A 03 B3 SPEC 051321.pdf

MINNESOTA

AIR NATIONAL GUARD

DULUTH INTERNATIONAL AIRPORT

CONTRACT NO. W912LM-17-D-0003

DELIVERY ORDER NO. W912LM19F0064P00001

PROJECT FMKM152015

ATFP REPAIR

ENTRY CONTROL POINTS

SPECIFICATIONS

B.3 Final Submittal

May 13, 2021

LHB Project No. 190273

LHB

21 West Superior Street, Ste 500

Duluth, Minnesota 55802

(218) 727-8446

FAX: (218) 727-8456

MnANG ATFP REPAIR

LHB #190273

FMKM152015

TABLE OF CONTENTS

TOC - 1

DIVISION 00 - PROCUREMENT AND CONTRACTING REQUIREMENTS

00 0105 CERTIFICATIONS PAGE

00 3100 AVAILABLE PROJECT INFORMATION

DIVISION 01 - GENERAL REQUIREMENTS

01 1000 SUMMARY

01 1005 GOVERNING SPECIFICATIONS

01 2500 SUBSTITUTION PROCEDURES

01 3000 ADMINISTRATIVE REQUIREMENTS

01 3260 ENVIRONMENTAL REQUIREMENTS

01 4000 QUALITY REQUIREMENTS

01 4533 CODE-REQUIRED SPECIAL INSPECTIONS AND PROCEDURES

01 5000 TEMPORARY FACILITIES AND CONTROLS

01 5713 TEMPORARY EROSION AND SEDIMENT CONTROL

01 6000 PRODUCT REQUIREMENTS

01 6116 VOLATILE ORGANIC COMPOUND (VOC) CONTENT RESTRICTIONS

01 7000 EXECUTION AND CLOSEOUT REQUIREMENTS

01 7419 CONSTRUCTION WASTE MANAGEMENT AND DISPOSAL

01 7800 CLOSEOUT SUBMITTALS

DIVISION 03 - CONCRETE

03 0516 UNDERSLAB VAPOR BARRIER

03 1000 CONCRETE FORMING AND ACCESSORIES

03 2000 CONCRETE REINFORCING

03 3000 CAST-IN-PLACE CONCRETE

03 3511 CONCRETE FLOOR FINISHES

03 3900 CONCRETE CURING

03 4500 PRECAST ARCHITECTURAL CONCRETE

DIVISION 04 - MASONRY

04 2001 MASONRY VENEER

04 2900 ENGINEERED UNIT MASONRY

DIVISION 05 - METALS

05 1200 STRUCTURAL STEEL FRAMING

05 5000 METAL FABRICATIONS

DIVISION 06 - WOOD, PLASTICS, AND COMPOSITES

06 1000 ROUGH CARPENTRY

06 6110 SOLID POLYMER FABRICATIONS

DIVISION 07 - THERMAL AND MOISTURE PROTECTION

07 2100 THERMAL INSULATION

07 2119 FOAMED-IN-PLACE INSULATION

07 4113 METAL ROOF PANELS

07 4213 METAL WALL PANELS

07 9200 JOINT SEALANTS

TOC - 2

DIVISION 08 - OPENINGS

08 1113 HOLLOW METAL DOORS AND FRAMES

08 3323 OVERHEAD COILING DOORS

08 5113 ALUMINUM WINDOWS

08 7100 DOOR HARDWARE

08 8000 GLAZING

DIVISION 09 - FINISHES

09 2116 GYPSUM BOARD ASSEMBLIES

09 3000 TILING

09 5100 ACOUSTICAL CEILINGS

09 9000 PAINTING AND COATING

DIVISION 10 - SPECIALTIES

10 1400 SIGNAGE

DIVISION 11 - EQUIPMENT

11 1200 ACCESS CONTROL EQUIPMENT

11 1233.10 VEHICLE LANE GATES AND OPERATORS

11 1233.20 F.O.D. GATES AND OPERATORS

DIVISION 23 - HEATING, VENTILATING, AND AIR-CONDITIONING (HVAC)

23 0501 HVAC GENERAL PROVISIONS

23 0719 HVAC PIPING INSULATION

23 2300 REFRIGERANT PIPING

23 8126.13 SMALL-CAPACITY SPLIT-SYSTEM AIR CONDITIONERS

23 8200 CONVECTION HEATING AND COOLING UNITS

DIVISION 26 - ELECTRICAL

26 0500 COMMON WORK RESULTS FOR ELECTRICAL

26 0519 LOW VOLTAGE ELECTRICAL POWER CONDUCTORS AND CABLES

26 0526 GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS

26 0529 HANGERS AND SUPPORTS FOR ELECTRICAL SYSTEMS

26 0533.13 CONDUIT

26 0533.16 BOXES

26 0553 IDENTIFICATION FOR ELECTRICAL SYSTEMS

26 0800 TESTING FOR ELECTRICAL SYSTEMS

26 2416 PANELBOARDS

26 2716 ELECTRICAL CABINETS AND ENCLOSURES

26 2717 EQUIPMENT WIRING

26 2813 FUSES

26 2818 ENCLOSED SWITCHES

26 5600 EXTERIOR LIGHTING

SITE AND INFRASTRUCTURE SUBGROUP - DIVISIONS 31 THROUGH 35

30 1000 BASIC CIVIL REQUIREMENTS

DIVISION 31 - EARTHWORK

31 1000 SITE CLEARING

31 2200 GRADING

31 2316 EXCAVATION

31 2323 FILL

31 3219 GEOTEXTILE SOIL STABILIZATION AND LAYER SEPARATION

31 3700 RIPRAP

TOC - 3

DIVISION 32 - EXTERIOR IMPROVEMENTS

32 1123 AGGREGATE BASE COURSES

32 1216 ASPHALT PAVING

32 1313 CONCRETE PAVING

32 1723.13 PAINTED PAVEMENT MARKINGS

32 3113 CHAIN LINK FENCES AND GATES

32 3119 LOUVERED METAL FENCE SYSTEMS

32 3136 VERTICAL PIVOT LIFT GATES

32 3136.10 VERTICAL LIFT BEEM BARRIER

32 9219 SEEDING

32 9223 SODDING

DIVISION 33 - UTILITIES

33 4100 SUBDRAINAGE

33 4211 STORMWATER GRAVITY PIPING

LHB #190273

FMKM152015

B.3 Final Submittal

CERTIFICATIONS PAGE

00 0105 - 1

SECTION 00 0105

CERTIFICATIONS PAGE

CIVIL ENGINEER

I HEREBY CERTIFY THAT THIS PLAN, SPECIFICATION, OR REPORT WAS PREPARED BY ME OR

UNDER MY DIRECT SUPERVISION AND I AM A DULY LICENSED ENGINEER UNDER THE LAWS

OF THE STATE OF MINNESOTA.

