24-0301 Minnewashta Pkwy REVISED Geo Report Bundle
July 16, 2024 HGTS Project Number: 24-0301
REVISED
Mr. Wade Hogen
Wooddale Builders
6117 Blue Circle Drive, Suite 101
Minnetonka, MN 55343
Re: Revised Geotechnical Exploration Report, Proposed Residential Development,
Chanhassen, Minnesota
Dear Mr. Hogen:
We recently completed a geotechnical exploration report for the proposed residential
development in Chanhassen, Minnesota. The results were presented in our report dated June
5, 2024. At that time specific civil engineering plans were not available. Since then, grading
plans have been completed and we were asked to review our geotechnical report especially
related to groundwater levels and proposed floor grades. This revised report provides further
discussion related to groundwater conditions below the site.
Details regarding our procedures, results and recommendations including but not limited to;
site grading, compaction, backfilling, below grade wall design, interior and exterior slab
design, utilities and pavement design were presented in the initial report dated June 5, 2024
and remain unchanged.
Thank you for the opportunity to assist you on this project. If you have any questions or need
additional information, please contact Paul Gionfriddo at 612-729-2959.
Sincerely,
Haugo GeoTechnical Services
Nic Alfonso, G.I.T. Paul Gionfriddo, P.E.
Project Geologist Senior Engineer
GEOTECHNICAL EXPLORATION REPORT
REVISED
PROJECT:
Proposed Residential Development
6870 Minnewashta Parkway
Chanhassen, Minnesota 55331
PREPARED FOR:
Wooddale Builders
6117 Blue Circle Drive
Minnetonka, Minnesota 55343
PREPARED BY:
Haugo GeoTechnical Services
2825 Cedar Avenue South
Minneapolis, Minnesota 55407
Haugo GeoTechnical Services Project: 24-0301
July 16, 2024
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.
Paul Gionfriddo, P.E.
Senior Engineer
License Number: 23093
Table of Contents
1.0 INTRODUCTION 1
1.1 Project Description 1
1.2 Purpose 1
1.3 Site Description 1
1.4 Scope of Services 1
1.5 Documents Provided 2
1.6 Locations and Elevations 2
2.0 FIELD PROCEDURES 2
3.0 RESULTS 3
3.1 Soil Conditions 3
3.2 Groundwater 3
3.3 Laboratory Testing 4
3.4 OSHA Soil Classification 4
4.0 DISCUSSION AND RECOMMENDATIONS 5
4.1 Proposed Construction 5
4.2 Discussion 5
4.3 Site Grading Recommendations 6
4.4 Dewatering 8
4.5 Interior Slabs 8
4.6 Below Grade Walls 8
4.7 Exterior Slabs 9
4.8 Site Grading and Drainage 10
4.9 Utilities 10
5.0 CONSTRUCTION CONSIDERATIONS 11
5.1 Excavation 11
5.2 Observations 11
5.3 Backfill and Fills 11
5.4 Testing 11
5.5 Winter Construction 12
6.0 PROCEDURES 12
6.1 Soil Classification 12
6.2 Groundwater Observations 12
7.0 GENERAL 12
7.1 Subsurface Variations 12
7.2 Review of Design 13
7.3 Groundwater Fluctuations 13
7.4 Use of Report 13
7.5 Level of Care 13
APPENDIX
Boring Location Sketch, Figure 1
GPS Boring Locations, Figure 2
Soil Boring Logs, SB-1 thru SB-7
Descriptive Terminology
1
1.0 INTRODUCTION
1.1 Project Description
Wooddale Builders is preparing for construction of a residential development at 6870
Minnewashta Parkway in Chanhassen, Minnesota and retained Haugo GeoTechnical Services
(HGTS) to perform a geotechnical exploration to evaluate the suitability of site soil conditions
to support the proposed development.
We understand the project will include preparing house pads for 5 single-family homes along
with the associated underground utilities.
1.2 Purpose
The purpose of this geotechnical exploration was to characterize subsurface soil and
groundwater conditions and provide recommendations for foundation design and
construction.
1.3 Site Description
The project site is located at 6870 Minnewashta Parkway in Chanhassen, Minnesota. At the
time of this assessment, the project site existed as an approximate 3-acre residential property
that contained a house and barn. Areas not occupied by the structures were lawn covered and
landscaped with several trees throughout the property.
The site topography was slightly sloped downward to the east with the elevations at the soil
boring locations ranging from about 972 to 987 ½ feet above mean sea level (MSL).
1.4 Scope of Services
Our services were performed as requested and authorized by Wooddale Builders. Our
services were performed under the terms of our General Conditions and were limited to the
following tasks:
Completing seven (7) standard penetration test soil borings and extending to nominal
depths of 20 feet.
Sealing the boring in accordance with Minnesota Department of Health requirements.
Obtaining GPS coordinates and ground surface elevations at the soil boring location.
Visually/manually classifying samples recovered from the soil boring.
Performing laboratory tests on selected samples.
Preparing soil boring logs describing the materials encountered and the results of
groundwater level measurements.
Preparing an engineering report describing soil and groundwater conditions and
providing recommendations for foundation design and construction.
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1.5 Documents Provided
We were provided three site plans that were prepared by Sathre-Bergquist, Inc. Each of the
plans showed the proposed layout of the development including the lots and house locations.
We were also provided plan sheet 3 of 19 titled “Grading & Erosion Control Plan” that was
prepared by Sathre -Berquist, Inc and dated June 14, 2024 with a latest revision date of July 10,
2024. The plan sheet provided grading details and also showed the proposed basement
elevations of the homes.
Other than the provided plans, specific architectural, structural or civil documents were not
provided at the time of this assessment.
1.6 Locations and Elevations
The soil boring locations were selected and staked in the field by others. The approximate
locations of the soil borings are shown on Figure 1, “Soil Boring Location Sketch,” in the
Appendix. The sketch was prepared by HGTS using an aerial image from Google Earth as a
base.
