Arizona ROC R-2 Excavating, Grading and Oil Surfacing Examination

A residential building site requires removing 1,500 bank cubic yards (BCY) of dense clay during basement excavation. If the clay has a verified swell factor of 25%, what total loose volume in loose cubic yards (LCY) must be hauled away by dump trucks?

• A1,875 LCY
• B1,500 LCY
• C1,200 LCY
• D1,800 LCY

A contractor must place 2,500 compacted cubic yards (CCY) of structural embankment fill for a residential access road. The borrow pit soil has a shrinkage factor of 15% relative to bank measure and a swell factor of 20% from bank to loose measure. How many loose cubic yards (LCY) of borrow soil must be hauled to the site?

• A3,529 LCY
• B2,941 LCY
• C3,000 LCY
• D2,125 LCY

An excavation contractor needs to haul 2,000 bank cubic yards (BCY) of silt loam (swell factor 15%) from a residential subdivision. If each dump truck has a legal payload capacity of 14 loose cubic yards (LCY), how many total truck trips are required?

• A165 trips
• B143 trips
• C131 trips
• D172 trips

Using the Average End Area method, calculate the cut volume between Station 10+00 (cut end area = 150 sq ft) and Station 11+00 (cut end area = 210 sq ft), spaced 100 feet apart.

• A667 BCY
• B1,333 BCY
• C400 BCY
• D800 BCY

A 100 ft by 100 ft grid square on a residential lot requires excavation. The cut depths at the four grid corners are 1.2 ft, 1.8 ft, 2.4 ft, and 1.6 ft. What is the total volume of excavated soil from this grid square?

• A648 BCY
• B1,750 BCY
• C259 BCY
• D700 BCY

Which set of test specifications correctly defines the Standard Proctor Compaction Test (ASTM D698)?

• A5.5 lb rammer, 12-inch drop height, 3 soil layers, 25 blows per layer in a 4-inch mold
• B10 lb rammer, 18-inch drop height, 5 soil layers, 25 blows per layer in a 4-inch mold
• C5.5 lb rammer, 18-inch drop height, 5 soil layers, 56 blows per layer in a 6-inch mold
• D10 lb rammer, 12-inch drop height, 3 soil layers, 56 blows per layer in a 4-inch mold

What is the primary difference in compaction energy between the Modified Proctor Test (ASTM D1557) and the Standard Proctor Test (ASTM D698)?

• AModified Proctor applies approximately 56,250 ft-lbf/ft³, which is about 4.5 times greate…
• BModified Proctor applies 12,400 ft-lbf/ft³, which is about half the energy of Standard Pr…
• CModified Proctor uses the same hammer weight and drop height but requires 50 blows per la…
• DStandard Proctor applies higher compaction energy to simulate heavy airfields, whereas Mo…

When compacting a cohesive clay subgrade for a residential foundation pad, what occurs if the soil moisture content is significantly dry of optimum (OMC)?

• AHigh initial strength is achieved, but the soil is vulnerable to major post-construction…
• BThe dry density reaches its maximum possible value regardless of compaction effort
• CThe soil becomes completely impervious to water infiltration
• DPumping and rutting occur immediately under the compactor wheels

When using a Nuclear Density Gauge (ASTM D6938) to measure in-place soil density, why is Direct Transmission mode preferred over Backscatter mode for subgrade testing?

• ADirect transmission measures density through the entire layer depth up to 12 inches, redu…
• BBackscatter mode requires drilling a probe hole, whereas direct transmission rests purely…
• CDirect transmission mode measures soil moisture content only, while backscatter measures…
• DBackscatter mode cannot be used on clay soils due to gamma ray absorption

In a Sand Cone Test (ASTM D1556) conducted on a compacted aggregate base course, how is the volume of the excavated test hole determined?

• ABy filling the hole with standardized Ottawa sand of known bulk density and measuring the…
• BBy measuring the dimensions of the excavated hole using a calibrated micrometer depth gau…
• CBy pouring water directly into the excavated test hole and reading the volume on a gradua…
• DBy weighing the excavated soil and multiplying by the soil's specific gravity

Under the Unified Soil Classification System (USCS), a coarse-grained soil is classified as Well-Graded Gravel (GW) if it meets which particle size distribution criteria?

