894CM3044_AE18511_FSNC_G_GEOTECHNICAL REPORT_APPENDIX A_2025.08.25 - signed.pdf

Report Cover Page

Fort Snelling National Cemetery Gravesite Expansion

Geotechnical Engineering Report Minneapolis, Minnesota

August 28, 2025 | Terracon Project No. MP255054

Prepared for:

Anderson Engineering of Minnesota

13605 1st Ave N Ste 100

Plymouth, MN 55441

Prepared by:

Terracon Consultants

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.

Daniel B. Mahrt, PE License No. 42729 August 28, 2025

13400 15th Avenue North

Plymouth, MN 55441

P (763) 489-3100

Terracon.com

Facilities | Environmental | Geotechnical | Materials

Report Cover Letter to Sign

August 28, 2025

Anderson Engineering of Minnesota 13605 1st Ave N Ste 100 Plymouth, MN 55441

Attn: Edwin Brodmarkle, PE P: 763-412-4058 E: EBrodmarkle@ae-mn.com

Re: Geotechnical Engineering Report Fort Snelling National Cemetery Gravesite Expansion 7601 34th Avenue South Minneapolis, Minnesota Terracon Project No. MP255054

Dear Mr. Brodmarkle:

We have completed the scope of Geotechnical Engineering services for the above referenced project in general accordance with Terracon Proposal No. PMP255054 dated February 27, 2025. This report presents the findings of the subsurface exploration and provides geotechnical recommendations concerning earthwork and the design and construction of foundations, slabs, and pavements for the proposed project.

We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report or if we may be of further service, please contact us.

Sincerely, Terracon

Mike Tuel, EIT Daniel B. Mahrt, PE Senior Staff Engineer Senior Principal/Department Manager

Geotechnical Engineering Report

Fort Snelling National Cemetary & Gravesite Expansion | Minneapolis, Minnesota

August 28, 2025 | Terracon Project No. MP255054

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Table of Contents

Introduction Project Description Site Conditions Geotechnical Characterization

Groundwater Conditions Seismic Site Class Geotechnical Overview Earthwork

Subgrade Preparation Existing Fill Excavation Soil Stabilization Fill Material Types Grading and Drainage Earthwork Construction Considerations Construction Observation and Testing

Shallow Foundations Design Parameters – Compressive Loads Design Parameters – Overturning and Uplift Loads Foundation Construction Considerations

Floor Slabs Floor Slab Design Parameters Floor Slab Construction Considerations

Pavements General Pavement Comments Sand Subbase Pavement Section Thicknesses Pavement Drainage Pavement Maintenance

Environmental Considerations Frost Considerations General Comments

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Figures GeoModel

Attachments

Exploration and Testing Procedures Site Location and Exploration Plans Exploration and Laboratory Results Supporting Information

Note: This report was originally delivered in a web-based format. Blue Bold text in the report indicates a referenced section heading. The PDF version also includes hyperlinks which direct the reader to that section and clicking on the logo will bring you back to this page. For more interactive features, please view your project online at client.terracon.com.

Refer to each individual Attachment for a listing of contents.

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Introduction

This report presents the results of our subsurface exploration and Geotechnical Engineering services performed for the proposed columbarium and gravesite expansion to be located at the Fort Snelling National Cemetery in Minneapolis, Minnesota. The purpose of these services was to provide information and geotechnical engineering recommendations relative to:

Subsurface soil conditions

Groundwater conditions

Seismic site classification per IBC

Site preparation and earthwork

Foundation design and construction

Floor slab design and construction

Pavement design and construction

Environmental considerations

Frost considerations

The geotechnical engineering Scope of Services for this project included the advancement of test borings, laboratory testing, engineering analysis, and preparation of this report.

Drawings showing the site and boring locations are shown on the Site Location and Exploration Plan, respectively. The results of the laboratory testing performed on soil samples obtained from the site during our field exploration are included on the boring logs in the Exploration and Laboratory Results section.

Project Description

Our initial understanding of the project was provided in our proposal and was discussed during project planning. A period of collaboration has transpired since the project was initiated, and our final understanding of the project conditions is as follows:

Item Description

Information Provided

An email request for proposal was provided by Mr.

Brodmarkle on February 4, 2025. The request included proposed boring locations for the project. Following our initial exploration and geotechnical report, three additional borings were requested. This report includes test results and geotechnical recommendations for our initial exploration and the additional borings.

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Item Description

Project Description

The project involves the expansion of the Fort Snelling National Cemetery, which includes In-ground cremation (IGC) burials at the north part of the site (Borings B-1 through B-4) and a Columbarium, sidewalks, and new pavements/parking area at the south end of the site (Borings B-5 through B-11).

Proposed Structure We anticipate the Columbarium will be stone or concrete structures supported spread footings and grade-supported slabs.

