Soils and Foundations

Select all the advantages of cast in place concrete piles

Damage due to driving is eliminated. Pile length is known at time of concrete pour. Job site cuts of piles are eliminated.

The rise of water above the water table due to the void space in soil is

capillarity

Foundation non-performance may be related to ____________.

fill settlement downhill creep expansive clay

The vertical expansion of soil caused by freezing water is

frost heave

If expansive clay soils are causing foundation non-performance, placing piers under the foundation helps prevent those parts of the foundation from ________.

going down

The ability of water to flow through soil is

permeability

Constructability of piers or piles _________.

should be considered in the design.

When rivers bend, the water at the inside of the bend runs ______, and the water at the outside of the bend runs ______.

slower / faster

Select all the quality control steps that should be done on a drilled shaft.

- Keep record of soils encountered, -Take care not to let concrete strike the sides of the hole while pouring, -Check shaft alignment, -Check for proper reinforcement placement, -Inspect the shaft.

If a foundation has moved with a tilt exceeding ______ percent, it is cause for concern. Select best answer.

1

Sites with unconfined compressive strengths of ____________ psf or less are a site red light.

1500

The settlement of a pile group in sand can be _____ that of the settlement of a single test pile.

2-10x

Test piles should be loaded to _____% of the proposed design load.

200%

Select all of the following that are factors in determining the depth and location of the foundation.

==Adjacent structures ==Building codes ==Utility lines == Frost action == Soil volume change == Groundwater == Property lines == Caves

The _________ system of soil classification is used in highway construction and is followed by nearly all state highway departments.

AASHTO

The mass of the aggregate in this condition corresponds to the mass of the solids plus the mass of the water filling some of the pores.

Air-Dry

________ is the loading per unit area that the soil is able to support without unsafe movement.

Allowable bearing capacity

Negative skin friction can be caused by which of the following? Select all that apply.

Consolidation of soil after the pile is driven Lowering of the water table

Foundation non-performance may be related to ____________. Select all that apply.

Downhill creep, expansive clay, fill settlement

Select two places in a building structure where foundation non-performance is usually recognized.

Dry wall cracking, Door Fit

Select all the types of synthetic manufactured aggregates.

Expanded slate Expanded shale Styrofoam balls Expanded clay Vermiculite

A high water table increases the bearing capacity of the soil by exerting a hydrostatic uplifting force on the foundation.

False

Auger borings produce undisturbed samples.

False

Concrete piles are capable of carrying higher loads than timber and steel piles.

False

Concrete piles are the oldest form of pile foundations and were utilized by the Romans

False

Driving a Shelby tube in by hammer blows causes the least disturbance in the sample.

False

Earth and water pressure both exert lateral and vertical forces which are balanced.

False

Footings on slopes have the same bearing capacity as footings on level ground.

False

Groundwater will never need to be considered in the design.

False

Live load is only caused by the people that occupy or use the building.

False

Precast concrete piles come in only 2 shapes, square and circular, and they must be uniform in cross section because of the formwork needed to cast them.

False

Sieves are stacked with the finest sieves on top and the coarsest sieves on the bottom when doing a sieve analysis.

False

Tampers are good at compacting soils over large areas.

False

The Standard Proctor Compaction Test utilizes a 10 lb hammer dropped 12 in.

False

The vane test can be used too determine the in-place shear strength for soft sands.

False

Select all the methods to prevent cave ins of drilled shafts.

Filling the shaft with a bentonite slurry Casing

------- grained soils will have a higher capillary rise.

Fine

Which of the following is not a method of temporary dewatering?

French drains

What type of pile supports its load by adhesion to the soil?

Friction pile

The vertical expansion of soil as a result of the water in the soil freezing is called ________.

Frost heave

What type of aggregate is a blend of relatively small and relatively large aggregates without many particles in the mid-size range.

Gap graded aggregate

Which of the following geosynthetics would be used to restrict water movement in soil?

Geomembranes

Select all the advantages of steel piles.

Highest bearing capacity Capable of being driven to great depths Capable of being driven through stiff layers.

________ rocks form when magma (molten matter) cools sufficiently to solidify

Igneous

The ---- the pile group in sand, the ----- the settlement will generally be.

Larger, Larger

An eccentrically loaded footing can support _________ load, compared to a symmetrically loaded footing.

Less

________ rocks form when other rocks change their texture, structure, or mineral composition, as a result of heat, pressure, and shear.

Metamorphic

Reconnaissance can entail which of the following:

Observing aerial photographs Studying geological & topographic maps Looking at ground water table in nearby wells. Visiting the project site Noticing soils at nearby cuts & erosion sites such as railroads or quarries

Select all the aggregate moisture conditions that will pull water out of the concrete mix water.

Oven-Dry

________ refers to the movement of water within soil

Permeability

Compaction of clay soils can be done by:

Pneumatic rollers and Sheepsfoot rollers

Select all the types of recycled manufactured aggregates.

