CNST 241 exam 2

A sheepsfoot roller is better at compacting non-cohesive material than cohesive materials

False

rolling resistance is a major component of determining total resistance for tracked vehicles

False

OCM stands for _________________, when discussing the relationship between soil density and moisture content

Optimum Moisture Content

___________ roller is best suited for compaction of asphalt for pavement

Pnenmatiztird

a grade of _________% is equivalent to a rolling reistance of 20lbs/ton

1

a grade of ________% is equivalent to a rolling resistance of 60 lbs/ton

3%

the decrease in power for piece of equipment operating at an elevation of 2,000' above sea level instead of 1,000" is _________%

3%

When a building experiences differential settlement that causes building damage, often times the cracks on the wall will be observed at _________________ degrees to the direction the building is settling.

45

sandy material being placed for compaction under a building pad is typically placed in lifts that are no greater than

8" in depth

As the operating gear of a piece of equipment increases, the available power of that machine will also increase.

false

Clay and silt are considered to be non-cohesive soils.

false

Compacting a material to 95% of it's standard Proctor maximum dry density take more compactive effort than if you are required to compact it to 95% of it's modified Proctor maximum dry density.

false

Constructing a structurally supported concrete slab is typically more cost effective than a concrete slab on grade.

false

Silt and clay are considered to be granular materials.

false

The geotechnical engineer is ultimately responsible for the complete design of the foundation system for a proposed building.

false

As the coefficient of traction increases the maximum usable tractive force will _____________________ .

increase

As the thickness of a lift of soil material being placed and compacted increases the amount of compactive effort that needs to be applied to the material being placed must _______________________ in order to achieve the desired compaction %.

increase

As the coefficient of traction increases the maximum usable tractive force will _____________________ .

increases

what type of compactors are best used for backfilling foundations due to their small size?

remote operated and plate/jumping jacks

Placing a concrete slab on grade over soil material is one method that reduces seasonal moisture change in the soil.

true

The load factor is used to calculate the how much a soil sample will _____________________ when it is changes between loose and bank conditions.

true

Vibratory compactors are best used on non-cohesive soil materials.

true

as the weight in the drive wheels is increased for a wheeled piece of equipment the maximum usable tractive force

Increase

The ZAV line on moisture density curve represents the condition where a soil sample would not contain any of the following: (select the single best answer)

air

You are bidding a warehouse project for an owner that owns a large industrial park. The warehouse site is short, but the owner has a location on site where you can obtain material. This location is commonly referred to as a ______________ pit. (one word, lowercase, spelled correctly)

borrow

Void form is a construction material that is used to form concrete. Void forms are made from ________________ .

cardboard

Which soil material type typically will undergo the greatest volume change when moved between bank, loose, and compacted conditions on a project site?

clay

Which soil particle is the smallest in diameter?

clay

What type of settlement typically will cause the most damage to a building structure?

differential

the two main components of required to compact soil material are

effort and moisture

Refer to the boring log. What does the symbol that consists of a horizontal line and an upside down triangle represent?

elevation of groundwater

You are backfilling a utility trench with a sandy clay material. Which type of compactor will typically result in completing the backfill operation in the shortest amount of time, while still achieving the required compaction.

excavator mounted compactor wheel

When a drill rig is on site completing borings the elevation of the top of the boring will be the same as the ____________________ grades of the site.

existing

A CY of soil material in its bank condition weighs less than a CY of the same soil that has been placed as fill with compactive effort on a project site.

false

You are compacting fill material that is being placed under a building pad using a tamping foot roller. As you make multiple passes over the material being compacted you would expect the tamping feet to penetrate deeper in the surface of the fill material with each pass of the compactor.

false

a smooth drum vibratory roller will typically travel at a faster speed while compacting a material than a tamping foot roller

false

at the weight on drive wheels is increased for a wheeled piece of equipment the maximum usable tractive force decreases

false

consolidation is a faster method than compaction to increase the dry density of a soil material

false

generally, a wet surface has a higher coefficient of traction than a dry surface

false

placing aggregate base for a building slab

false

What party is typically responsible for designing the concrete and pavement thickness on a project site?

geotechnical engineer

Structural fill typically consists of which type of soil particles?

gravel

largest to smallest

gravel, sand, silt, clay

When over-excavating and recompacting expansive clay material under a building pad the material needs to be compacted at a moisture content that is ______________________ the optimum moisture content.