DAN G. SHAW

REG #46584 DATE:

ARCHITECT

I HEREBY CERTIFY THAT THIS PLAN, SPECIFICATION, OR REPORT WAS PREPARED BY ME OR

UNDER MY DIRECT SUPERVISION AND I AM A DULY LICENSED ARCHITECT UNDER THE LAWS

OF THE STATE OF MINNESOTA.

CYNTHIA I. POIRIER

REG #22021 DATE:

STRUCTURAL

I HEREBY CERTIFY THAT THIS PLAN, SPECIFICATION, OR REPORT WAS PREPARED BY ME OR

UNDER MY DIRECT SUPERVISION AND I AM A DULY LICENSED ENGINEER UNDER THE LAWS

OF THE STATE OF MINNESOTA.

JENNIFER M. BABCOCK

REG #40768 DATE:

MECHANICAL ENGINEER

I HEREBY CERTIFY THAT THIS PLAN, SPECIFICATION, OR REPORT WAS PREPARED BY ME OR

UNDER MY DIRECT SUPERVISION AND I AM A DULY LICENSED ENGINEER UNDER THE LAWS

OF THE STATE OF MINNESOTA.

STEWART D. CRAN

REG #21202 DATE:

ELECTRICAL ENGINEER

I HEREBY CERTIFY THAT THIS PLAN, SPECIFICATION, OR REPORT WAS PREPARED BY ME OR

UNDER MY DIRECT SUPERVISION AND I AM A DULY LICENSED PROFESSIONAL ENGINEER

UNDER THE LAWS OF THE STATE OF MINNESOTA.

MARK J. VINCENT

REG #52349 DATE:

END OF SECTION

05/13/2021

05/13/2021

05/13/2021

05/13/2021

05/13/2021

MnANG ATFP REPAIR ENTRY

CONTROL POINTS

LHB# 190273

FMKM152015

B.3 Final Submittal

CERTIFICATIONS PAGE

00 0105 - 2

LHB# 190273

FMKM152015

B.3 Final Submittal

AVAILABLE PROJECT INFORMATION

00 3100 - 1

SECTION 00 3100

AVAILABLE PROJECT INFORMATION

PART 1 GENERAL

1.01 EXISTING CONDITIONS

A. Certain information relating to existing surface and subsurface conditions is available to bidders but will not be part of Contract Documents, as follows:

B. Geotechnical Report: Entitled MnANG ATFP Repair Entry Control Points, dated Dec. 23, 2019.

1. A copy of the report is attached to this section.

2. This report identifies properties of below grade conditions and offers recommendations for the design of foundations, prepared primarily for the use of COR.

3. The recommendations described shall not be construed as a requirement of this Contract, unless specifically referenced in Contract Documents.

4. This report, by its nature, cannot reveal all conditions that exist on the site. Should subsurface conditions be found to vary substantially from this report, changes in the design and construction of foundations will be made, with resulting credits or expenditures to the Contract Price accruing to Government.

PART 2 PRODUCTS (NOT USED)

PART 3 EXECUTION (NOT USED)

END OF SECTION

LHB# 190273

FMKM152015

B.3 Final Submittal

AVAILABLE PROJECT INFORMATION

00 3100 - 2

Geotechnical Evaluation Report

MNANG ATFP Repair Entry Control Points 148th Minnesota Air National Guard Base Various Locations on Base Duluth, Minnesota

Prepared for

LHB, Inc.

Professional Certification:

I hereby certify that this plan, specification or report was prepared by me or under my direct supervision and that I am a duly licensed Professional Engineer under the laws of the State of Minnesota.

Joseph C. Butler, PE Principal / Senior Engineer License Number: 47600 December 23, 2019

Project B1910002

Braun Intertec Corporation

AA/EOE

Braun Intertec Corporation 4511 West First Street, Suite 4 Duluth, MN 55807

Phone: 218.624.4967 Fax: 218.624.0196 Web: braunintertec.com

December 23, 2019 Project B1910002

Daniel Shaw, PE

21 West Superior St. Suite 500 Duluth, MN 55802

Re: Geotechnical Evaluation MNANG ATFP Repair Entry Control Points 148th Minnesota Air National Guard Base Various Locations Duluth, Minnesota

Dear Daniel:

We are pleased to present this Geotechnical Evaluation Report for the proposed MNANG ATFP Repair Entry Control Points improvement project planned for the Minnesota Air National Guard base in Duluth, Minnesota.

Thank you for making Braun Intertec your geotechnical consultant for this project. If you have questions about this report, or if there are other services that we can provide in support of our work to date, please contact Kyle Warmuth at 218.624.4967 or kwarmuth@braunintertec.com.

