pavement design summary and materials ......pavement design summary may 25, 2012 rosemont copper...

PAVEMENT DESIGN SUMMARY AND MATERIALS DESIGN REPORT

ROSEMONT COPPER PROJECT ROSEMONT COPPER T-INTERSECTION

PIMA COUNTY, ARIZONA

PREPARED FOR: P S O M A S

333 East Wetmore Road, Suite 450 Tucson, Arizona 85705

PREPARED BY: Ninyo & Moore

Geotechnical and Environmental Sciences Consultants 1991 East Ajo Way, Suite 145

Tucson, Arizona 85713

May 25, 2012 Project No. 603596001

Pavement Design Summary May 25, 2012 Rosemont Copper T-Intersection Project No. 603596001 Pima County, Arizona

603596001R Pavement rev 2 i

TABLE OF CONTENTS

Page 1. INTRODUCTION ....................................................................................................................1

2. SCOPE OF SERVICES............................................................................................................1

3. SITE DESCRIPTION...............................................................................................................2

4. PROJECT DESCRIPTION ......................................................................................................3

5. DESIGN R-VALUE .................................................................................................................4

6. PAVEMENT DESIGN RECOMMENDATIONS ...................................................................5

7. CHECK OF PAVEMENT DESIGN SECTION ......................................................................6 7.1. Traffic Volumes and Truck Factor Growth Rates ........................................................6 7.2. Resilient Modulus.........................................................................................................6 7.3. Drainage Coefficient.....................................................................................................6 7.4. Serviceability ................................................................................................................7 7.5. Standard Deviation and Level of Reliability ................................................................7 7.6. Modulus of Subgrade Reaction ....................................................................................7 7.7. J Factor..........................................................................................................................7

8. STRUCTURAL NUMBER SUMMARY – AC PAVEMENT................................................7

Tables Table 1 – R-Value Summary ............................................................................................................4 Table 2 – Pavement Section Summary ............................................................................................5 Table 3 – Traffic Loading Summary ................................................................................................6 Table 4 – Structural Number Summary – New AC Pavement Sections ..........................................8

Appendices Appendix A – Materials Design Report Appendix B – DARWin Pavement Analysis Printouts Appendix C – R-value Calculation Spreadsheet Appendix D – ESAL Calculations


603596001R Pavement rev 2 1

1. INTRODUCTION

This report presents the results of our pavement design for the proposed improvements to SR 83,

roughly between Mile Post 46.64 and Mile Post 47.13 in Pima County, Arizona, for the design

and construction of the proposed T-Intersection project. The planned improvement is to construct

a T-Intersection with associated turn and travel lanes. This T-Intersection will provide permanent

access to the Rosemont Copper Project (mine) via a Primary Access Road. Therefore, the

existing SR 83 will need to carry additional heavy truck traffic associated with the mine. The

objectives of this geotechnical evaluation included:

• Evaluation of the existing SR 83 pavement and geotechnical conditions within the project limits,

• Providing recommendations for the new T-Intersection pavement structural sections; and

• Providing recommendations relative to the geotechnical aspects for the planned improvements.

For brevity, this report does not include explanations of field activities, discussion of laboratory

tests performed, or an evaluation of the geological setting and hazards. These items are presented

in the Geotechnical Evaluation Report for this project, which has been submitted separately.

2. SCOPE OF SERVICES

The scope of services for this project generally included:

• Conducting research into previously prepared reports and as-built plans for the SR 83 section under study.

• Preparing a drilling plan and associated permit application for submittal to Arizona Department of Transportation (ADOT) Permits.

• Conducting a field reconnaissance of the project alignment to mark out proposed exploration locations in the field and to visually evaluate the pavement condition. Arizona Blue Stake was notified of the proposed boring locations prior to excavating.

• Arranging for appropriate traffic control measures.

• Performing a field exploration consisting of:



Pavement coring and subgrade soil borings at four (4) locations (C-1 through C-4) on the SR 83 c/oexisting pavement.

Slope borings advanced at nine (9) locations (B-1 through B-9) along the project alignment to depths ranging between 2.5 and 14.8 feet bgs. A Ninyo & Moore employee observed the drilling fieldwork and logged the borings. Each boring was backfilled with drilling spoils. The borings within the existing pavement were patched with cold asphaltic patch. Representative samples were collected in the field and returned to a Ninyo & Moore laboratory for further analysis and testing.

