The URL can be used to link to this page

Home My WebLink About008 - Appendix G - Geotechnical ReportMONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA JOB NO. B21-054 / B21-055 September 2021 REPORT OF GEOTECHNICAL INVESTIGATION CLIENT ENGINEER Good Housing Partnership, LLC 104 E Main Street, Suite 104 Bozeman, MT 59715 TD&H Engineering 234 East Babcock, Suite 3 Bozeman, MT 59715 Engineer: Kyle Scarr, PE REPORT OF GEOTECHNICAL INVESTIGATION 9TEN MIXED USE BUILDINGS BOZEMAN, MONTANA 406.586.0277 tdhengineering.com 234 East Babcock, Suite 3 Bozem an, MT 59715 9TEN MIXED USE BUILDINGS BOZEMAN, MONTANA Courtesy of Intrinsik Architecture 9/16/2021 9Ten Mixed Use Buildings Table of Contents Bozeman, Montana i Table of Contents 1.0 EXECUTIVE SUMMARY .................................................................................................... 1 2.0 INTRODUCTION .................................................................................................................. 2 2.1 Purpose and Scope ....................................................................................................... 2 2.2 Project Description ........................................................................................................ 2 3.0 SITE CONDITIONS .............................................................................................................. 3 3.1 Geology and Physiography .......................................................................................... 3 3.2 Surface Conditions ........................................................................................................ 3 3.3 Subsurface Conditions .................................................................................................. 4 3.3.1 Soils .......................................................................................................................... 4 3.3.2 Ground Water ......................................................................................................... 5 4.0 ENGINEERING ANALYSIS ............................................................................................... 6 4.1 Introduction ..................................................................................................................... 6 4.2 Site Grading and Excavations ..................................................................................... 6 4.3 Conventional Shallow Foundations on EAP Improved Soils .................................. 6 4.4 Foundation and Retaining Walls ................................................................................. 7 4.5 Floor Slabs ...................................................................................................................... 8 4.6 Exterior Concrete Flatwork .......................................................................................... 8 4.7 Pavements ...................................................................................................................... 8 5.0 RECOMMENDATIONS ..................................................................................................... 10 5.1 Site Grading and Excavations ................................................................................... 10 5.2 Conventional Shallow Foundations on EAP Improved Soil .................................. 12 5.3 Foundation and Retaining Walls ............................................................................... 13 5.4 Floor Slabs .................................................................................................................... 13 5.5 Exterior Flatwork .......................................................................................................... 13 5.6 Pavements .................................................................................................................... 14 5.7 Continuing Services .................................................................................................... 15 6.0 SUMMARY OF FIELD AND LABORATORY STUDIES .............................................. 17 6.1 Field Explorations ........................................................................................................ 17 6.2 Laboratory Testing ...................................................................................................... 17 7.0 LIMITATIONS ..................................................................................................................... 19 9Ten Mixed Use Buildings Appendix Bozeman, Montana ii APPENDIX  Boring/Test Pit Location Map (Figure 1)  Logs of Exploratory Borings/Test Pits (Figures 2 through 10)  Laboratory Test Data (Figures 11 through 27)  Soil Classification and Sampling Terminology for Engineering Purposes  Classification of Soils for Engineering Purposes 9TEN MIXED USE BUILDINGS Executive Summary BOZEMAN, MONTANA Page 1 GEOTECHNICAL REPORT 9TEN MIXED USE BUILDINGS BOZEMAN, MONTANA 1.0 EXECUTIVE SUMMARY The geotechnical investigation for the 9Ten Development to be located northeast of the North 8th Street and Aspen Road intersection, encountered surficial lean clay soils overlying native gravel. The gravel was encountered at depths ranging from 15.5 to 17.0 feet below ground surface. The seismic site class is D and the risk of seismically-induced liquefaction or soil settlement is considered low and does not warrant additional evaluation. The primary geotechnical concern regarding this project is the presence of compressible clay soil. This zone is relatively weak and unable to support typical foundation bearing pressures associated with multi-story construction. We recommend that the project utilize a rammed aggregate pier (RAP) system, designed by others, to improve the subgrade conditions sufficiently to support a conventional footing system while controlling the potential for settlement. The recommended allowable bearing pressure for RAP improved soil will be specified by the RAP designer but is anticipated to be between 4,000 and 6,000 psf. Slab-on-grade construction utilizing an increased thickness of base course gravel is acceptable for this project; however, RAP improvements could also be utilized beneath the slab systems if it is economical. This option can be discussed with the RAP designer. 