Finished Floor Elevation

Not provided; we anticipate the finished slab elevations for the Columbarium to be within 2 feet of existing grades.

Maximum Loads

Not provided; In the absence of information provided by the design team, we used the following loads in estimating settlement based on our experience with similar projects.

Walls: 1 to 2 kips per linear foot (klf)

Slabs: 150 pounds per square foot (psf)

Grading/Slopes Not provided; we anticipate no more than 2 feet of cut/fill will be required to establish final grades.

Pavements

We assume both rigid (concrete) and flexible (asphalt) pavement sections are being considered. We assume traffic loading will not exceed 50,000 ESALs in standard-duty sections.

In addition, lightly loaded pavement sections such as pedestrian paths/sidewalks are also planned for the project.

For these lightly-loaded pavement sections, we assume pavement loading will consist primarily of foot traffic and occasional maintenance vehicles such as UTVs.

Terracon should be notified if any of the above information is inconsistent with the planned construction, especially the grading limits, as modifications to our recommendations may be necessary.

Site Conditions

The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps.

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Item Description

Parcel Information

The project is located at 7601 34th Avenue South in Minneapolis, Minnesota.

Latitude/Longitude: 44.8647°, -93.2210° (approximate)

See Site Location

Existing Improvements

Existing Cemetery

Current Ground Cover

Manicured lawn at Borings B-1, B-2, and B-5 through B-11. Long grass/weeds at Borings B-3 and B-4

Existing Topography

Based on review of MnTOPO, the north portion of the project area (Borings B-1 through B-4) has a rolling terrain with elevations ranging from about 824 to 841 feet. The south portion of the project area is generally flat with elevations ranging from about 810 to 812 feet at Borings B-5 through B-8 and elevations ranging from 816 to 817 feet at Borings B-9 through B-11.

Geotechnical Characterization

We have developed a general characterization of the subsurface conditions based upon our review of the subsurface exploration, laboratory data, geologic setting and our understanding of the project. This characterization, termed GeoModel, forms the basis of our geotechnical calculations and evaluation of the site. Conditions observed at each exploration point are indicated on the individual logs. The individual logs can be found in the Exploration and Laboratory Results and the GeoModel can be found in the Figures attachment of this report.

As part of our analyses, we identified the following model layers within the subsurface profile. For a more detailed view of the model layer depths at each boring location, refer to the GeoModel.

Model Layer

Layer Name General Description

1 Topsoil/Rootzone Rootzone/topsoil ranging from about 4 to 12 inches thick

2 Existing fill

Silty sand, clayey sand, sandy silt, or sandy lean clay, brown, dark brown, dark gray, and/or black, trace roots, variable amounts of gravel and debris. Hydrocarbon odor noted in borings B-1, B-3, and B-4.

3 Silty Sand Brown, loose to medium dense

4 Clean Sand Trace gravel, brown, very loose to medium dense

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Groundwater Conditions

The boreholes were observed while drilling for the presence and level of groundwater.

The water levels observed in the boreholes can be found on the boring logs in Exploration and Laboratory Results. Groundwater was observed in Boring B-4 during drilling at a depth of about 20 feet below grade. Groundwater was not observed in the remaining borings at the time of drilling; however, this does not necessarily mean the boring terminated above groundwater. A relatively long period is often necessary for a groundwater level to develop and stabilize in a borehole. Long term observations in piezometers or observation wells, sealed from the influence of surface water, are recommended if it is necessary to define groundwater levels.

Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structure will vary. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project.

Seismic Site Class

The seismic design requirements for buildings and other structures are based on Seismic Design Category. Site Classification is required to determine the Seismic Design Category for a structure. The Site Classification is based on the upper 100 feet of the site profile defined by a weighted average value of either shear wave velocity, standard penetration resistance, or undrained shear strength in accordance with Section 20.4 of ASCE 7 and the International Building Code (IBC). Based on the soil properties observed at the site and as described on the exploration logs and results, our professional opinion is for that a Seismic Site Classification of D be considered for the project. Subsurface explorations at this site were extended to a maximum depth of 24.5 feet. The site properties below the boring depth to 100 feet were estimated based on our experience and knowledge of geologic conditions of the general area. Additional deeper borings or geophysical testing may be performed to confirm the conditions below the current boring depth.

Geotechnical Overview

The primary geotechnical considerations at this site are the presence of environmentally impacted soils, existing fill, and frost-susceptible soils:

Environmentally impacted soils. As part of our subsurface exploration, it is our policy to have personnel report the presence of unusual odors in drill samples or cuttings. As noted in Geotechnical Characterization, an apparent hydrocarbon odor was identified

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Facilities | Environmental | Geotechnical | Materials 5 in Borings B-1, B-3, and B-4 from a depth of about 5 to 9 feet below ground surface extending to boring termination depths. We recommend an environmental assessment be conducted to evaluate the extent of the impacted soils and to establish remediation options.

