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2021-08-31 American Engineering Testing Report of Geotechnical Exploration
AAMERICAN ENGINEERING - TESTING, INC, CONSULTANTS REPORT OF • ENVIRONMENTAL • GEOTECHNICAL GEOTECHNICAL EXPLORATION • MATERIALS • FORENSICS Oak Park Heights Park Dental 13961 60th Street North Oak Park Heights AET No. P-0004506 Date: August 3,2021 Prepared for: Frauenshuh Companies c/o Sperides Reiners Architects, Inc. 6442 City W Pkwy, Suite 300 Eden Prairie,MN 55344 www.amengtest.com CONSULTANTS AMERICAN • ENVIRONMENTAL ENGINEERING • GEOTECHNICAL • MATERIALS ® TESTING, INC. • FORENSICS August 3, 2021 Frauenshuh Companies c/o Sperides Reiners Architects, Inc. 6442 City W Pkwy, Suite 300 Eden Prairie, MN 55344 Attn: Mr. Jonah Ritter RE: Geotechnical Exploration Oak Park Heights Park Dental Oak Park Heights, Minnesota AET P-0004506 Dear Mr. Ritter: American Engineering Testing, Inc. (AET) is pleased to present the results of our subsurface exploration program and geotechnical engineering review for the new Oak Park Heights Park Dental facility located in Oak Park Heights, Minnesota. These services were performed according to our proposal to you dated July 9,2021. We are submitting one electronic (.pdf) copy of the report to you. Additional copies can be sent on your behalf to other parties per your request. Please contact me if you have any questions about the report. Sincerely, L --A Scan Engineering Te ting,Inc. .: c (,.... 0 ._ ohn Starke, PE Senior Geotechnical Engineer Phone: (651) 659-1335 jstarke@amengtest.com 550 Cleveland Avenue NorthISt.Paul,MN 55114 Phone 651-659-9001IToll Free 800-972-6364 I Fax 651-659-1379 www.amengtest.com IAA/EEO This document shall not be reproduced,except in full,without written approval from American Engineering Testing,Inc. Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. SIGNATURE PAGE Prepared for: Prepared by: Frauenshuh Companies American Engineering Testing, Inc. c/o Sperides Reiners Architects, Inc. 550 Cleveland Avenue North 6442 City W Pkwy, Suite 300 St. Paul, MN 55114 Eden Prairie, MN 55344 (651) 659-9001/www.amengtest.com Attn: Mr. Jonah Ritter • Authored by: Reviewed by: John Starke, PE Jay Brekke,PE Senior Geotechnical Engineer Senior Engineer 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 Minnesota Statute Section 326.02 to 326.15 Name: Date:August 3,2021 License#: 23546 Copyright 2021 American Engineering Testing,Inc. All Rights Reserved Unauthorized use or copying of this document is strictly prohibited by anyone other than the client for the specific project. Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. TABLE OF CONTENTS 1.0 INTRODUCTION 1 2.0 SCOPE OF SERVICES 1 3.0 PROJECT INFORMATION 1 4.0 SUBSURFACE EXPLORATION AND TESTING 2 4.1 Field Exploration Program 2 4.2 Laboratory Testing 2 5.0 SITE CONDITIONS 2 5.1 Surface Observations 2 5.2 Subsurface Soils/Geology 3 5.3 Groundwater 4 6.0 RECOMMENDATIONS 4 6.1 Site Preparation 4 6.2 Foundations 6 6.3 Floor Slab Design 7 6.4 Exterior Building Backfilling 7 6.5 Pavements 8 6.6 Exterior Underground Utilities 8 7.0 CONSTRUCTION CONSIDERATIONS 9 7.1 Potential Difficulties 9 7.2 Construction Shoring 10 7.3 Excavation Backsloping 10 7.4 Observation and Testing 10 8.0 ASTM STANDARDS 10 9.0 LIMITATIONS 10 STANDARD SHEETS Floor Slab Moisture/Vapor Protection Freezing Weather Effects on Building Construction Bedding/Foundation Support of Buried Pipe Standard Recommendations for Utility Excavation Backfilling Bituminous Pavement Subgrade Preparation and Design APPENDIX A—Geotechnical Field Exploration and Testing Boring Log Notes Unified Soil Classification System Boring Locations Map—Figure 1 Subsurface Boring Logs APPENDIX B—Geotechnical Report Limitations and Guidelines for Use Page i Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. 1.0 INTRODUCTION We understand Park Dental is planning to construct a new dental building located in Oak Park Heights, Minnesota. To assist with this project planning and design you have authorized American Engineering Testing, Inc. (AET) to conduct a subsurface exploration program at the site, conduct soil laboratory testing, and perform a geotechnical engineering review. This report presents the results of the above services and provides our engineering recommendations based upon our project understanding. 2.0 SCOPE OF SERVICES AET's services were performed according to our proposal to you dated July 9, 2021 and authorized by Frauenshuh Companies on July 12, 2021. The authorized scope of work consisted of the following. • Arrange utility clearance through Gopher-State-One Call. • Drill six Standard Penetration Test(SPT)borings to depths of about 141/2 feet each. • Submit Minnesota Department of Health(MDH)borehole notification. • Conduct soil laboratory testing on selected soil samples. • Prepare a geotechnical report presenting the results of our field exploration and geotechnical recommendations. These services are intended for geotechnical purposes only. The scope is not intended to explore for the presence or extent of environmental contamination in the soil or groundwater. 3.0 PROJECT INFORMATION We understand Park Dental is planning on constructing a new dental building located at 13961 60th Street North, Oak Park Heights, Minnesota. The project is in the initial planning stages however, for purposes of our review we have assumed the new dental building would be a single-story, wood framed structure, supported by conventional cast-in-place concrete footings and interior columns. Based upon similar projects we have worked on, we expect foundation wall and column loads to be not more than 5 kips per foot and 35 kips, respectively. We assume new bituminous pavement would be constructed around the building for customer parking and service vehicle deliveries. Page 1 of 10 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. The above stated information represents our understanding of the proposed construction. This information is an integral part of our engineering review. It is important that you contact us if there are changes from that described so that we can evaluate whether modifications to our recommendations are appropriate. 4.0 SUBSURFACE EXPLORATION AND TESTING 4.1 Field Exploration Program The subsurface exploration program conducted for this project consisted of drilling six (6) SPT borings to depths of about 14'/z feet each. The logs of the borings and details of the methods used appear in Appendix A. The logs contain information concerning soil layering, soil classification, geologic origins, and moisture condition. A density description or consistency is also noted for the natural soils,which is based on the standard penetration resistance (N-values). The approximate boring locations are shown on Figure 1 in Appendix A. The borings were located by AET personnel referenced from the existing site buildings. Ground surface elevations at the boring locations were reference from an existing manhole top cover (elevation 936.05) located off of 60th Street North. The longitude and latitude coordinates were measured in the field by AET personnel using GP S. The ground surface elevations and coordinates are shown on the top of the boring logs. 4.2 Laboratory Testing Laboratory testing was performed on selected soil samples to determine soil natural water content. The test results appear in Appendix A on the individual boring logs adjacent to the samples upon which they were performed. 5.0 SITE CONDITIONS 5.1 Surface Observations The subject property contains three existing commercial single-story buildings surrounded by bituminous paving for vehicle parking. The property is bounded on the north side by 60th Street North. Other existing commercial buildings are located west and south of the property. An existing multi-story apartment building is located adjacent to the property southeast corner. The property is relatively flat, ground surface elevations ranged for 936.3 feet at Boring B-5 to 938.7 at Boring B-3. Page 2 of 10 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. 5.2 Subsurface Soils/Geology The site geology consists of fill soils at the surface underlain by till and alluvial soils. 5.2.1 Existing Pavement All but one of the borings (B-1) encountered bituminous pavement at the surface. The bituminous pavement thicknesses ranged from about 3 inches to 4 inches, averaging about 3'/2 inches. An assessment of bituminous quality or integrity was not part of our scope of work. Below the bituminous pavement was about 2 to 4 inches of crushed limestone aggregate base. 5.2.2 Fill At Borings B-1, B-2, B-3, and B-6 fill soils were present below the bituminous pavement section, extending to depths ranging from about 1/2 foot to 3 feet. The fill soils generally consisted of clayey sand or sand with vary amounts of gravel. Due to its variable composition, it is our opinion the existing fill soils should not be used for building support. 5.2.3 Till At borings B-i and B-3, till soil consisting of Silty Sand (SM) with vary amounts of gravel was encountred below the fill to depths of about 7 feet and 8 feet,respectively. Based upon SPT blow counts (N-values) the relative density of silty sand deposits ranged from loose to medium dense. We judge the till soil to have moderate bearing capacity and strength and would be moderately susceptible to freeze-thaw movements if exposed to freezing weather. 5.2.4 Alluvium Both fine grained and coarse-grained alluvial soils were present in all the borings. At Borings B- 2 and B-5 fine grained alluvial soil consisting of Silt (ML) with lenses and/or laminations of fine-grained sand was encountered from about 2 feet to 9'/2 feet and from about %2 foot to 14'/2 feet, respectively. Based upon SPT blow counts (N-values), the relative density of fine alluvial deposits ranged from loose to medium dense. We judge the encountered silt soils to have moderate bearing capacity and strength and are highly susceptible to freeze-thaw movements if exposed to freezing weather. With the exception at Boring B-5, coarse grained alluvial soils consisting of Sand (SP) and Sand with Silt (SP-SM) with vary amounts of gravel were encountered beneath the fill soils extending to the maximum depths of the borings (14'/2 feet). Coarse alluvial soils were not encountered at Boring B-5. The relative density of the sand deposits based upon SPT blow counts (N-values) ranged from loose to medium dense. We judge the encountered sand deposits to have moderate bearing capacity and strength and slightly susceptible to freeze-thaw movements if exposed to Page 3 of 10 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING, INC. freezing weather. 