9TEN MIXED USE BUILDINGS Introduction BOZEMAN, MONTANA Page 2 2.0 INTRODUCTION 2.1 Purpose and Scope This report presents the results of our geotechnical study for the 9Ten Mixed Use Buildings to be located northeast of the North 8th Street and Aspen Road intersection (Lots 13-18 and the south 35 feet of Lot 12 of Durston Second Subdivision). The purpose of the geotechnical study is to determine the general surface and subsurface conditions at the proposed site and to develop geotechnical engineering recommendations for support of the proposed structure and design of related facilities. This report describes the field work and laboratory analyses conducted for this project, the surface and subsurface conditions encountered, and presents our recommendations for the proposed foundations and related site development. Our field work included drilling five soil borings and excavating four test pits across the proposed site. Samples were obtained from the borings / test pits and returned to our Great Falls laboratory for testing. Laboratory testing was performed on selected soil samples to determine engineering properties of the subsurface materials. The information obtained during our field investigations and laboratory analyses was used to develop recommendations for the design of the proposed foundation systems. This study is in general accordance with the proposal submitted by Kyle Scarr, PE of our firm dated June 16, 2021. Our work was authorized to proceed by Geoff Anderson of Good Housing Partnership, LLC by his signed acceptance of our proposal. 2.2 Project Description It is our understanding that the proposed project consists of, in part, two four-story, wood-framed structures. The structures are each approximately 50,500 gross square feet (sf) and 12,500 sf in plan. The structures are proposed to be supported on conventional shallow spread footings incorporating slab-on-grade construction. Estimated structural loads were provided by Matt Cloninger, PE with IMEG and include wall loads on the order of five to six kips per lineal foot and column loads up to 25 kips. Site development will most likely include landscaping, exterior concrete flatwork, asphalt pavement for streets, parking lots, and access roads. If loadings, locations or conditions are significantly different from those described above, we should be notified to reevaluate the recommendations contained in this report. 9TEN MIXED USE BUILDINGS Site Conditions BOZEMAN, MONTANA Page 3 3.0 SITE CONDITIONS 3.1 Geology and Physiography The site is geologically characterized as alluvium to the north in the stream valleys and Upper Tertiary sediment or sedimentary rock to the south. The alluvium is a mixture of gravel, sand, silt, and clay deposits associated with the stream and river channels and adjacent flood plains. The Upper Tertiary deposits consist of conglomerate, tuffaceous sandstone and siltstone, marlstone, and equivalent sediment and ash beds. These deposits contain light, porous rock formed by consolidation of volcanic ash. Geologic Map of Montana, Edition 1.0 (2007) Montana Bureau of Mines & Geology Based on the subsurface conditions encountered, the site falls under seismic Site Class D. The structural engineer should utilize the site classification above to determine the appropriate seismic design data for use on this project in accordance with current applicable building codes. The likelihood of seismically-induced soil liquefaction or settlement for this project is low and does not warrant additional evaluation. 3.2 Surface Conditions The proposed project site is located northeast of the North 8th Street and Aspen Road intersection (Lots 13-18 and the south 35 feet of Lot 12 of Durston Second Subdivision) in Bozeman, Montana, and presently consists of undeveloped land. Based on background information and site observations, the site slopes are variable due to past disturbance and are generally described as sloping downward toward the northeast at slopes of approximately 2 percent. The topography is best described as gently sloping to nearly level. BOZEMAN, MONTANA 9TEN MIXED USE BUILDINGS Site Conditions BOZEMAN, MONTANA Page 4 3.3 Subsurface Conditions 3.3.1 Soils The subsurface soil conditions appear to be relatively consistent based on our exploratory drilling/excavating and soil sampling. In general, the subsurface soil conditions encountered within the borings consist of approximately 15.5 to 17.0 feet of compressible lean clay over poorly-graded gravel with sand. The upper 1.5 feet of lean clay (approximately) contained elevated organics and was classified as topsoil. The poorly-graded gravel extends to a depth of at least 21.5 feet, the maximum depth investigated. The subsurface soils are described in detail on the enclosed boring and test pit logs and are summarized below. The stratification lines shown on the logs represent approximate boundaries between soil types and the actual in situ transition may be gradual vertically or discontinuous laterally. LEAN CLAY Lean clay was encountered at the surface of each boring/test pit and ranged in depth from 15.5 to 17.0 feet. The lean clay is soft to very stiff as indicated by penetration resistance values which ranged from 3 to 27 blows per foot (bpf) and averaged 11 bpf. This material is compressible as indicated by the consolidation test results shown on Figures 23 and 24. Samples of the material contained between 0.0 and 4.6 percent gravel, between 3.3 and 22.6 percent sand, and between 72.8 and 96.7 percent silt and clay. The lean clay exhibited liquid limits between 36 and 50 percent and plasticity indices between 13 and 28 percent. The natural moisture contents varied from 8.3 to 23.9 percent and averaged 17.2 percent. The lean clay contained slightly higher sand content at the contact with underlying gravel. Lab testing at this elevation indicated the lean clay transitioned into lean clay with sand above the native gravels. POORLY-GRADED GRAVEL WITH SAND Native poorly-graded gravel with sand was encountered in each boring at depths ranging from 15.5 to 17.0 feet below existing site grades. The gravel is very dense as indicated by penetration resistance values which ranged from 75 to greater than 100 bpf and averaged 85 bpf. Samples of the material contained between 41.0 and 41.8 percent gravel, between 42.3 and 43.4 percent sand, and between 15 and 16.7 percent silt and clay. Sampling coarse gravels during drilling generally results in samples which do not accurately represent the material present on site due to material degradation and segregation during drilling. Thus, it is our opinion that the percent gravel observed in this sample is not a good representation of the onsite conditions and the actual materials contain a larger percentage of gravel with sizes estimated to be up to 6-inch based on drilling observations. The natural moisture contents varied from 1.9 to 6.4 percent and averaged 4.1 percent. 9TEN MIXED USE BUILDINGS Site Conditions BOZEMAN, MONTANA Page 5 3.3.2 Ground Water Ground water was not encountered within the borings to depths up to 21.5 feet below the ground surface. The presence or absence of observed ground water may be directly related to the time of the subsurface investigation. Numerous factors contribute to seasonal ground water occurrences and fluctuations, and the evaluation of such factors is beyond the scope of this report. 