Existing Fill. Existing fill was encountered in the borings performed at the north portion of the site (B-1 through B-4) to depths ranging from about 6.5 feet to 24.5 feet below existing grades. At the south end of the site, existing fill was encountered in borings B-5, and B-7 through B-10 to depths ranging from approximately 1 to 3 ½ feet below existing grades. Documentation regarding placement and compaction of the existing fill was not provided for our review and the fill varies in consistency across the site.

Although some compaction effort may have been used, the fill does not appear to have been uniformly compacted to a high degree. The presence of existing fill on the site presents risks that unsuitable materials or voids may be present and concealed by the fill. If existing fill remains in place below planned structures (foundations, slabs, or pavements), there is an elevated risk of unacceptable settlement. Structures supported over undocumented fills often do not perform predictably.

Based on the variable materials noted in the borings and lack of documentation of the fill, we consider the existing fill to be uncontrolled, and not suitable for support of foundations and slabs. Our recommendations therefore include removal of the existing fill from below the columbarium structures and the appropriate oversize area and replacement with structural fill. The Shallow Foundations section addresses shallow foundation considerations for support of the structures directly bearing on engineered fill or native soils.

Support of pavements on or above existing fill materials is discussed in this report.

However, even with the recommended construction procedures, an inherent risk remains for the owner that compressible fill or unsuitable material, within or buried by the fill, will not be discovered. This risk of unforeseen conditions cannot be eliminated without completely removing the existing fill but can be reduced by following the recommendations contained in this report. To take advantage of the cost benefit of not removing the entire amount of undocumented fill, the owner must be willing to accept the risk of increased differential performance which can result in increased cracking and abrupt differential settlement. Should this risk be acceptable, pavements can be supported above the fill.

Frost-susceptible soils. The near-surface soils encountered on the site are frost susceptible. Frost heave can be detrimental to slabs supporting unheated structures as well as pavements, reducing service life, and requiring significant annual maintenance and repairs. If protection against subgrade movement related to frost heave is needed, foundations and slabs bearing above the frost line should be constructed to bear on non-frost susceptible (NFS) granular materials extending to a minimum depth of 5 feet below final grades. Alternatively, consideration could be given to constructing a frost-protected

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Facilities | Environmental | Geotechnical | Materials 6 shallow foundation (FPSF) in accordance with ASCE 32, which would incorporate both insulation and imported granular fill below the structure. Where practical in critical pavement and sidewalk areas, we recommend incorporating a granular subbase below the aggregate base layer to improve pavement performance.

The recommendations contained in this report are based upon the results of field and laboratory testing (presented in the Exploration and Laboratory Results), engineering analyses, and our current understanding of the proposed project. The General Comments section provides an understanding of the report limitations.

Earthwork

Earthwork is anticipated to include clearing and grubbing, excavations, and engineered fill placement. The following sections provide recommendations for use in the preparation of specifications for the work. Recommendations include critical quality criteria, as necessary, to render the site in the state considered in our geotechnical engineering evaluation for foundations, slabs, and pavements.

Subgrade Preparation

Prior to placing fill or formwork, existing fill, vegetation, and root mats should be removed. If movement of the structures due to frost heave needs to be minimized, we recommend completely removing frost-susceptible soils to a depth of 5 feet below the columbarium footprints and oversizing areas and replacing these soils with NFS fill, or designing a FPSF. In addition, where excavations terminate in low permeability clay or silts soils, we recommend placing draintile at the base of the sand layer and routing the drain tile to a suitable disposal outlet.

The table below provides estimated removal depths at the borings completed for the planned columbarium areas for removal of unsuitable soils below foundations and slabs.

Boring Location

Approximate Ground Surface

Elevation

(feet) 3

Anticipated Excavation Depth

(feet) 1, 2

Anticipated Bottom Elevation

(feet) 3

B-5 811 3.5 807.5

B-6 811 1 810

B-7 812 2.5 809.5

B-8 810 2 808

B-9 817 2 815

B-10 817 1 816

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Boring Location

Approximate Ground Surface

Elevation

(feet) 3

Anticipated Excavation Depth

(feet) 1, 2

Anticipated Bottom Elevation

(feet) 3

B-11 816 1 815

1. Depth to suitable soils below columbarium footprints to be confirmed by a geotechnical engineer at the time of construction.

2. Excavations may run deeper if movement due to frost heave cannot be tolerated

3. Elevations estimated from MnTOPO.

The subgrade should be proofrolled with an adequately loaded vehicle such as a fully-loaded tandem-axle dump truck in fine-grained (clays and silts) soils or a smooth drum roller in coarse-grained soils (sands and gravels). The proofrolling should be performed under the observation of the Geotechnical Engineer or representative. Areas excessively deflecting under the proofroll should be delineated and subsequently addressed by the Geotechnical Engineer.

