MT Learning Center - Infrastructure Upgrade - Add. #1

CASNE & ASSOCIATES, INC.
ADDENDUM #1
Montana Learning Center
Infrastructure Improvements - 2026
November 3, 2026
General Civil:
1. Geotech Report is attached.
2. Pulverization of existing asphalt and base is permissible. With moisture conditioning,
created product (50/50 blend) can be used as initial layer of the Crushed Base Course
section. Pulverization is not a requirement. See revised Bid Proposal (Bid Item #208),
Measurement and Payment section, and Special Provisions (Article 11 and Article 17).
3. 2nd layer of the Crushed Base Course must be virgin material. See revised Bid Proposal (Bid
Item #211), Measurement and Payment section, and Special Provisions (Article 11).
4. Sidewalk in front of dumpster pad must be 6" depth. See revised Bid Proposal (Bid Item
#215), and Measurement and Payment section.
5. Details now include a Dumpster Pad detail. See revised plan sheet RD1. Unit of Measure is
Lump Sum (LS). See revised Measurement and Payment section.
6. Bid Item #217 quantity increased to 300SF.
7. Bid Item #109 description has been modified.
8. Bid Item #110 description has been modified. The DEQ had concerns with the original 2"
blowoffs. 34" frost-free yard hydrants are now required. See revised detail sheet.
9. Bid Item #115 description has been modified. See revised sheet WD2.
10. Coordinate with Bureau of Reclamation regarding possible weight/length/width restrictions
on Canyon Ferry Dam. Refer to Special Provision Article 18 for information recently
received from Dustin Ramoie and the Canyon Ferry Field Office.
11. If a Contractor/Bidder/Plumber needs to see the inside basement of any building, please
contact the MLC Maintenance Manager, Chris Gillette at 406.599.1720 to setup an appt.
Please provide 24-48 hours notice.
12. A transmittable CAD file is not available during the Advertise period. A transmittable CAD
file will be available after Project Award, to the successful Contractor.
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13. The project has received final approval from Montana DEQ.
14. Article 14 of the Special Provisions was modified to clarify the BOR-owned area near the
beginning of the project.
15. The Bid Proposal/Form includes multiple updates. See revised Bid Proposal/Form and use
this document for submitting bid.
Civil Specification Changes:
* Replace original Bid Proposal, Measurement and Payment, and Special Provisions with the
new/revised documents that are marked "Addendum #1, 11-3-26".
Civil Plan Sheet Changes:
* Phase 1 - Water Improvements: Remove previous sheets W1, W2, and WD2. Replace with
attached sheets W1, W2, and WD2 all marked "Addendum #1".
* Phase 2 - Roadway Improvements: Remove previous sheets R1 and RD1. Replace with
attached sheets R1 and RD1 both marked "Addendum #1".
- End of Document -
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TECHNICAL MEMORANDUM
Montana Learning Center - Pavement Typical Section Design
Date: 8/4/2026
To: Jason Sorenson, P.E., Casne and Associates, Inc.
From: Adam Fetherston, P.E., Pioneer Technical Services, Inc.
CC:
Table of Contents
1 INTRODUCTION AND PURPOSE 1 Introduction and Purpose ..............1
2 Investigation ..................................1
This technical memorandum presents the pavement typical
2.1 Soil Lithology .............................. 1
section design for the Montana Learning Center east of 2.2 Laboratory Testing ..................... 1
Helena, Montana, near Canyon Ferry Reservoir. The typical 3 Traffic Design Parameters ..............2
section design was prepared for removal and replacement of 4 Pavement Typical Section Design ..2
4.1 Calculated Structural Number ... 3
the 500-foot-long Montana Learning Center cul-de-sac off of
5 Construction Recommendations ...4
Canyon Ferry Road.
6 Basis of Recommendations ............4
7 References .....................................6
2 INVESTIGATION
Figure 1. Montana Learning Center
Pioneer Technical Services, Inc. (Pioneer) drilled two
Borehole Locations
boreholes (BH-01 and BH-02) to depths of 5 feet below
ground surface at locations shown on Figure 1. The drilling
Attachment A Borehole Logs
work was performed on May 18, 2026, by Boland Drilling
Attachment B Photograph Log
under subcontract to Pioneer. The borehole was advanced
Attachment C Laboratory Data
using a Mobile B-57 truck-mounted drill rig using hollow Attachment D Pavement Typical
stem augers. An engineer from Pioneer logged borehole Section Design
lithology, existing section thicknesses, and collected samples
for laboratory testing.
2.1 Soil Lithology
The native subgrade below the existing road was comprised of light brown sandy lean clay. The
existing section material was comprised of approximately 2 inches of asphalt overlying 4 inches
of base course and 1 to 1.5 feet of subbase course. The subbase course consisted of brown clayey
sand with gravel. Detailed borehole logs are included in Attachment A and a photograph log of
the investigation is included in Attachment B.
2.2 Laboratory Testing
Laboratory data are summarized in Table 1 and included in Attachment C.