greater than

A contractor is compacting a material that has a moisture content greater than the optimum moisture content and they are having a difficult time meeting the compaction requirements. Which of the following reasons could keep the material from obtaining it's maximum dry density since it is over the OMC?

high water pressure between particles

What type of compactor can also effectively be used to demolish existing roadways?

impact roller

You are looking at the plans for a project site and completed a quantity takeoff on the amount of material that will need to be moved on this project. Your calculations indicate that the site will require 300,000 CY of material to be cut and 500,000 CY of material to be placed as fill. Based on these numbers, the site is an ______________________________ condition.

import

You are placing fill on a project site. In which state does a CY of soil weigh the least?

loose

topsoil typically cannot be used as fill under building pads due to the high amount of_____________

organics

Who typically will request a geotechnical report and who will typically be responsible for paying for the report?

owner

Which of the following design recommendations are typically contained in a geotechnical report

pavements exterior flatwork foundation

In which construction operation would you expect smooth drum vibratory roller to be utilized?

placing aggregate base for a building slab

What type of rollers are typically used to compact asphalt during road construction

pneumatic tired smooth drum

You are reviewing the results of the soils test for three different samples. The results are as follows: Sample No. 1 - Liquid Limit = 45, Plastic Limit = 18 Sample No. 2 - Liquid Limit = 35, Plastic Limit = 20 Sample No. 3 - Liquid Limit = 40, Plastic Limit = 24 Which sample has greatest capacity of volume change when exposed to moisture?

sample 1

Which type of compactor will create the largest disturbance in the top few inches of the material being compacted

sheep foot

compaction roller best for clay material

sheepsfoot

If the available power for a piece of wheeled equipment is larger than the maximum tractive force available, the wheels will _______________ when available power is applied

slip

If the available power of a piece of equipment is greater than the maximum useable tractive force the wheels of a piece of equipment will _______________ when the throttle is applied.

slip

As the thickness of a lift of soil material being placed and compacted increases the amount of compactive effort that needs to be applied to the material being placed must _______________________ in order to achieve the desired compaction %.

slower

A geotechnical report will often provide the bearing capacity of the onsite material so that the foundations can be designed correctly. The bearing capacity is typically indicated as a value of pounds per _______________ that the soil can withstand.

square foot

The load factor is used to calculate the how much a soil sample will _____________________ when it is changes between loose and bank conditions.

swell

The coefficient of traction for a two-wheel drive vehicle is ________________________ the coefficient of traction for four-wheel drive vehicle.

the same as

The leaning tower of Pisa is a famous example of soil settlement. Which of the following type of settlement has the tower experienced? (select the single best answer)

tipping

A geotechnical engineering takes sample of material for project site they are working and completes lab tests. The wet unit weight of the soil sample will be greater than the dry unit weight of the same sample.

true

A sample of claystone with a SPT resistance value of 50/6 is harder than a claystone sample with a SPT resistance value of 50/9

true

As the operating gear of a piece of equipment increases, the available power of that machine will also increase.

true

You are a general contractor bidding an earthwork project and the bid instructions state that you will "accept the site as an unclassified site." This means that you will be responsible to for handling any material that is found on that site, even if it is not indicated in the geotech report or any of the contract documents.

true

a piece of equipment could experience a positive effective grade(total resistance) while it is driving downhill on a slope

true

compacting a sand material to 95% of a standard proctor maximum density takes less effort than compacting a sand material to 100% of a modified proctor maximum density.

true

rimpull performance charts can be used when a haul road grade us negative downhill, but the total resistance expressed at a grade % is positive

true

soil cement is typically used to stabilize granular material while lime stabilization is typically used to stabilize cohesive materials

true

the total resistnace that a piece of equipment is exposed to in a construction site is comprised of rolling resistance and grade resistance

true

When 1 CY soil is excavated on a project site and changes from a bank condition to a loose condition, which of the following changes volume.

volume of void space, volume of water

If the available power of a piece of equipment is greater than the maximum useable tractive force the wheels of a piece of equipment will _______________ when the throttle is applied.

will move forward

if the available power for a piece of wheeled equipment is less than the required power needed to overcome the total resistance, the wheels _____________ when the available power is abled

won't move