All exposed areas which will receive fill, once properly cleared and sloped where necessary, should be scarified to a minimum depth of 10 inches, moisture conditioned as necessary, and compacted per the compaction requirements in this report. Compacted structural fill soils should then be placed to the proposed design grade and the moisture content and compaction of subgrade soils should be maintained until foundation or pavement construction.

Based upon the subsurface conditions determined from the geotechnical exploration, subgrade soils exposed during construction are anticipated to be relatively workable;

however, the workability of the subgrade may be affected by precipitation, repetitive construction traffic or other factors. If unworkable conditions develop, workability may be improved by scarifying and drying.

Existing Fill

As noted in Geotechnical Characterization, borings encountered previously placed fill to depths ranging from about 6.5 feet to boring termination depth of 24.5 feet in the north portion of the project site (Borings B-1 through B-4), and depths of 1 to 3 ½ feet in the south portion of the project site (Borings B-5, and B-7 through B-10) We understand no structures are planned for the north portion of the project site; however, a hydrocarbon odor was detected in most of the fill samples in Borings B-1, B-3, and B-

4. General considerations for remediation of impacted soils are provided below in the Environmental Considerations section.

We understand the south portion of the site is where new structures and pavements are to be constructed. We have no records to indicate the degree of control, and consequently, the fill is considered unreliable for support of the columbarium

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Facilities | Environmental | Geotechnical | Materials 8 foundations and slabs. Support of new sidewalks and pavements on or above existing fill soils is discussed in this report. However, even with the recommended construction procedures, inherent risk exists for the owner that compressible fill or unsuitable material, within or buried by the fill will not be discovered. This risk of unforeseen conditions cannot be eliminated without completely removing the existing fill but can be reduced by following the recommendations contained in this report.

If the owner elects to construct pavements and sidewalks on the existing fill, the following protocol should be followed. Following stripping operations and once the planned subgrade elevation has been reached, the entire pavement area should be proofrolled. Areas of soft or otherwise unsuitable material should be undercut and replaced with either new structural fill or suitable, existing on site materials.

Excavation

We anticipate that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. The bottom of excavations should be thoroughly cleaned of loose soils and disturbed materials prior to backfill placement and/or construction.

Soil Stabilization

If unsuitable areas are observed, methods of subgrade improvement, as described below, could include scarification, moisture conditioning and recompaction or removal of unstable materials and replacement with granular fill. The appropriate method of improvement, if required, would be dependent on factors such as schedule, weather, the size of area to be stabilized, and the nature of the instability. More detailed recommendations can be provided during construction as the need for subgrade stabilization occurs. Performing site grading operations during warm seasons and dry periods would help reduce the amount of subgrade stabilization required.

If the exposed subgrade is unstable during proofrolling operations, it could be stabilized using one of the methods outlined below.

Scarification and Recompaction - It may be feasible to scarify, dry, and recompact the exposed soils. The success of this procedure would depend primarily upon favorable weather and sufficient time to dry the soils. Stable subgrades likely would not be achievable if the thickness of the unstable soil is greater than about 1 foot, if the unstable soil is at or near groundwater levels, or if construction is performed during a period of wet or cool weather when drying is difficult.

Crushed Stone - The use of crushed stone or crushed gravel is a common procedure to improve subgrade stability. The use of high modulus geotextiles

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(i.e., engineering fabric or geogrid) could also be considered after underground work such as utility construction is completed. Prior to placing the fabric or geogrid, we recommend that all below grade construction, such as utility line installation, be completed to avoid damaging the fabric or geogrid. Equipment should not be operated above the fabric or geogrid until one full lift of crushed stone fill is placed above it. The maximum particle size of granular material placed over geotextile fabric or geogrid should not exceed 1-½ inches.

Fill Material Types

Fill required to achieve design grade should be classified as structural fill and general fill.

Structural fill is material used below or within 10 feet of structures. General fill is material used to achieve grade outside of these areas.

Imported fill materials or reused on-site soils should meet the following material property requirements. Portions of the existing granular fill materials encountered that are free of contamination, debris, and organic material are suitable for reuse as structural fill; however, the existing fill materials are frost susceptible and should not be reused if movement of the structure due to frost heave needs to be minimized. Please note that the fill encountered in the northern portion of the site (Borings B-1 through B-

4) had hydrocarbon odors; we recommend these materials be further characterized with an environmental assessment to determine possible impacts and remedial actions.

Regardless of its source, compacted fill should consist of approved materials that are free of organic matter and debris. Frozen material should not be used, and fill should not be placed on a frozen subgrade.