5.3 Groundwater Groundwater was not observed in any of borings during or after drilling. Groundwater levels fluctuate due to varying seasonal and annual rainfall and snow melt amounts, as well as other factors. Although not observed during our field program, perched groundwater could be present in the upper fill materials that could seep towards open excavations. 6.0 RECOMMENDATIONS 6..1 Site Preparation The existing buildings should be razed and removed from within the project site including subsurface structures such as basement walls, foundations, and utilities. Existing bituminous pavement and concrete aprons and sidewalks should also be excavated and removed from the project site. Construction rubble and debris should not be used as backfill into open excavations which could cause unstable subgrade conditions for future construction. In landscaped areas, topsoil should be stripped from the construction area and stockpile for future reuse. It is our opinion the existing fill and possible fill soils at the project site are not suitable for building foundation support. Table 3 presents the recommended minimum excavation depths at the boring locations to establish a competent subgrade for building support. Table 3 -Minimum Recommended Excavation Depths Boring ID Estimated Minimum Ground Surface Estimated Subgrade Excavation Depth Elevation(ft) Elevation(nearest 1/2 ft) (nearest 1/2 V) B-1 4 938.2 934 B-2 3 938.0 935 B-3 2 938.7 9361/2 B-4 2 937.2 935'1 B-5 2 936.6 9341/2 B-6 2 937.0 935 (I) Further excavation may be required to satisfy minimum foundation frost depth requirements. Page 4 of 10 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. Excavations should be observed by a qualified geotechnical engineer. If soft or loose soils are present at the base of the excavations further subcutting may be required. Excavations that extend below the planned foundation subgrade elevation should be oversize to allow for lateral support of the foundation load. The oversize should extend laterally a minimum I:1(H:V) to provide for adequate load distribution through the foundation subgrade soils. For excavations that are planned close to existing building foundation, care should be performed by the excavating contractor not to undermine the existing building foundation. If an excavation is required below an existing foundation, shoring, or bracing of the foundation may be required. We should be contacted to aid the design team with geotechnical recommendations if foundation shoring or bracing is needed. Excavations should be performed no closer than 1:1 (H:V) beneath the existing foundation subgrade to prevent undermining and disturbance to the existing foundation subgrade. Silt soils were encountered in a number of borings that could be present at the foundation subgrade elevation. Disturbance of these soil types due water infiltration or excessive construction activities can reduce the soil strength and bearing capacity. Care should be performed by the contractor to minimize subgrade disturbance if these soils are present. If the subgrade soils become loose or disturbed, we recommend subcutting 1 foot and replacing with a coarse crushed aggregate to the planned foundation subgrade elevation. If very soft conditions are encountered we recommend placing a geotextile fabric over the excavated base, below the crushed aggregate stabilization layer. We did not encounter groundwater during our field program however, if groundwater seepage occurs into excavations, the contractor should dewater as practicable and subcut the distributed soil. In order to stabilize the subgrade a coarse crushed aggregate should be placed at the excavation bottom. All excavation backsloping should be performed as discussed in Section 7.3. 6.1.2 Backfilling and Compaction Fill placed to attain grade for foundation support should be compacted in thin lifts, such that the entire lift achieves a minimum compaction level of 98% of the standard maximum dry unit weight per ASTM: D698 (Standard Proctor test). Fill placed which supports the floor slab only (outside of the 1:1 oversize zone below footings) can have a reduced minimum compaction level of 95%of the standard maximum dry unit weight. If there are areas where fill is placed on slopes, we recommend benching the sloped surface Page 5of10 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,TNC. (benches cut parallel to the slope contour) prior to placing the fill. Benching is recommended where slopes are steeper than 4:1 (H:V). Imported fill should consist of sand(SP) or sand with silt(SP-SM) with no more than 12% of the particles (by weight) finer than the#200 sieve and no more than 50% of the particles (by weight) finer than the #40 sieve. Fill placed below the footings and floor slabs should not contain gravel larger than 3 inches. If the contractor proposes a different type of fill, a sample should be submitted to the Geotechnical Engineer for approval. The on-site existing fill soils may be suitable for engineered fill provided further testing be performed to demonstrate acceptable density and strength conditions can be achieved during compaction. All fill should be free of debris, rubble, organics, oversized cobbles and rocks, and other unsuitable materials. All fill soils should be compacted with equipment which will densify the entire lift of fill. Fill should not be placed over frozen soils, and frozen soils should not be used as fill. If earthwork operations take place during freezing weather, all frozen soils, snow, and ice should be stripped from the areas to be filled prior to new fill placement. The new fill should not be allowed to freeze during transit, placement, or compaction. We refer you to the sheet entitled "Freezing Weather Effects on Building Construction"for additional information. 6.2 Foundations After the site preparation has been performed as described above, the building can be supported on a conventional spread footing foundation bearing on competent till soils or compacted fill. We recommend that perimeter foundations for heated building areas bear at a minimum depth of 42 inches below exterior grade for frost protection. The bottom of exterior foundations (those foundations not bordering heated building areas) should be extended to a minimum depth of 60 inches below exterior grade, because deeper frost penetration can occur away from the heated building. Column foundations should also bear on the natural soils or compacted fill soils. Interior columns can be placed at a suitable distance below the floor slab. Based on the conditions found in our borings and our recommended soil correction and grading/compaction procedures, it is our opinion that the footings may be proportioned for a maximum net allowable soil bearing pressure of 2,500 pounds per square foot. The factor of safety with respect to the ultimate soil bearing capacity for this design would exceed 3. We recommend a minimum footing width of 18 inches for strip footings and 24 inches of column Page 6 of 10 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. pads, regardless of bearing pressure. Provided the foundation subgrade has been prepared as described above, we estimate foundation total and differential settlements would be less than 1- inch and '/2-inch,respectively. 6.3 Floor Slab Design All fill soils that are placed below on-grade floor slabs should be compacted to at least 95% of the Standard Proctor maximum dry density.This includes fill soils that are placed adjacent to footings and walls, as well as utility trench backfill. The fill soils should be placed in loose lift thicknesses which are thin enough to allow compaction of the entire layer with the equipment being used. The on-grade slabs of the building can be supported by the new compacted fill. Assuming the subgrade soils will consist of the recommended sand or sand with silt soils described in Section 6.1.2, we recommend using a modulus of subgrade reaction(Ks value) of 180 psi/inch to be used for the concrete floor slab design. For recommendations pertaining to moisture and vapor protection of interior floor slabs,we refer you to the attached standard sheet entitled "Floor Slab Moisture/Vapor Protection." Typically, the use of moisture and vapor protection of interior slabs is recommended if moisture sensitive floor coverings will be placed over the on-grade slab. 6.4 Exterior Building Backfilling Fill that is placed below sidewalks, stoops, and exterior slabs should be compacted to a minimum of 95% of the standard Proctor maximum dry density. Fill placed in landscaped areas should be compacted to a minimum of 90%of the standard Proctor maximum dry density. The sands and sands with silt fill soils, as described in Section 6.1.2 should also be used as exterior wall backfill rather than silts, clays, silty sands, clayey sands to reduce potential frost- related slab movements outside the buildings. For details, we refer you to the attached sheet entitled"Freezing Weather Effects on Building Construction." Most of the on-site soils are considered moderately frost susceptible. Because of this, certain design considerations are needed to mitigate these frost effects. For details, we refer you to the attached sheet entitled"Freezing Weather Effects on Building Construction." Page 7 of 10 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No. P-0004506 TESTING,INC. 6.5 Pavements 6.5.1 Subgrade Preparation Subgrade preparation for pavement construction should consist of stripping existing surface gravels or pavement (if present) within the project area. The critical pavement zone is the subgrade upper 2'/2 feet for light-duty traffic areas. If heavy-duty traffic areas are needed, we should be contacted to discuss additional subgrade preparation procedures. Any soft or excessively wet soils present in the pavement subgradc should also be removed. We recommend the pavement subgrade be compacted to at least 98% of the standard proctor density. Excess vehicle traffic over the subgrade should be avoided to prevent softening and pumping of the subgrade soils. Where fill is required to raise the subgrade,we recommend using compacted sand as previously described in Section 6.1.2. New fill placed within the upper 3 feet of pavement subgrade should be compacted to 100%of the standard Proctor dry density. For additional information regarding pavement subgrade preparation, we refer you to the standard sheet entitled "Bituminous Pavement Subgrade Preparation and Design" at the end of this report. 