• Conducting laboratory tests of representative samples for developing parameters for pavement design and earthwork factors during construction. Testing generally included in-situ moisture content and dry density, gradation analysis, No. 200 sieve analysis, Atterberg limits, maximum density/optimum moisture relationship, consolidation (response to wetting), R-value, and corrosivity characteristics (including pH, minimum electrical resistivity, soluble sulfates, and chlorides).

• Preparing a Geotechnical Evaluation Report that presents our findings, conclusions, and geotechnical recommendations. This report is provided under separate cover.

• Preparing this Pavement Design Summary and Materials Design Report, presenting new structural pavement sections.

3. SITE DESCRIPTION

The proposed project site is located southeast of Tucson in Pima County, Arizona, on SR 83

roughly between Mile Post 46.64 and Mile Post 47.13 (approximately 11 miles south of Exit 281

on Interstate 10). This reach of SR 83 generally passes through a rural mountainous region

comprised of desert and high desert topography. The average project elevation is 4,486 feet

Mean Sea Level (MSL) with a slope from the west down to the east. A large incised drainage is

present along the east side of the road in this area. Land use within the study limits surrounding

SR 83 is primarily undeveloped. The existing undivided roadway is comprised of one-lane in

each direction of travel, generally in a southwest to northeast direction in the project vicinity.

The cut and fill slopes along the existing SR 83 roadway are up to approximately 15 feet in

relative height and inclination varying typically between 1.5:1 (Horizontal:Vertical) and 3:1, and

flatter. The existing cut slope faces exposed sand and gravel deposits, with variable weak to



moderate cementation. Some signs of surficial erosion were visible; however, the existing slopes

appear to remain generally stable. No evidence of slope instability was observed.

4. PROJECT DESCRIPTION

Rosemont Copper Company (Rosemont) plans to construct a T-Intersection at SR 83 near MP

46.82 with associated turn and travel lanes. This T-Intersection will provide permanent access to

the Rosemont Copper Mine via a Primary Access Road. Therefore, the existing SR 83 will need

to be improved to accommodate the additional lanes and truck traffic associated with the mine.

The existing SR 83 2-lane roadway associated with the new T-intersection project will be

reconstructed within the project limits to include 1) a northbound left turn lane, 2) a southbound

right turn lane, and 3) a merging northbound acceleration lane.

New cuts and fills associated with this project will generally be up to about 15 feet in total height

with 2:1 (H:V) or flatter slopes. In addition, the project will include installation of a cattle guard

on the T-Intersection and the removal and replacement of a corrugated metal pipe (CMP) culvert

at Station 187+00.

It is anticipated that the existing SR 83 pavement will be removed within the project limits. New

pavement structural sections will include a Portland cement concrete (PCCP) and asphaltic

concrete (AC). The PCCP will be utilized approximately 100 to 200 feet north and south of the

T-intersection along SR 83 as well as for the access road turnout to the cattle guard. The AC

pavement will be placed on the remainder of the SR83 project alignment, including the access

road turnout from the cattle guard to the right-of-way boundary. An outside shoulder treatment

will be provided along the PCCP section.

The project will also include a turnout connecting to a Forest Service unpaved roadway and

temporary pavement for traffic control purposes during construction.



5. DESIGN R-VALUE

The subsurface soils encountered in the borings consisted mainly of silty sand, clayey sand, or

clayey gravel. Occasional weak to moderate cementation was also encountered at some

locations. Table 1 below summarizes the laboratory and correlated R-values as measured by

Ninyo & Moore on soil samples obtained within the upper 2.5 to 5 feet below the existing

pavement.

Table 1 – R-Value Summary

Boring No. Approximate Station; Offset

Sample Depth (ft.)

Correlated R-value

LaboratoryR-value

B-3 171+00; 40RT 0-5 26 B-5 176+00; 40RT 0-5 27 B-6 180+00; 40LT 0-5 32 C-1 169+50; 10LT 1-5 46 32 C-2 175+50; 10LT 1-4.4 48 C-3 182+00; 10RT 1-2.5 24 C-4 188+50; 10RT 1-5 62 28

Based on the procedure for calculating the mean R-value outlined in the ADOT Preliminary

Engineering and Design Manual (PEDM), a mean R-value (Rmean) of 30 was calculated. A

calculation spreadsheet, which includes the test results, is included as Appendix C of this report.