HGTS obtained the GPS coordinates and ground surface elevations at the soil boring locations
using GPS technology based on the US State Plane Coordinate System. GPS coordinates and
ground surface elevations are shown on Figure 2 in the Appendix.
2.0 FIELD PROCEDURES
The standard penetration test borings were advanced on May 22nd and 23rd, 2024 by HGTS
with a rotary drilling rig, using continuous flight augers to advance the boreholes.
Representative samples were obtained from the borings, using the split-barrel sampling
procedures in general accordance with ASTM Specification D-1586. In the split-barrel
sampling procedure, a 2-inch O.D. split-barrel spoon is driven into the ground with a 140-
pound hammer falling 30 inches. The number of blows required to drive the sampling spoon
the last 12 inches of an 18-inch penetration is recorded as the standard penetration resistance
value, or "N" value. The results of the standard penetration tests are indicated on the boring
logs. The samples were sealed in containers and provided to HGTS for testing and soil
classification.
A field log of each boring was prepared by HGTS. The logs contain visual classifications of the
soil materials encountered during drilling, as well as the driller's interpretation of the
subsurface conditions between samples and water observation notes. The final boring logs
included with this report represent an interpretation of the field logs and include
modifications based on visual/manual method observation of the samples.
The soil boring logs, general terminology for soil description and identification, and
classification of soils for engineering purposes are also included in the appendix. The soil
boring logs identify and describe the materials encountered, the relative density or consistency
based on the Standard Penetration resistance (N-value, “blows per foot”) and groundwater
observations.
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The strata changes were inferred from the changes in the samples and auger cuttings. The
depths shown as changes between strata are only approximate. The changes are likely
transitions, variations can occur beyond the location of the borings.
3.0 RESULTS
3.1 Soil Conditions
At the surface, the soil borings encountered about 2 feet of topsoil consisting of sandy lean
clay, silty clayey sand and clayey sand that was dark brown and black in color.
Below the topsoil, the soil borings encountered native glacial till soils that extended to the
termination depths of the borings. The glacial till soils consisted of clayey sand and sandy lean
clay that was brown and grey in color.
Penetration resistance values (N-Values), shown as blows per foot (bpf) on the boring logs,
within the clayey sand glacial till soils ranged from 0 to 5 bpf indicating a very loose to loose
relative density.
N-Values within the sandy lean clay glacial till soils range from 3 to 15 bpf indicating a soft to
stiff consistency.
3.2 Groundwater
Groundwater was encountered in four of the soil borings while drilling and sampling at
depths ranging from about 5 to 20 feet below the ground surface corresponding to elevations
of about 963 to 973 feet above mean sea level (MSL).
Groundwater was not encountered in each boring and was not encountered at a consistent
elevation in the borings. Groundwater appears to be perched with the clayey glacial till soil
and is likely associated with sand seams or more permeable layers within the clayey glacial
till that were not apparent during drilling. The observed water levels are summarized in Table
1. Lowest floor slab elevations on each lot are refenced for convenience.
Table 1. Summary of Groundwater Levels
Boring
Number
Measured
Surface
Elevation (feet)
Estimated Depth
to Groundwater
(feet)*
Estimated
Groundwater
Elevation (feet)*
Lot/Lowest Floor
Slab Elevation
SB-1 977.1 NE - Lot 4, 975.1
SB-2 977.8 15 963 Lot 5, 975.1
SB-3 972.2 5 967 Lot 4, 975.1
SB-4 984.4 20 964 ½ Lot 1, 978.6
SB-5 984.2 NE - Lot 1, 978.6
SB-6 980.0 NE - Lot 3, 981.4
SB-7 987.5 14 ½ 973 Lot 2, 979.1
* = Depths and elevations were rounded to the nearest ½ foot. NE = Not Encountered
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Based on a brief review of the Minnesota Department of Natural Resources website, the
Ordinary High-Water Level of nearby Lake Minnewashta is 944.5 feet. The lowest and highest
recorded water levels were reported to be 942.2 and 946.26 feet, respectively.
Water levels were measured on the dates as noted on the boring logs and the period of water
level observations was relatively short. Given the cohesive native of the soils encountered in
the borings it is possible there was insufficient time for groundwater to seep into the borehole
and rise to its hydrostatic level. Groundwater monitoring wells or piezometers would be
required to more accurately determine water levels. Seasonal and annual fluctuations in the
groundwater levels should be expected.
3.3 Laboratory Testing
Laboratory moisture content tests were performed on selected samples recovered from the
soil borings. Laboratory soil moisture contents ranged from about 20 to 33 ½ percent
indicating that the soils were likely above their assumed optimum moisture content based on
the standard Proctor test. Laboratory tests results are summarized in Table 2 and are shown
on the boring logs adjacent to the samples tested.
Table 2. Summary of Laboratory Tests
Boring Number Sample
Number
Depth
(feet)
Moisture Content
(%) *
SB-1 SS-18 2 ½ 20
SB-1 SS-20 7 ½ 23 ½
SB-2 SS-11 5 31 ½
SB-2 SS-13 10 26 ½
SB-3 SS-3 5 24
SB-3 SS-4 7 ½ 27 ½
SB-4 SS-51 5 24 ½
SB-4 SS-53 10 22 ½
SB-5 SS-42 2 ½ 33 ½
SB-5 SS-45 10 20 ½
SB-6 SS-27 5 20
SB-6 SS-30 12 ½ 18 ½
SB-7 SS-34 2 ½ 27
SB-7 SS-36 7 ½ 23
SB-7 SS-28 12 ½ 25
*Moisture content values rounded to the nearest ½ percent.
3.4 OSHA Soil Classification
The soils encountered in the borings consisted of clayey sand and sandy lean clay meeting the
ASTM Classifications of SC and CL. Soils classified as SC will generally be Type C soils under
Department of Labor Occupational Safety and Health Administration (OSHA) guidelines.
Soils classified as CL will generally be Type B soils under OSHA guidelines.
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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.