6.5.2 Section Thicknesses We are presenting flexible pavement designs for light-duty traffic situations. The light-duty design refers to parking areas which are intended only for automobiles and passenger truck/ vans. If heavy-duty pavement sections are required,we should be contacted to provide additional pavement section design guidance. A summary of our recommended bituminous pavement thickness design is presented in Table 2. Table 2—Light-Duty Pavement Thickness Design MnDOT Material Type Light-Duty Pavement Course (Spec.) (Automobile) (inches) Bituminous Wear Course SPWEA240F (PG58V-34) 1'/2 Bituminous Non-wear Course SPNWB23OE (PG58H-28) 2 Aggregate Base Class 5, 5Q, or 6 (3138) 6 6.6 Exterior Underground Utilities The location and depth of the proposed utilities are not known. However, we assume utilities would be installed at depth not more than 8 feet below grade. If wet or saturated conditions are present at the subgrade, we recommend subcutting an addition 12-inches and replacing with sand Page 8 of 10 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. fill as described above in Section 6.1.2 to provide a stable foundation for utility support. Differing bedding thicknesses and/or material types may be needed in cases of instability or if water is present. The bedding material should be compacted to at least 95% of the Standard Proctor maximum dry density. Backfill placed above the utilities can consist of inorganic sands, silty sands, or clayey sands. If the pavement subgrades have already been prepared at the time of utility installation, the utility contractor should attempt to backfill the critical subgrade zone using soils similar to those in place in the adjoining pavement areas. The fill may require moisture conditioning of these soils to obtain the recommended compaction levels. Details regarding utility bedding and backfilling can be found on the two attached standard sheets entitled: • Bedding/Foundation Support of Buried Pipe • Standard Recommendations for Utility Excavation Backfilling The existing fill soils and till deposits encountered by the borings typically have moderate to high corrosion potential. Suitable cathodic protection should be provided if ductile iron pip (DIP) is used for the project. If you desire, additional field and laboratory testing could be performed to better judge the corrosion potential of the site soils and provide specific recommendations. 7.0 CONSTRUCTION CONSIDERATIONS 7.1 Potential Difficulties 7.1.1 Runoff Water in Excavation Water can be expected to collect in the excavation bottom during times of inclement weather or snow melt. To allow observation of the excavation bottom, to reduce the potential for soil disturbance, and to facilitate filling operations,we recommend water be removed from within the excavation during construction. Z1.2 Disturbance of Soils The on-site soils can be disturbed under construction traffic, especially if the soils are wet. If soils become disturbed, they should be subcut to the underlying undisturbed soils. The subcut soils can then be dried and recompacted back into place,or they should be removed and replaced with drier imported fill. 7.1.3 Cobbles and Boulders The soils at this site can include cobbles and boulders. This may make excavating procedures somewhat more difficult than normal if they are encountered. Page 9 of 10 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING, INC. 7.2 Construction Shoring Due to possible limited construction area, temporary shoring of slopes may be required for utility installations or for excavations close to existing structures. Depending on the depth of excavation and height of the soil slope to be reinforced, different methods of temporary shoring could be used including sheet piling or soldier piling with wood lagging. If temporary construction shoring is required for this project, we should be contacted to aid the design team with a geotechnical assessment of the selected shoring method. For deep utility excavations and installations, when the soil excavation back slope is restricted the use of a trench shoe or other approved mobile shoring devices should be used by the contractor. 7.3 Excavation Backsloping If excavation faces are not retained, the excavations should maintain maximum allowable slopes in accordance with OSHA Regulations (Standards 29 CFR), Part 1926, Subpart P, "Excavations" (can be found on www.osha.gov). Even with the required OSHA sloping, water seepage or surface runoff can potentially induce sideslope erosion or sloughing which could require slope maintenance. 7.4 Observation and Testing The recommendations in this report are based on the subsurface conditions found at our test boring locations. Since the soil conditions can be expected to vary away from the soil boring locations, we recommend on-site observation by a geotechnical engineer/technician during construction to evaluate these potential changes. Soil density testing should also be performed on new fill placed to document that project specifications for compaction have been satisfied. 8.0 ASTM STANDARDS When we refer to an ASTM Standard in this report, we mean that our services were performed in general accordance with that standard. Compliance with any other standards referenced within the specified standard is neither inferred nor implied. 9.0 LIMITATIONS Within the limitations of scope, budget, and schedule, we have endeavored to provide our services according to generally accepted geotechnical engineering practices at this time and location. Other than this, no warranty, express or implied, is intended. Important information regarding risk management and proper use of this report is given in Appendix B entitled "Geotechnical Report Limitations and Guidelines for Use." Page 10 of 10 FLOOR SLAB MOISTURE/VAPOR PROTECTION Floor slab design relative to moisture/vapor protection should consider the type and location of two elements, a granular layer and a vapor membrane (vapor retarder, water resistant barrier or vapor barrier). In the following sections, the pros and cons of the possible options regarding these elements will be presented, such that you and your specifier can make an engineering decision based on the benefits and costs of the choices. GRANULAR LAYER In American Concrete Institute (ACI) 302.1R-15, a "base material" is recommended over the vapor membrane, rather than the conventional clean "sand cushion" material. The base layer should be a minimum of 4 inches (100 mm)thick, trimmable, compactable, granular fill (not sand), a so-called crusher-run material. Usually graded from 11/2 inches to 2 inches(38 to 50 mm) down to rock dust is suitable. Following compaction,the surface can be choked off with a fine-grade material, We refer you to ACI 302.1R-15 for additional details regarding the requirements for the base material. In cases where potential static water levels or significant perched water sources appear near or above the floor slab, an under floor drainage system may be needed wherein a draintile system is placed within a thicker clean sand or gravel layer. Such a system should be properly engineered depending on subgrade soil types and rate/head of water inflow. VAPOR MEMBRANE The need for a vapor membrane depends on whether the floor slab will have a vapor sensitive covering, will have vapor sensitive items stored on the slab, or if the space above the slab will be a humidity controlled area. If the project does not have this vapor sensitivity or moisture control need,placement of a vapor membrane may not be necessary. Your decision will then relate to whether to use the ACI base material or a conventional sand cushion layer.However,if any of the above sensitivity issues apply,placement of a vapor membrane is recommended. Some floor covering systems (adhesives and flooring materials)require installation of a vapor membrane to limit the slab moisture content as a condition of their warranty. VAPOR MEMBRANE/GRANULAR LAYER PLACEMENT A number of issues should be considered when deciding whether to place the vapor membrane above or below the granular layer. The benefits of placing the slab on a granular layer, with the vapor membrane placed below the granular layer,include reduction of the following: • Slab curling during the curing and drying process. • Time of bleeding,which allows for quicker finishing. • Vapor membrane puncturing. • Surface blistering or delamination caused by an extended bleeding period. • Cracking caused by plastic or drying shrinkage. The benefits of placing the vapor membrane over the granular layer include the following: • A lower moisture emission rate is achieved faster. • Eliminates a potential water reservoir within the granular layer above the membrane. • Provides a"slip surface",thereby reducing slab restraint and the associated random cracking. If a membrane is to be used in conjunction with a granular layer,the approach recommended depends on slab usage and the construction schedule.The vapor membrane should be placed above the granular layer when: • Vapor sensitive floor covering systems are used or vapor sensitive items will be directly placed on the slab. • The area will be humidity controlled,but the slab will be placed before the building is enclosed and sealed from rain. • Required by a floor covering manufacturer's system warranty. The vapor membrane should be placed below the granular layer when: • Used in humidity controlled areas (without vapor sensitive coverings/stored items), with the roof membrane in place,and the building enclosed to the point where precipitation will not intrude into the slab area. Consideration should be given to slight sloping of the membrane to edges where draintile or other disposal methods can alleviate potential water sources, such as pipe or roof leaks, foundation wall damp proofing failure,fire sprinkler system activation,etc. There may be cases where membrane placement may have a detrimental effect on the subgrade support system(e.g., expansive soils). In these cases,your decision will need to weigh the cost of subgrade options and the performance risks. 