For the pavement design, an R-value of 30 was used. For construction control, an R-value of 24

was used. For purposes of construction, it is assumed that soils placed within 3 feet of the

finished roadway subgrade will exhibit a construction control R-value of 24 or more.

In order to provide a relatively consistent subgrade base for construction, it is recommended that

the subgrade soils be scarified to a depth of 10 inches or more, moisture conditioned to a

moisture content generally near the optimum and re-compacted to 95 percent or more relative

compaction, in accordance with ASTM D 698. Subgrade soils should not contain organic matter

and should meet the project specifications as noted in the Geotechnical Evaluation Report dated

April 11, 2012. Subgrade soils within 3 feet of finish subgrade should have a construction control



R-value of 24 or more. Improvement may be needed if the exposed subgrade material does not

meet the requirements of the Subgrade Acceptance Chart provided in the Materials Design

Report (Appendix A).

Unacceptable pavement subgrade soils, if encountered during construction, can be improved by

over excavating the soils to a depth of 3 feet or more below the bottom of the base layer, and

replacing with adequately moisture-conditioned and compacted engineered fill with an R-value

of 24 or more.

6. PAVEMENT DESIGN RECOMMENDATIONS

The following sections present the design parameters and recommendations for new pavements

within the project limits. It is recommended that the pavement sections provided in Table 2 be

used for pavement improvements associated with this project.

Table 2 – Pavement Section Summary

Pavement Section

Cement Treated

Subgrade

AC – Miscellaneous

Structural (Special Mix)

PCCP Fog

Coat

Chip

Seal

Coat

AB-Class 2

Aggregate Subbase-Class 6

Total Thickness

Section No. 1 (AC) - 6 - Yes Yes 5 - 11

Optional Section No. 1 (AC)* 6 4 - Yes Yes 4 - 14

Section No. 2 (PCCP) - - 9 - - 4 - 13

Outside Shoulder Treatment

- - - - - - varies varies

Turnout** - 2 - Yes - 4 - 6

Temporary Pavement*** - 2.5 - - - 5 - 7.5

* Optional pavement structural section, not included in Appendix A – Materials Design Report. **Typical Turnout pavement section to be used for this project. ** *For traffic control purposes.



7. CHECK OF PAVEMENT DESIGN SECTION

The pavement sections recommended above are based on the design R-value, available traffic

count information, and the pavement design procedures outlined in the PEDM. The sections,

tables, or figures referenced by the procedure are included in the PEDM. Printouts of the analysis

performed using DARWin software are presented in Appendix B.

7.1. Traffic Volumes and Truck Factor Growth Rates

The traffic loading data were provided in a letter entitled ESAL Calculations to Support the

Pavement Design Memorandum, prepared by PSOMAS, dated September 15, 2011 (see

Appendix D). The design equivalent single axle loads (ESAL’s) for the pavement design

period is 1,836,447, as provided in the letter. For the temporary pavement, the traffic loading

was assumed based on the 6-month period of operation in the year 2012. For conservatism,

the anticipated ESAL’s were estimated for the Rosemont mine scenario. Table 3 summarizes

the design equivalent single axle loads (ESAL’s) for the roadways under consideration.

Table 3 – Traffic Loading Summary

Roadway Segment Approximate Design ESAL’s

SR 83 1,836,447 Temporary Pavement 40,331

7.2. Resilient Modulus

As discussed previously, a design R-value of 30 was utilized in the analysis of new

pavement sections. Based on an R-value of 30 and a seasonal variation factor of 2.2 taken

from Figure 202.02-1 in the PEDM, a resilient modulus of 11,138 pounds per square inch

(psi) was calculated.

7.3. Drainage Coefficient

A drainage coefficient of 0.92 was obtained from Table 202.02-7 in the PEDM, based on a

seasonal variation factor of 2.2 and fair drainage conditions.



7.4. Serviceability

An initial serviceability of 4.1 and a terminal serviceability of 2.6 were used for the design

of the new pavement sections. The resulting serviceability index loss is 1.5.