Soil Type 1, 2 USCS Classification

Acceptable Parameters (for Structural Fill)

Acceptable Location for Placement

On-site soils or imported materials

SP, SP-SM, SM

ML and CL soils (silts and clays) are not considered suitable for reuse as

Structural Fill

100% passing 3-inch sieve

Organic Content less than 3 %

Below foundations, slabs, and pavements

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Soil Type 1, 2 USCS Classification

Acceptable Parameters (for Structural Fill)

Acceptable Location for Placement

Non Frost- Susceptible

(NFS)

materials3

GW, GP

SW, SP

100% passing 3-inch sieve

Less than 50% passing No. 40 sieve Less than 5% passing

No. 200 sieve Organic Content less than 3 %

Below foundations or slabs bearing above frost line with NFS materials extending to a minimum depth of 5 feet below finished grade

1. Structural and general fill should consist of approved materials free of organic matter and debris. Frozen material should not be used, and fill should not be placed on a frozen subgrade.

2. Based on subsurface exploration. Actual material suitability for native soils should be determined in the field at time of construction.

3. Native NFS material (SP) was noted in the southern borings (B-5 through B-11) at depths of roughly 2 to 6 feet.

Fill Placement and Compaction Requirements

Structural and general fill should meet the following compaction requirements.

Item Structural Fill General Fill

Maximum Lift Thickness

8 inches or less in loose thickness when heavy, self-propelled compaction equipment is used

4 to 6 inches in loose thickness when hand-guided equipment (i.e. jumping jack or plate compactor) is used

Same as structural fill

Minimum Compaction

Requirements 1

98% of maximum below foundations

95% of maximum above foundations 92% of max.

Water Content

Range 1 Granular: -3% to +3% of optimum

As required to achieve minimum compaction requirements

1. Maximum density and optimum water content as determined by the standard Proctor test (ASTM D 698)

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Grading and Drainage

All grades must provide effective drainage away from the structures and after construction and should be maintained throughout the life of the structures. Water retained next to the structures can result in soil movements greater than those discussed in this report.

Where paving or flatwork abuts the structure, a maintenance program should be established to effectively seal and maintain joints and prevent surface water infiltration.

Earthwork Construction Considerations

Upon completion of filling and grading, care should be taken to maintain the subgrade water content prior to construction of grade-supported improvements such as floor slabs and pavements. Construction traffic over the completed subgrades should be avoided.

The site should also be graded to prevent ponding of surface water on the prepared subgrades or in excavations. Water collecting over or adjacent to construction areas should be removed. If the subgrade freezes, desiccates, saturates, or is disturbed, the affected material should be removed, or the materials should be scarified, moisture conditioned, and recompacted prior to floor slab construction.

As a minimum, excavations should be performed in accordance with OSHA 29 CFR, Part 1926, Subpart P, “Excavations” and its appendices, and in accordance with any applicable local and/or state regulations.

Construction site safety is the sole responsibility of the contractor who controls the means, methods, and sequencing of construction operations. Under no circumstances shall the information provided herein be interpreted to mean Terracon is assuming responsibility for construction site safety or the contractor's activities; such responsibility shall neither be implied nor inferred.

Excavations or other activities resulting in ground disturbance have the potential to affect adjoining properties and structures. Our scope of services does not include review of available final grading information or consider potential temporary grading performed by the contractor for potential effects such as ground movement beyond the project limits. A preconstruction/ precondition survey should be conducted to document nearby property/infrastructure prior to any site development activity. Excavation or ground disturbance activities adjacent or near property lines should be monitored or instrumented for potential ground movements that could negatively affect adjoining property and/or structures.

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Construction Observation and Testing

The earthwork efforts should be observed by the Geotechnical Engineer (or others under their direction). Observation should include documentation of adequate removal of surficial materials (vegetation, topsoil, and pavements), evaluation and remediation of existing fill materials, as well as proofrolling and mitigation of unsuitable areas delineated by the proofroll.

Each lift of compacted fill should be tested, evaluated, and reworked, as necessary, as recommended by the Geotechnical Engineer prior to placement of additional lifts. Each lift of fill should be tested for density and water content at a frequency of at least one test for every 2,500 square feet of compacted fill in the structure areas and 5,000 square feet in pavement areas. Where not specified by local ordinance, one density and water content test should be performed for a minimum of one test performed for every 12 vertical inches of compacted backfill.

In areas of foundation excavations, the bearing subgrade should be evaluated by the Geotechnical Engineer. If unanticipated conditions are observed, the Geotechnical Engineer should prescribe mitigation options.

In addition to the documentation of the essential parameters necessary for construction, the continuation of the Geotechnical Engineer into the construction phase of the project provides the continuity to maintain the Geotechnical Engineer’s evaluation of subsurface conditions, including assessing variations and associated design changes.

Shallow Foundations

If the site has been prepared in accordance with the requirements noted in Earthwork, the following design parameters are applicable for shallow foundations.