01REP013(1/21) AMERICAN ENGINEERING TESTING,INC. FREEZING WEATHER EFFECTS ON BUILDING CONSTRUCTION GENERAL Because water expands upon freezing and soils contain water,soils which are allowed to freeze will heave and lose density. Upon thawing, these soils will not regain their original strength and density. The extent of heave and density/strength loss depends on the soil type and moisture condition. Heave is greater in soils with higher percentages of fines (silts/clays). High silt content soils are most susceptible, due to their high capillary rise potential which can create ice lenses.Fine grained soils generally heave about 1/4"to 3/8"for each foot of frost penetration.This can translate to 1"to 2"of total frost heave.This total amount can be significantly greater if ice lensing occurs. DESIGN CONSIDERATIONS Clayey and silty soils can be used as perimeter backfill, although the effect of their poor drainage and frost properties should be considered.Basement areas will have special drainage and lateral load requirements which are not discussed here.Frost heave may be critical in doorway areas.Stoops or sidewalks adjacent to doorways could be designed as structural slabs supported on frost footings with void spaces below.With this design,movements may then occur between the structural slab and the adjacent on-grade slabs.Non-frost susceptible sands(with less than 40%by weight passing a#40 sieve and no more than 5%by weight passing a#200 sieve)can be used below such areas.Depending on the function of surrounding areas,the sand layer may need a thickness transition away from the area where movement is critical. With sand placement over slower draining soils, subsurface drainage would be needed for the sand layer.High density extruded polystyrene insulation could be used within the sand to reduce frost penetration,thereby reducing the sand thickness needed.We caution that insulation placed near the surface can increase the potential for ice glazing of the surface. The possible effects of adfreezing should be considered if clayey or silty soils are used as backfill. Adfreezing occurs when backfill adheres to rough surfaced foundation walls and lifts the wall as it freezes and heaves.This occurrence is most common with masonry block walls, unheated or poorly heated building situations and clay backfill.The potential is also increased where backfill soils are poorly compacted and become saturated.The risk of adfreezing can be decreased by placing a low friction separating layer between the wall and backfill. Adfreezing can occur on exterior piers(such as deck,fence,or other similar pier footings),even if a smooth surface is provided. This is more likely in poor drainage situations where soils become saturated. Additional footing embedment and/or widened footings below the frost zones(which include tensile reinforcement)can be used to resist uplift forces. Specific designs would require individual analysis. CONSTRUCTION CONSIDERATIONS Foundations,slabs and other improvements which may be affected by frost movements should be insulated from frost penetration during freezing weather.If filling takes place during freezing weather,all frozen soils,snow and ice should be stripped from areas to be filled prior to new fill placement. The new fill should not be allowed to freeze during transit,placement or compaction.This should be considered in the project scheduling,budgeting and quantity estimating. It is usually beneficial to perform cold weather earthwork operations in small areas where grade can be attained quickly rather than working larger areas where a greater amount of frost stripping may be needed. If slab subgrade areas freeze,we recommend the subgrade be thawed prior to floor slab placement.The frost action may also require reworking and recompaction of the thawed subgrade. 01REP015 (07/18) AMERICAN ENGINEERING TESTING,INC. BEDDING/FOUNDATION SUPPORT OF BURIED PIPE GENERAL This page addresses soil bedding and foundation support of rigid pipe,such as reinforced concrete,and flexible pipe, such as steel and plastic.This does not address selection of pipe based on loads and allowable deflections,but rather addresses the geotechnical/soil aspects of uniform pipe support. Bedding/foundation support needs relate to local conditions directly beneath and to the sides of the pipe zone, which may be influenced by soft in-situ ground conditions or by soil disturbance due to soil sensitivity or ground water. Bedding relates to granular materials placed directly beneath the bottom of the pipe (usually 4" to 6" thick), which is intended to provide increased support uniformity. We refer to foundation soils as thicker layers of sands and/or gravels (beneath the bedding zone) intended to provide increased foundation strength support, usually needed due to soft,unstable and/or waterbearing conditions. GRANULAR BEDDING With circular pipes, high local loads (approaching point loads) develop if pipes are placed on hard surfaces. Load distribution is improved by placing granular bedding materials beneath the pipe, which are either shaped to match the pipe bottom or are placed without compaction to allow "settling in." The bedding should be placed in such a manner that the pipe will be at the proper elevation and slope when the pipe is laid on the bedding. Common bedding material is defined in MnDOT Specification 3149.2F, Granular Bedding. Published documents recommend rigid pipes having a diameter of 12"to 54"be placed on a bedding thickness of 4",which increases to 6"of bedding for pipe diameters ranging from 54" to 72". Beyond a 72" diameter,the bedding thickness can be equal to the pipe outside diameter divided by 12. Typically,the need for bedding under small diameter pipes(less than 12")depends on the pipe designer's specific needs,although in obvious point loads situations(bedrock,cobbles,significant coarse gravel content),bedding is recommended.Note that bedding should also account for larger diameter bells at joints. FOUNDATION FILL Positive uniform strength is usually compromised in soft or unstable trench bottom conditions. In this case, deeper subcuts and foundation fill placement is needed beneath the pipe. In moderate instability conditions, improvement can likely be accomplished with a thicker bedding layer. However, in more significant instability situations, particularly where ground water is present, coarser materials may be needed to provide a stronger foundation. Thicker gravel layers can also be a favorable media from which to dewater. The following materials would be appropriate for stability improvement, with the coarser materials being appropriate for higher instability/ground water cases. • Fine Filter Aggregate—MnDOT Specification 3149.2J • Coarse Filter Aggregate—MnDOT Specification 3149.2H When using a coarser material which includes significant void space, we highly recommend enveloping the entire gravel layer within a geotextile separation fabric. The gravel material includes open void space, and the fabric acts as a separator which minimizes the intrusion of fines into the open void space. If additional granular bedding sand is used above foundation gravel, the fabric would also prevent downward infiltration of bedding sand into the rock void space. Although it is preferred to not highly compact thin granular bedding zones directly beneath the pipe center, it is desirable to compact the foundation materials to prevent more significant pipe settlement. We recommend foundation fill be compacted to a minimum of 95%of the Standard Proctor density(ASTM:D698).It is not possible to test coarse rock fill,although this material should still be well compacted/tamped. Often, pipes entering structures such as catch basins, lift stations, etc., enter the structure at a higher elevation than the structure bottom,and are therefore placed on the structure backfill.Fill beneath these pipes should be considered foundation fill. Depending on the flexibility of the connection design, it may be necessary to increase the minimum compaction level to reduce differential settlements,particularly with thicker fills. SIDE FILL SUPPORT If the pipe designer requires support from the side fill,granular bedding should also be placed along the sides of the pipe.In poor soil conditions,the sand fill may need to be placed laterally up to two pipe diameters on both sides of the pipe. With rigid pipe, compacted sand placement up to the spring line (within the haunch area) is usually sufficient. With flexible pipe, side fill should be placed and compacted at least to the top of the pipe. For positive support, it is very important to properly compact the sands within the haunch area. 01REP017(07/14) AMERICAN ENGINEERING TESTING,INC. UTILITY EXCAVATION BACKFILLING GENERAL Clayey and silty soils are often difficult to compact,as they may be naturally wet or dry, or may become wet due to ground water or runoff water during construction. Soils will need to be placed within a certain range of water (moisture) content to attain desired compaction levels. Moisture conditioning to within this range can be time consuming and labor intensive,and will require favorable weather. The degree of compaction and the soil type used for backfill within open cut utility excavations depends on the eventual function of the overlying land surface.Details are as follows: ROADWAYS Where trenches are located below roadways, we recommend using inorganic fill and compacting these soils per MnDOT Specification 2105.3Fl (Specified Density Method). On MnDOT funded roads, the 2016 Specification requires 100%compaction over the entire trench depth. On non-MnDOT funded roads,we feel the specification can be relaxed to the previous version of achieving 100%of the Standard Proctor density in the upper 3-foot subgrade zone, and 95% below this depth. Note that this specification also includes moisture content range requirements which are important for proper subgrade stability. Where available soils are wet or of poor quality, it may be possible to use the "Quality Compaction Method" (MnDOT Specification 2105.3F2) for soils below the upper 3-foot subgrade zone if you can tolerate some subsidence.However, a high level of stability is still important within the upper subgrade zone and recommend that the "Specified Density Method" be used in this upper subgrade area. We caution that if backfill soils