4.0 DISCUSSION AND RECOMMENDATIONS
4.1 Proposed Construction
We understand that the project will include preparing lots and house pads for 5 single-family
homes along with the associated underground utilities. We were not provided specific
architectural, structural or civil construction plans, but we assume the homes will include one
or two stories above grade with walkout, lookout or full basements. We anticipate below grade
construction consisting of cast-in-place concrete foundation walls supported on concrete
spread footings. The above grade construction is assumed to consist of wood framing, a
pitched roof and asphalt shingles.
Based on the assumed construction we estimate wall loadings will range from about 2 to 3
kips (2,000 to 3,000 pounds) per lineal foot and column loads, if any, will be on the order of 75
kips (75,000 pounds).
We anticipate the buildings will be constructed at or near existing site grades so that cuts or
fill for permanent grade changes will generally be on the order of 5 feet or less.
We have attempted to describe our understanding of the project. If the proposed loads exceed
these values or if the design or location of the proposed development changes, we should be
informed. Additional analyses and revised recommendations may be necessary.
4.2 Discussion
Structures existed on the project site that we anticipate will be removed/demolished to make
was for the proposed development. We recommend that all remnants of the structures
including footings, floor slabs, foundation walls, exterior flatwork and underground utilities
be removed from within the proposed building and oversize areas and be properly disposed
of off-site.
The vegetation and topsoil are not suitable for foundation or utility support and will need to
be removed from below the building pads, utilities and oversize areas and replaced with
suitable competed engineered fill, as needed, to attain design grades.
It is our opinion that the underlying native glacial till soils are generally suitable for
foundation support. However, the upper portions of the clayey glacial till soils had a soft
consistency or very loose relative density and will need to be removed and replaced with
suitable compacted engineered fill or excavated, dried and recompacted. If the homes will
have a basement level, then removal of some, or all, of the soft or very loose soil could be
incidental to construction.
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The underlying stiffer/denser glacial till soils, in our opinion are suitable for foundation
support.
Soil moisture contents ranged from about 20 to 49 ½ percent indicating that the soils were
likely above their assumed optimum moisture content based on the standard Proctor test.
Soils that will be excavated and reused as fill or backfill will likely require some moisture
conditioning (drying) to meet the recommended compaction levels. Summer months are
typically more favorable for drying wet soils.
Groundwater was encountered in four of the soil borings while drilling and sampling at
depths of about 5 to 20 feet below the ground surface, corresponding to elevations ranging
from about 963 to 973 feet above mean sea level. Based on the Grading & Erosion Control Plan
the lowest floor slabs for the proposed homes will bear at elevation ranging from 975.1 to 981.4
which are above the water levels observed in the boring. We do not anticipate that
groundwater will be encountered during foundation construction.
Soil corrections are anticipated to extend about 7 feet below the ground surface at boring SB-
3. With perched water encountered in boring SB-3 at about 5 feet below the ground surface,
groundwater could be encountered during soil corrections and dewatering could be required.
If groundwater is encountered then the successful contractor may need to develop and submit
a dewatering plan.
The following sections provide recommendations for foundation design and construction.
4.3 Site Grading Recommendations
Excavation We recommend that all vegetation, topsoil and any soft or otherwise unsuitable
soils, if encountered, be removed from below the proposed building, utility and oversize areas.
We recommend that all remnants of the structures including footings, floor slabs, foundation
walls, exterior flatwork and underground utilities be removed from within the proposed
building, utility and oversize areas. Table 3 summarizes the anticipated excavation depths at
the soil boring locations. Excavation depths may vary and could be deeper.
Table 3. Anticipated Excavation Depths
Boring
Number
Measured
Surface
Elevation
(feet)
Anticipated
Excavation
Depth (feet)*
Anticipated
Excavation
Elevation (feet)*
Approximate
Groundwater
Elevation
(feet)*
SB-1 977.1 7 970 NE
SB-2 977.8 4 ½ 973 ½ 963
SB-3 972.2 7 965 967
SB-4 984.4 7 977 ½ 964 ½
SB-5 984.2 4 ½ 979 ½ NE
SB-6 980 4 ½ 975 ½ NE
SB-7 987.5 7 985 ½ 973
* = Excavation depths and elevations were rounded to nearest ½ foot.
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Oversizing In areas where the excavations for soil corrections extend below the proposed
footing elevations, the excavations require oversizing. We recommend the perimeter of the
excavation be extended a foot outside the proposed footprint for every foot below footing
grade (1H:1V oversizing). The purpose of the oversizing is to provide lateral support of the
foundation.
Fill Material Additional fill required to attain design grades can consist of any mineral soil
provided it is free of debris, organic soil and any soft or otherwise unsuitable materials. Except
we recommend that fill or backfill placed in wet excavations or within 2 feet of the
groundwater table, if encountered, consist of “clean coarse sand” with less than 5 percent
passing the number 200 sieve and at least 50 percent retained on the number 40 sieve.
The on-site native glacial till soils appear to be suitable for reuse as structural fill or backfill
provided it is free of debris, organic soils or other unsuitable materials. Laboratory soil
moisture contents ranged from about 20 to 33 ½ percent indicating that the soils were likely
above their assumed optimum moisture content based on the standard Proctor test. Soils that
will be excavated and reused as fill and backfill will likely require some moisture conditioning
(drying) to achieve the recommended compaction levels.
Topsoil or other soils that are black in color are not suitable for reuse as structural fill or
backfill.
Backfilling We recommend that backfill placed to attain site grades be compacted to a
minimum of 95 percent of its standard Proctor density (ASTM D 698). Granular fill classified
as SP or SP-SM should be placed within 65 percent to 105 percent of its optimum moisture
content as determined by the standard Proctor. Other fill soils should be placed within 3
percentage points above and 1 percentage point below its optimum moisture content as
determined by the standard Proctor. All fill should be placed in thin lifts and be compacted
with a large self-propelled vibratory compactor operating in vibratory mode.