Montana Learning Center - Pavement Typical Section Design
Table 1. Laboratory Data
GRADATION ANALYSIS PROCTOR
BORE LIQUID PLASTIC PLASTICITY
HOLE DEPTH USCS LIMIT LIMIT INDEX GRAVEL SAND FINES MAX DRY OPT. CBR
NO. (feet) SYMBOL (%) (%) (%) (%) (%) (%) DENSITY MOIST. (%)
(pcf) (%)
BH-02 2-5 CL 27 19 8 4 37 59 115 14.2 5.5
USCS: Unified Soil Classification System. pcf: pounds per cubic foot. CBR: California Bearing Ratio.
3 TRAFFIC DESIGN PARAMETERS
The typical section design is based on traffic volumes provided by Casne and Associates, Inc.
Traffic design parameters are summarized below:
1. Average daily traffic of 25 trips per day (passenger vehicles).
2. Average of one garbage truck per week.
3. Average of five delivery trucks per week.
4. 20-year design life.
5. Growth rate of 0% per year.
6. Truck factor of 1.7 Equivalent Single Axle Load (ESAL)/truck.
These parameters yield a total 18-kip ESAL value of approximately 31,000 ESALs (calculations
are included in Attachment D). For the typical section design, Pioneer has conservatively
assumed a total 18-kip ESAL value of 50,000 ESALs.
4 PAVEMENT TYPICAL SECTION DESIGN
The American Association of State Highway and Transportation Officials (AASHTO, 1993)
flexible pavement design method was used to determine a design Structural Number (SN )
design
for the typical section. The Structural Number (SN) represents the overall structural requirement
needed to sustain the design's traffic loading. The SN value represents the structural strength of a
given typical section consisting of pavement, base course, and subbase material. The parameters
for the SN include:
design
1. Initial Serviceability (p ) value of 4.2. Initial Serviceability is a measure of the
0
pavement's smoothness or rideability immediately after construction. Montana
Department of Transportation (MDT) Pavement Design Manual (MDT, 2018)
recommends an Initial Serviceability of 4.2.
2. Terminal Serviceability (p) value of 2.5. Terminal Serviceability is the minimum
t
tolerable serviceability of a pavement. The MDT Pavement Design Manual (MDT, 2018)
recommends a Terminal Serviceability of 2.5.
3. Reliability Level (R) of 75%. Reliability Level is the probability that a pavement
structure will survive the design period traffic. The MDT Pavement Design Manual
(MDT, 2018) recommends a Reliability Level of 75% for secondary routes.
4. Overall Standard Deviation (S ) of 0.45. Overall Standard Deviation accounts for all
o
variability associated with design and construction inputs, including variability in
material properties, roadbed soil properties, traffic estimates, climatic conditions, and
Technical Memorandum | Page 2