in the lower trench area are significantly unstable, it may be difficult or even impossible to properly compact soils within the upper 3-foot subgrade zone. In this case, road subgrade stability can be improved by placing a geotextile reinforcement fabric directly over the unstable soils followed by properly drained granular fill placement. STRUCTURAL AREAS If fill is placed beneath or within the significant zone of influence of a structure (typically a 1:1 lateral oversize zone), the soil type and minimum compaction level will need to be evaluated on an individual basis. Because trenches result in variable fill depths over a short lateral distance,higher than normal compaction levels and/or more favorable (sandy) soil fill types may be needed. If this situation exists, it is important that special geotechnical engineering review be performed. NON-STRUCTURAL AREAS In grass/ditch areas, backfill soils should be placed in reasonable lift thicknesses and compacted to a minimum of 90%of the Standard Proctor density(ASTM:D698)and/or per the MnDOT"Quality Compaction Method."If lower compaction levels are accepted, more noticeable subsidence at the surface can occur. Steep or high slopes require special consideration, and if this situation exists, it is important that special geotechnical engineering review be performed. SPECIAL CASES Structural retention systems are often used to reduce impacts on adjacent streets/improvements. If localized excavations/pits or annular spaces are created which need to be backfilled, it may not be possible to place and compact soils by the conventional means of backfilling. Retraction of structural systems can also leave soils loosened. Significant settlement can occur in areas where backfill cannot be compacted. If these situations are located in non-structural or non-paved areas,it may be reasonable to accept the settlements and associated follow-up maintenance in order avoid the high cost of trying to compact the soil or placing flowable lean concrete fill. However, there may be areas where fill settlement needs to be avoided, especially as the settlement will be differential from the surrounding surface,or differential from a buried structure in the case of higher piping entering the structure. Where settlement needs to be avoided, the specification should require that the contractor submit a backfill compaction plan along with the retention plan. Improper sequencing of retention system removal and backfilling of the pits could result in excessive settlement and/or lateral movement of nearby improvements. OLREP018(06/16) AMERICAN ENGINEERING TESTING,INC. BITUMINOUS PAVEMENT SUBGRADE PREPARATION AND DESIGN GENERAL Bituminous pavements are considered layered"flexible" systems. Dynamic wheel loads transmit high local stresses through the bituminous/base onto the subgrade. Because of this, the upper portion of the subgrade requires high strength/stability to reduce deflection and fatigue of the bituminous/base system.The wheel load intensity dissipates through the subgrade such that the high level of soil stability is usually not needed below about 2 feet to 4 feet (depending on the anticipated traffic and underlying soil conditions). This is the primary reason for specifying a higher level of compaction within the upper subgrade zone versus the lower portion. Moderate compaction is usually desired below the upper critical zone, primarily to avoid settlements/sags of the roadway. However, if the soils present below the upper 3 feet subgrade zone are unstable,attempts to properly compact the upper 3 feet zone to the 100%level may be difficult or not possible.Therefore,control of moisture just below the 3 feet level may be needed to provide a non-yielding base upon which to compact the upper subgrade soils. Long-term pavement performance is dependent on the soil subgrade drainage and frost characteristics. Poor to moderate draining soils tend to be susceptible to frost heave and subsequent weakening upon thaw. This condition can result in irregular frost movements and "pop-outs," as well as an accelerated softening of the subgrade. Frost problems become more pronounced when the subgrade is layered with soils of varying permeability. In this situation, the free-draining soils provide a pathway and reservoir for water infiltration which exaggerates the movements. The placement of a well-drained sand subbase layer as the top of subgrade can minimize trapped water, smooth frost movements and significantly reduce subgrade softening. In wet, layered and/or poor drainage situations,the long-term performance gain should be significant. If a sand subbase is placed, we recommend it be a "Select Granular Borrow"which meets Mn/DOT Specification 3149.2B2. PREPARATION Subgrade preparation should include stripping surficial vegetation and organic soils; where the exposed soils are within the upper "critical" subgrade zone (generally 2 feet deep for "auto only" areas and 3 feet deep for "heavy duty" areas), they should be evaluated for stability. Excavation equipment may make such areas obvious due to deflection and rutting patterns. Final evaluation of soils within the critical subgrade zone should be done by test rolling with heavy rubber-tired construction equipment,such as a loaded dump truck. Soils which rut or deflect 1" or more under the test roll should be corrected by either subcutting or replacement; or by scarification, drying, and recompaction. Reworked soils and new fill should be compacted per the "Specified Density Method" outlined in Mn/DOT Specification 2105.3F1 (a minimum of 100% of Standard Proctor density in the upper 3 feet subgrade zone,and a minimum of 95%below this). Subgrade preparation scheduling can be an important consideration. Fall and Spring seasons usually have unfavorable weather for soil drying. Stabilizing non-sand subgrades during these seasons may be difficult, and attempts often result in compromising the pavement quality. Where construction scheduling requires subgrade preparation during these times,the use of a sand subbase becomes even more beneficial for constructability reasons. SUBGRADE DRAINAGE If a sand subbase layer is used,it should be provided with a means of subsurface drainage to prevent water build-up. This can be in the form of draintile lines which dispose into storm sewer systems,or outlets into ditches.Where sand subbase layers include sufficient sloping and water can migrate to lower areas,draintile lines can be limited to finger drains at the catch basins.Even if a sand layer is not placed,strategically placed draintile lines can aid in improving pavement performance. This would be most important in areas where adjacent non-paved areas slope towards the pavement.Perimeter edge drains can aid in intercepting water which may infiltrate below the pavement. 01REP016(12/08) AMERICAN ENGINEERING TESTING,INC. Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. Appendix A Geotechnical Field Exploration and Testing Boring Log Notes Unified Soil Classification System Boring Locations Map —Figure 1 Subsurface Boring Logs Appendix A Geotechnical Field Exploration and Testing Report No. P-0004506 A.1 FIELD EXPLORATION The subsurface conditions at the site were explored by drilling and sampling six(6)standard penetration test borings.The locations of the borings appear on Figure 1,preceding the Subsurface Boring Logs in this appendix. A.2 SAMPLING METHODS A.2.1 Split-Spoon Samples(SS)-Calibrated to N6o Values Standard penetration (split-spoon) samples were collected in general accordance with ASTM: Dl586 with one primary modification. The ASTM test method consists of driving a 2-inch O.D. split-barrel sampler into the in-situ soil with a 140-pound hammer dropped from a height of 30 inches.The sampler is driven a total of 18 inches into the soil.After an initial set of 6 inches, the number of hammer blows to drive the sampler the final 12 inches is known as the standard penetration resistance or N-value. Our method uses a modified hammer weight,which is determined by measuring the system energy using a Pile Driving Analyzer (PDA)and an instrumented rod. In the past, standard penetration N-value tests were performed using a rope and cathead for the lift and drop system. The energy transferred to the split-spoon sampler was typically limited to about 60%of its potential energy due to the friction inherent in this system.This converted energy then provides what is known as an No blow count. The most recent drill rigs incorporate an automatic hammer lift and drop system, which has higher energy efficiency and subsequently results in lower N-values than the traditional N60 values. By using the PDA energy measurement equipment,we are able to determine actual energy generated by the drop hammer.With the various hammer systems available,we have found highly variable energies ranging from 55% to over 100%. Therefore, the intent of AET's hammer calibrations is to vary the hammer weight such that hammer energies lie within about 60%to 65%of the theoretical energy of a 140-pound weight falling 30 inches. The current ASTM procedure acknowledges the wide variation in N-values, stating that N-values of 100% or more have been observed. Although we have not yet determined the statistical measurement uncertainty of our calibrated method to date,we can state that the accuracy deviation of the N-values using this method is significantly better than the standard ASTM Method. A.2.2 Disturbed Samples(DS)/Spin-up Samples(SU) Sample types described as"DS"or"SU" on the boring logs are disturbed samples,which are taken from the flights of the auger. Because the auger disturbs the samples,possible soil layering and contact depths should be considered approximate. A.2.3 Sampling Limitations Unless actually observed in a sample,contacts between soil layers are estimated based on the spacing of samples and the action of drilling tools.Cobbles,boulders,and other large objects generally cannot be recovered from test borings,and they may be present in the ground even if they are not noted on the boring logs. Determining the thickness of"topsoil"layers is usually limited,due to variations in topsoil definition,sample recovery, and other factors. Visual-manual description often relies on color for determination, and transitioning changes can account for significant variation in thickness judgment. Accordingly, the topsoil thickness presented on the logs