• AMore than 50% retained on #4 sieve, less than 5% fines passing #200 sieve, Cu ≥ 4, and 1…
• BMore than 50% passing #200 sieve, Liquid Limit < 50, and Plasticity Index > 7
• CMore than 50% passing #4 sieve, Cu < 4, and Cc > 3
• D100% passing 3-inch sieve, 50% passing #40 sieve, and Plasticity Index < 4

In the USCS soil classification system, what metric separates high-plasticity fine-grained soils (CH, MH) from low-plasticity fine-grained soils (CL, ML)?

• ALiquid Limit (LL) of 50%
• BPlasticity Index (PI) of 25%
• CPlastic Limit (PL) of 30%
• DMoisture Content of 15%

A soil sample tested in a geotechnical laboratory yields a Liquid Limit (LL) of 44% and a Plastic Limit (PL) of 18%. What is the Plasticity Index (PI) of this soil?

• A26%
• B62%
• C2.44
• D36%

According to ASTM D4318, how is the Plastic Limit (PL) of a soil specimen determined in the laboratory?

• AIt is the moisture content at which a soil thread crumbles when hand-rolled to a diameter…
• BIt is the moisture content at which a soil groove closes for 1/2 inch after 25 blows in a…
• CIt is the moisture content at which soil transitions from a solid to a liquid slurry unde…
• DIt is the dry density achieved after 50 blows of a Standard Proctor rammer

Which type of compaction equipment is most effective for compacting heavy cohesive clay soils on a residential embankment fill?

• ASheepsfoot (tamping foot) roller
• BSmooth drum non-vibratory roller
• CHigh-frequency smooth drum vibratory roller
• DHeavy steel tandem static roller

When compacting clean cohesionless sand or crushed aggregate base for a residential driveway, which compactor yields maximum density?

• AVibratory smooth drum roller
• BSheepsfoot roller
• CGrid roller
• DManual pneumatic tamper

What operational advantage does a self-propelled pneumatic-tired (rubber-tired) roller offer when compacting subgrade soils?

• AIts flexible rubber tires exert uniform kneaded contact pressure that seals surface voids…
• BIt provides high-impact impact forces capable of breaking rock outcroppings
• CIt compacts lift thicknesses up to 24 inches in a single pass
• DIt operates at high speeds above 25 mph while maintaining 100% density

Which compacting tool is specifically engineered for achieving required density in narrow trench excavations around residential utility lines?

• AGasoline-powered tamping rammer (jumping jack)
• B30-ton vibratory smooth drum roller
• CTow-behind grid roller
• D5-ton static steel roller

What is the standard maximum loose lift thickness specified for engineered soil backfill placed beneath residential structural footings?

• A6 to 8 inches
• B18 to 24 inches
• C2 to 3 feet
• D12 to 16 inches

When building a residential slab-on-grade over highly expansive clay soil, what standard geotechnical earthwork remediation is commonly executed?

• AOver-excavating 2 to 4 feet of expansive soil and replacing it with moisture-conditioned…
• BWetting the clay until it becomes a liquid slurry to eliminate air voids
• CCompacting the top 2 inches of clay with a 1-ton plate compactor
• DCovering the expansive clay with a thin plastic sheet without excavation

How does chemical lime stabilization improve high-plasticity clay soils during subgrade preparation?

• ALime reduces the Plasticity Index (PI), increases workability, and causes long-term pozzo…
• BLime dissolves the clay minerals to transform the soil into clean coarse sand
• CLime acts as a lubricant to allow soil compaction at zero moisture content
• DLime neutralizes soil pH to prevent root growth under asphalt

For which type of subgrade soil is Portland cement stabilization most effective?

• AGranular coarse-grained sands, gravels, and low-plasticity silty soils
• BHighly plastic fat clays with PI greater than 40
• COrganic peats and topsoils containing heavy vegetation
• DSaturated quicksand deposits below the groundwater table

Why is flake calcium chloride frequently applied to unpaved residential site access roads and haul paths?

• AIt is hygroscopic and absorbs moisture from the air, binding soil fines and suppressing f…
• BIt acts as a permanent waterproofing sealant equivalent to hot-mix asphalt
• CIt accelerates grass seed germination along road shoulders
• DIt softens subgrade rock to allow scrapers to grade without rippers

Per standard residential building codes (IRC/IBC), what is the minimum required slope for ground surface drainage away from exterior foundation walls?