Montana Learning Center - Pavement Typical Section Design
quality of construction. MDT Pavement Design Manual (MDT, 2018) recommends an
Overall Standard Deviation of 0.45.
5. Roadbed Soil Resilient Modulus (M ) of 7,152 pounds per square inch. The Roadbed
R
Soil Resilient Modulus is a material property used to characterize the support
characteristics of the roadbed soil in flexible pavement design. In general terms, it is a
measure of the soil's deformation in response to repeated applications of a load much
smaller than a failure load. The Roadbed Soil Resilient Modulus value was estimated
based on correlations with a design California Bearing Ratio (CBR) value of 5.
6. Total 18-kip ESAL value of 50,000 ESALs.
Based on these criteria, the required SN is given in Table 2. The calculated SN value is
design design
included in Attachment D.
Table 2. Design Structural Numbers
DESIGN
ROAD ESALs STRUCTURAL
NUMBER
Montana Learning Center
50,000 1.94
Cul-De-Sac
ESAL: Equivalent Single Axle Load
4.1 Calculated Structural Number
For the design to be effective, the calculated SN should be greater than the SN . To obtain a
design
calculated SN, the drainage coefficient (m) and a structural coefficient (a) are multiplied by a
typical section layer thickness (D) and summed as:
SN = a D m + a D m +... a D m
1 1 1 2 2 2 n n n
The drainage coefficient is a coefficient based on the effect of drainage within the pavement
section. The drainage coefficient for each layer is conservatively assumed as 1.0 (MDT, 2018).
Structural coefficients were taken from the MDT Pavement Design Manual (MDT, 2018) for
plant mix asphalt and crushed base course materials. Pioneer's proposed typical section design
and corresponding SN calculation is presented in Table 3 and Attachment D.
Table 3. Pavement Typical Section
DESIGN LAYER LAYER CALCULATED
ROAD ESALs STRUCTURAL MATERIAL THICKNESS COEFFICIENT1 STRUCTURAL
NUMBER (inches) (per inch) NUMBER2
Asphalt 3 0.41
Montana Learning Center
50,000 1.94 Base Course 8 0.14 2.35
Cul-De-Sac
Total 11 -
ESAL: Equivalent Single Axle Load
1Note: Per MDT Pavement Design Manual, Exhibit 5-6 (MDT, 2018).
2Note: The calculated SN must be greater than or equal to the SNdesign value.
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Montana Learning Center - Pavement Typical Section Design
5 CONSTRUCTION RECOMMENDATIONS
To construct the proposed asphalt typical section, Pioneer recommends the following:
1. Strip existing asphalt. Excavate to design subgrade as warranted.
2. Moisture condition subgrade soil to plus or minus 2% of optimum moisture content and
compact to a standard relative compaction of at least 95% (ASTM D698).
3. Place base course meeting the gradation specifications listed in Table 4. Place in 8-inch
(maximum) loose lifts and compact each lift to a standard relative compaction of at least
95%.
4. Provide asphalt plant mix with binder material meeting PG 58-28 grade and aggregates
meeting Montana Public Works Standard Specifications (MPWSS) Type B grading
requirements.
5. Compact asphalt to at least 93% of its Rice density.
6. Pioneer recommends a minimum compaction testing frequency of 1 test per 250 lineal
feet of road per layer.
Table 4. MPWSS 1.5-inch Minus Base Course
SIEVE SIZE PERCENT PASSING
1.5-inch 100
No. 4 25 - 60
No. 200 0 - 8
6 BASIS OF RECOMMENDATIONS
The analyses and recommendations submitted in this calculation summary are based upon data
obtained from the investigation boreholes. Often, variations occur between boreholes, the nature
and extent of which do not become evident until additional exploration or construction is
conducted. Pioneer recommends that, during earthmoving operations, a qualified geotechnical
engineer be present to evaluate the soil to verify its resemblance to that encountered during the
investigation.
This report is based on Pioneer's understanding of the proposed Montana Learning Center
pavement removal and replacement project. If the design or design traffic volumes change,
please consult Pioneer to verify that these recommendations are still applicable.
This report is for the exclusive use of Casne and Associates, Inc. and their design team. In the
absence of Pioneer's written approval, Pioneer makes no representation and assumes no
responsibility to other parties regarding this report. The data, analyses, and recommendations
may not be appropriate for other roads or purposes. Other parties contemplating other roads or
purposes should contact Pioneer. If you are not a designated or authorized recipient, further
review, dissemination, distribution, or copying of this report is strictly prohibited.
Services performed by Pioneer Technical Services, Inc. personnel for this project have been
conducted with the level of care and skill ordinarily exercised by members of the profession
currently practicing in this area under similar budget and time restraints. No warranty, expressed
or implied, is made.
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Montana Learning Center - Pavement Typical Section Design
Professional Certification
I hereby certify that this report was prepared
by me and that I am a duly Licensed Professional
Engineer under the laws of the State of Montana.
Adam Fetherston, P.E.
Geotechnical Engineer
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Montana Learning Center - Pavement Typical Section Design
7 REFERENCES
AASHTO, 1993. AASHTO Guide for Design of Pavement Structures. 1993.
MDT, 2018. Pavement Design Manual, Montana Department of Transportation Materials
Bureau. 2018.
Technical Memorandum | Page 6

Montana Learning Center - Pavement Typical Section Design
FIGURES
Figure 1. Montana Learning Center Borehole Locations

BH-01
C
A
N
Y
O
N
F
E
R
R
Y
BH-02
R
D
FIGURE 1
MT LEARNING CENTER
DISPLAYED AS:
BOREHOLE LOCATION COORD SYS/ZONE: MT STATE PLANE BOREHOLE LOCATIONS
DATUM: NAD83
UNITS: FEET
N SOURCE: ----
PIONEER
TECHNICAL SERVICES
www.pioneer-technical.com
(406) 782-5177 DATE: JULY 2026
7/7/2026 3:16:19 PM Z:\SHARED\ACTIVE PROJECTS\GEOTECH\BH LOCATION FIGURES\MT LEARNING CENTER.DWG