should not be the sole basis for calculating topsoil stripping depths and volumes. If more accurate information is needed relating to thickness and topsoil quality definition,alternate methods of sample retrieval and testing should be employed. A.3 CLASSIFICATION METHODS Soil descriptions shown on the boring logs are based on the Unified Soil Classification (USC) system. The USC system is described in ASTM: D2487 and D2488. Where laboratory classification tests (sieve analysis or Atterberg Limits) have been performed, accurate classifications per ASTM: D2487 are possible. Otherwise, soil descriptions shown on the boring logs are visual-manual judgments. Charts are attached which provide information on the USC system,the descriptive terminology,and the symbols used on the boring logs. The boring logs include descriptions of apparent geology. The geologic depositional origin of each soil layer is interpreted primarily by observation of the soil samples,which can be limited. Observations of the surrounding topography, vegetation, and development can sometimes aid this judgment. Appendix A-Page 1 of 2 AMERICAN ENGINEERING TESTING,INC. Appendix A Geotechnical Field Exploration and Testing Report No. P-0004506 A.4 WATER LEVEL MEASUREMENTS The groundwater level measurements are shown at the bottom of the boring logs.The following information appears under"Water Level Measurements"on the logs: • Date and Time of measurement • Sampled Depth: lowest depth of soil sampling at the time of measurement • Casing Depth:depth to bottom of casing or hollow-stem auger at time of measurement • Cave-in Depth: depth at which measuring tape stops in the borehole • Water Level:depth in the borehole where free water is encountered • Drilling Fluid Level:same as Water Level,except that the liquid in the borehole is drilling fluid The true location of the water table at the boring locations may be different than the water levels measured in the boreholes.This is possible because there are several factors that can affect the water level measurements in the borehole. Some of these factors include: permeability of each soil layer in profile, presence of perched water, amount of time between water level readings, presence of drilling fluid,weather conditions,and use of borehole casing. A.5 LABORATORY TEST METHODS A.5.1 Water Content Tests Conducted per AET Procedure 01-LAB-010,which is performed in general accordance with ASTM:D2216 and AASHTO: T265. A.6 TEST STANDARD LIMITATIONS Field and laboratory testing is done in general conformance with the described procedures. Compliance with any other standards referenced within the specified standard is neither inferred nor implied. A.7 SAMPLE STORAGE Unless notified to do otherwise,we routinely retain representative samples of the soils recovered from the borings for a period of 30 days. Appendix A-Page 2 of 2 AMERICAN ENGINEERING TESTING,INC. BORING LOG NOTES DRILLING AND SAMPLING SYMBOLS TEST SYMBOLS Symbol Definition Symbol Definition AR: Sample of material obtained from cuttings blown out CONS: One-dimensional consolidation test the top of the borehole during air rotary procedure. DEN: Dry density,pcf B,H,N: Size of flush joint casing DST: Direct shear test CAS: Pipe casing, number indicates nominal diameter in E: Pressuremeter Modulus,tsf inches HYD: Hydrometer analysis COT: Clean-out tube LL: Liquid Limit,% DC: Drive casing;number indicates diameter in inches LP: Pressuremeter Limit Pressure,tsf DM: Drilling mud or bentonite slurry OC: Organic Content,% DR: Driller(initials) PERM: Coefficient of permeability(K)test;F-Field; DS: Disturbed sample from auger flights L-Laboratory DP: Direct push drilling; a 2.125 inch OD outer casing PL: Plastic Limit,% with an inner 11 inch ID plastic tube is driven qp: Pocket Penetrometer strength,tsf(approximate) continuously into the ground. qc: Static cone bearing pressure,tsf FA: Flight auger; number indicates outside diameter in qu: Unconfined compressive strength,psf J inches R: Electrical Resistivity,ohm-cms HA: Hand auger;number indicates outside diameter RQD: Rock Quality Designation of Rock Core, in percent HSA: Hollow stem auger;number indicates inside diameter (aggregate length of core pieces 4" or more in length in inches as a percent of total core run) LG: Field logger(initials) SA: Sieve analysis MC: Column used to describe moisture condition of TRX: Triaxial compression test samples and for the ground water level symbols VSR: Vane shear strength,remolded(field),psf N(BPF): Standard penetration resistance(N-value)in blows per VSU: Vane shear strength,undisturbed(field),psf foot(see notes) WC: Water content,as percent of dry weight NQ: NQ wireline core barrel %-200: Percent of material finer than#200 sieve PQ: PQ wireline core barrel RDA: Rotary drilling with compressed air and roller or drag STANDARD PENETRATION TEST NOTES bit. (Calibrated Hammer Weight) RDF: Rotary drilling with drilling fluid and roller or drag bit The standard penetration test consists of driving a split-spoon REC: In split-spoon(see notes),direct push and thin-walled sampler with a drop hammer(calibrated weight varies to provide tube sampling, the recovered length (in inches) of N60 values)and counting the number of blows applied in each of sample. In rock coring,the length of core recovered three 6" increments of penetration. If the sampler is driven less (expressed as percent of the total core run). Zero than 18" (usually in highly resistant material), permitted in indicates no sample recovered. ASTM:D1586,the blows for each complete 6"increment and for SS: Standard split-spoon sampler (steel; 1.5" is inside each partial increment is on the boring log.For partial increments, diameter; 2" outside diameter); unless indicated the number of blows is shown to the nearest 0.1'below the slash. otherwise SU Spin-up sample from hollow stem auger The length of sample recovered,as shown on the"REC"column, TW: Thin-walled tube;number indicates inside diameter in may be greater than the distance indicated in the N column.The inches • disparity is because the N-value is recorded below the initial 6" WASH: Sample of material obtained by screening returning set (unless partial penetration defined in ASTM: D1586 is rotary drilling fluid or by which has collected inside encountered)whereas the length of sample recovered is for the the borehole after"falling"through drilling fluid entire sampler drive(which may even extend more than 18"). WH: Sampler advanced by static weight of drill rod and hammer WR Sampler advanced by static weight of drill rod 94mm: 94 millimeter wireline core barrel : Water level directly measured in boring 0: Estimated water level based solely on sample appearance 01REP052C(7/11) AMERICAN ENGINEERING TESTING,INC. • • UNIFIED SOIL CLASSJYLCATION SYSTEM AMERICA` ASTM Designations:D 2487,D2488 ENGIN ERENG ` ' TESTING,INC. • Soil Classification Notes Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Group Group Names . ABased on the material passing the 3-in Symbol '(75-mm) sieve. Coarse-Grained Gravels More Clean Gravels •Cu>4 and l<Cc<35 GW Well graded gravel°' alffield sample contained cobbles or Soils More .than 50%coarse Less than 5% boulders,or both, add"with cobbles or than 50% • fraction. retained fines° Cu<4 and/or 1>Cc>3a GP Poorly graded gravely boulders,or both"to group name. retained on on No.4 sieve cGravels with 5 to 12%fines require dual No.200 sieve Gravels with Fines classify as ML or MH . GM ' Silty gravely-"1i symbols: Fines moreGW-GM well-graded gravel with silt - - than 12%fines c Fines classify as CL or CH GC Clayey gravel'''' GW-GC well-graded gravel with clay n GP-GM poorly graded gravel with silt Sands 50%or Clean Sands Cu`>6 and I<Cc<3 SW Well-graded sand' GP-GC poorly graded gravel with clay more of coarse Less than 5% - DSands with 5 to 12%fines require dual fractionpasses fines Cu<6 and/or 1>Cc> SP Poorly-graded sand' symbols: No.4 sieve SW-SM well-graded sand with silt Sands with Fines classify as ML or MH SM Silty sane.'" SW-SC well-graded sand with clay Fines more SP-SM poorly graded sand with silt than 12%fines D Fines classify as CL or CH SC Clayey sand"-"-1 SP-SC poorly graded sand with clay Fine-Grained Sills and Clays. inorganic PI>7 and plots on or above CL Lean clay"' ' Soils 50%or Liquid limit less • "A"line' (D30 2 • more passes than 50 PI<4 or plots below 3 . Si12'- Ilea=D60/Dio, Cc= the No,200 A"line Drox Dso sieve organic Lima d limit—oven dried<0.75 ' OL Organic cis!'" Liquid limit—not dried o• ref soil contains>15%sand,add"with (sea Plasticity Organic si1tK i h/ sand"to group name. Chart below) °if fines classify as CL-MCS use dual Silts and Clays inorganic PI plots on or above"A"line CH 'Fat clays- smbol GC-GM,or SC-SM. uy Liquid limit 50 If fines are organic,add"with organic or more PI plots below"A"line MH Blastic silt"" fines"to group name. • rlf soil contains>15%gravel,add"with organic Liquid limit—oven dried<035 011 Organic clay' ravel"to group name. Liquid limit—not dried MQ ffAtterberg limits plot is hatched area - Organic silt' soil is a CL-ML silty clay. Highly organic Primarily organic matter, dark PT Peal" zifsoil contains 15 to 29%plus No.200 soil - in color,and organic in odor add"with sand"or "with gravel", whichever is predominant. I'If soil contains>30%plus No,200, SIEVEANALYSIS 50 ��,Q"yalpy�_�,,,__ I Pa dncsfi�sonottmeominetl and predominantlysani add "sandy"to Pr=aFmsr.canfned soDc. groupname. 