In areas where fill depths will exceed 10 feet, if any, we recommend that compaction levels be
increased to a minimum of 100 percent of standard Proctor density. Even with the increased
compaction levels a construction delay may be required to allow for post settlement of the fill
mass.
Fill and backfill placed on slopes, if any, must be “benched” into the underlying suitable soils
to reduce the potential for slip places to develop between the fill and underlying soil. We
recommend “benching” or excavating into the slope at 5 feet vertical intervals to key the fill
into the slope. We recommend each bench be a minimum of 10 feet wide.
Foundations We recommend the perimeter footings bear a minimum of 42 inches below the
exterior grade for frost protection. Interior footings may be placed immediately below the
slab provided construction does not occur during below freezing weather conditions.
Foundation elements in unheated areas (i.e., deck or porch footings) should bear at least 5 feet
below exterior grade for frost protection.
We anticipate the foundations and floor slabs will bear on compacted clayey engineered fill or
clayey native glacial till soils. With the building pads prepared as recommended, it is our
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opinion the footings can be designed for a net allowable bearing pressure up to 2,000 pounds
per square foot (psf).
We anticipate total and differential settlement of the foundations will be less than 1 inch and
½ inch, respectively, across a 30-foot span.
4.4 Dewatering
Groundwater was encountered in 4 of the borings at depths ranging from about 5 to 20 feet
below the ground surface, corresponding to elevations of about 963 to 973 feet above mean
sea level and appears to perched within the clayey glacial till soils. We do not anticipate that
groundwater will be encountered during foundation construction but could be encountered
during soil corrections, especially in the vicinity of soil boring SB-3
If groundwater is encountered and dewatering is required then the successful contractor may
need to develop and submit a dewatering plan.
4.5 Interior Slabs
The anticipated floor subgrade will consist of compacted clayey engineered fill or clayey
native glacial till soils. It is our opinion a modulus of subgrade reaction, k, of 50 pounds per
square inch per inch of deflection (psi) may be used to design the floor.
If floor coverings or coatings less permeable than the concrete slab will be used, we
recommend that a vapor retarder or vapor barrier be placed immediately beneath the slab.
Some contractors prefer to bury the vapor barrier or vapor retarder beneath a layer of sand to
reduce curling and shrinkage, but this practice often traps water between the slab and vapor
retarder or barrier. Regardless of where the vapor retarder or vapor barrier is placed, we
recommend consulting the floor covering manufacturer regarding the appropriate type, use
and installation of the vapor retarder or vapor barrier to preserve the warranty.
We recommend following all state and local building codes with regards to a radon mitigation
plan beneath interior slabs.
4.6 Below Grade Walls
We recommend general waterproofing of the below grade walls. We recommend either
placing drainage composite against the backs of the exterior walls or backfilling adjacent to
the walls with sand having less than 50 percent of the particles by weight passing the #40 sieve
and less than 5 percent of the particles by weight passing the #200 sieve. The sand backfill
should be placed within 2 feet horizontally of the wall. We recommend the balance of the
backfill for the walls consist of sand however the sand may contain up to 20 percent of the
particles by weight passing the #200 sieve.
We recommend installing drain tile behind the below grade walls, adjacent to the wall footing
and below the slab elevation. Preferably the drain tile should consist of perforated pipe
embedded in gravel. A geotextile filter fabric should encase the pipe and gravel. The drain
tile should be routed to a storm sewer, sump pump or other suitable disposal site.
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Foundation walls or below grade (basement) walls will have lateral loads from the
surrounding soil transmitted to them. Active earth pressures can be used to design the below
grade walls if the walls are allowed to rotate slightly. If wall rotation cannot be tolerated, then
below grade wall design should be based on at-rest earth pressures. It is our opinion that the
estimated soil parameters presented in Table 4 can be used for below grade wall design. These
estimated parameters are based on the assumptions that the walls are drained, there are no
surcharge loads within a horizontal distance equal to the height of the wall and the backfill is
level.
Table 4. Estimated Soil Parameters
Soil Type
Estimated
Unit
Weight
(pcf)
Estimated
Friction
Angle
(degrees)
At-Rest
Pressure
(pcf)
Active
Soil
Pressure
(pcf)
Passive Soil
Pressure
(pcf)
Sand
(SP & SP-SM) 120 32 55 35 390
Other Soils
(CL & SC) 135 28 70 50 375
Resistance to lateral earth pressures will be provided by passive resistance against the wall
footings and by sliding resistance along the bottom of the wall footings. We recommend a
sliding coefficient of 0.35. This value does not include a factor of safety.
4.7 Exterior Slabs
Exterior slabs will likely be underlain by clayey soils which are considered to be moderately
to highly frost susceptible. If these soils become saturated and freeze, frost heave may occur.
This heave can be a nuisance in front of doors and at other critical grade areas. One way to
help reduce the potential for heaving is to remove the frost-susceptible soils below the slabs
down to bottom of footing grades and replace them with non-frost-susceptible backfill
consisting of sand having less than 5 percent of the particles by weight passing the number
200 sieve.
If this approach is used and the excavation bottoms terminate in non-free draining granular
soil, we recommend a drain tile be installed along the bottom outer edges of the excavation to
collect and remove any water that may accumulate within the sand. The bottom of the
excavation should be graded away from the building.
If the banks of the excavations to remove the frost-susceptible soils are not sloped, abrupt
transitions between the frost-susceptible and non-frost-susceptible backfill will exist along
which unfavorable amounts of differential heaving may occur. Such transitions could exist
between exterior slabs and sidewalks, between exterior slabs and pavements and along the
slabs themselves if the excavations are confined to only the building entrances. To address
this issue, we recommend sloping the excavations to remove frost-susceptible soils at a
minimum 3:1 (horizontal:vertical) gradient.
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Another alternative for reducing frost heave is to support the slabs on frost depth footings. A
void space of at least 4 inches should be provided between the slab and the underlying soil to
allow the soil to heave without affecting the slabs.