9TEN MIXED USE BUILDINGS Engineering Analysis BOZEMAN, MONTANA Page 6 4.0 ENGINEERING ANALYSIS 4.1 Introduction The primary geotechnical concern regarding this project is the presence of compressible lean clay in the upper 15.5 to 17.0 feet. Based on laboratory consolidation testing and anticipated structural loads, conventional spread footings bearing on unimproved native soils are anticipated to exceed generally accepted industry standards for allowable settlement, potentially in excess of three inches. As a result, subgrade modifications are recommended to control settlement of the structure. 4.2 Site Grading and Excavations The ground surface at the proposed site is relatively flat to strongly sloping. The general project area exhibits a two percent regional slope downward to the northeast. There are localized areas on the site that deviate from the regional slope percentages and directions as a result of past disturbance and construction activities. Based on our field work and preliminary proposed finished floor elevations of 4,787.4 and 4,789.4 feet, compressible lean clay soil will be encountered in foundation excavations to the depths anticipated. Based on the borings, ground water should be below the anticipated depths of footing and utility excavations; however, depending on the time of year, occasional pockets of trapped or perched ground water associated with recent precipitation events should be anticipated. 4.3 Conventional Shallow Foundations on EAP Improved Soils The existing lean clay soils encountered across the site are not suitable to support foundation loads due to the compressibility of the soil and the associated risk of settlement and bearing failure. Complete removal of the compressible clay soils would require up to 17 feet of removal and replacement with engineered fill. Based on our experience, this magnitude of removal is cost- prohibitive. An alternative to the complete removal and replacement of the surficial clay soils includes using an engineered aggregate pier system (EAP), also known as a rammed aggregate pier (RAP) system. This system is specialized and proprietary; thus, design would be performed by specialized firms such as GTFC – West (Hillsboro, Oregon) or Montana Helical Pier (Whitefish, Montana). This subgrade improvement system has been recently used on numerous projects throughout Bozeman. EAPs are installed by drilling a hole of a specified depth and diameter and constructing rock columns comprised of very dense, highly compacted aggregate. Ramming of thin lifts takes place with a high-energy beveled tamper that densifies the aggregate and forces it laterally into the sidewalls of the hole. This action increases the lateral stress in the surrounding soil, thereby providing a stabilized composite soil mass. The result of the EAP installation is a significant strengthening and stiffening of the subsurface soils that would then support conventional footings. This allows for improved performance of the lean clay soils without requiring it to be completely removed thus reducing the overall cost of the project. EAPs can be installed in a variety of ground 9TEN MIXED USE BUILDINGS Engineering Analysis BOZEMAN, MONTANA Page 7 water conditions using varying methods and may or may not warrant some level of site dewatering during construction. This should be discussed with the EAP designer / installer based on their available equipment and abilities. Based on our experience with the EAP system in similar conditions, we anticipate EAP elements to utilize 24-inch to 30-inch diameter piers and lengths sufficient to tie the aggregate columns into the underlying native gravel to provide adequate subgrade improvement for support of typical foundation loads. EAPs constructed in this manner generally allow for a design bearing pressure on the order of 4,000 to 6,000 psf. Footings supported on EAP improved soils are generally designed to limit potential settlements to less than ¾ to 1 inch with differential settlements being less than ½- inch; however, stricter design criteria could be utilized and would likely result in more EAP elements extending to potentially greater depths. On EAP projects, the EAP designer typically works closely with the design team, and they create their own EAP installation plans to be included as part of the overall package. They then provide the specialized construction and quality control during the installation of this system. Their design is prepared utilizing the data provided in this report and structural loads provided by the project structural engineer. We anticipate this approach to be more economical and provide for a shorter construction schedule than the complete removal and replacement of the lean clay beneath the structures. Other deep foundation options are available and analysis of those options can be completed through addendums to this report, if desired. For example, helical piers, driven piles, and cast-in- place drilled piers may be suitable options; however, generally less economical that EAPs. The lateral resistance of spread footings is controlled by a combination of sliding resistance between the footing and the foundation material at the base of the footing and the passive earth pressure against the side of the footing in the direction of movement. Design parameters are given in the recommendations section of this report. 4.4 Foundation and Retaining Walls Foundation walls and other soil retaining structures will be subjected to horizontal loading due to lateral earth pressures. The lateral earth pressures are a function of the natural and backfill soil types and acceptable wall movements, which affect soil strain to mobilize the shear strength of the soil. More soil movement is required to develop greater internal shear strength and lower the lateral pressure on the wall. To fully mobilize strength and reduce lateral pressures, soil strain and allowable wall rotation must be greater for clay soils than for cohesionless, granular soils. The lowest lateral earth pressure against walls for a given soil type is the active condition and develops when wall movements occur. Passive earth pressures are developed when the wall is forced into the soil, such as at the base of a wall on the side opposite the retained earth side. When 9TEN MIXED USE BUILDINGS Engineering Analysis BOZEMAN, MONTANA Page 8 no soil strain is allowed by the wall, this is the "at-rest" condition, which creates pressures having magnitudes between the passive and active conditions. The distribution of the lateral earth pressures on the structure depends on soil type and wall movements or deflections. In most cases, a triangular pressure distribution is satisfactory for design and is usually represented as an equivalent fluid unit weight. Design parameters are given in the recommendations section of this report. 