Design Parameters – Compressive Loads

Item Description

Maximum Net Allowable Bearing

Pressure 1, 2 3,000 psf

Required Bearing Stratum 3 Native soils or structural fill extending to native soils

Ultimate Passive Resistance4

(equivalent fluid pressures) 360 pcf (granular backfill)

Sliding Resistance 5 0.33 allowable coefficient of friction (granular material)

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Item Description

Minimum Embedment below

Finished Grade 6 Exterior footings in unheated areas: 60 inches

Estimated Total Settlement from

Structural Loads 2 Less than about 1 inch

Estimated Differential Settlement 2, 7 About 2/3 of total settlement

1. The maximum net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. Values assume that exterior grades are no steeper than 20% within 10 feet of structure.

2. Values provided are for maximum loads noted in Project Description. Additional geotechnical consultation will be necessary if higher loads are anticipated.

3. Unsuitable or soft soils should be overexcavated and replaced per the recommendations presented in Earthwork.

4. Use of passive earth pressures require the sides of the excavation for the spread footing foundation to be nearly vertical and the concrete placed neat against these vertical faces or that the footing forms be removed and compacted structural fill be placed against the vertical footing face. Assumes no hydrostatic pressure.

5. Can be used to compute sliding resistance where foundations are placed on suitable soil/materials. Frictional resistance for granular materials is dependent on the bearing pressure which may vary due to load combinations. For fine-grained materials, lateral resistance using cohesion should not exceed ½ the dead load.

6. Embedment necessary to minimize the effects of frost and/or seasonal water content variations. For sloping ground, maintain depth below the lowest adjacent exterior grade within 5 horizontal feet of the structure.

7. Differential settlements are noted for equivalent-loaded foundations and bearing elevation as measured over a span of 50 feet.

Design Parameters – Overturning and Uplift Loads

Shallow foundations subjected to overturning loads should be proportioned such that the resultant eccentricity is maintained in the center-third of the foundation (e.g., e < b/6, where b is the foundation width). This requirement is intended to keep the entire foundation area in compression during the extreme lateral/overturning load event.

Foundation oversizing may be required to satisfy this condition.

Uplift resistance of spread footings can be developed from the effective weight of the footing and the overlying soils with consideration to the IBC basic load combinations.

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Foundation Construction Considerations

As noted in Earthwork, the footing excavations should be evaluated under the observation of the Geotechnical Engineer. The base of all foundation excavations should be free of water and loose soil, prior to placing concrete. Concrete should be placed soon after excavating to reduce bearing soil disturbance. Care should be taken to prevent wetting or drying of the bearing materials during construction. Excessively wet or dry material or any loose/disturbed material in the bottom of the footing excavations should be removed/reconditioned before foundation concrete is placed.

Sensitive soils exposed at the surface of footing excavations may require surficial compaction with hand-held dynamic compaction equipment prior to placing structural fill, steel, and/or concrete. Should surficial compaction not be adequate, construction of a working surface consisting of either crushed stone or a lean concrete mud mat may be required prior to the placement of reinforcing steel and construction of foundations.

If unsuitable bearing soils are observed at the base of the planned footing excavation, the excavation should be extended deeper to suitable soils, and the footings could bear directly on these soils at the lower level or on lean concrete backfill placed in the excavations. The lean concrete replacement zone is illustrated on the sketch below.

Item Description

Soil Moist Unit Weight 100 pcf

Soil Effective Unit Weight1 40 pcf

Soil weight included in uplift resistance

Soil included within the prism extending up from the top perimeter of the footing at an angle of 20 degrees from vertical to ground surface

1. Effective (or buoyant) unit weight should be used for soil above the foundation level and below a water level. The high groundwater level should be used in uplift design as applicable. Based on groundwater depth observed in Boring B-4, we do not anticipate this to apply at this site unless deep structures are planned.

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Overexcavation for structural fill placement below footings should be conducted as shown below. The overexcavation should be backfilled up to the footing base elevation, with structural fill placed, as recommended in the Earthwork section.

Floor Slabs

Design parameters for floor slabs assume the requirements for Earthwork have been followed. Specific attention should be given to positive drainage away from the structure and positive drainage of the aggregate base beneath the floor slab.

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Floor Slab Design Parameters

Item Description

Floor Slab

Support1

Minimum 6 inches of free-draining (less than 5% passing the U.S. No. 200 sieve) crushed aggregate compacted to at least

95% of ASTM D 698 2, 3

Subgrade compacted to recommendations in Earthwork

Estimated Modulus of Subgrade

Reaction 2 150 pounds per square inch per inch (psi/in) for point loads

1. Floor slabs should be structurally independent of building footings or walls to reduce the possibility of floor slab cracking caused by differential movements between the slab and foundation.