7.5. Standard Deviation and Level of Reliability

A standard deviation of 0.25 and 0.35 was used for the design of the PCCP and AC

pavement, respectively. A level of reliability of 90 percent was utilized for the design. A

standard normal deviation (ZR) value of -1.282 was utilized for 90 percent reliability.

7.6. Modulus of Subgrade Reaction

Using the resilient modulus obtained above, and Figures 202.03-1, 202.03-2, and Table

202.03-2, the recommended modulus of subgrade reaction, k, is 230 pounds per cubic inch.

7.7. J Factor

A load transfer coefficient of 3.9, obtained from Table 202.03-1, was utilized in the design of

the PCCP section.

8. STRUCTURAL NUMBER SUMMARY – AC PAVEMENT

In accordance with the AASHTO procedure for flexible pavement design, and using the

parameters presented in Section 7, the minimum needed structural number (SN) for new AC

pavement section was calculated. Table 4 presents a summary of the required and design

structural numbers.



Table 4 – Structural Number Summary – New AC Pavement Sections

Pavement Section Subgrade Minimum Required

Structural Number Structural Number of Recommended Section

Untreated 3.21 3.23 New AC Pavement Section

No. 1 Cement Stabilized 3.21 3.55

Temporary Pavement Untreated 1.66 1.74


603596001R Pavement rev 2

APPENDIX A

MATERIALS DESIGN REPORT



MATERIALS DESIGN REPORT

RE: Rosemont Copper Project Rosemont Copper T-Intersection Sonoita - Mountain View Highway (SR 83) MP 46.64 to 47.13 Pima County, Arizona

Report No.:

Report Type: Final

SECTION I – PAVEMENT STRUCTURE

ITEM 1 – Structural Thickness (in inches)

Pavement Structural

Section Number

Approximate Stations

AB-Class

2

Aggregate Subbase -

Class 6 PCCP Fog

Coat

Chip Seal Coat

AC -Miscellaneous

Structural (Special Mix)

Total Thickness

1. (AC)

SR 83: 165+22 to 170+50 SR 83: 180+00 to 191+30 Access Rd: 19+00 to 19+14

5.0 - - Yes Yes 6.0 11.0

2. (PCCP)

SR 83: 170+50 to 180+00 Access Rd: 19+23 to 19+70

4.0 - 9.0 - - - 13.0

Outside Shoulder Treatment

SR 83: 170+50 to 180+00 Access Rd: 19+23 to 19+70

- Varies - - - - Varies

Turnout SR 83: 181+24 4.0 - - Yes - 2.0 6.0 Temporary Pavement

SR 83: 165+22 to 191+30 5.0 - - - - 2.5 7.5

TYPICAL SECTIONSFIGURE

A-2

file no: 3596sec0412f

NOT TO SCALE

PROJECT NO:

603596001

ROSEMONT COPPER T-INTERSECTIONPIMA COUNTY, ARIZONA

PAVEMENT STRUCTURAL SECTION No. 6SOUTH DETOUR

5” AGGREGATE BASECLASS - 2

MIN 10” OF SCARIFIED,MOISTURE CONDITIONED, AND

RECOMPACTED SUBGRADE

2.5” AC - END PRODUCTSHRP VOLUMETRIC MIX

6

DATE:

5/12






PAVEMENT STRUCTURAL SECTION No. 1


2.5” AC (3/4)FOGCOAT

SUBGRADE


4” PCCP

SUBGRADE


PAVEMENT STRUCTURALSECTION No. 1 OR 2

TYPICAL SECTIONSTA 165+22 TO 173+50STA 176+50 TO 191+30

TYPICAL SECTIONSTA 19+00 TO 19+14

5” AGGREGATE BASECLASS 2

3” AC (MISC STR)

TACK COAT

SUBGRADE

3” AC (MISC STR)

PAVEMENT STRUCTURAL SECTION


TYPICAL SECTIONSTA 173+50 TO 174+20STA 174+20 TO 175+80STA 175+80 TO 176+50


9” PCCP

SUBGRADE

PAVEMENT STRUCTURAL SECTION 2


PAVEMENT STRUCTURAL SECTION 2 OUTSIDE SHOULDER TREATMENT

TYPICAL SECTIONSFIGURE

A-4

file no: 3596sec0412g

NOT TO SCALE

PROJECT NO:

603596001

ROSEMONT COPPER T-INTERSECTIONPIMA COUNTY, ARIZONA






6

DATE:

5/12








2.5” AC (3/4)FOGCOAT

SUBGRADE


4” PCCP

SUBGRADE


PAVEMENT STRUCTURALSECTION No. 1 OR 2




3” AC (MISC STR)

TACK COAT

SUBGRADE

3” AC (MISC STR)

PAVEMENT STRUCTURAL SECTION

Shoulder Buildup


TYPICAL SECTIONSTA 173+50 TO 174+20STA 174+20 TO 175+80STA 175+80 TO 176+50

Shoulder Buildup



SUBGRADE

SHOULDER BUILDUP

TEMPORARY PAVEMENT

E

E

TEMPORARY PAVEMENT

2.5 Inches AC(Misc Str) (Special Mix)

5.0 Inches AB(Class 2)

Subgrade



SECTION II – SUBGRADE, SUBBASES, AND BASES

ITEM 1 – SUBGRADE CONSTRUCTION CONTROL

The attached Subgrade Acceptance Chart shall be used during construction for determining whether subgrade materials are suitable as outlined in Section 203.03 (D) of the ADOT Construction Manual.

ITEM 2 – AGGREGATE BASE (CLASS 2)

The Aggregate Base shall consist of one or more of the following:

1. The Aggregate Base shall be Class 2 and shall be as specified in Section 303 of the Standard Specifications.

2. The Aggregate Base shall be Class 2 and shall be as specified in Section 303 of the Standard Specifications, and Contracts and Specifications Stored Specifications “303SALV.”

The estimated haul distance for the Aggregate Base is 20 miles.

ITEM 3 – AGGREGATE SUBBASE (CLASS 6)

The Aggregate Subbase shall consist of one or more of the following:

1. The Aggregate Subbase shall be Class 6 and shall be as specified in Section 303 of the Standard Specifications.

2. The Aggregate Subbase shall be Class 6 and shall be as specified in Section 303 of the Standard Specifications, and Contracts and Specifications Stored Spec. “303SALV.”

The grading shall be as follows:

Sieve Size % Passing

3” 100 ¼” 45 - 75

#200 0 – 15.0

The plasticity index shall not exceed 5.

The estimated haul distance for the Aggregate Subbase is 20 miles.



SECTION III – SURFACE TREATMENTS AND PAVEMENTS

ITEM 1 – TACK COAT

A tack coat shall be applied as necessary to provide proper bonding prior to the placement of each lift of AC (Miscellaneous Structural – Special Mix) over an underlying bituminous surface, or PCCP surface.

The tack coat shall be as specified in Section 404 of the Standard Specifications and Contracts and Specifications Stored Specifications "404BITUM."

ITEM 2 - PORTLAND CEMENT CONCRETE PAVEMENT

The work under this Item shall consist of furnishing all materials and constructing a Plain Jointed Portland Cement Concrete Pavement as specified in Section 401 of the Standard Specifications, and Contracts and Specifications Stored Specifications "401PCCP" and “1011JMAT”.

ITEM 3 - ASPHALTIC CONCRETE (MISCELLANEOUS STRUCTURAL-SPECIAL

MIX)

The asphaltic concrete shall be as specified in Section 409 of the Standard Specifications, and Contracts and Specification Stored Spec. "409AGGR", with the following exception:

409-2.01 Mineral Aggregate: “Carbonates” and “Note 1” are added to the table:

Mineral Aggregate Characteristics Test Method Requirement

Carbonates (1) Arizona Test Method 238 Maximum 20%

(1): Testing for carbonates only applies if either of the following conditions exist: (a) The asphaltic concrete is the designed final pavement surface normally used by traffic. (b) The asphaltic concrete, temporary or otherwise, will be subject to traffic for more than 60 days.

For estimating purposes, the unit weight of the bituminous mix is 145 pounds per cubic foot.

The asphalt cement type shall be PG 64-22.

The estimated haul distance for the asphaltic concrete is 20 miles.