4.5 Floor Slabs The natural on-site soils, exclusive of topsoil, are suitable to support lightly to moderately loaded, slab-on-grade construction. A leveling course of granular fill directly beneath the slab is recommended to provide a structural cushion, a capillary-break from the subgrade, and a drainage medium. Our analysis assumes a minimum of 18 inches of compacted granular fill beneath slabs. 4.6 Exterior Concrete Flatwork The natural on-site soils, exclusive of topsoil, are suitable to support lightly to moderately loaded, exterior slab-on-grade construction provided some risk of settlement or upward movement can be accepted for these elements. The native lean clay is a moderate to high plasticity soil anticipated to exhibit slight swell and moderate frost susceptibility potential. This type of material can exhibit seasonal movement especially during winter or wet periods when soil moistures are elevated and/or frozen. A leveling course of granular fill directly beneath all exterior concrete flatwork is recommended to provide a structural cushion, a capillary-break from the subgrade, and a drainage medium. Construction typically utilizes six inches of compacted granular fill beneath exterior slabs; however, the requirements may vary locally. Such construction, which is considered conventional, should incorporate proper subgrade compaction to achieve typical performance levels. With proper fill placement and compaction, we do not anticipate potential settlements using conventional construction to be detrimental to the function of exterior flatwork; however, such construction is not intended to reduce or mitigate potential settlement or heave risk. Slab movement resulting from winter conditions is not uncommon and may be unavoidable using conventional exterior slab construction methods. The potential risk and magnitude of movement can be reduced with additional gravel below the exterior flatwork. We assume conventional construction methods and the associated risks are acceptable to the owner. 4.7 Pavements A pavement section is a layered system designed to distribute concentrated traffic loads to the subgrade. Performance of the pavement structure is directly related to the physical properties of the subgrade soils and the magnitude and frequency of traffic loadings. Pavement design procedures are based on strength properties of the subgrade and pavement materials, along with the design 9TEN MIXED USE BUILDINGS Engineering Analysis BOZEMAN, MONTANA Page 9 traffic conditions. Traffic loading on the proposed streets, alleys, access ways, and parking lots will be typical of low volume local streets primarily composed of passenger vehicles with occasional truck traffic associated with deliveries and garbage collection. We have utilized the City of Bozeman minimum ESALs design requirement of 50,000 ESALs for the pavement design. The potential worst case subgrade material is lean clay which is classified as an A-6 in accordance with the American Association of State Highway and Transportation Officials (AASHTO) classification. AASHTO considers this soil type to be a fair to poor subgrade. Typical California Bearing Ratio (CBR) values for this type of soil range from 2 to 5 percent. It will be necessary to scarify and recompact the subgrade soils prior to placing fill material associated with the pavement section. The fill should be selected, placed, and compacted in accordance with our recommendations. A geotextile acting as a separator is recommended between the pavement section gravels and the clay subgrade. The geotextile will prevent the upward migration of fines and the loss of aggregate into the subgrade, thereby prolonging the structural integrity and performance of the pavement section. The pavement section presented in this report is based on an assumed CBR value of 3.7 percent, assumed traffic loadings, recommended pavement section design information presented in the Asphalt Institute and AASHTO Design Manuals, and our past pavement design experience in Bozeman. 9TEN MIXED USE BUILDINGS Recommendations BOZEMAN, MONTANA Page 10 5.0 RECOMMENDATIONS 5.1 Site Grading and Excavations 1. All topsoil and organic material, asphalt, concrete and related construction debris should be removed from the proposed building and pavement areas and any areas to receive site grading fill. 2. All fill and backfill should be non-expansive, free of organics and debris and should be approved by the project geotechnical engineer. We do not recommend use of the on-site lean clay soils for backfill under structures, concrete flatwork, or roadways on this project due to the difficultly compacting and the sensitivity of the clay to moisture. The native lean clay may be used for general grading in landscape or open space areas. All fill should be placed in uniform lifts not exceeding 8 inches in thickness for fine-grained soils and not exceeding 12 inches for granular soils. All materials compacted using hand compaction methods or small walk-behind units should utilize a maximum lift thickness of 6 inches to ensure adequate compaction throughout the lift. All fill and backfill shall be compacted to the following percentages of the maximum dry density determined by a standard proctor test which is outlined by ASTM D698 or equivalent (e.g. ASTM D4253-D4254). a) Below Foundations or Spread Footings ...................................... 98% b) Below Slab-on-Grade Construction ............................................. 98% c) Foundation Wall Backfill .............................................................. 95% d) Below Streets, Parking Lots, or Other Paved Areas ................... 95% e) General Landscaping or Nonstructural Areas ............................. 95% f) Utility Trench Backfill, To Within 2 Feet of Surface ...................... 95% For your consideration, verification of compaction requires laboratory proctor tests to be performed on a representative sample of the soil prior to construction. These tests can require up to one week to complete (depending on laboratory backlog) and this should be considered when coordinating the construction schedule to ensure that delays in construction or additional testing expense is not required due to laboratory processing times or rush processing fees. 9TEN MIXED USE BUILDINGS Recommendations BOZEMAN, MONTANA Page 11 3. Imported structural fill should be non-expansive, free of organics and debris, and selected per the following gradation requirements: Screen or Sieve Size Percent Passing by Weight 3-inch 100 1½-inch 80 – 100 ¾-inch 60 – 100 No. 4 25 – 60 No. 200 10 maximum 4. Develop and maintain site grades which will rapidly drain surface and roof runoff away from foundation and subgrade soils; both during and after construction. 