2. Modulus of subgrade reaction is an estimated value based upon our experience with the subgrade condition, the requirements noted in Earthwork, and the floor slab support as noted in this table. It is provided for point loads. For large area loads the modulus of subgrade reaction would be lower.

3. Free-draining granular material should have less than 5 percent fines (material passing the #200 sieve). Other design considerations such as cold temperatures and condensation development could warrant more extensive design provisions.

Saw-cut contraction joints should be placed in the slab to help control the location and extent of cracking. For additional recommendations, refer to the ACI Design Manual.

Joints or cracks should be sealed with a waterproof, non-extruding compressible compound specifically recommended for heavy duty concrete pavement and wet environments.

Where floor slabs are tied to perimeter walls or turn-down slabs to meet structural or other construction objectives, our experience indicates differential movement between the walls and slabs will likely be observed in adjacent slab expansion joints or floor slab cracks beyond the length of the structural dowels. The Structural Engineer should account for potential differential settlement through use of sufficient control joints, appropriate reinforcing or other means.

Floor Slab Construction Considerations

Finished subgrade, within and for at least 10 feet beyond the floor slab, should be protected from traffic, rutting, or other disturbance and maintained in a relatively moist condition until floor slabs are constructed. If the subgrade should become damaged or desiccated prior to construction of floor slabs, the affected material should be removed, and structural fill should be added to replace the resulting excavation. Final conditioning

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Facilities | Environmental | Geotechnical | Materials 17 of the finished subgrade should be performed immediately prior to placement of the floor slab support course.

The Geotechnical Engineer should observe the condition of the floor slab subgrades immediately prior to placement of the floor slab support course, reinforcing steel, and concrete. Attention should be paid to high traffic areas that were rutted and disturbed earlier, and to areas where backfilled trenches are located.

Pavements

General Pavement Comments

Pavement designs are provided for the traffic conditions and pavement life conditions as noted in Project Description and in the following sections of this report. A critical aspect of pavement performance is site preparation. Pavement designs noted in this section must be applied to the site which has been prepared as recommended in the Earthwork section.

Sand Subbase

Due to the near surface clayey and silty soils, consideration should be given to including a sand subbase layer of 12 inches in the pavement section. Drainage should be provided for any sand subbase placed over the on-site slow-draining soils. Drain tile wrapped in a filter sock should be placed at the base of the sand cushion and tied into catch basins.

The sand subbase should at least meet the requirements of MnDOT Specification 3149.2B.2 for Select Granular Material. Placement of this sand subbase layer will reduce periods of saturation and thaw weakening and will better control frost movements and improve the long-term pavement performance.

We recommend placement of a geotextile fabric meeting the requirements of MnDOT Specification 3733, Type VII beneath the sand subbase and above the on-site clayey/silty soils to limit mixing of the granular materials with the underlying clayey/silty subgrade.

Pavement Section Thicknesses

Opinions of pavement thicknesses are based on the subsurface conditions encountered at the borings, general characterization of the subgrade, our experience on similar projects, and consider that the subgrade is proofrolled, tested, and evaluated as recommended in this report. Testing such as California Bearing Ratio (CBR), resilient modulus (MR), resistance value (R-Value), etc. was not part of our scope of service for

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Facilities | Environmental | Geotechnical | Materials 18 this project to evaluate the support characteristics of the subgrade; however, these can be performed upon request. The thickness of pavements for these scenarios should be in accordance with local city or county ordinances.

Thickness recommendations for Standard Duty sections based on primarily light passenger vehicle (gross weight less than 4 tons) traffic, and the occasional truck traffic are according to ACI Traffic Category A.

Thickness recommendations for Pedestrian Walking Path sections will be light and will primarily consist of foot traffic and small maintenance vehicles, such as UTVs.

The following tables summarizes the estimated minimum Portland cement concrete (PCC) and asphaltic cement concrete (ACC) pavement thicknesses for the anticipated traffic conditions for the facility. These sections are based on the subsurface conditions encountered at the borings and our experience on similar projects and consider that all materials are placed on a subgrade prepared and evaluated as recommended in this report.

Asphaltic Cement Concrete Design

Layer 1 Thickness (inches)

Pedestrian Walking Path Standard Duty

Pavement

ACC 2 ½ 3 ½ (two lifts) 2

Aggregate Base 6 8

1. Pavement materials, mix design, and construction should conform to the current Minnesota Department of Transportation (MnDOT) Standard Specifications for Construction.

2. A minimum 1.5-inch surface course should be used on standard-duty ACC pavements.

The following table provides our estimated minimum thickness of PCC pavements.

Portland Cement Concrete Design

Layer 1 Thickness (inches)

Pedestrian Walking Path/Sidewalks

Standard Duty Pavement

PCC 4 5

Aggregate Base 6 6

1. Pavement materials, mix design, and construction should conform to the current Minnesota Department of Transportation (MnDOT) Standard Specifications for Construction.