4.8 Site Grading and Drainage
We recommend the site be graded to provide positive run-off away from the proposed
buildings. We recommend landscaped areas be sloped a minimum of 6 inches within 10 feet
of the building and slabs be sloped a minimum of 2 inches. In addition, we recommend
downspouts with long splash blocks or extensions.
We recommend the lowest floor grades be constructed to meet City of Chanhassen
requirements with respect to groundwater separation distances.
4.9 Utilities
We anticipate that new utilities will be installed as part of this project. We further anticipate
that new utilities will bear at depths ranging from about 7 to 10 feet below the ground surface.
At these depths, we anticipate that the pipes will bear on compacted engineered fill or native
glacial till soils, which in our opinion are suitable for pipe support. We recommend removing
all vegetation, topsoil and any soft or otherwise unsuitable soils, if any, beneath utilities prior
to placement.
We recommend bedding material be thoroughly compacted around the pipes. We recommend
trench backfill above the pipes be compacted to a minimum of 95 percent beneath slabs and
pavements, the exception being within 3 feet of the proposed pavement subgrade, where 100
percent of standard Proctor density is required. In landscaped areas, we recommend a
minimum compaction of 90 percent.
Groundwater was encountered in the borings at depths ranging from about 5 to 20 feet below
the ground surface. See Section 4.4 for dewatering considerations.
4.10 Estimated Infiltration Rates
We anticipate that stormwater management areas, such as ponds or rain gardens, could be
constructed as part of the project. Information regarding the locations or depths of any ponds
or rain gardens was not provided. Below the topsoil the soils encountered in the borings
consisted of clayey sand and sandy lean clay that correspond to the ASTM Classifications of
SC and CL, respectively. It is our opinion that the infiltration rates presented in Table 5, which
were obtained from the Minnesota Storm Water Manual, can be used for infiltration basin
design.
Table 5. Estimated Design Infiltration Rates
Soil Description & ASTM
Classification
Hydrologic Soil
Group
Estimated Design
Infiltration Rate (in/hr.)
Clayey Sand (SC) D 0.06
Sandy Lean Clay (CL) D 0.06
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It should be noted that infiltration rates can vary due to; soil moisture content, soil compaction,
the placement or introduction of fine-grained soils, topsoil or biofiltration media and changes
or variations in local groundwater levels. These variations may result in additional
construction costs and it is suggested that a contingency be provided for this purpose.
Field tests (double ring infiltrometer) can be performed within the proposed basin areas to
verify infiltration rates of the in-situ soils. We would be pleased to provide these services if
required or requested.
5.0 CONSTRUCTION CONSIDERATIONS
5.1 Excavation
The soils encountered in the borings consisted of clayey sand and sandy lean clay meeting the
ASTM Classifications of SC and CL. Soils classified as SC will generally be Type C soils under
Department of Labor Occupational Safety and Health Administration (OSHA) guidelines.
Soils classified as CL will generally be Type B soils under OSHA guidelines.
Temporary excavations in Type C soils should be constructed at a minimum of 1 ½ foot
horizontal to every 1-foot vertical within excavations. Temporary excavations in Type B soils
should be constructed at a minimum of 1 foot horizontal to every 1-foot vertical within
excavations. Slopes constructed in this manner may still exhibit surface sloughing. If site
constraints do not allow the construction of slopes with these dimensions, then temporary
shoring may be required.
5.2 Observations
A geotechnical engineer or a qualified engineering technician should observe the excavation
subgrade to evaluate if the subgrade soils are similar to those encountered in the borings and
adequate to support the proposed construction.
5.3 Backfill and Fills
The on-site soils appear to be above their assumed optimum soil moisture content. If these
soils will be used or reused as structural fill or backfill, some drying of the soils could be
required to meet the recommend compaction levels. We recommend moisture conditioning
all soils that will be used as fill or backfill in accordance with Section 4.3 above. We recommend
that fill and backfill be placed in lifts not exceeding 4 to 12 inches, depending on the size of
the compactor and materials used.
5.4 Testing
We recommend density tests of backfill and fills placed for the proposed foundations. Samples
of the proposed materials should be submitted to our laboratory prior to placement for
evaluation of their suitability and to determine their optimum moisture content and maximum
dry density (Standard Proctor).
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5.5 Winter Construction
If site grading and construction is anticipated to proceed during cold weather, all snow and
ice should be removed from cut and fill areas prior to additional grading and placement of
fill. No fill should be placed on frozen soil and no frozen soil should be used as fill or backfill.
Concrete delivered to the site should meet the temperature requirements of ASTM and/or
ACI. Concrete should not be placed on frozen soil. Concrete should be protected from
freezing until the necessary strength is obtained. Frost should not be permitted to penetrate
below the footings.
6.0 PROCEDURES
6.1 Soil Classification
The drill crew chief visually and manually classified the soils encountered in the borings in
general accordance with ASTM D 2488, “Description and Identification of Soils (Visual-
Manual Procedure).” Soil terminology notes are included in the Appendix. The samples were
returned to our laboratory for review of the field classification by a soils engineer. Samples
will be retained for a period of 30 days.
6.2 Groundwater Observations
Immediately after taking the final samples in the bottom of the boring, the hole was checked
for the presence of groundwater. Immediately after removing the augers from the borehole
the hole was once again checked and the depth to water and cave-in depths were noted.
7.0 GENERAL
7.1 Subsurface Variations
The analyses and recommendations presented in this report are based on data obtained from
a limited number of soil borings. Variations can occur away from the boring, the nature of
which may not become apparent until additional exploration work is completed, or
construction is conducted. A reevaluation of the recommendations in this report should be
made after performing on-site observations during construction to note the characteristics of
any variations. The variations may result in additional foundation costs and it is suggested
that a contingency be provided for this purpose.
It is recommended that we be retained to perform the observation and testing program during
construction to 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, specifications and construction methods. This
will allow correlation of the soil conditions encountered during construction to the soil borings
and will provide continuity of professional responsibility.