Sincerely, BRAUN INTERTEC CORPORATION

Kyle P. Warmuth, EIT Staff Engineer

Joseph C. Butler, PE Principal / Senior Engineer mailto:kwarmuth@braunintertec.com

Table of Contents

Description Page

A. Introduction

A.1. Project Description A.2. Purpose A.3. Background Information and Reference Documents A.4. Site Conditions A.5. Scope of Services

B. Results B.1. Exploration Logs

B.1.a. Log of Boring Sheets B.1.b. Geologic Origins

B.2. Geologic Profile B.2.a. Geologic Materials B.2.b. Groundwater

C. Basis for Recommendations C.1. Design and Construction Considerations

C.1.a. General C.1.b. Existing Fill C.1.c. Organic Materials C.1.d. Reuse of On-Site Soils C.1.e. Groundwater C.1.f. Frost Protection C.1.g. Construction Disturbance

D. Recommendations D.1. Foundation Subgrade Preparation

D.1.a. Excavations D.1.b. Excavation Oversizing D.1.c. Excavated Slopes D.1.d. Excavation Dewatering D.1.e. Engineered Fill Materials and Compaction

D.2. Footings and Foundations D.3. Drilled Pier Foundation

D.3.a. Frost Heave and Embedment Depth D.3.b. Design Parameters D.3.c. Drilled Shaft Support D.3.d. Settlement D.3.e. Concrete Construction D.3.f. Dewatering D.3.g. Concrete Materials

D.4. Pavements and Exterior Slabs D.4.a. Pavement and Exterior Slab Subgrade Preparation D.4.b. Pavement Subgrade Proofroll D.4.c. Design Sections D.4.d. Concrete Pavements D.4.e. Subgrade Drainage D.4.f. Performance and Maintenance

Table of Contents (continued)

Description Page

D.5. Frost Protection D.5.a. General D.5.b. Frost Heave Mitigation

D.6. Utilities D.6.a. Subgrade Stabilization D.6.b. Corrosion Potential

D.7. Stormwater D.8. Construction Quality Control

D.8.a. Excavation Observations D.8.b. Observations and Materials Testing D.8.c. Special Inspections of Soils D.8.d. Pavement Subgrade Proofroll D.8.e. Cold Weather Precautions

E. Procedures E.1. Penetration Test Borings E.2. Material Classification and Testing

E.2.a. Visual and Manual Classification E.2.b. Laboratory Testing

E.3. Groundwater Measurements F. Qualifications

F.1. Variations in Subsurface Conditions F.1.a. Material Strata F.1.b. Groundwater Levels

F.2. Continuity of Professional Responsibility F.2.a. Plan Review F.2.b. Construction Observations and Testing

F.3. Use of Report F.4. Standard of Care

Appendix Boring Location Sketch Log of Boring Sheets ST-1 through ST-10 Drilled Pier Design Parameters Descriptive Terminology of Soil

A. Introduction

A.1. Project Description

This Geotechnical Evaluation Report addresses the proposed MNANG ATFP Repair Entry Control Points improvement project planned for the Minnesota Air National Guard base in Duluth, Minnesota.

The will include several facility improvements; including the following:

Reconstruction of the pavement area around Building 211.

Lighting improvements around buildings 211 and 223.

Lighting improvements around the gates at the intersection of Phantom Drive and Viper Street, and the gate at the intersection of Ridgeview Road and the runway access road.

Various freestanding privacy walls, new gates, sally ports are included around parking spaces as well as new gate, sally ports, and light poles across the site.

Drilled shaft and frost depth spread footings foundations are being considered for support of the project’s structural elements. The foundations will have column loads of less than 20 kips and strip footing loads of less than 5 kips per foot.

Upgrades to the main gate are included in the project however, the main gate is not included in this report.

Table 1. Pavement Description

Aspect Description

Pavement type(s) Rigid (Concrete)

Flexible (Bituminous)

Provided/Assumed pavement loads Light-duty: 75,000 ESALs*

Heavy-duty: 150,000 ESALs*

Grade changes Less than 2 (Assumed)

*Equivalent 18,000-lb single axle loads based on 20-year design.

December 23. 2019

A.2. Purpose

The purpose of our geotechnical evaluation will be to characterize subsurface geologic conditions at selected exploration locations and evaluate their impact on the design and construction of the pavement reconstruction, various entry control points, privacy fences and light poles.

A.3. Background Information and Reference Documents

We reviewed the following information:

Minnesota Geologic Map. “Geologic Map of Minnesota, Quaternary Geology”, prepared by

Hobbes and Goebel, dated 1982.

Aerial photos from Google Earth©.

Geotechnical Scope Map, prepared by LHB, Inc., not dated.

Request for proposal, prepared by Departments of the Army and the Air Force, dated

April 17, 2019.

We have described our understanding of the proposed construction and site to the extent others reported it to us. Depending on the extent of available information, we may have made assumptions based on our experience with similar projects. If we have not correctly recorded or interpreted the project details, the project team should notify us. New or changed information could require additional evaluation, analyses and/or recommendations.

A.4. Site Conditions

The project site consists of various locations at the Minnesota Air National Guard Base in Duluth, Minnesota. Including around building 211, building 223, at the intersection of Phantom Drive and Viper

Street and at the intersection of Ridgeview Road and the runway access road.

Photograph 1. Aerial Photograph of the Site in 2017 with proposed work areas

Provided by Google Earth Pro©

A.5. Scope of Services

Our scope of services for this project was originally submitted as quote QTB099231 to LHB, Inc. Tasks performed in accordance with our authorized scope of services included:

Reviewing the background information and reference documents previously cited.

Staking and clearing the exploration location of underground utilities. LHB, Inc. selected and we staked the new exploration locations. We acquired the surface elevations and locations with GPS technology using the State of Minnesota’s permanent GPS base station network.

The Soil Boring Location Sketch included in the Appendix shows the approximate locations of the borings.

Performing ten (10) standard penetration test (SPT) borings, denoted as ST-1 to ST-10, to nominal depths of 10 to 15 feet below grade across the site.

Performing laboratory testing on select samples to aid in soil classification and engineering analysis.

Perform engineering analysis including settlement.

Preparing this report containing a boring location sketch, logs of soil borings, a summary of the soils encountered, recommendations for structure and pavement subgrade preparation and the design of foundations, exterior slabs, utilities, stormwater improvements and pavements.

B. Results

B.1. Exploration Logs

B.1.a. Log of Boring Sheets

Log of Boring sheets for our penetration test borings are included in the Appendix. The logs identify and describe the geologic materials that were penetrated and present the results of penetration resistance and laboratory tests performed on penetration test samples retrieved from them, and groundwater measurements.

Strata boundaries were inferred from changes in the penetration test samples and the auger cuttings.