5. At a minimum, downspouts from roof drains should discharge at least six feet away from the foundation or beyond the limits of foundation backfill, whichever is greater. All downspout discharge areas should be properly graded away from the structure to promote drainage and prevent ponding. 6. Irrigation around the perimeter of individual structures should be avoided. Landscaping around foundation walls should consider plant varieties that do not require significant irrigation such as drought-resistant species. 7. Site utilities should be installed with proper bedding in accordance with pipe manufacturer’s requirements. 8. It is the responsibility of the Contractor to provide safe working conditions in connection with underground excavations. Temporary construction excavations greater than four feet in depth, which workers will enter, will be governed by OSHA guidelines given in 29 CFR, Part 1926. For planning purposes, subsoils encountered in the upper 15 feet of the borings are considered Type B for the lean clay. The soil conditions on site can change due to changes in soils moisture or disturbances to the site prior to construction. Thus, the contractor is responsible to provide an OSHA knowledgeable individual during all excavation activities to regularly assess the soil conditions and ensure that all necessary safety precautions are implemented and followed. 9TEN MIXED USE BUILDINGS Recommendations BOZEMAN, MONTANA Page 12 5.2 Conventional Shallow Foundations on EAP Improved Soil When EAP systems are utilized, the EAP design must be performed by a licensed design/build contractor. The recommendations below are intended to be preliminary guidelines based on our experience with this system. These recommendations shall not be utilized for final design of the foundation system without being verified by a licensed EAP designer. 9. Both interior and exterior footings should bear on EAP improved soils and be designed using the maximum allowable bearing pressure to be issued by the EAP designer. For preliminary planning purposes, we understand that an allowable soil bearing pressure of approximately 4,000 to 6,000 psf is typical for these systems. EAP elements are anticipated to be 24 to 30 inches in diameter with lengths extending down into the native gravel stratum. However, alternative EAP sizes may be specified by the designer of record based on their analysis. Any compacted gravel specified by the EAP designer as a capping substrate shall be compacted and installed per the EAP designer requirements. 10. Footings shall be sized to satisfy the minimum requirements of the applicable building codes while not exceeding the maximum allowable bearing pressures provided by the EAP designer. 11. Exterior footings and footings beneath unheated areas should be placed at least 48 inches below finished exterior grade for frost protection unless otherwise specified by the EAP designer. 12. Lateral loads are resisted by sliding friction between the footing base and the supporting soil and by lateral pressure against the footings opposing movement. For design purposes, a preliminary friction coefficient of 0.5 is typical of EAP improved soils; however, this value shall be verified by the EAP designer during the final design process. A lateral resistance pressure of 150 psf per foot of depth is appropriate for exterior backfill consisting of processed and compacted on site soils. This value may be increase to 300 psf per foot of depth for backfill consisting of imported structural fill meeting the requirements of Item 3. 13. The EAP system is considered a subgrade improvement and is not addressed in the International Building Code (IBC). Because EAPs are proprietary subgrade improvements and not deep foundation systems, the designer / installer typically provides their own internal quality control system. 14. A representative of the project geotechnical engineer should be retained to observe all footing excavations and backfill phases prior to the placement of concrete formwork. 9TEN MIXED USE BUILDINGS Recommendations BOZEMAN, MONTANA Page 13 5.3 Foundation and Retaining Walls The design and construction criteria presented below should be observed for foundation walls. The construction details should be considered when preparing the project documents. 15. Backfill should be selected, placed, and compacted per Item 2 above. Care should be taken not to over-compact the backfill since this could cause excessive lateral pressure on the walls. Only hand-operated compaction equipment should be used within 5 feet of foundation walls. 16. Exterior footing drains are not required for this project when slab-on-grade construction is utilized. 5.4 Floor Slabs 17. For normally loaded, slab-on-grade construction, a minimum 18-inch cushion course consisting of free-draining, crushed gravel should be placed beneath the slabs and compacted to the requirements of Item 2 above. This material should conform to the requirements outlined in Section 02235 of the Montana Public Works Standard Specifications (MPWSS) and incorporate a maximum particle size of ¾-inch. Use of uniform ¾” minus crushed angular “cushion” gravel in the top six inches is acceptable. Prior to placing the cushion course, the upper six inches of subgrade should be compacted per Item 2 followed by placement of a geotextile fabric (Mirafi HP 270 or equal). 18. Geotechnically, an underslab vapor barrier is not required for this project. A vapor barrier is normally used to limit the migration of soil gas and moisture into occupied spaces through floor slabs. The need for a vapor barrier should be determined by the architect and/or structural engineer based on interior improvements and/or moisture and gas control requirements. 5.5 Exterior Flatwork 19. For normally loaded, exterior concrete flatwork, a typical cushion course (Item 17) consisting of free-draining, crushed gravel should be placed beneath the concrete and compacted to the requirements of Item 2c above. Cushion course thicknesses generally range from four to six inches but may vary based on local requirements. Conventional construction, as has been described, is not intended to mitigate expansion or settlement concerns associated with the lean clay subgrade conditions encountered. 9TEN MIXED USE BUILDINGS Recommendations BOZEMAN, MONTANA Page 14 5.6 Pavements 20. The following pavement section or an approved equivalent section should be selected in accordance with the discussions in the Engineering Analysis. Pavement Component Component Thickness Asphaltic Concrete Pavement 3 Crushed Base Course 6 Crushed Subbase Course 12 Total (inches) 21 † The pavement section provided is not intended to support construction traffic or vehicles associated with this project including cranes, haul trucks, concrete trucks, etc. Additional evaluation is warranted if the parking lot area will be utilized regularly by construction traffic following gravel or asphalt placement. 