ITEM 4 – POLYMER CHIP SEAL COAT

The Chip Seal Coat shall be as specified in Section 404 of the Standard Specifications, and

Contracts and Specifications Stored Spec. “404BITUM”, with the following exception.

404-3.14 Chip Seal Coat: the second and third paragraphs of the Standard

Specifications are revised to read:

The type of bituminous material shall be CRS-2P and shall be applied at the approximate

rate of 0.50 gallons per square yard.

Cover material shall be applied at the rate of approximately 0.012 cubic yards per square

yard; however, the Engineer will specify the exact rate to be applied based on the

characteristics of the aggregate material and the surface to be treated.

The gradation of cover material shall meet the requirements for Class 1.

The estimated haul distance for the cover material is 20 miles.

The average elevation of the roadway for this project is 4,486 feet.

ITEM 5 – FOG COAT

The fog coat shall be as specified in Section 404 of the Standard Specifications and Contracts and Specifications Stored Spec. "404BITUM."

The bituminous material shall be SS-1.

The bituminous material shall be applied at a rate of 0.08 gallons per square yard.

The blotter material shall be applied at a total rate of approximately 2 pounds per square yard.

The estimated haul distance for the blotter material is 20 miles.



SECTION IV – MATERIALS SOURCES – GEOTECHNICAL ANALYSIS

ITEM 1 – BORROW REQUIREMENTS (CONTRACTOR-FURNISHED SOURCE)

There is no Department furnished source for borrow on this project. Borrow shall be as specified in Section 203-9 of the Standard Specifications. Borrow placed within three (3) feet of finished subgrade elevation shall meet the following requirements:

The Plasticity Index (PI) (AASHTO T90) and the percent passing the No. 200 Sieve (Minus 200) (Ariz. Test Method 201) when used in the equation below, shall give a value of X that does not exceed 87.

X = (Minus 200) + [2.83 (PI)]

ITEM 2 – MATERIAL SOURCES

Materials sources shall be as specified in Contracts and Specifications Section Stored Specifications “1001MATL” and “104ENVIR”.

ITEM 3 – EARTHWORK FACTORS AND SLOPES

We recommend an earthwork factor of 10 percent shrink. Permanent cut or fill slopes associated with this project should be constructed no steeper than 2:1 (H:V).

ITEM 4 – GROUND COMPACTION

The following ground compaction factors shall be compensated for on embankment sections outside the existing roadway prism.

Station Ground Compaction (ft)

165+22.00 to 191+30.00 0.2

ITEM 5 – EARTHWORK FACTORS AND SLOPES

The following excavation factors and slopes shall be used for the project development.

Station Excavation Factor Slope

165+22.00 to 191+30.00 10% (shrink) 2(H):1(V)



ITEM 6 – PH AND RESISTIVITY

If corrugated metal pipe culverts are to be used, then the type of metal pipe and coating should be determined by the pH and resistivity of in-place materials listed below:

Corrosivity Test Results

Test Location Approximate Station, Offset

Water Soluble Sulfate Content

in Soil, %

Chloride Content,

ppm pH Resistivity

(ohm-cm)

HS-1 187+00; 80RT 0.002 10 7.0 3,488

ITEM 7 – WATER

Approximately 90 gallons of water per cubic yard may be estimated for compaction of embankment materials, and approximately 70 gallons of water per cubic yard for compaction of AB materials.

The application of water estimated for subgrade materials is considerably higher than the amount calculated based upon the difference between in-situ and optimum compaction moisture content, and includes a conservative overrun for losses due to seepage, evaporation, inadequate mixing, spillage, etc. Precipitation during and/or before construction may reduce the required amount of water.



SECTION V – MISCELLANEOUS

ITEM 1 – BITUMINOUS PAVEMENT REMOVAL

The work under this Item consists of removal and disposal of the asphaltic concrete pavement material as specified in Section 202 of the Standard Specifications.

ITEM 3 – DISPOSAL OF EXISTING ASPHALTIC CONCRETE

Upon removal, disposal of the existing asphaltic concrete shall be the responsibility of the contractor.

ITEM 4 – TEMPORARY CONNECTIONS AND DETOURS

The temporary surfacing shall consist of 2.5 inches of AC (Miscellaneous Structural – Special Mix) placed over 5 inches of Aggregate Base (Class 2).