Because sampling was not performed continuously, the strata boundary depths are only approximate.

The boundary depths likely vary away from the boring locations, and the boundaries themselves may also occur as gradual rather than abrupt transitions.

B.1.b. Geologic Origins

Geologic origins assigned to the materials shown on the logs and referenced within this report were based on: (1) a review of the background information and reference documents cited above, (2) visual classification of the various geologic material samples retrieved during the course of our subsurface exploration, (3) penetration resistance testing performed for the project, (4) available common knowledge of the geologic processes and environments that have impacted the site and surrounding area in the past.

B.2. Geologic Profile

B.2.a. Geologic Materials

Table 2 provides a summary of the soil boring results, in the general order we encountered the strata.

Please refer to the Log of Boring sheets in the Appendix for additional details. The Descriptive

Terminology sheets in the Appendix include definitions of abbreviations used in Table 2.

Table 2. Subsurface Profile Summary*

Strata

Soil Type -

ASTM

Classification

Range of Penetration

Resistances Commentary and Details

Pavement section Bituminous thickness varied from 3 to 5 inches.

Fill SP-SM, SM

Moisture condition is generally moist.

Thicknesses at boring locations varied from 2 to 10 feet.

Highly variable, soils intermixed.

Existing fill contained variable amounts of debris, including concrete.

Possible cobbles and boulders.

Glacial deposits

SP-SM, SM

3 to 35 Blows per

Foot (BPF) Possible cobbles and boulders.

Variable amounts of gravel

Moisture condition is generally moist. ML 3 to 11 BPF

*Abbreviations defined in the attached Descriptive Terminology sheets.

For simplicity in this report, we define existing fill to mean existing, uncontrolled or undocumented fill.

B.2.b. Groundwater

Groundwater was measured in boring ST-10 to be approximately 12 1/2 feet below the ground surface as our augers were advanced. This depth corresponds to an elevation of 1395.

Seasonal and annual fluctuations of groundwater should also be anticipated.

C. Basis for Recommendations

C.1. Design and Construction Considerations

C.1.a. General

The overall project includes pavement reconstruction around Building 211 and various site structures at various locations across the project areas. The site structures include, but are not limited to; light poles, privacy barriers and automated gates. Borings were performed at many of these locations however, geotechnical was not obtained at all locations. Based on the borings we anticipate the structure foundations will be founded on or in glacial soils or structural fill. Due to the variety of conditions that could be encountered during construction, we recommend a geotechnical engineer or their representative review the soils encountered in excavations to determine if they are similar to those encountered in the borings.

C.1.b. Existing Fill

Fill materials (material placed by man rather than nature) were encountered in several of the borings.

The existing fill was variable and does not appear to have been placed in a controlled manner. We recommend the existing fill not be relied upon for the structural support of foundations, the existing fill should be removed and replaced with structural fill to reach the desired grades.

C.1.c. Organic Materials

Topsoil and black soils contain organic materials. Organic materials absorb water, become weak, and frost susceptible. We recommend removing any organic materials from within 3 feet of finished pavement and exterior slab grades. Compacted fill can then be placed to reach desired grades.

C.1.d. Reuse of On-Site Soils

The onsite soils generally consist of silty sands, silts, and poorly graded sand. The silty sands and silts are high in silt content and therefore will hold moisture. While these materials may be suitable for use as grading material and structural fill, moisture conditioning (drying) will be required to meet compaction requirements. The drying season in the project area is generally limited to July and August. It may be possible to segregate the dryer soils from the wet soils and conduct grading outside of this window, but it will be significantly more difficult.

As an alternative to drying onsite materials for use as backfills, we recommend imported engineered fill be utilized for fill in foundation and pavement areas. Outside of these areas, the use of imported fill is likely cost prohibitive, to accommodate potential settlement of soils that could not be compacted due to excessive moisture, the project team could consider a construction delay. We should be notified if this approach is used as it contains risks and additional discussion with the project team may be needed.

C.1.e. Groundwater

Groundwater was measured in boring ST-10 to be approximately 12 1/2 feet below the ground surface as our augers were advanced. We suspect the groundwater is perched within sandy layers or zones of looser soil. If encountered, groundwater should be removed from excavations. Sump pumps can be considered for this project.

C.1.f. Frost Protection

We encountered silty sand and silt soils at the selected the boring locations. We consider silty sand and silt to be highly frost susceptible. Soils of this type can retain moisture and heave upon freezing. Once frozen, unfavorable amounts of general and isolated heaving of the soils and the surface structures supported on them could develop. This type of heaving could affect the performance of the proposed structure foundations, frost protected foundations should be used in the design.

C.1.g. Construction Disturbance

The contractor should note the on-site, silty soils are highly susceptible to disturbance, due to repeated construction traffic. Disturbance of these soils may cause areas that were previously prepared, or that were suitable for pavement or structure support, to become unstable and require moisture conditioning and compaction. Subcutting and replacing the disturbed material with crushed, coarse gravel, free of fines is also an alternative. The contractor should use means and methods to limit disturbance of the soils.

D. Recommendations

D.1. Foundation Subgrade Preparation

D.1.a. Excavations

We recommend removing unsuitable materials from beneath the proposed foundations. We define unsuitable materials as existing fill, frozen materials, organic soils, existing structures, existing utilities, vegetation, soft/loose soils.

Excavation depths will vary between the borings. Portions of the excavations may also extend deeper than indicated by the borings. A geotechnical representative should observe the excavations to make the necessary field judgments regarding the suitability of the exposed soils.

The contractor should use equipment and techniques to minimize soil disturbance. If soils become disturbed or are wet, we recommend excavation and replacement.

D.1.b. Excavation Oversizing

When removing unsuitable materials below structures or pavements, we recommend the excavation extend outward and downward at a slope of 1H:1V (horizontal:vertical) or flatter. See Figure 1 for an illustration of excavation oversizing.