21. Crushed base course shall conform to the material properties outlined in Section 02235 of the Montana Public Works Standard Specifications (MPWSS). All gradations outlined in this specification are acceptable for this application based on the local availability and contractor preference. Crushed subbase course shall conform to the material properties outlined in Section 02234 of the MPWSS. All gradations outlined in this specification are acceptable for this application based on the local availability and contractor preference 22. Where the existing grades will be raised more than the thickness of the pavement section, all fill should be placed, compacted and meet the general requirements given in Item 2d and 25 above. 23. A geotextile is recommended between the pavement section and the prepared subgrade to prevent the migration of fines upward into the gravel and the loss of aggregate into the subgrade. A Mirafi HP270, or equivalent geotextile is appropriate. 9TEN MIXED USE BUILDINGS Recommendations BOZEMAN, MONTANA Page 15 24. Ideally, the asphaltic cement should be a Performance Graded (PG) binder having the following minimum high and low temperature values based on the desired pavement reliability. Reliability Min. High Temp Rating Min. Low Temp Rating Ideal Oil Grade 50% 35.6 -23.6 PG 52-28 98% 39.5 -32.5 PG 52-34 However, based on our experience neither of these materials are available through local suppliers, and significant additional expense would be realized using these products. In order to use locally available products, we recommend the use of a PG 58-28 oil for any asphalt pavement included in this project. This product will provide similar low temperature resistance to thermal cracking and improved high temperature performance with respect to rutting and shoving. 5.7 Continuing Services Three additional elements of geotechnical engineering service are important to the successful completion of this project. 25. Consultation between the geotechnical engineer and the design professionals during the design phases is highly recommended. This is important to ensure that the intentions of our recommendations are incorporated into the design, and that any changes in the design concept consider the geotechnical limitations dictated by the on-site subsurface soil and ground water conditions. 26. Observation, monitoring, and testing during construction is required to document the successful completion of all earthwork and foundation phases. A geotechnical engineer from our firm should be retained to observe the excavation, earthwork, and foundation phases of the work to determine that subsurface conditions are compatible with those used in the analysis and design. 27. During site grading, placement of all fill and backfill should be observed and tested to confirm that the specified density has been achieved. We recommend that the Owner maintain control of the Construction Quality Control by retaining the services of an Accredited/Certified Construction Materials Testing Laboratory. We are available to provide construction inspection services as well as materials testing of compacted soils and the placement of Portland cement concrete and asphalt. In the absence of project specific testing frequencies, TD&H recommends the following minimum testing frequencies by used: 9TEN MIXED USE BUILDINGS Recommendations BOZEMAN, MONTANA Page 16 Compaction Testing Beneath Column Footings 1 Test per Footing per Lift Beneath Wall Footings 1 Test per 50 LF of Wall per Lift Beneath Slabs 1 Test per 1,500 SF per Lift Foundation Backfill 1 Test per 100 LF of Wall per Lift Parking Lot & Access Roads 1 Test per 2,500 SF per Lift LF = Lineal Feet SF = Square Feet Concrete Testing Structural Concrete† 1 Test per 50 CY per Day Non-Structural Concrete 1 Test per Day † Structural concrete includes all footings, stem walls, slabs, and other load bearing elements CY = Cubic Yards 9TEN MIXED USE BUILDINGS Summary of Field & Laboratory Studies BOZEMAN, MONTANA Page 17 6.0 SUMMARY OF FIELD AND LABORATORY STUDIES 6.1 Field Explorations The field exploration program was conducted on June 24, July 22, and July 23, 2021. A total of five borings were drilled and four test pits were excavated to depths ranging from 8.4 to 21.5 feet at the locations shown on Figure 1 to observe subsurface soil and ground water conditions. The borings were advanced through the subsurface soils using a CME 75 drill rig equipped with 8-inch hollowstem augers. The tests pits were excavated using a Komatsu PC88 excavator. The subsurface exploration and sampling methods used are indicated on the attached boring and test pit logs. The borings and test pits were logged by Mr. Derek Christensen, PE of TD&H Engineering. The location and elevation of the borings and test pits were estimated in the field based on the topographic survey completed by our company. Samples of the subsurface materials were taken using 1⅜-inch I.D. split spoon samplers. The samplers were driven 18 inches, when possible, into the various strata using a 140-pound drop hammer falling 30 inches onto the drill rods. For each sample, the number of blows required to advance the sampler each successive six-inch increment was recorded, and the total number of blows required to advance the sampler the final 12 inches is termed the penetration resistance (“N- value”). This test is known as the Standard Penetration Test (SPT) described by ASTM D1586. Penetration resistance values indicate the relative density of granular soils and the relative consistency of fine-grained soils. Samples were also obtained by hydraulically pushing a 3-inch I.D., thin-walled Shelby tube sampler into the subsoils. Logs of all soil borings/test pits, which include soil descriptions, sample depths, and penetration resistance values, are presented on the Figures 2 through 10. No evidence of ground water was encountered. Drilling tools appeared dry, free water was not observed on cuttings or soil samples. 6.2 Laboratory Testing Samples obtained during the field exploration were returned to our materials laboratory where they were observed and visually classified in general accordance with ASTM D2487, which is based on the Unified Soil Classification System. Representative samples were selected for testing to determine the engineering and physical properties of the soils in general accordance with ASTM or other approved procedures. Tests Conducted: To determine: Natural Moisture Content Representative moisture content of soil at the time of sampling. Grain-Size Distribution Particle size distribution of soil constituents describing the percentages of clay/silt, sand and gravel. 