At a time specified by the Engineer, the bituminous surfacing and the base material shall be broken up, picked up separately, and stockpiled individually at sites designated by the Engineer. The remaining detour roadways shall be removed, and the natural subgrade shall be restored as nearly as practicable to the condition existing prior to the construction of the detour.

No measurements for payment will be made for the work of removing the detours and stockpiling the material, the cost being considered as included in the cost of the contract items.



PRELIMINARY PAVEMENT STRUCTURE COST ESTIMATE

ITEM NO. ITEM DESCRIPTION UNIT QNTY UNIT PRICE ($) AMOUNT($)

3030022 Aggregate Base, Class 2 CY 2,755 50 137,750

3030026 Aggregate Subbase, Class 6 CY 318 70 22,260

4010009 Portland Cement Concrete Pavement (9”) SY 4,912 65 319,280

4040073 Emulsified Asphalt (CRS-2P) Ton 13 1,000 13,000

4040125 Fog Coat Ton 1 1,500 1,500

4040162 Cover Material CY 77 80 6,160

4040163 Blotter Material Ton 3 50 150

4090006 AC (Miscellaneous Structural) (Special Mix) Ton 4,310 90 387,900

TOTAL 888,000



APPENDIX B

DARWIN PAVEMENT ANALYSIS PRINTOUTS



APPENDIX C

R-VALUE CALCULATION SPREADSHEET

ROSEMONT COPPER T-INTERSECTION,PIMA COUNTY

AASHTO FLEXIBLE PAVEMENT CALCULATIONS

Project Name: Rosemont Copper T_IntersectionProject Number: 603596001

Date: 3/29/12Calculations by: MJK

Mean R-Value CalculationEquations: Rm=[Nt*Rt*SDc

2+NcRcSDt2]/(Nt*SDc

2+NcSDt2)

Rc= 10(2.0-0.006(%pass)-0.017(PI))

MR=1815+225*(Rm)+2.4(Rm)2/0.6(SVF)0.6

SVF= from Table 202.02-4

Nt=number of measured R-valuesNc=number of correlated R-valuesRt=adjusted average of the measured valuesRc=adjusted average of the correlated valuesSDt=std deviation of the measured valuesSDc=std deviation of the correlated values

Boring Depth %pass#200 PI Rc RtC-1 2 22 12 46 32C-2 2 22 11 48C-3 2 39 23 24C-4 2 20 5 62 28B-3 3 32 23 26B-5 3 25 25 27B-6 3 22 21 32

SVF = 2.2 avg 33 30count 7 2sd 14.52 2.83

R-value 30 Construction Control R-value

Degrees of freedom= 6Critical t value= 1.44 (from Table 202.02-5)

Design R-value 30 Std Dev Rc= 14.52Design Mr 11,138 Rc min= 24

Ninyo & Moore, Project #603596001; 4/11/2012 Page 1



APPENDIX D

ESAL CALCULATIONS to Support the Pavement Design Memorandum, SR83 T-Intersection at Rosemont Mine

Entrance, Psomas #7ROS110110

P S O M A S

September 15, 2011

Marek J. Kasztalski, PE, PMP, LEED AP

Senior Geotechnical Engineer

Ninyo & Moore

1991 East Ajo Way, Suite 145

Tucson, Arizona 85713

Re: ESAL Calculations to Support the Pavement Design Memorandum

SR83 T-Intersection at Rosemont Mine Entrance

Psomas #7ROS110101

Dear Mr. Kasztalski:

Pursuant to recent discussions and data review, Rosemont Copper has requested that some

additional information be included in order to revise the preliminary pavement report to be used

as part of the SR 83 T-intersection project. This letter provides the Equivalent single Axel Loads

(ESAL) values to be used for that analysis, as well as the justification for the Average Daily

Traffic (ADT) volumes, vehicle distribution and methodology used in developing the ESALs.

Traffic Volumes (ADT and projections)

Traffic Volumes were obtained from the Traffic Impact Analysis Report, Rosemont Primary

Access Road Intersection Project prepared by Tetra Tech in April 4, 2011. Using the K factor of

12% indicated in Section 1.3 of the report, and the peak volumes (without the project) from the

peak season HCS Segment reports, the current ADT is 2,467 (296/0.12). This volume is

consistent with historic ADOT counts, except the 2009 which showed a significantly lower

volume. That lower volume could have been due to construction activities or other factors.