111 Y. 10 Z .40m mao _ If soil contains>30% lus No.200, ' g�,■■■■■•■'° L. HH't®snno fl Oto 41=255. A/ 11311111111111111111111111 M predominantly gravel,add"gravelly" n31■■1■i■■��1 NeoPa°sat�avi / O ,•� tpredo o i natty w,"I■NME■�MI °"d 41 ne �r y NPl>4 and lots'en pr above"A"line. 15 ���II�n""' ■O�1w Q vin°Pl"s5(11elp=7i G bel<4or plots below"A"rine. °¢ I'I'1NI ��■ME ' o a6 f 5P1 plots on or above"A"line. Ao- .w i1,1111���MINI w M % aV °Pl plots below A"line. 11n■bt, na®zsmm NM' g , 20' �' RFiber Content description shown below. • 1■1■■■]EI_�M1 a • // C MH OR OH • �,",■■�■'11" r.e0.D76mm .t0- 1III■■S�■1.1 �/-mr/ M.L eR ol. - ® W e ' a"., " ¢;" •D0 .10 .la 211 50 AO SD 50 70 AD 50 .100 .110 • PA411C1,5 SIZE IN AttWMErasts LIQUID MAT(t.4 ' m Plasticity Chart ADDITIONAL TERMINOLOGY NOTES USED BYAET FOR SOIL IDENTIFICATIONANJ DESCRIPTION - Grain Size Gravel Percentases Consistency of Plastic Soils Relative Density of Non-Plastic Soils Term . Particle Size Term Percent Term N Value,BPF Term 11 Value,BPF Boulders Over 12" A Little Gravel 3%-14% Very Soft less than 2 Very Loose 0-4 Cobbles 3"to 12' With Gravel 15%-29% Soft 2-4 Loose 5-10 Gravel #4 sieve to 3" Gravelly ,.20%-50% Film 5-8 Medium Dense 11-30 Sand #200 to#4 sieve. Stiff 9-15 ' Dense 31-50 Fines(silt&clay) Pass dt200 sieve - • Very Stiff 16-30 Very Dense Greater than 50 Hard Greater _ Moisture/Frost Condition Layering Notes PeatDescriotlon Organic Description(if no lab tests) (MC Column) . Soils are described as organic if soil is not peat D(Dry): Absence of moisture,dusty,dry to and is judged to have sufficient organic fines touch. Laminations: Layers less Fiber'Content content to influence the Liquid Limit properties. p gh '/i"thick of Term (Visual Estimate). ,xtgniv organic used for borderline cases. M(Moist): Damp,elthou freewaternot ) visible. Soil may still have a high differing materiel water content(over"o • or color. Fibric Peat: Greater than 67% lodgRooted Inclusions "optimum"). ° With roots: lodged to have sufficient quantity W(Wet/ . Free water visible,intended to Hernia Peet es33—67/a of roots to influence the soil Waterbearing): describenon-plasticso}•ls. Lenses: Pockets ozlayers 5apricPeat Iessthan33% properties. Waterbearing usually relates to greater than V2" Trace roots: Small roots present,.but not judged amid and sand with silt thick of differing to be in sufficient quantity to F(Frozen): Soil frozen material or color. ,,,•,;•s,,,,,Ft<,9 ..+r,,:1.,.,.....-«:.- 4-1 dCD tl) N •tiff — y war r E ;` �`'�., O © (� ,e, j %' - .'is. : 'A.i,t_.4'.,,;,f- ''''.;Z:--;,,,.-',. ..'-ii--',. -?-*t.,.•-•• ...7',..'...'11-..--,.)-- -4--:..*,',-_'.--.i/, 4'..: ikit itioc-, ,. „•7.,•;',,.' .7y ' 4:41'... '‘:•;-: 717; --rist.v.3 kifi (4 Nti,. ,t„,-.:, .. , .- -',77- in- 114 1 1 O,.♦ e s�♦ taom I1 t `1 m 1- I c o Lij CO QQ x r x .Xtls� — a aAm od i. • 1 frit 1 rol .. tk , . -14- 1 N . 10 mosouris : + . . 4 . ca 1 1 , .. , . .iii 0 ime ,,4 _, .;.,_ .4 , ... .. . .: : , ......., t. * si vp � C/] a z I. , Ai - i V w 1 z t f , �/ % — W may- r ._ C7 cn t ot! W Qw I tI i' j i !fit `" AAMERICAN ENGINEERING TESTING,INC. SUBSURFACE BORING LOG AET JOB NO: P-0004506 LOG OF BORING NO. B-1 (p. 1 of 1) PROJECT: Park Dental; 13961 60th St.N.; Oak Park Heights,MN SURFACE ELEVATION: 938.2 LATITUDE: 45.03548641 LONGITUDE: -92.82556623 DEPTHFIELD&LABORATORY TESTS SAMPLE REC IN MATERIAL DESCRIPTION GEOLOGY N MC TYPE IN. FEET WC DEN LL PL %-#20( FILL,mostly silty sand,a little gravel,trace FILL \roots,brown 1 FILL,mostly clayey sand,a little gravel,brown 8 M A SS 18 9 2- 3 TILL 5 M I SS 18 11 SILTY SAND,a little gravel,reddish brown, moist,loose to medium dense(SM) 4- Ili 5 - 14 M SS 18 A r ? SAND,fine grained,light brown,moist,loose to ' COARSE 8- medium dense,lens of silt(SP) ALLUVIUM Ll VIUM 7 M SS 18 9- 1i 10- 8 M SS 20 11 — A 12- 1� 13 - 14 M SS 20 14- END OF BORING s-', b N F 0. 0 7I N O W O N W E) .t- -,a 0 0 DEPTH: DRILLING METHOD WATER LEVEL MEASUREMENTS NOTE: REFER TO DATE TIME SAMPLED CASING CAVE-IN DRILLING WATER THE ATTACHED C7 0-12W 3.25"HSA DEPTH DEPTH DEPTH FLUID LEVEL LEVEL Z ° 7/20/21 10:35 14.5 12.5 14.5 NoneiL SHEETS FOR AN EXPLANATION OF 1 COMPLETED: 7/20/21 TERMINOLOGY ON U THIS LOG DR: TA LG: RG Rig: 41 03/2011 01-DHR-060 AAMERICAN ENGINEERING TESTING,INC. SUBSURFACE BORING LOG immi AET JOB NO: P-0004506 LOG OF BORING NO. B-2 (p. 1 of 1) PROJECT: Park Dental; 13961 60th St.N.; Oak Park Heights,MN SURFACE ELEVATION: 938.4 LATITUDE: 45.0353616 LONGITUDE: -92.82545368 DEPTH &LABORATORY TESTS IN MATERIAL DESCRIPTION GEOLOGY N MC SAMPLE REC FEET TYPE IN. WC DEN LL PL 1/0-#200 3.5"Bituminous pavement /---FILL 1 3.5"FILL,mostly crushed limestone,light ' FILL COARSE brown ALLUVIUM/ 11 M Y SS 12 2 SAND,a little gavel,fine grained,light brown - A moist,medium dense(SP)(possible fill) / FINE 3 SILT,brown,moist,medium dense to loose, ALLUVIUM 13 M SS 16 18 laminations of sand(ML) , 4 Iii 5 10 M 1 SS 20 15 6 7 �; SILT,brown,moist,medium dense,lenses of 8 sand(ML) 13 M SS 22 9 tIll 10 SAND WITH SILT,fine grained,brown,moist, COARSE loose to medium dense(SP-SM) ALLUVIUM 10 M , SS 18 11 12 II 13 13 M SS 20 14 END OF BORING N c N n I- 0 UI NI 0 CT, 0 N W I � U W Q a 0 o DEPTH: DRILLING METHOD WATER LEVEL MEASUREMENTS NOTE: REFER TO 0 o_ DATE TIME SAMPLED CASING CAVE-IN DRILLING WATER THE ATTACHED z 0 121/i' 3.25" HSA DEPTH DEPTH DEPTH FLUID LEVEL LEVEL ° 7/20/21 12:00 14.5 12.5 14.5 None SHEETS FOR AN EXPLANATION OF BORIN0 COMPLETED: 7/20/21 TERMINOLOGY ON U a THIS LOG DR: TA LG: RG Rig: 41 03/2011 01-DHR-060 AAMERICAN ENGINEERING SUBSURFACE BORING LOG TESTING,INC. I_ AET JOB NO: P-0004506 LOG OF BORING NO. B-3 (p.1 of 1) PROJECT: Park Dental; 13961 60th St.N.; Oak Park Heights,MN SURFACE ELEVATION: 938.7 LATITUDE: 45.03509775 LONGITUDE: -92.82533419 DEPTHFIELD&LABORATORY TESTS IN MATERIAL DESCRIPTION GEOLOGY N MC REC TSAMPLE TYPE IN,FEET WC DEN LL PL %-#201 -\3"Bituminous pavement `—FILL 1 1 _12"FILL,mostly crushed limestone,light brown / ,FILL,mostly sand,a little gravel,brown 14 M A SS 10 7 7 2 CLAYEY SAND,a little gravel,reddish brown, ' TILL stiff(SC) 3 _ SILTY SAND,a little gravel,reddish brown, 33 Mir SS 8 dense to medium dense(SM) A 4— • i 5 — 17 M A SS 18 6— 7— Iii 8 COARSE 13 M P SS 18 SAND WITH SILT,brown,moist,medium dense(SP-SM) ALLUVIUM 9— iii 10— 13 M SS 22 11 — Ali 12— i1 13 — 20 M H SS 22 14— END OF BORING N F- 0 U' N' O C E. N, J J W 3 H a U 0 a 6 a DEPTH: DRILLING METHOD WATER LEVEL MEASUREMENTS NOTE: REFER TO S DATE TIME SAMPLED CASING CAVE-IN DRILLING WATER THE ATTACHED z 0-12'/x' 3.25"HSA DEPTH DEPTH DEPTH FLUID LEVEL LEVEL 0 7/20/21 12:45 14.5 12.5 14.5 None SHEETS FOR AN EXPLANATION OF I. COMPLETED: 7/20/21 TERMINOLOGY ON U DR: TA LG: RG Rig: 41 THIS LOG a 03/2011 01-DHR-060 AAMERICAN ENGINEERING SUBSURFACE BORING LOG TESTING,INC. mom AET JOB NO: P-0004506 LOG OF BORING NO. B-4 (p. 1 of 1) PROJECT: Park Dental; 13961 60th St.N.;Oak Park Heights,MN SURFACE ELEVATION: 937.2 LATITUDE: 45.0353651 LONGITUDE: -92.82528428 DEPTHSAMPLE REC FIELD&LABORATORY TESTS IN MATERIAL DESCRIPTION GEOLOGY N MC FEET TYPE IN. WC DEN LL PL %-#20( -.4"Bituminous pavement ,--FILL • 1 _FILL,mostly crushed limestone,light brown / FINE SILT,brown,moist,medium dense,laminations ALLUVIUM 14 M SS 14 15 2 of sand(ML-SP) _ , SAND WITH SILT,brown,moist,medium COARSE 3dense(SP SM) ALLUVIUM 12 M SS 16 SAND,a little gravel,fine to medium grained, 4— light brown,moist,medium dense(SP) SAND,fine grained,light brown,moist,loose 5 — (SP) 8 M SS 10 6— ? SAND,fine grained,light brown,moist,loose, lens of silt(SP) 8— 8 M SS 22 20 9 - 1 SAND WITH SILT,brown,moist,loose to medium dense(SP-SM) 8 M SS 22 11 — 12— 1 13 — 14 M SS 22 14— END OF BORING N N 0 0 C7 NI 0 0, NI W F- a U Iu� a (9 g DEPTH: DRILLING METHOD WATER LEVEL MEASUREMENTS NOTE: REFER TO DATE TIME SAMPLED CASING CAVE-IN DRILLING WATER THE ATTACHED DEPTH FLUID LEVEL LEVEL c 0-12W 3.25" HSA DEPTH DEPTH ° 7/20/21 11:35 14.5 12.5 14.5None SHEETS FOR AN EXPLANATION OF BORING TERMINOLOGY ON U COMPLETED: 7/20/21 THIS LOG DR: TA LG: RG Rig: 41 03/2011 01-DHR-060 AAMERICAN ENGINEERING SUBSURFACE BORING LOG TESTING,INC. AET JOB NO: P-0004506 LOG OF BORING NO. B-5 (p. 1 of 1) PROJECT: Park Dental; 13961 60th St.N.;Oak Park Heights,MN SURFACE ELEVATION: 936.6 LATITUDE: 45.03551168 LONGITUDE: -92.82522674 DEPTHFIELD&LABORATORY TESTS IN MATERIAL DESCRIPTION GEOLOGY N MC REC TYPEL SAMPLE IN. FEET WC DEN LL PL V-#20( -\4"Bituminous pavement / FILL _l4"FILL,mostly crushed limestone,light brown / FINE SILT WITH SAND,light brown,moist,loose to ALLUVIUM 9 M 1111 SS 12 8 2— medium dense,laminations of sand(ML SP) 3 — 9 M , SS 18 9 4- 5 - 13 M SS 18 10 6— 7 SILT,brown,moist,medium dense(ML) 8 — 22 M SS 22 15 9— 10- 15 M , SS 22 18 11 — 12— E11 13 - 17 M SS 22 19 14 — END OF BORING N 1,!1- 6 F N JJJ U W 6 0 o DEPTH: DRILLING METHOD WATER LEVEL MEASUREMENTS NOTE: REFER TO a 1 , DATE TIME SAMPLED DEPTH CASINGEPTHDEPTH FLUID LEVEL LEVEL THE ATTACHED Z 0-12h 3.25"HSA 7/20/21 11:15 14.5 12.5 14.5 None SHEETS FOR AN EXPLANATION OF BORING TERMINOLOGY ON o COMPLETED: 7/20/21 DR: TA LG: RG Rig: 41 THIS LOG 03/2011 01-DHR-060 AAMERICAN ENGINEERING SUBSURFACE BORING LOG TESTING,INC. AET JOB NO: P-0004506 LOG OF BORING NO. B-6 (p.1 of 1) PROJECT: Park Dental;13961 60th St.N.; Oak Park Heights,MN SURFACE ELEVATION: 937.0 LATITUDE: 45.03555783 LONGITUDE: -92.82536065 DEPTHSAMPLE REC FIELD&LABORATORY TESTS IN MATERIAL DESCRIPTION GEOLOGY N MC FEET TYPE IN. WC DEN LL PL '/-#20( 4"Bituminous pavement r—FILL 1 — 3"FIT.T,mostly crushed limestone,brown COARSE — 18 M V SS 16 FILL,mostly clayey sand with organic fines, .••ALLUVIUM •2— dark brown I SAND WITH SILT,fine grained,brown,moist, ' 3 — medium dense(SP-SM) 20 M SS 18 4 - A 5 — 13 M , SS 18 6— , 7— 21 M SS 18 8 - A 9— 16 M SS 18 10- , 11 - 17 M SS 20 12— , 13 — 11 M SS 20 14 END OF BORING N N N n r O 0. •C N E z E, "I J >W } f- a U } F W 4 a co 0 $ DEPTH: DRILLING METHOD WATER LEVEL MEASUREMENTS NOTE: REFER TO a DATE TIME SAMPLED CASING CAVE-IN DRILLING WATER THE ATTACHED 0 0-12' 3.25"HSA DEPTH DEPTH DEPTH FLUID LEVEL LEVEL z 2 7/20/21 10:00 14.0 12.0 14.0 None SHEETS FOR AN EXPLANATION OF z BBOMPLETED: 7/20/21 TERMINOLOGY ON ui THIS LOG Llii DR: TA LG: RG Rig: 41 03/2011 01-DHR-060 Report of Geotechnical Exploration Oak Park Heights Park Dental;Oak Park Heights,Minnesota AMERICAN August 3,2021 ENGINEERING Report No.P-0004506 TESTING,INC. Appendix B Geotechnical Report Limitations and Guidelines for Use Appendix B Geotechnical Report Limitations and Guidelines for Use Report No. P-0004506 B.1 REFERENCE This appendix provides information to help you manage your risks relating to subsurface problems which are caused by construction delays, cost overruns, claims, and disputes. This information was developed and provided by GBA1, of which, we are a member firm. B.2 RISK MANAGEMENT INFORMATION B.2.1 Understand the Geotechnical Engineering Services Provided for this Report Geotechnical engineering services typically include the planning,collection, interpretation,and analysis of exploratory data from widely spaced borings and/or test pits. Field data are combined with results from laboratory tests of soil and rock samples obtained from field exploration(if applicable),observations made during site reconnaissance, and historical information to form one or more models of the expected subsurface conditions beneath the site. Local geology and alterations