9TEN MIXED USE BUILDINGS Summary of Field & Laboratory Studies BOZEMAN, MONTANA Page 18 Atterberg Limits A method of describing the effect of varying water content on the consistency and behavior of fine-grained soils. Consolidation Measurements of the percent compression experienced under various loading conditions. For use in settlement analysis and foundation design. Unconfined Compression Undrained shear strength properties of cohesive soils determined in the laboratory by axial compression. Moisture-Density Relationship A relationship describing the effect of varying moisture content and the resulting dry unit weight at a given compactive effort. Provides the optimum moisture content and the maximum dry unit weight. Also called a Proctor Curve. California Bearing Ratio The measure of a subgrade’s or granular base’s ability to resist deformation due to penetration during a saturated condition. Used to assist in pavement thickness designs. The laboratory testing program for this project consisted of 33 moisture-visual analyses, 6 sieve (grain-size distribution) analyses, and 4 Atterberg Limits analyses. The results of the water content analyses are presented on the boring/test pit logs, Figures 2 through 10. The grain-size distribution curves and Atterberg limits are presented on Figures 11 through 20. In addition, two consolidation tests, and two unconfined compression tests, one proctor (moisture-density) test, and one California Bearing Ratio (CBR) test were performed. The consolidation and unconfined compression results are presented on Figures 21 through 24. The CBR and moisture density relationships are shown on Figures 25 and 26. An infiltration test was completed for use in subsurface storm water infiltration and is included in the Appendix as Figure 27. 9TEN MIXED USE BUILDINGS Limitations BOZEMAN, MONTANA Page 19 7.0 LIMITATIONS This report has been prepared in accordance with generally accepted geotechnical engineering practices in this area for use by the client for design purposes. The findings, analyses, and recommendations contained in this report reflect our professional opinion regarding potential impacts the subsurface conditions may have on the proposed project and are based on site conditions encountered. Our analysis assumes that the results of the exploratory borings/test pits are representative of the subsurface conditions throughout the site, that is, that the subsurface conditions everywhere are not significantly different from those disclosed by the subsurface study. Unanticipated soil conditions are commonly encountered and cannot be fully determined by a limited number of soil borings/test pits and laboratory analyses. Such unexpected conditions frequently require that some additional expenditures be made to obtain a properly constructed project. Therefore, some contingency fund is recommended to accommodate such potential extra costs. The recommendations contained within this report are based on the subsurface conditions observed in the borings/test pits and are subject to change pending observation of the actual subsurface conditions encountered during construction. TD&H cannot assume responsibility or liability for the recommendations provided if we are not provided the opportunity to perform limited construction inspection and confirm the engineering assumptions made during our analysis. A representative of TD&H should be retained to observe all construction activities associated with subgrade preparation, foundations, and other geotechnical aspects of the project to ensure the conditions encountered are consistent with our assumptions. Unforeseen conditions or undisclosed changes to the project parameters or site conditions may warrant modification to the project recommendations. Long delays between the geotechnical investigation and the start of construction increase the potential for changes to the site and subsurface conditions which could impact the applicability of the recommendations provided. If site conditions have changed because of natural causes or construction operations at or adjacent to the site, TD&H should be retained to review the contents of this report to determine the applicability of the conclusions and recommendations provide considering the time lapse or changed conditions. Misinterpretation of the geotechnical information by other design team members is possible and can result in costly issues during construction and with the final product. We strongly advise that TD&H be retained to review those portions of the plans and specifications which pertain to earthwork and foundations to determine if they are consistent with our recommendations and to suggest necessary modifications as warranted. In addition, TD&H should be involved throughout the construction process to observe construction, particularly the placement and compaction of all fill, preparation of all foundations, and all other geotechnical aspects. Retaining the geotechnical engineer who prepared your geotechnical report to provide construction observation is the most effective method of managing the risks associated with unanticipated conditions. 9TEN MIXED USE BUILDINGS Limitations BOZEMAN, MONTANA Page 20 This report was prepared for the exclusive use of the owner and architect and/or engineer in the design of the subject facility. It should be made available to prospective contractors and/or the contractor for information on factual data only and not as a warranty of subsurface conditions such as those interpreted from the boring/test pit logs and presented in discussions of subsurface conditions included in this report. Prepared by: Reviewed by: Kyle Scarr PE Craig Nadeau PE Geotechnical Engineer Geotechnical Manager TD&H ENGINEERING TD&H ENGINEERING REVISIONSHEETDESIGNED BY:QUALITY CHECK:JOB NO.FIELDBOOKDRAWN BY:DATE:B21-055 GEOTECHREV DATE NOT FORCONSTRUCTION ANE 9TEN MIXED USE BOZEMAN, MONTANA GEOTECHNICAL INVESTIGATION TEST PIT LOCATION OVERVIEW B21-05520210730.DWGDFCEngineering 234 E. BABCOCK ST., SUITE 3 • BOZEMAN, MONTANA 59715 406.586.0277 • tdhengineering.comSOUTH BUILDINGNORTH BUILDINGN. 