Using the same methodology, the 2030 ADT without the project is projected as 4,175 (501/0.12).

The truck traffic from Rosemont is expected to be 88 roundtrips per day.

Vehicle Classification

The Traffic Impact Analysis Report, Rosemont Primary Access Road Intersection Project has

conflicting information in this area. While the text in Section 1.3 mentions that trucks and buses

make up 6-12% of the traffic, Illustration 1.1 shows only 3.6% trucks and buses. ADOT data

(http://mpd.azdot.gov/mpd/data/Reports/PDF/SHSKDTFactorTable.pdf) indicates a truck factor

of 11% in 2008 and 12% in 2009. The 2009 truck factor breaks down into 6% single trucks

(buses and medium trucks), and 6% Combo trucks (TS, TT, TST). Given the inconsistencies in

the traffic report, the 2009 ADOT truck factors will be used in the analysis. The remaining

vehicles (88%) were evenly split between autos and light trucks.


Page 2

09/14/11

P S O M A S

Methodology

Given that the specific breakdown of TS, TT and TST vehicle types is not available, the

approximation method described in page 174 of the ADOT Materials Preliminary Engineering

and Design Manual was used. This is also consistent with a preliminary analysis prepared by

ADOT (SR83 Overlay.doc) received from Rosemont on 8/24/2011. The loads of the existing

combo trucks on SR83 were estimated to be Medium loads (similar to those on a US Highway),

which results in an ESAL factor of 1.0. the new trucks from Rosemont were estimated to be

Heavy loads (similar to those on Interstate highways), which results in an ESAL factor of 1.2.

The ESAL factors for autos, light trucks and medium trucks are 0.0008, 0.01, and 0.4,

respectively

The following table presents the anticipated ESAL loads with and without the Rosemont mine

resulting from the methodology described above

Vehicle Autos LT

Single

Truck (MT

& Buses)

Combo Trucks

(TS, TT, TST) -

Medium Load

ESALs

without

Rosemont

Rosemont

Combo Trucks

Heavy Load

ESALs with

Rosemont

ESAL 0.0008 0.01 0.40 1.00 1.20

% of traffic 44% 44% 6% 6%

Year 2-Way ADT

2010 2,467

2011 2,533 1,114 1,114 152 152 82,047 176 159,135

2012 2,600 1,144 1,144 156 156 84,234 176 161,322

2013 2,670 1,175 1,175 160 160 86,480 176 163,568

2014 2,741 1,206 1,206 164 164 88,785 176 165,873

2015 2,814 1,238 1,238 169 169 91,151 176 168,239

2016 2,889 1,271 1,271 173 173 93,581 176 170,669

2017 2,966 1,305 1,305 178 178 96,075 176 173,163

2018 3,045 1,340 1,340 183 183 98,636 176 175,724

2019 3,126 1,375 1,375 188 188 101,265 176 178,353

2020 3,209 1,412 1,412 193 193 103,964 176 181,052

2021 3,295 1,450 1,450 198 198 106,735 176 183,823

2022 3,383 1,488 1,488 203 203 109,580 176 186,668

2023 3,473 1,528 1,528 208 208 112,501 176 189,589

2024 3,565 1,569 1,569 214 214 115,500 176 192,588

2025 3,660 1,611 1,611 220 220 118,578 176 195,666

2026 3,758 1,654 1,654 225 225 121,739 176 198,827

2027 3,858 1,698 1,698 231 231 124,984 176 202,072

2028 3,961 1,743 1,743 238 238 128,315 176 205,403

2029 4,067 1,789 1,789 244 244 131,736 176 208,824

2030 4,175 1,837 1,837 251 251 135,247 176 212,335

Two-Way ESALs 2,131,134 3,672,894

% in Design Lane 50% 50%

Design ESALs 1,065,567 1,836,447


Page 3

09/14/11

P S O M A S

If you have any questions regarding this evaluation, please contact me at (520) 292-2300 or via

e-mail at [email protected].

Sincerely,

Alejandro Angel, PhD, P.E., PTOE

Traffic Engineering Manager

[email protected]

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