• AMinimum 5% slope (6 inches drop within the first 10 feet)
• BMinimum 1% slope (1 inch drop within the first 10 feet)
• CMinimum 10% slope (12 inches drop within the first 5 feet)
• DNo slope requirement if gutters and downspouts are installed

To prevent standing water and sediment accumulation in a grass-lined residential drainage swale, what minimum longitudinal slope should be maintained?

• AMinimum 2%
• BMinimum 0.1%
• CMinimum 10%
• DExact 0.0% level

What are 'blue tops' used for during final motor grader operations on a residential subdivision street subgrade?

• AWooden grade stakes driven so their tops represent the exact finished subgrade elevation,…
• BBlue plastic cones placed to mark underground fiber optic lines
• CWater elevation markers placed inside catch basins
• DSurvey monuments marking property corners

What is the standard crown cross-slope applied to a residential gravel driveway or subgrade to shed surface water?

• A2% to 4% sloping downward from the road centerline to the shoulders
• B10% to 15% sloping toward the high side of the lot
• C0% flat cross-section across the entire width
• D1% slope toward the road centerline

When installing a perforated PVC drainage pipe in a gravel-filled trench for a basement foundation drain (French drain), how should the perforations be oriented?

• AFacing DOWNward toward the trench bedding
• BFacing UPward toward the ground surface
• CFacing horizontally toward the foundation wall
• DAlternating upward and downward every 3 feet

What primary functional purpose does permeable non-woven geotextile fabric serve when lining a subsurface trench drain?

• AIt acts as a filter to prevent surrounding soil fines from entering and clogging the drai…
• BIt provides structural tensile reinforcement to hold the foundation wall upright
• CIt seals the trench to prevent groundwater from entering the drain pipe
• DIt chemical neutralizes acidic groundwater before discharge

Before backfilling against a newly poured residential concrete basement wall, what critical structural precaution must be satisfied?

• AThe concrete must achieve specified design strength and floor framing/bracing must be ins…
• BThe backfill soil must be saturated with water to lubricate the wall surface
• CThe wall must be sprayed with lime slurry to harden the concrete surface
• DBackfilling should occur within 24 hours of pouring forms while concrete is soft

To function correctly as a sediment barrier, how must the bottom edge of a synthetic silt fence fabric be installed?

• AEntrenched in a 6-inch deep trench facing uphill, backfilled and compacted (toe-in)
• BLaid flat on top of the un-excavated grass with wooden stakes driven through the fabric
• CSuspended 2 inches above ground level to allow stormwater runoff to pass underneath
• DFolded double over the top support wire without ground contact

Where and how should straw wattles (fiber rolls) be placed on a newly graded residential slope to control erosion?

• AAlong slope contours perpendicular to runoff flow, entrenched 3 to 5 inches into shallow…
• BParallel to slope contours running straight up and down the hill
• CAt the peak of the hill above the grade break only
• DFlat on paved driveways at the site entrance

What is the primary function of temporary rock check dams placed in unlined residential site drainage ditches?

• ATo reduce flow velocity, dissipate hydraulic energy, and trap coarse sediment
• BTo permanently impound water for residential irrigation ponds
• CTo filter dissolved chemical pollutants from site runoff
• DTo increase water velocity to scour out the ditch bottom

During subgrade inspection for a residential street, what indicator signifies subgrade failure during a proof roll test with a loaded 10-ton dump truck?

• AVisible rutting, deep deflection, or soil pumping under the truck tires
• BDust rising from the aggregate surface
• CTire tread imprints less than 1/4 inch deep
• DSlight squeaking from the truck suspension springs

What soil condition causes 'pumping' (elastic waving and shearing) under heavy compaction equipment during subgrade preparation?

• AHigh moisture content near or above saturation in fine-grained silty/clayey soils
• BExcessive compaction of clean dry gravel
• CLow ambient humidity during roller operation
• DPresence of angular crushed granite aggregate

Why must organic topsoil be stripped and stockpiled separately prior to commencing mass excavation on a building site?