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Thicker pavement sections could be used to reduce maintenance and extend the expected service life of the pavements.

Construction traffic on the pavements was not considered in developing the recommended minimum pavement thicknesses. If the pavements will be subject to traffic by construction equipment/vehicles, the pavement thicknesses should be revised to consider the effects of the additional traffic loading.

Although not required for structural support, a minimum 6-inch thick base course layer is recommended to help reduce potential for slab curl, shrinkage cracking, and subgrade pumping through joints. Proper joint spacing will also be required to prevent excessive slab curling and shrinkage cracking. Joints should be sealed to prevent entry of foreign material and doweled where necessary for load transfer. PCC pavement details for joint spacing, joint reinforcement, and joint sealing should be prepared in accordance with ACI 330 and ACI 325.

Where practical, we recommend early-entry cutting of crack-control joints in PCC pavements. Cutting of the concrete in its “green” state typically reduces the potential for micro-cracking of the pavements prior to the crack control joints being formed, compared to cutting the joints after the concrete has fully set. Micro-cracking of pavements may lead to crack formation in locations other than the sawed joints, and/or reduction of fatigue life of the pavement.

Pavement Drainage

Pavements should be sloped to provide rapid drainage of surface water. Water allowed to pond on or adjacent to the pavements could saturate the subgrade and contribute to premature pavement deterioration. In addition, the pavement subgrade should be graded to provide positive drainage within the granular base section. Appropriate sub-drainage or connection to a suitable daylight outlet should be provided to remove water from the granular subbase.

Pavement Maintenance

The pavement sections represent minimum recommended thicknesses and, as such, periodic upkeep should be anticipated. Preventive maintenance should be planned and provided for through an ongoing pavement management program. Maintenance activities are intended to slow the rate of pavement deterioration and to preserve the pavement investment. Pavement care consists of both localized (e.g., crack and joint sealing and patching) and global maintenance (e.g., surface sealing). Additional engineering consultation is recommended to determine the type and extent of a cost-effective program. Even with periodic maintenance, some movements and related cracking may still occur, and repairs may be required.

P4 8#yP4 8#y

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Pavement performance is affected by its surroundings. In addition to providing preventive maintenance, the civil engineer should consider the following recommendations in the design and layout of pavements:

Final grade adjacent to paved areas should slope down from the edges at a minimum 2%.

Subgrade and pavement surfaces should have a minimum 2% slope to promote proper surface drainage.

Install pavement drainage systems surrounding areas anticipated for frequent wetting.

Install joint sealant and seal cracks immediately.

Seal all landscaped areas in or adjacent to pavements to reduce moisture migration to subgrade soils.

Environmental Considerations

As part of our subsurface exploration, it is our policy to have personnel report the presence of unusual odors in drill samples or cuttings. As noted on the appended boring logs for Borings B-1, B-3, and B-4, an apparent hydrocarbon odor was noted in the samples recovered from depths of approximately 5 to 9 feet below ground surface to boring termination depths ranging from 12.2 to 24.5 feet below existing grades. The reported odors should not be construed as providing any level of environmental site assessment. Terracon’s scope of geotechnical services for this project does not include any environmental assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. The geotechnical recommendations included in this report do not address the potential effects of vapor accumulation, disposal requirements for materials removed during construction, or changes in the subsurface conditions due to remediation efforts. We recommend an environmental assessment be carried out to characterize the impacted soils and to establish necessary remediation options. Terracon would be happy to provide these services.

Frost Considerations

The soils on this site are frost susceptible, and small amounts of water can affect the performance of the slabs on-grade, sidewalks, and pavements. Exterior slabs should be anticipated to heave during winter months. If frost action needs to be eliminated in critical areas, we recommend the use of non-frost susceptible (NFS) fill or structural slabs (for instance, structural stoops in front of building doors). Placement of NFS material in large areas may not be feasible; however, the following recommendations are provided to help reduce potential frost heave:

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Facilities | Environmental | Geotechnical | Materials 21

Provide surface drainage away from the columbarium structures and slabs, and toward the site drainage system.

Install drains around the perimeter of the structures, below exterior slabs and pavements, and connect them to the site drainage system.

Grade clayey subgrades so groundwater potentially perched in overlying fill or aggregate base, slope toward a site drainage system.

Place NFS fill as backfill beneath slabs and pavements critical to the project.

Place a 3 horizontal to 1 vertical (3H:1V) transition zone between NFS fill and other soils.

Place NFS materials in critical sidewalk areas.

General Comments

Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration.

Variations will occur between exploration point locations or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until construction. Terracon should be retained as the Geotechnical Engineer, where noted in this report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations.

Our Scope of Services does not include either specifically or by implication any environmental or…