of the site surface and subsurface by previous and proposed construction are also important considerations. Geotechnical engineers apply their engineering training, experience, and judgment to adapt the requirements of the prospective project to the subsurface model(s). Estimates are made of the subsurface conditions that will likely be exposed during construction as well as the expected performance of foundations and other structures being planned and/or affected by construction activities. The culmination of these geotechnical engineering services is typically a geotechnical engineering report providing the data obtained,a discussion of the subsurface model(s),the engineering and geologic engineering assessments and analyses made, and the recommendations developed to satisfy the given requirements of the project. These reports may be titled investigations, explorations, studies, assessments, or evaluations. Regardless of the title used, the geotechnical engineering report is an engineering interpretation of the subsurface conditions within the context of the project and does not represent a close examination,systematic inquiry,or thorough investigation of all site and subsurface conditions. B.2.2 Geotechnical Engineering Services are Performed for Specific Purposes, Persons, and Projects, and At Specific Times Geotechnical engineers structure their services to meet the specific needs, goals, and risk management preferences of their clients. A geotechnical engineering study conducted for a given civil engineer will not likely meet the needs of a civil-works constructor or even a different civil engineer. Because each geotechnical engineering study is unique, each geotechnical engineering report is unique,prepared solely for the client. Likewise, geotechnical engineering services are performed for a specific project and purpose. For example, it is unlikely that a geotechnical engineering study for a refrigerated warehouse will be the same as one prepared for a parking garage; and a few borings drilled during a preliminary study to evaluate site feasibility will not be adequate to develop geotechnical design recommendations for the project. Do not rely on this report if your geotechnical engineer prepared it: • for a different client; • for a different project or purpose; • for a different site(that may or may not include all or a portion of the original site);or • before important events occurred at the site or adjacent to it; e.g., man-made events like construction or environmental remediation,or natural events like floods,droughts,earthquakes,or groundwater fluctuations. Note, too, the reliability of a geotechnical-engineering report can be affected by the passage of time, because of factors like changed subsurface conditions;new or modified codes,standards, or regulations; or new techniques or tools. If you are the least bit uncertain about the continued reliability of this report, contact your geotechnical engineer before applying the recommendations in it. A minor amount of additional testing or analysis after the passage of time— if any is required at all— could prevent major problems. 1 Geoprofessional Business Association, 1300 Piccard Drive,LL14,Rockville,MD 20850 Telephone:301/565-2733:www.geoprofessional.org,2019 Appendix B—Page 1 of 3 AMERICAN ENGINEERING TESTING,INC Appendix B Geotechnical Report Limitations and Guidelines for Use Report No. P-0004506 B.2.3 Read the Full Report Costly problems have occurred because those relying on a geotechnical-engineering report did not read the report in its entirety. Do not rely on an executive summary. Do not read selective elements only.Read and refer to the report in full. B.2.4 You Need to Inform Your Geotechnical Engineer About Change Your geotechnical engineer considered unique, project-specific factors when developing the scope of study behind this report and developing the confirmation-dependent recommendations the report conveys.Typical changes that could erode the reliability of this report include those that affect: • the site's size or shape; • the elevation, configuration, location, orientation, function or weight of the proposed structure and the desired performance criteria; • the composition of the design team;or • project ownership. As a general rule, always inform your geotechnical engineer of project or site changes — even minor ones — and request an assessment of their impact. The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered. B.25 Most of the"Findings"Related in This Report Are Professional Opinions Before construction begins, geotechnical engineers explore a site's subsurface using various sampling and testing procedures. Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing is performed. The data derived from that sampling and testing were reviewed by your geotechnical engineer, who then applied professional judgement to form opinions about subsurface conditions throughout the site. Actual sitewide-subsurface conditions may differ—maybe significantly—from those indicated in this report. Confront that risk by retaining your geotechnical engineer to serve on the design team through project completion to obtain informed guidance quickly,whenever needed. B.2.6 This Report's Recommendations Are Confirmation-Dependent The recommendations included in this report — including any options or alternatives — are confirmation-dependent. In other words,they are not final,because the geotechnical engineer who developed them relied heavily on judgement and opinion to do so. Your geotechnical engineer can finalize the recommendations only after observing actual subsurface conditions exposed during construction. If through observation your geotechnical engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon, assuming no other changes have occurred. The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation-dependent recommendations if you fail to retain that engineer to perform construction observation. B.2.7 This Report Could Be Misinterpreted Other design professionals' misinterpretation of geotechnical engineering reports has resulted in costly problems. Confront that risk by having your geotechnical engineer serve as a continuing member of the design team,to: • confer with other design-team members; • help develop specifications; • review pertinent elements of other design professionals'plans and specifications;and • be available whenever geotechnical engineering guidance is needed. You should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction-phase observations. B.2.8 Give Constructors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can shift unanticipated-subsurface-conditions liability to constructors by limiting the information they provide for bid preparation. To help prevent the costly, contentious problems this practice has caused, include the complete geotechnical engineering report,along with any attachments or appendices,with your contract documents, but be certain to note conspicuously that you've included the material for information purposes only. To avoid misunderstanding,you may also want to note that"informational purposes"means constructors have no right to rely on the interpretations, opinions,conclusions, or recommendations in the report. Be certain that constructors know they may learn about Appendix B—Page 2 of 3 AMERICAN ENGINEERING TESTING,INC Appendix B Geotechnical Report Limitations and Guidelines for Use Report No. P-0004506 specific project requirements, including options selected from the report, only from the design drawings and specifications. Remind constructors that they may perform their own studies if they want to,and be sure to allow enough time to permit them to do so. Only then might you be in a position to give constructors the information available to you,while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. Conducting prebid and preconstruction conferences can also be valuable in this respect. B.2.9 Read Responsibility Provisions Closely Some client representatives, design professionals, and constructors do not realize that geotechnical engineering is far less exact than other engineering disciplines.This happens in part because soil and rock on project sites are typically heterogeneous and not manufactured materials with well-defined engineering properties like steel and concrete.That lack of understanding has nurtured unrealistic expectations that have resulted in disappointments, delays, cost overruns, claims, and disputes. To confront that risk, geotechnical engineers commonly include explanatory provisions in their reports. Sometimes labeled "limitations," many of these provisions indicate where geotechnical engineers' responsibilities begin and end, to help others recognize their own responsibilities and risks. Read these provisions closely. Ask questions. Your geotechnical engineer should respond fully and frankly. B.2.10 Geoenvironmental Concerns Are Not Covered The personnel, equipment, and techniques used to perform an environmental study — e.g., a "phase-one" or "phase-two" environmental site assessment — differ significantly from those used to perform a geotechnical engineering study. For that reason, a geotechnical engineering report does not usually provide environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Unanticipated subsurface environmental problems have led to project failures. If you have not obtained your own environmental information about the project site,ask your geotechnical consultant for a recommendation on how to find environmental risk-management guidance. B.2.11 Obtain Professional Assistance to Deal with Moisture Infiltration and Mold While your geotechnical engineer may have addressed groundwater, water infiltration, or similar issues in this report, the engineer's services were not designed, conducted, or intended to prevent migration of moisture—including water vapor—from the soil through building slabs and walls and into the building interior,where it can cause mold growth and material-performance deficiencies.Accordingly,proper implementation of the geotechnical engineer's recommendations will not of itself be sufficient to prevent moisture infiltration. Confront the risk of moisture infiltration by including building-envelope or mold specialists on the design team.Geotechnical engineers are not building-envelope or mold specialists. 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