• AOrganic material decomposes over time, causing severe structural settlement if incorporat…
• BTopsoil contains natural concrete retarders that destroy foundation strength
• CTopsoil expands by 300% when exposed to sunlight
• DFederal law requires all topsoil to be shipped off-site to landfills

When placing structural fill on an existing natural hillside with a slope steeper than 5:1 (horizontal to vertical), what earthwork technique is required?

• ABenching horizontal steps into competent material across the slope as fill progresses upw…
• BDumping loose fill from the top of the ridge until it reaches its natural angle of repose
• CInstalling vertical timber retaining walls every 2 feet up the slope
• DSpraying the hillside with liquid asphalt before dumping fill

Why does a motor grader operator lean the front wheels toward the direction material is drifting off the moldboard?

• ATo counteract the side-draft thrust created by the angled blade loading
• BTo increase grader travel speed by 15 mph
• CTo reduce engine fuel consumption during fine grading
• DTo lift the rear tandem drive wheels off the ground

What operational advantage does 'slot dozing' provide during mass earthmoving operations with a crawler tractor?

• AIt utilizes side windrows from prior passes to reduce blade spillage, increasing load vol…
• BIt allows the bulldozer to dig 20 feet deep without track slippage
• CIt eliminates the need for soil compaction testing after grading
• DIt automatically grades subgrade to within 1/16 inch accuracy without GPS controls

When estimating hydraulic excavator production in moist loam or clay, why can the bucket fill factor equal or exceed 100% of heaped rating?

• ACohesive soils heap above the side plates and stick together, creating a crowned bucket l…
• BLoose dry sand expands inside the bucket due to air suction
• CExcavator buckets shrink by 20% when exposed to hydraulic fluid pressure
• DGeotechnical standards require all bucket loads to be weighed before swinging

What is the primary objective of push-loading single-engine wheel tractor scrapers with a crawler dozer in the cut zone?

• ATo assist the scraper in filling its bowl rapidly in dense soils, reducing loading time a…
• BTo steer the scraper down the haul road to the dump area
• CTo compact the cut floor to 100% Modified Proctor density while loading
• DTo scrape topsoil off the scraper tires during travel

What does the term 'angle of repose' describe when stockpiling loose aggregate or soil on a jobsite?

• AThe maximum angle relative to horizontal at which loose unconfined material naturally rem…
• BThe angle of the excavator boom when digging at maximum depth
• CThe slope angle of a concrete foundation footing notch
• DThe angle of inclination of a conveyor belt drive motor

A soil lift containing 500 compacted cubic yards (CCY) of dry soil weighs 110 lbs/cu ft dry density. Geotechnical specs require raising the moisture content from 8% to 12% to reach OMC. How many gallons of water must be added and thoroughly mixed into this lift? (Water weighs 8.34 lbs/gal)

• A7,122 gallons
• B264 gallons
• C21,367 gallons
• D3,560 gallons

In the Rubber Balloon Method (ASTM D2167) for in-place soil density testing, how is the volume of the excavated test hole measured?

• AA liquid-filled flexible rubber membrane is forced into the test hole under pressure, and…
• BAir pressure is pumped into the hole until the soil wall yields
• CThe hole is filled with glass beads of unknown density
• DA laser scanner measures surface light reflections inside the hole

A structural fill specification requires 95% relative compaction per Modified Proctor (ASTM D1557). If the laboratory Maximum Dry Density (MDD) is 122.0 pcf, what is the minimum acceptable field dry density?

• A115.9 pcf
• B122.0 pcf
• C110.0 pcf
• D118.5 pcf

What does a California Bearing Ratio (CBR) laboratory test evaluate for pavement subgrade materials?

• AThe relative mechanical strength and shearing resistance of soil compared to standard cru…
• BThe total chemical salt concentration in soil pore water
• CThe rate of capillary water rise through fine silts
• DThe exact percentage of organic matter in topsoil

On an earthwork mass haul diagram, what condition is represented where the cumulative volume curve intersects a horizontal balance line?

• AExcavation (cut) volume exactly equals embankment (fill) volume between those stations
• BThe haul distance has exceeded 5 miles
• CThe equipment fleet has reached zero fuel status
• DThe grade change transitions from positive 10% to negative 10%