13
7.2 Review of Design
This report is based on the design of the proposed structures as related to us for preparation
of this report. It is recommended that we be retained to review the geotechnical aspects of the
design and specifications. With the review, we will evaluate whether any changes have
affected the validity of the recommendations and whether our recommendations have been
correctly interpreted and implemented in the design and specifications.
7.3 Groundwater Fluctuations
We made water level measurements in the borings at the times and under the conditions stated
on the boring log. The data was interpreted in the text of this report. The period of observation
was relatively short and fluctuations in the groundwater level may occur due to rainfall,
flooding, irrigation, spring thaw, drainage, and other seasonal and annual factors not evident
at the time the observations were made. Design drawings and specifications and construction
planning should recognize the possibility of fluctuations.
7.4 Use of Report
This report is for the exclusive use of Wooddale Builders and their design team to use to design
the proposed structures and prepare construction documents. In the absence of our written
approval, we make no representation and assume no responsibility to other parties regarding
this report. The data, analysis and recommendations may not be appropriate for other
structures or purposes. We recommend that parties contemplating other structures or
purposes contact us.
7.5 Level of Care
Haugo GeoTechnical Services has used the degree of skill and care ordinarily exercised under
similar circumstance by members of the profession currently practicing in this locality. No
warranty expressed or implied is made.
APPENDIX
Haugo GeoTechnical Services, LLC
2825 Cedar Avenue South
Minneapolis, MN 55407
Figure #: 1
Drawn By: NA
Date: 5/28/24
Scale: None
Project #: 24-0301
Soil Boring Location Sketch
6870 Minnewashta Parkway
Chanhassen, Minnesota
SB-3 SB-1
Legend
Approximate Soil Boring Location
SB-4
SB-5 SB-7
SB-6
Disclaimer: Map and parcel data are believed to be accurate, but accuracy is not guaranteed.
This is not a legal document and should not be substituted for a title search, appraisal, survey, or for zoning verification.
SB-2
HGTS# 24-0301
Figure 2: GPS Boring Locations
Referencing US State Plane Coordinate System
Boring Number Elevation
(US Feet)
Northing
Coordinate
Easting
Coordinate
SB-1 977.1 1013656.68973003 2722911.80153255
SB-2 977.8 1013718.65724176 2722908.28218058
SB-3 972.2 1013656.38213933 2723058.15070034
SB-4 984.4 1013631.840879 2722619.5991845
SB-5 984.2 1013732.69825125 2722600.72337484
SB-6 980.0 1013758.66634966 2722807.88863268
SB-7 987.5 1013737.20949562 2722807.88863268
Sandy Lean Clay, dark brown, moist (Topsoil)
(SC) Clayey Sand, trace Gravel, brown, wet, loose (Glacial Till)
(CL) Sandy Lean Clay, brown, moist, rather soft to stiff (Glacial
Till)
Bottom of borehole at 21.0 feet.
AU
17
SS
18
SS
19
SS
20
SS
21
SS
22
SS
23
SS
24
1-3-2
(5)
1-2-3
(5)
2-3-3
(6)
3-4-4
(8)
4-5-5
(10)
4-5-5
(10)
5-7-8
(15)
20
23.5
NOTES
GROUND ELEVATION 977.1 ft
LOGGED BY NC/MS
DRILLING METHOD Hollow Stem Auger/Split Spoon
DRILLING CONTRACTOR HGTS- 45 GROUND WATER LEVELS:
CHECKED BY PG
DATE STARTED 5/22/24 COMPLETED 5/22/24
AT TIME OF DRILLING --- Not Encountered
AT END OF DRILLING --- Not Encountered
AFTER DRILLING --- Not Encountered
HOLE SIZE 3 1/4 inches
DEPTH(ft)0
5
10
15
20 GRAPHICLOGMATERIAL DESCRIPTION
SAMPLE TYPENUMBERRECOVERY %(RQD)BLOWCOUNTS(N VALUE) SPT N VALUE
20 40 60 80
Moisture Content(%) FINES CONTENT (%)
20 40 60 80
20 40 60 80
PL LLMC
PAGE 1 OF 1
BORING NUMBER SB-1
CLIENT Wooddale Builders
PROJECT NUMBER 24-0301
PROJECT NAME 6870 Minnewashta Parkway
PROJECT LOCATION Chanhassen, MN
GEOTECH BH PLOTS - GINT STD US LAB.GDT - 6/5/24 10:05 - C:\USERS\ALICE HAUGO\HGTS DROPBOX\LAB HAUGO\HAUGO GEOTECHNICAL SERVICES\GINT PROJECT BACKUP\PROJECTS\24-0301 BORING LOG DRAFT.GPJHaugo GeoTechnical Services
2825 Cedar Ave South
Minneapolis, MN, 55407
Telephone: 612-729-2959
Fax: 763-445-2238
Sandy Lean Clay, dark brown, moist (Topsoil)
(CL) Sandy Lean Clay, brown, moist to wet, rather soft to stiff
(Glacial Till)
Bottom of borehole at 21.0 feet.