Figure 1. Generalized Illustration of Oversizing

1. Engineered fill as defined in C.2

2. Excavation oversizing minimum of 1 to 1

(horizontal to vertical) slope or flatter

3. Engineered fill as required to meet pavement support or landscaping requirements as defined in C.2

4. Backslope to OSHA requirements

D.1.c. Excavated Slopes

Based on the borings, we anticipate on-site soils in excavations will consist of silty sands and poorly graded sands. These soils are typically considered Type C Soil under OSHA (Occupational Safety and

Health Administration) guidelines. OSHA guidelines indicate unsupported excavations in Type C soils should have a gradient no steeper than 1 1/2H:1V. Slopes constructed in this manner may still exhibit surface sloughing. OSHA requires an engineer to evaluate slopes or excavations over 20 feet in depth.

An OSHA-approved qualified person should review the soil classification in the field. Excavations must comply with the requirements of OSHA 29 CFR, Part 1926, Subpart P, “Excavations and Trenches.” This document states excavation safety is the responsibility of the contractor. The project specifications should reference these OSHA requirements.

D.1.d. Excavation Dewatering

If present, we recommend groundwater or accumulated water be removed from excavations or subgrades to facilitate proper backfilling or concrete placement. Project planning should include temporary sumps and pumps for short-term dewatering activities to remove perched or collected water.

We recommend sump pits be located outside of the building pad and oversize areas.

D.1.e. Engineered Fill Materials and Compaction

Table 3 below contains our recommendations for engineered fill materials.

Table 3. Engineered Fill Materials*

Locations To Be Used

Engineered Fill

Classification

Possible Soil Type

Descriptions Gradation

Additional

Requirements

Below foundations Structural fill 100% passing 2-inch sieve

< 20% passing #200 sieve

< 2% Organic

Content (OC)

Drainage layer

Non-frost-susceptible

Free-draining

Non-frost-susceptible fill

GP, GW, SP, SW

100% passing 1-inch sieve

< 50% passing #40 sieve

< 5% passing #200 sieve

< 2% OC

Beyond drainage layer Retained fill SP-SM, SM, ML 100% passing 3-inch sieve

< 20% passing #200 sieve

< 2% OC

Plasticity Index (PI)

< 4%

Pavements Pavement fill SP, SM, 100% passing 3-inch sieve

< 2% OC

PI < 15%

Below landscaped surfaces, where subsidence is not a concern

Non-structural fill 100% passing 6-inch sieve < 10% OC

We recommend spreading engineered fill in loose lifts of approximately 8 to 12 inches thick. We recommend compacting engineered fill in accordance with the criteria presented below in Table 4. The project documents should specify relative compaction of engineered fill, based on the structure located above the engineered fill, and vertical proximity to that structure.

Table 4. Compaction Recommendations Summary

Reference

Relative

Compaction, percent

(ASTM D698 –

Standard Proctor)

Moisture Content Variance from Optimum, percentage points

< 12% Passing #200 Sieve

(typically SP, SP-SM)

> 12% Passing #200 Sieve

(typically, ML, SM)

Below foundations and oversizing zones 95 ±3 -1 to +3

Below interior slabs 95 ±3 -1 to +3

Within 3 feet of pavement subgrade 100 ±3 -1 to +3

More than 3 feet below pavement subgrade 95 ±3 ±3

The project documents should not allow the contractor to use frozen material as engineered fill or to place engineered fill on frozen material. Frost should not penetrate under foundations during construction.

We recommend performing density tests in engineered fill to evaluate if the contractors are effectively compacting the soil and meeting project requirements.

D.2. Footings and Foundations

Table 5 below contains our recommended parameters for foundation design.

Table 5. Recommended Spread Footing Design Parameters

Item Description

Maximum net allowable bearing pressure (psf) 3,000

Minimum factor of safety for bearing capacity failure 3.0

Minimum embedment below final exterior grade for heated structures (inches)

Minimum embedment below final exterior grade for unheated structures or for footings not protected from freezing temperatures during construction (inches)

Total estimated settlement (inches) Less than 1

D.3. Drilled Pier Foundation

D.3.a. Frost Heave and Embedment Depth

Soils near the ground surface will adhere to the sides of the pier if allowed to freeze. As the soils freeze, it will heave the pier upward.

The estimated maximum frost penetration depth for the area is approximately 90 inches (7 ½ feet). To reduce the potential effect of frost, we recommend that drilled pier foundations extend to a minimum of twice that depth (15 feet) for lightly loaded or unloaded conditions.

Care must be given to forming the drilled pier within the anticipated frost penetration depths. The drilled pier should be formed within this zone such that the pier sidewalls are as near vertical and smooth as possible. Alternatively, to reduce the potential for heave of the piers, consideration may be given to forming the pier within the anticipated frost depth with a sonotube to limit skin friction/adhesion. If a sonotube is used, the frictional resistance within the depth of the sonotube should be reduced to zero.

D.3.b. Design Parameters

Design parameters for drilled pier design are provided in the tables in Appendix A.

D.3.c. Drilled Shaft Support

We anticipate that the pier shaft foundation will use a sonotube or will be temporarily cased through granular and soft soil layers to prevent caving.

D.3.d. Settlement

We anticipate that settlement of the drilled foundation will be less than 1 inch.

D.3.e. Concrete Construction

We recommend installing the pier in accordance with the American Concrete Institute (ACI) 336-89, “Standard Specification for the Construction of Drilled Piers.” It is possible to pull telescoping casing in such a way as to construct the drilled shaft at its design diameter for its entire length. This practice, however, risks leaving loose material against the pier and effectively reducing confinement offered to the pier. To avoid problems associated with this situation, we recommend that the concrete be placed to the full diameter of the drilled shaft, i.e. concrete placed for the full excavation diameter against undisturbed soil or a sonotube be used.

D.3.f. Dewatering

Groundwater was encountered in the boring at a depth of 12 1/2 feet below the ground surface, this depth is within the anticipated drilled pier depth. If water is present in the hole, a pump should be lowered to the bottom of the hole to dewater.

Alternatively, the concrete can be placed with a tremie pipe, although the concrete should then be designed for a slump between approximately 4 and 6 inches.

