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