AU
9
SS
10
SS
11
SS
12
SS
13
SS
14
SS
15
SS
16
2-2-3
(5)
5-3-5
(8)
3-4-4
(8)
3-2-3
(5)
1-2-3
(5)
2-3-4
(7)
5-6-8
(14)
31.5
26.5
NOTES
GROUND ELEVATION 977.8 ft
LOGGED BY NC/MS
DRILLING METHOD Hollow Stem Auger/Split Spoon
DRILLING CONTRACTOR HGTS- 45 GROUND WATER LEVELS:
CHECKED BY PG
DATE STARTED 5/22/24 COMPLETED 5/22/24
AT TIME OF DRILLING 15.00 ft / Elev 962.80 ft
AT END OF DRILLING --- Not Encountered
AFTER DRILLING --- Not Encountered
HOLE SIZE 3 1/4 inches
DEPTH(ft)0
5
10
15
20 GRAPHICLOGMATERIAL DESCRIPTION
SAMPLE TYPENUMBERRECOVERY %(RQD)BLOWCOUNTS(N VALUE) SPT N VALUE
20 40 60 80
Moisture Content(%) FINES CONTENT (%)
20 40 60 80
20 40 60 80
PL LLMC
PAGE 1 OF 1
BORING NUMBER SB-2
CLIENT Wooddale Builders
PROJECT NUMBER 24-0301
PROJECT NAME 6870 Minnewashta Parkway
PROJECT LOCATION Chanhassen, MN
GEOTECH BH PLOTS - GINT STD US LAB.GDT - 6/5/24 10:05 - C:\USERS\ALICE HAUGO\HGTS DROPBOX\LAB HAUGO\HAUGO GEOTECHNICAL SERVICES\GINT PROJECT BACKUP\PROJECTS\24-0301 BORING LOG DRAFT.GPJHaugo GeoTechnical Services
2825 Cedar Ave South
Minneapolis, MN, 55407
Telephone: 612-729-2959
Fax: 763-445-2238
Sandy Lean Clay, trace Grass, dark brown, moist (Topsoil)
(SC) Clayey Sand, brown, wet to waterbearing at about 5 feet,
very loose (Glacial Till)
(CL) Sandy Lean Clay, brown, moist, rather stiff (Glacial Till)
(CL) Sandy Lean Clay, grey, moist, medium to rather stiff (Glacial
Till)
Bottom of borehole at 21.0 feet.
AU
1
SS
2
SS
3
SS
4
SS
5
SS
6
SS
7
SS
8
0-0-0
(0)
0-0-0
(0)
3-5-6
(11)
3-5-7
(12)
3-5-6
(11)
2-4-5
(9)
3-3-5
(8)
24
27.5
NOTES
GROUND ELEVATION 972.2 ft
LOGGED BY NC/MS
DRILLING METHOD Hollow Stem Auger/Split Spoon
DRILLING CONTRACTOR HGTS- 45 GROUND WATER LEVELS:
CHECKED BY PG
DATE STARTED 5/22/24 COMPLETED 5/22/24
AT TIME OF DRILLING 5.00 ft / Elev 967.20 ft
AT END OF DRILLING --- Not Encountered
AFTER DRILLING --- Not Encountered
HOLE SIZE 3 1/4 inches
DEPTH(ft)0
5
10
15
20 GRAPHICLOGMATERIAL DESCRIPTION
SAMPLE TYPENUMBERRECOVERY %(RQD)BLOWCOUNTS(N VALUE) SPT N VALUE
20 40 60 80
Moisture Content(%) FINES CONTENT (%)
20 40 60 80
20 40 60 80
PL LLMC
PAGE 1 OF 1
BORING NUMBER SB-3
CLIENT Wooddale Builders
PROJECT NUMBER 24-0301
PROJECT NAME 6870 Minnewashta Parkway
PROJECT LOCATION Chanhassen, MN
GEOTECH BH PLOTS - GINT STD US LAB.GDT - 6/5/24 10:05 - C:\USERS\ALICE HAUGO\HGTS DROPBOX\LAB HAUGO\HAUGO GEOTECHNICAL SERVICES\GINT PROJECT BACKUP\PROJECTS\24-0301 BORING LOG DRAFT.GPJHaugo GeoTechnical Services
2825 Cedar Ave South
Minneapolis, MN, 55407
Telephone: 612-729-2959
Fax: 763-445-2238
Sandy Lean Clay, black, moist (Topsoil)
(CL) Sandy Lean Clay, brown, wet, rather soft to rather stiff
(Glacial Till)
Bottom of borehole at 21.0 feet.
AU
49
SS
50
SS
51
SS
52
SS
53
SS
54
SS
55
SS
56
1-2-2
(4)
2-2-2
(4)
3-9-5
(14)
3-4-6
(10)
4-6-6
(12)
5-6-8
(14)
3-5-7
(12)
24.5
22.5
NOTES
GROUND ELEVATION 984.4 ft
LOGGED BY NC/MS
DRILLING METHOD Hollow Stem Auger/Split Spoon
DRILLING CONTRACTOR HGTS- 45 GROUND WATER LEVELS:
CHECKED BY PG
DATE STARTED 5/23/24 COMPLETED 5/23/24
AT TIME OF DRILLING 20.00 ft / Elev 964.40 ft
AT END OF DRILLING --- Not Encountered
AFTER DRILLING --- Not Encountered
HOLE SIZE 3 1/4 inches
DEPTH(ft)0
5
10
15
20 GRAPHICLOGMATERIAL DESCRIPTION
SAMPLE TYPENUMBERRECOVERY %(RQD)BLOWCOUNTS(N VALUE) SPT N VALUE
20 40 60 80
Moisture Content(%) FINES CONTENT (%)
20 40 60 80
20 40 60 80
PL LLMC
PAGE 1 OF 1
BORING NUMBER SB-4
CLIENT Wooddale Builders
PROJECT NUMBER 24-0301
PROJECT NAME 6870 Minnewashta Parkway
PROJECT LOCATION Chanhassen, MN
GEOTECH BH PLOTS - GINT STD US LAB.GDT - 6/5/24 10:05 - C:\USERS\ALICE HAUGO\HGTS DROPBOX\LAB HAUGO\HAUGO GEOTECHNICAL SERVICES\GINT PROJECT BACKUP\PROJECTS\24-0301 BORING LOG DRAFT.GPJHaugo GeoTechnical Services
2825 Cedar Ave South
Minneapolis, MN, 55407
Telephone: 612-729-2959
Fax: 763-445-2238
Sandy Lean Clay, black, wet (Topsoil)
(CL) Sandy Lean Clay, brown, moist, rather soft to stiff (Glacial
Till)
Bottom of borehole at 21.0 feet.
