Nonuniform settlement over the foundation area will cause differential movement in the structural frame, leading to the development of stresses. Settlement caused by live or dead loads, provided they are within the designed limits, are accounted for in the structural design. Large and uniform settlement over the entire foundation area would also be accounted for in the design. Lateral loads, such as wind or seismic loads, also result in stresses in the structural frame, but settlement is not the cause.

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.

Accepted Answer

A strap footing is typically used when columns in a building abut the property line, allowing for load distribution without extending the foundation into neighboring properties.

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

Accepted Answer

The answer of Which of the following foundation items must...

Question 13

A strip footing is generally used under a
A)wall.
B)drilled pier.
C)column.
D)pile.
E)all of the above.

Accepted Answer

A strip footing is typically used under a wall to distribute the load of the wall to the soil below. It is not typically used for drilled piers, columns, or piles, which often require their own individual foundations. While it is possible that a strip footing may be used in conjunction with other types of foundations, the most common application is under a wall. Therefore, the best choice is A.

Question 14

A raft foundation is a shallow foundation system.

Accepted Answer

A raft foundation is a type of shallow foundation that consists of a reinforced concrete slab covering the entire area beneath a structure and transmitting the loads from the structure to the soil or rock below.

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.

Accepted Answer

The most effective foundation drainage system includes a perforated drain pipe set within a layer of crushed stone or gravel, with the entire layer wrapped in filter fabric to prevent soil clogging.

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

Accepted Answer

Pier or pile foundations are used when there are variable soil conditions or when the building is constructed on a slope. The foundation consists of isolated columns or piles that support the building's weight, rather than a continuous system that extends for the entire footprint. Mat, slab-on-grade, and raft foundations are all continuous foundation systems that extend for the entire footprint of the building.

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.

Accepted Answer

A tremmie is specifically used for placing concrete underwater or in deep foundations, not for the purposes listed in options A, B, C, or D. It ensures the concrete is placed without mixing with water or air, maintaining its integrity.

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.

Accepted Answer

A reinforced concrete slab-on-ground foundation is suitable for lightly loaded low-rise buildings on stable soils, as these conditions do not require the additional structural support needed for expansive soils or heavier buildings.

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.

Accepted Answer

A ribbed reinforced concrete slab-on-ground foundation has a lower cost compared to a constant-thickness slab foundation while providing the same strength and stiffness. Additionally, it can be constructed more quickly due to the use of less concrete and can also avoid the need for control joints. The formwork for both types of slab foundations is typically similar.

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.

Accepted Answer

Pier hole augers use a rotary operation with a helix-type blade cutter to bore holes in the soil. This allows for efficient and precise excavation of the pier hole without damaging the surrounding soil.

Quiz 12: Below-Grade Construction Foundation Systems and Basements

Pile foundations are commonly used in coastal areas.

Drilled piers used as foundation elements consist of

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

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

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

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

A deep foundation system consists of a

Which of the following foundation systems has large voids?

In expansive soils, drilled piers are subjected to

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

A strap footing is generally used where

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

A strip footing is generally used under a

A raft foundation is a shallow foundation system.

A commonly used foundation drainage system consists of

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

A tremmie is used during the drilling of a pier to

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

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

The augers used for boring pier holes generally use