D.3.g. Concrete Materials

We recommend specifying 5 to 8 percent entrained air for concrete exposed to frost to provide resistance to freeze-thaw deterioration. We recommend using a water/cement ratio of 0.50 or less for exposed concrete.

D.4. Pavements and Exterior Slabs

D.4.a. Pavement and Exterior Slab Subgrade Preparation

We recommend the following steps for pavement and exterior slab subgrade preparation, understanding the site will have a grade change of 2 feet or less. Note that project planning may need to require additional subcuts to limit frost heave.

1. Strip unsuitable soils consisting of topsoil, organic soils, peat, vegetation, existing structures and pavements from the area, within 3 feet of the surface of the proposed pavement grade.

2. Have a geotechnical representative observe the excavated subgrade to evaluate if additional subgrade improvements are necessary.

3. Slope subgrade soils to areas of sand or drain tile to allow the removal of accumulating water.

4. Scarify, moisture condition and surface compact the subgrade with at least 3 passes of a large roller with a minimum drum diameter of 3 1/2 feet.

5. Place pavement engineered fill to grade and compact in accordance with Section D.1 to bottom of pavement and exterior slab section. See Section D.5_ for additional considerations related to frost heave.

6. Proofroll the pavement or exterior slab subgrade as described in Section D.4.b.

To improve long-term pavement performance, we recommend incorporating 12 inches of free-draining engineered fill in paved areas, in addition to the recommendations above, as a sand subbase. Section

D.4.c provides recommended pavement design sections with the sand subbase. Note, we recommend sloping subgrade soils to promote drainage and removal of accumulated water.

D.4.b. Pavement Subgrade Proofroll

After preparing the subgrade as described above and prior to the placement of the aggregate base, we recommend proofrolling the subgrade soils with a fully loaded tandem-axle truck. We also recommend having a geotechnical representative observe the proofroll. Areas that fail the proofroll likely indicate soft or weak areas that will require additional soil correction work to support pavements.

The contractor should correct areas that display excessive yielding or rutting during the proofroll, as determined by the geotechnical representative. Possible options for subgrade correction include moisture conditioning and recompaction, subcutting and replacement with soil or crushed aggregate, chemical stabilization and/or geotextiles. We recommend performing a second proofroll after the aggregate base material is in place, and prior to placing bituminous or concrete pavement.

D.4.c. Design Sections

Our scope of services for this project did not include laboratory tests on subgrade soils to determine an

R-value for pavement design. Based on our experience with similar native silt soils anticipated at the pavement subgrade elevation, we recommend pavement design assume an R-value of 20. Note the contractor may need to perform limited removal of unsuitable or less suitable soils to achieve this value.

Table 6 provides recommended pavement sections, based on the soils support and traffic loads.

We based the concrete pavement designs on a modulus of subgrade reaction (k) of 75 pci.

Table 6. Recommended Bituminous Pavement Sections

Use

Light Duty

(Bituminous)

Light Duty

(Concrete)

Heavy Duty

(Bituminous)

Heavy Duty

(Concrete)

Minimum asphalt thickness (inches) 4 --- 5 ---

Minimum concrete thickness (inches) --- 6 --- 8

Minimum aggregate base thickness

(inches)

8 8 12 10

Minimum granular subbase 12 12 12 12

D.4.d. Concrete Pavements

We assumed the concrete pavement sections in Table 6 will have edge support. We recommend placing an aggregate base below the pavement to provide a suitable subgrade for concrete placement, reduce faulting and help dissipate loads. Appropriate mix designs, panel sizing, jointing, doweling and edge reinforcement are critical to performance of rigid pavements. We recommend you contact your civil engineer to determine the final design or consult with us for guidance on these items.

D.4.e. Subgrade Drainage

We recommend installing perforated drainpipes throughout pavement areas at low points, around catch basins, and behind curb in landscaped areas. We also recommend installing drainpipes along pavement and exterior slab edges where exterior grades promote drainage toward those edge areas. The contractor should place drainpipes in small trenches, extended at least 8 inches below the granular subbase layer, or below the aggregate base material where no subbase is present.

D.4.f. Performance and Maintenance

We based the above pavement designs on a 20-year performance life for bituminous and for concrete.

This is the amount of time before we anticipate the pavement will require reconstruction. This performance life assumes routine maintenance, such as seal coating and crack sealing. The actual pavement life will vary depending on variations in weather, traffic conditions and maintenance.

It is common to place the non-wear course of bituminous and then delay placement of wear course. For this situation, we recommend evaluating if the reduced pavement section will have sufficient structure to support construction traffic.

Many conditions affect the overall performance of the exterior slabs and pavements. Some of these conditions include the environment, loading conditions and the level of ongoing maintenance. With regard to bituminous pavements in particular, it is common to have thermal cracking develop within the first few years of placement, and continue throughout the life of the pavement. We recommend developing a regular maintenance plan for filling cracks in exterior slabs and pavements to lessen the potential impacts for cold weather distress due to frost heave or warm weather distress due to wetting and softening of the subgrade.

D.5. Frost Protection

D.5.a. General

Silt and silty sand will underlie all or some of the exterior slabs and pavements. We consider silty sand highly frost susceptible. Soils of this type can retain moisture and heave upon freezing. In general, this characteristic is not an issue unless these soils become saturated, due to surface runoff or infiltration, or are excessively wet in situ. Once frozen, unfavorable amounts of general and isolated heaving of the soils and the surface structures supported on them could develop. This type of heaving could affect design drainage patterns and the performance of exterior slabs and pavements, as well as any isolated exterior footings and piers.

Note that general runoff and infiltration from precipitation are not the only sources of water that can saturate subgrade soils and contribute to frost heave. Roof drainage and irrigation of landscaped areas in close proximity to exterior slabs, pavements, and isolated footings and piers, contribute as well.

D.5.b. Frost Heave Mitigation

To address most of the heave related issues, we recommend setting general site grades and grades for exterior surface features to direct surface drainage away from buildings, across large paved areas and away from walkways. Such grading will limit the potential for saturation of the subgrade and subsequent heaving. General grades should also have enough “slope” to tolerate potential larger areas of heave, which may not fully settle after thawing.