AU
41
SS
42
SS
43
SS
44
SS
45
SS
46
SS
47
SS
48
2-2-2
(4)
2-3-5
(8)
4-5-5
(10)
5-6-5
(11)
3-4-4
(8)
3-4-5
(9)
3-6-7
(13)
33.5
20.5
NOTES
GROUND ELEVATION 984.2 ft
LOGGED BY NC/MS
DRILLING METHOD Hollow Stem Auger/Split Spoon
DRILLING CONTRACTOR HGTS- 45 GROUND WATER LEVELS:
CHECKED BY PG
DATE STARTED 5/23/24 COMPLETED 5/23/24
AT TIME OF DRILLING --- Not Encountered
AT END OF DRILLING --- Not Encountered
AFTER DRILLING --- Not Encountered
HOLE SIZE 3 1/4 inches
DEPTH(ft)0
5
10
15
20 GRAPHICLOGMATERIAL DESCRIPTION
SAMPLE TYPENUMBERRECOVERY %(RQD)BLOWCOUNTS(N VALUE) SPT N VALUE
20 40 60 80
Moisture Content(%) FINES CONTENT (%)
20 40 60 80
20 40 60 80
PL LLMC
PAGE 1 OF 1
BORING NUMBER SB-5
CLIENT Wooddale Builders
PROJECT NUMBER 24-0301
PROJECT NAME 6870 Minnewashta Parkway
PROJECT LOCATION Chanhassen, MN
GEOTECH BH PLOTS - GINT STD US LAB.GDT - 6/5/24 10:05 - C:\USERS\ALICE HAUGO\HGTS DROPBOX\LAB HAUGO\HAUGO GEOTECHNICAL SERVICES\GINT PROJECT BACKUP\PROJECTS\24-0301 BORING LOG DRAFT.GPJHaugo GeoTechnical Services
2825 Cedar Ave South
Minneapolis, MN, 55407
Telephone: 612-729-2959
Fax: 763-445-2238
Silty Clayey Sand, black, moist (Topsoil)
(CL) Sandy Lean Clay, brown, moist, soft to rather stiff (Glacial
Till)
Bottom of borehole at 21.0 feet.
AU
25
SS
26
SS
27
SS
28
SS
29
SS
30
SS
31
SS
32
2-1-2
(3)
2-3-3
(6)
2-2-3
(5)
3-4-6
(10)
2-4-5
(9)
3-4-5
(9)
3-4-5
(9)
20
18.5
NOTES
GROUND ELEVATION 980 ft
LOGGED BY NC/MS
DRILLING METHOD Hollow Stem Auger/Split Spoon
DRILLING CONTRACTOR HGTS- 45 GROUND WATER LEVELS:
CHECKED BY PG
DATE STARTED 5/23/24 COMPLETED 5/23/24
AT TIME OF DRILLING --- Not Encountered
AT END OF DRILLING --- Not Encountered
AFTER DRILLING --- Not Encountered
HOLE SIZE 3 1/4 inches
DEPTH(ft)0
5
10
15
20 GRAPHICLOGMATERIAL DESCRIPTION
SAMPLE TYPENUMBERRECOVERY %(RQD)BLOWCOUNTS(N VALUE) SPT N VALUE
20 40 60 80
Moisture Content(%) FINES CONTENT (%)
20 40 60 80
20 40 60 80
PL LLMC
PAGE 1 OF 1
BORING NUMBER SB-6
CLIENT Wooddale Builders
PROJECT NUMBER 24-0301
PROJECT NAME 6870 Minnewashta Parkway
PROJECT LOCATION Chanhassen, MN
GEOTECH BH PLOTS - GINT STD US LAB.GDT - 6/5/24 10:05 - C:\USERS\ALICE HAUGO\HGTS DROPBOX\LAB HAUGO\HAUGO GEOTECHNICAL SERVICES\GINT PROJECT BACKUP\PROJECTS\24-0301 BORING LOG DRAFT.GPJHaugo GeoTechnical Services
2825 Cedar Ave South
Minneapolis, MN, 55407
Telephone: 612-729-2959
Fax: 763-445-2238
Clayey Sand, black, wet (Topsoil)
(SC) Clayey Sand, brown, wet, very loose (Glacial Till)
(CL) Sandy Lean Clay, brown, wet, rather soft to rather stiff
(Glacial Till)
Bottom of borehole at 21.0 feet.
AU
33
SS
34
SS
35
SS
36
SS
37
SS
38
SS
39
SS
40
3-2-1
(3)
3-2-2
(4)
9-4-4
(8)
3-3-4
(7)
3-3-4
(7)
2-2-4
(6)
4-4-6
(10)
27
23
25
NOTES
GROUND ELEVATION 987.5 ft
LOGGED BY NC/MS
DRILLING METHOD Hollow Stem Auger/Split Spoon
DRILLING CONTRACTOR HGTS- 45 GROUND WATER LEVELS:
CHECKED BY PG
DATE STARTED 5/23/24 COMPLETED 5/23/24
AT TIME OF DRILLING 14.50 ft / Elev 973.00 ft Not Encountered
AT END OF DRILLING --- Not Encountered
AFTER DRILLING --- Not Encountered
HOLE SIZE 3 1/4 inches
DEPTH(ft)0
5
10
15
20 GRAPHICLOGMATERIAL DESCRIPTION
SAMPLE TYPENUMBERRECOVERY %(RQD)BLOWCOUNTS(N VALUE) SPT N VALUE
20 40 60 80
Moisture Content(%) FINES CONTENT (%)
20 40 60 80
20 40 60 80
PL LLMC
PAGE 1 OF 1
BORING NUMBER SB-7
CLIENT Wooddale Builders
PROJECT NUMBER 24-0301
PROJECT NAME 6870 Minnewashta Parkway
PROJECT LOCATION Chanhassen, MN
GEOTECH BH PLOTS - GINT STD US LAB.GDT - 6/5/24 10:05 - C:\USERS\ALICE HAUGO\HGTS DROPBOX\LAB HAUGO\HAUGO GEOTECHNICAL SERVICES\GINT PROJECT BACKUP\PROJECTS\24-0301 BORING LOG DRAFT.GPJHaugo GeoTechnical Services
2825 Cedar Ave South
Minneapolis, MN, 55407
Telephone: 612-729-2959
Fax: 763-445-2238