Recycled plastics Blast furnace slag Steel slag pulverized fuel ash Recycled concrete Incinerated sewage sludge Recycled glass

Which of the following are in-place soil unit weight tests?

Sand-cone method ASTM D 2937 Rubber-balloon method Drive cylinder method Nuclear method

________ rocks are formed when mineral particles, fragmented rock particles, and remains of certain organisms are transported by wind, water, and ice and deposited in layers.

Sedimentary

________ rocks form the largest percentage of the rocks on the earth's surface.

Sedimentary

_________ is the water content that is just sufficient to fill the voids when the soil is at the minimum volume it will attain on drying. In other words, the smallest water content at which the soil can be completely saturated.

Shrinkage limit

Select all the factors that affect soil compaction & maximum dry unit weight.

Soil particle shape, Soil specific gravity, Grain-size distribution of soil, Compaction energy/unit volume, Moisture content, Amount & type of clay minerals

Select all the types of shallow foundations.

Strap footing, Raft Foundation, Individual Footing, Continuous Footing, Mat Footing, Combined footing

A soil's bearing capacity can be reduced when the ground water table is at or near the level of the footing.

True

Compaction involves expelling air from the soil and is done during the construction phase; whereas, consolidation involves expelling water from the soil and occurs over months to years.

True

Core borings are used to take rock samples.

True

Edge-lift distortions occur when the perimeter of the foundation is higher than the interior.

True

If water is not drained away from retaining walls then hydrostatic pressure can develop that could destabilize the retaining wall causing it to topple over.

True

In most cases, dry soil can best be compacted if an amount of water is added to the soil.

True

Installing drain pipes around the perimeter is one method of providing permanent dewatering around a foundation.

True

It is customary to cover a boring hole for at least 24 hours with plywood and then to return to record the water level in the boring to determine the ground water table.

True

Monitoring pile penetration resistance can help avoid damage due to overdriving.

True

Shallow foundations are located immediately below the structure that they support.

True

Soils that remain where they were formed near their parent rock are called residual soils.

True

Standard penetration test results are more reliable for cohesionless soils and less reliable for cohesive soils.

True

Sumps are low points from which water is pumped out.

True

Test pits can be used to get undisturbed soil samples

True

The bottom of a structure's foundation should be below the maximum frost penetration depth.

True

Timber piles are limited in length to around 100 feet in most areas of the nation.

True

Transported soil deposits can be classified by the mechanism that transported the soil to the deposit.

True

You can use the number of blows per inch of pile driven to know when to stop driving piles, except if the soil is soft clay or silt.

True

What type of aggregate has a large percentage made up of a small range of grain sizes, a high percentage of voids, and provides excellent drainage for base material?

Uniformly graded aggregate

Weight of known volume aggregate/Volume calibrated container is the equation for what quantity.

Unit weight

Compaction of granular (cohesionless) soils can be best be done by:

Vibratory roller

What type of aggregate is composed of a large range of grain sizes, has excellent interlocking, and very few voids?

Well graded aggregate

Sites with organic deposits or landfills can cause _______________.

a settlement problem, a problem with flammable or toxic gas

Mechanical weathering disintegrates rocks into small particles by: (select all that apply)

abrasion running water rainfall temperature changes ice wind frost action

Chemical weathering causes chemical decomposition of rocks by reactions with: (select all that apply)

acids oxygen salt water

A technique typically used for remediation of foundations that have settled or heaved deferentially.

adding supporting piers or piles

Soil compression is usually a result of the squeezing out of ______ from the soil. (Select all that apply)

air water

Which of the following is not a type of load that the foundation is designed to support.

atmospheric pressure

Heave of expansive clays may occur due to natural environmental conditions or because of ----

concentration of water due to poor drainage

Proper soil compaction increases the soil's _________. (select all that apply)

density shear strength

The ________ is the dividing line between the liquid and solid state.

liquid limit

Disturbed soil samples can be used to do or determine which of the following? (select all that apply)

liquid limit compaction grain-size analysis specific gravity California bearing ratio plastic limit

Alluvial deposits have been transported there by:

moving water

The settlement of piles ending on hard bedrock will generally be -------- ; whereas, the settlement of piles on soft bedrock generally are --------- .

not objectionable, difficult to predict

D60 would indicate that 60% of the soil would ______ a sieve with that size sieve opening.

pass

Uniformly graded soil has a ________ slope when plotted.

steep

A foundation plan red light could be that ______________.

the foundation location differs from the site investigation location. the foundation design is not responsive to the geotechnical report. the foundation plans are not adequate or complete.

Structures located below the groundwater table are subjected to ______ from pore water.

uplift pressure

Drilled shaft settlements on bedrock are generally very small; however, the presence of what at the bottom of the shaft can cause the settlement to increase.

water