Even small amounts of frost-related differential movement at walkway joints or cracks can create tripping hazards. Project planning can explore several subgrade improvement options to address this condition.

One of the more conservative subgrade improvement options to mitigate potential heave is removing any frost-susceptible soils present below the exterior slab areas down to a minimum depth of 6 feet below subgrade elevations. We recommend filling the resulting excavation with non-frost-susceptible fill.

We also recommend sloping the bottom of the excavation toward one or more collection points to remove any water entering the engineered fill. This approach will not be effective in controlling frost heave without removing the water.

An important geometric aspect of the excavation and replacement approach described above is sloping the banks of the excavations to create a more gradual transition between the unexcavated soils considered frost susceptible and the engineered fill in the excavated area, which is not frost susceptible.

The slope allows attenuation of differential movement that may occur along the excavation boundary.

We recommend slopes that are 3H:1V, or flatter, along transitions between frost-susceptible and non-frost-susceptible soils.

Figure 2 shows an illustration summarizing some of the recommendations.

Figure 2. Frost Protection Geometry Illustration

Another option is to limit frost heave in critical areas, such as doorways and entrances, via frost-depth footings or localized excavations with sloped transitions between frost-susceptible and non-frost-susceptible soils, as described above.

Over the life of slabs and pavements, cracks will develop and joints will open up, which will expose the subgrade and allow water to enter from the surface and either saturate or perch atop the subgrade soils.

This water intrusion increases the potential for frost heave or moisture-related distress near the crack or joint. Therefore, we recommend implementing a detailed maintenance program to seal and/or fill any cracks and joints. The maintenance program should give special attention to areas where dissimilar materials abut one another, where construction joints occur and where shrinkage cracks develop.

D.6. Utilities

D.6.a. Subgrade Stabilization

Earthwork activities associated with utility installations located inside the building area should adhere to the recommendations in Section D.1.

For exterior utilities, we anticipate the soils at typical invert elevations will be suitable for utility support.

However, if construction encounters unfavorable conditions such as soft clay, organic soils or perched water at invert grades, the unsuitable soils may require some additional subcutting and replacement with sand or crushed rock to prepare a proper subgrade for pipe support. Project design and construction should not place utilities within the 1H:1V oversizing of foundations.

D.6.b. Corrosion Potential

Based on our experience, the soils encountered by the borings are moderately corrosive to metallic conduits, but only marginally corrosive to concrete. We recommend specifying non-corrosive materials or providing corrosion protection, unless project planning chooses to perform additional tests to demonstrate the soils are not corrosive.

D.7. Stormwater

We estimated infiltration rates for some of the soils we encountered in our soil borings, as listed in Table

7. These infiltration rates represent the long-term infiltration capacity of a practice and not the capacity of the soils in their natural state. Field testing, such as with a double-ring infiltrometer (ASTM D3385), may justify the use of higher infiltration rates. However, we recommend adjusting field test rates by the appropriate correction factor, as provided for in the Minnesota Stormwater Manual or as allowed by the local watershed. We recommend consulting the Minnesota Stormwater Manual for stormwater design.

Table 7. Estimated Design Infiltration Rates Based on Soil Classification

Soil Type

Infiltration Rate *

(inches/hour)

Silty sands, silty gravelly sands 0.45

Silts, very fine sands, silty or clayey fine sands 0.2

* From Minnesota Stormwater Manual. Rates may differ at individual sites.

Fine-grained soils (silts and clays), topsoil or organic matter that mixes into or washes onto the soil will lower the permeability. The contractor should maintain and protect infiltration areas during construction. Furthermore, organic matter and silt washed into the system after construction can fill the soil pores and reduce permeability over time. Proper maintenance is important for long-term performance of infiltration systems.

This geotechnical evaluation does not constitute a review of site suitability for stormwater infiltration or evaluate the potential impacts, if any, from infiltration of large amounts of stormwater.

D.8. Construction Quality Control

D.8.a. Excavation Observations

We recommend having a geotechnical engineer observe all excavations related to subgrade preparation and spread footing, slab-on-grade and pavement construction. The purpose of the observations is to evaluate the competence of the geologic materials exposed in the excavations, and the adequacy of required excavation oversizing.

D.8.b. Observations and Materials Testing

We recommend density tests be taken in excavation backfill and additional required fill placed below spread footings, slab-on-grade construction, beside foundation walls, and below pavements.

We recommend Marshall tests on bituminous mixes to evaluate strength and air voids, and density tests to evaluate compaction.

We also recommend slump, air content and strength tests of Portland cement concrete.

D.8.c. Special Inspections of Soils

We recommend including the site grading and placement of engineered fill within the building pad under the requirements of Special Inspections, as provided in Chapter 17 of the International Building Code, which is part of the Minnesota State Building Code. Special Inspection requires observation of soil conditions below engineered fill or footings, evaluations to determine if excavations extend to the anticipated soils, and if engineered fill materials meet requirements for type of engineered fill and compaction condition of engineered fill. A licensed geotechnical engineer should direct the Special

Inspections of site grading and engineered fill placement. The purpose of these Special Inspections is to evaluate whether the work is in accordance with the approved Geotechnical Report for the project.

Special Inspections should include evaluation of the subgrade, observing preparation of the subgrade

(surface compaction or dewatering, excavation oversizing, placement procedures and materials used for engineered fill, etc.) and compaction testing of the engineered fill.

We recommend the installation of the drilled pier be observed by a geotechnical engineer of a geotechnical engineering technician working under the direction of a geotechnical engineer. Cuttings from the hole should be observed to see if they are similar in composition to the soils encountered in the test boring and to verify the pier embedment. We also recommend periodic or continuous observations of the construction of the pier be performed to aid in verifying the contractor’s conformance to ACI

Specification 336.1 “Standard Specification for the Construction of Drilled Piers”.

D.8.d. Pavement Subgrade Proofroll

We recommend that proofrolling of the pavement subgrades be observed by a geotechnical engineer to determine if the results of the procedure meet project specifications, or delineate the extent of additional pavement subgrade preparation work.

D.8.e. Cold Weather Precautions

If site grading and construction is anticipated during cold weather, all snow and ice should be removed from cut and fill areas prior to additional grading. No fill should be placed on frozen subgrades. No frozen soils should be used as fill.

Concrete delivered to the site should meet the temperature requirements of ASTM C 94. Concrete should not be placed on frozen subgrades. Concrete should be protected from freezing until the necessary strength is attained. Frost should not be permitted to penetrate below footings.

E. Procedures

E.1. Penetration Test Borings

The penetration test borings were drilled with a float tire-mounted core and auger drill equipped with hollow-stem auger. The borings were performed in accordance with ASTM D 1586. Penetration test samples were taken at 2 1/2- or 5-foot intervals. Actual sample intervals and corresponding depths are shown on the boring logs.

Penetration test boreholes that met the Minnesota Department of Health (MDH) Environmental

Borehole criteria were sealed with an MDH-approved grout. A sealing record for those boreholes will be forwarded to the Minnesota Department of Health Well Management Section.

E.2. Material Classification and Testing

E.2.a. Visual and Manual Classification

The geologic materials encountered were visually and manually classified in accordance with ASTM

Standard Practice D 2488. A chart explaining the classification system is attached. Samples were placed in jars or bags and returned to our facility for review and storage.

E.2.b. Laboratory Testing

The results of the laboratory tests performed on geologic material samples are noted on or follow the appropriate attached exploration logs. The tests were performed in accordance with ASTM or AASHTO procedures.

E.3. Groundwater Measurements

The drillers checked for groundwater as the penetration test borings were advanced, and again after auger withdrawal. The boreholes were then backfilled, as noted on the boring logs.

F. Qualifications

F.1. Variations in Subsurface Conditions

F.1.a. Material Strata

Our evaluation, analyses and recommendations were developed from a limited amount of site and subsurface information. It is not standard engineering practice to retrieve material samples from exploration locations continuously with depth, and therefore strata boundaries and thicknesses must be inferred to some extent. Strata boundaries may also be gradual transitions, and can be expected to vary in depth, elevation and thickness away from the exploration locations.

Variations in subsurface conditions present between exploration locations may not be revealed until additional exploration work is completed, or construction commences. If any such variations are revealed, our recommendations should be re-evaluated. Such variations could increase construction costs, and a contingency should be provided to accommodate them.

F.1.b. Groundwater Levels

Groundwater measurements were made under the conditions reported herein and shown on the exploration logs, and interpreted in the text of this report. It should be noted that the observation periods were relatively short, and groundwater can be expected to fluctuate in response to rainfall, flooding, irrigation, seasonal freezing and thawing, surface drainage modifications and other seasonal and annual factors.

F.2. Continuity of Professional Responsibility

F.2.a. Plan Review

This report is based on a limited amount of information, and a number of assumptions were necessary to help us develop our recommendations. It is recommended that our firm review the geotechnical aspects of the designs and specifications, and evaluate whether the design is as expected, if any design changes have affected the validity of our recommendations, and if our recommendations have been correctly interpreted and implemented in the designs and specifications.

F.2.b. Construction Observations and Testing

It is recommended that we be retained to perform observations and tests during construction. This will allow correlation of the subsurface conditions encountered during construction with those encountered by the borings, and provide continuity of professional responsibility.

F.3. Use of Report

This report is for the exclusive use of the parties to which it has been addressed. Without written approval, we assume no responsibility to other parties regarding this report. Our evaluation, analyses and recommendations may not be appropriate for other parties or projects.

F.4. Standard of Care

In performing its services, Braun Intertec used that degree of care and skill ordinarily exercised under similar circumstances by reputable members of its profession currently practicing in the same locality. No warranty, express or implied, is made.

Appendix

Elev./ Depth ft

1429.0 0.3

1427.2 2.0

1424.7 4.5

1419.2 10.0

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

BITUMINOUS, 3 inches FILL: SILTY SAND (SM), fine to medium-grained Sand, with Gravel, black, dry FILL: POORLY GRADED SAND with SILT (SP- SM), fine to medium-grained Sand, with Gravel, brown, moist

SILTY SAND (SM), fine to medium-grained Sand, with Gravel, brown, moist, soft (GLACIAL

TILL)

END OF BORING

Boring then backfilled with auger cuttings

Sa m pl e Blows

(N-Value) Recovery

7-10-9 (19) 15"

4-5-5 (10) 14"

2-2-1 (3) 14"

4-7-7 (14) 16" qₚ tsf

MC

% Tests or Remarks

Water not observed while drilling.

LOG OF BORING

See Descriptive Terminology sheet for explanation of abbreviations

Project Number B1910002 Geotechnical Evaluation MNANG ATFP Repair Entry Control Points 4680 Viper Street Duluth, Minnesota

BORING: ST-1

LOCATION: See attached sketch

NORTHING: 3364280 EASTING: 4826397

DRILLER: M. Swenson LOGGED BY: K. Warmuth START DATE: 11/04/19 END DATE: 11/04/19

SURFACE

ELEVATION: 1429.2 ft RIG: 7504 METHOD: 3 1/4" HSA SURFACING: WEATHER: 35 degrees, overcast

B1910002 Braun Intertec Corporation ST-1 page 1 of 1 ft

1428.5 0.4

1426.4 2.5

1418.9 10.0

W at er Le ve l Description of Materials

(Soil-ASTM D2488 or 2487; Rock-USACE EM 1110-1-2908)

BITUMINOUS, 5 inches FILL: SILTY SAND (SM), fine to medium-grained Sand, with Gravel, brown, moist

SILTY SAND (SM), fine to medium-grained Sand, with Gravel, brown, moist, very stiff to hard (GLACIAL TILL)

END OF BORING

Boring then backfilled with auger cuttings

Sa m pl e Blows

(N-Value) Recovery

6-8-11 (19) 14"

8-15-17 (32) 14"

4-13-17 (30) 13"

11-12-19 (31) 14" qₚ tsf

MC

% Tests or Remarks

Water not observed while drilling.

LOG OF BORING

See…