8TH AVE.W. ASPEN ST.U-HAULGALLATIN VALLEYFURNITURECAT'SPAWALLEYNOTES:·DISPLAYED TEST PIT & BORING HOLE LOCATIONS & ELEVATIONS ARE APPROXIMATEFIGURE 1 0 2.5 5 7.5 10 12.5 15 17.5 TOPSOIL: Lean CLAY, appears firm, dark brown, moist Lean CLAY, soft to very stiff, medium brown, slightly moist Poorly-Graded GRAVEL with Sand, dense to very dense, light grayish brown, slightly moist 1.5 16.0 4-4-5 2-1-2 3-3-4 5-8-13 4-9-18 LEGEND LOG OF SOIL BORING Hole #1SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 22, 2021 B21-055-001 No sample recovery Figure No. 2 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,787.25 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 1 of 2 20 22.5 25 27.5 30 32.5 35 Bottom of Boring 21.5 Ground water not encoun- tered 18-35- 40 75 LEGEND LOG OF SOIL BORING Hole #1SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 22, 2021 B21-055-001 No sample recovery Figure No. 2 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,787.25 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 2 of 2 0 2.5 5 7.5 10 12.5 15 17.5 TOPSOIL: Lean CLAY, appears firm, dark brown, moist Lean CLAY, firm to stiff, medium brown, slightly moist - See Figures 21 and 23 for unconfined compression and consolidation test results Poorly-Graded GRAVEL with Sand, dense to very dense, light grayish brown, slightly moist 1.5 16.2 6-5-4 PUSH 3-3-5 4-4-5 2-4-23 T LEGEND LOG OF SOIL BORING Hole #2SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 23, 2021 B21-055-001 No sample recovery Figure No. 3 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,785.53 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 1 of 2 20 22.5 25 27.5 30 32.5 35 Bottom of Boring 20.6 Ground water not encoun- tered 40-50/ 2"50/2" LEGEND LOG OF SOIL BORING Hole #2SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 23, 2021 B21-055-001 No sample recovery Figure No. 3 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,785.53 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 2 of 2 0 2.5 5 7.5 10 12.5 15 17.5 TOPSOIL: Lean CLAY, appears firm, dark brown, moist Lean CLAY, firm to stiff, medium brown, slightly moist Poorly-Graded GRAVEL with Sand, dense to very dense, light grayish brown, slightly moist 1.5 15.5 4-5-2 3-3-2 3-3-3 4-5-7 17-33- 46 79 LEGEND LOG OF SOIL BORING Hole #3SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 23, 2021 B21-055-001 No sample recovery Figure No. 4 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,785.58 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 1 of 2 20 22.5 25 27.5 30 32.5 35 Bottom of Boring 21.5 Ground water not encoun- tered 16-38- 42 80 LEGEND LOG OF SOIL BORING Hole #3SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 23, 2021 B21-055-001 No sample recovery Figure No. 4 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,785.58 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 2 of 2 0 2.5 5 7.5 10 12.5 15 17.5 TOPSOIL: Lean CLAY, appears firm, dark brown, moist Lean CLAY, soft to stiff, medium brown, slightly moist Poorly-Graded GRAVEL with Sand, dense to very dense, light grayish brown, slightly moist 1.5 16.3 4-3-2 2-1-3 3-3-4 3-5-4 4-8-16 LEGEND LOG OF SOIL BORING Hole #4SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 23, 2021 B21-055-001 No sample recovery Figure No. 5 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,787.84 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 1 of 2 20 22.5 25 27.5 30 32.5 35 Bottom of Boring 21.5 Ground water not encoun- tered 44-46- 31 77 LEGEND LOG OF SOIL BORING Hole #4SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 23, 2021 B21-055-001 No sample recovery Figure No. 5 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,787.84 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 2 of 2 0 2.5 5 7.5 10 12.5 15 17.5 TOPSOIL: Lean CLAY, appears firm, dark brown, moist Lean CLAY, firm to stiff, medium brown, slightly moist - See Figures 22 and 24 for unconfined compression and consolidation test results Poorly-Graded GRAVEL with Sand, dense to very dense, light grayish brown, slightly moist 1.5 17.0 5-5-2 4-3-3 PUSH 3-4-5 7-7-9 T LEGEND LOG OF SOIL BORING Hole #5SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 23, 2021 B21-055-001 No sample recovery Figure No. 6 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,789.76 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 1 of 2 20 22.5 25 27.5 30 32.5 35 Bottom of Boring 20.8 Ground water not encoun- tered 36-50/ 2"50/2" LEGEND LOG OF SOIL BORING Hole #5SPT blows per foot Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Derek Christensen, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted CME-75 with 8-inch HSA2-1/2-inch I.D. ring sampler GNP = Granular and Nonplastic 3-inch I.D. thin-walled sampler Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 23, 2021 B21-055-001 No sample recovery Figure No. 6 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,789.76 ft DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 2 of 2 0 2 4 6 8 10 12 14 Poorly-Graded GRAVEL with Sand (1.5" Minus Surface Course), relatively dense, grayish brown, slightly moist Lean CLAY, appears firm to stiff, brown, moist Bottom of Test Pit 0.3 9.0 Ground water not encoun- tered G G LEGEND LOG OF TEST PIT TP #1Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Derek Christensen, PE Excavated by:Earth Surgeons Komatsu PC88 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. June 24, 2021 B21-054 Figure No. 7 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Gravel Surface Course SURFACE ELEVATION:4,789.4 ft DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears firm, brown, slightly most, trace gravels Lean CLAY, appears firm to stiff, brown, moist - See Figures 25 and 26 for result of composite proctor and CBR Bottom of Test Pit 1.0 9.0 Ground water not encoun- tered G LEGEND LOG OF TEST PIT TP #2Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Derek Christensen, PE Excavated by:Earth Surgeons Komatsu PC88 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. June 24, 2021 B21-054 Figure No. 8 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,787.5 ft DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears firm, brown, slightly most, trace gravels Lean CLAY, appears firm to stiff, brown, moist - See Figures 25 and 26 for result of composite proctor and CBR Bottom of Test Pit 1.0 8.4 Ground water not encoun- tered G LEGEND LOG OF TEST PIT TP #3Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Derek Christensen, PE Excavated by:Earth Surgeons Komatsu PC88 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. June 24, 2021 B21-054 Figure No. 9 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,786.4 ft DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears firm, brown, slightly most, trace gravels Lean CLAY, appears firm to stiff, brown, moist - See Figures 25 and 26 for result of composite proctor and CBR Bottom of Test Pit 1.0 10.5 Ground water not encoun- tered G LEGEND LOG OF TEST PIT TP #4Atterberg Limits Field Moisture content ANE - North 8th Improvements Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Derek Christensen, PE Excavated by:Earth Surgeons Komatsu PC88 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. June 24, 2021 B21-054 Figure No. 10 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:4,786.4 ft DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 Tested By: WJC Checked By: 8-18-2021 11 (no specification provided) PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= * Lean CLAY (Visual) 3/8" #4 #10 #20 #40 #60 #80 #100 #200 100.0 99.9 99.9 99.8 99.6 99.3 99.0 98.8 95.8 CL Report No. A-23918-206 Good Housing Project ANE - North 8th Improvements Bozeman, Montana B21-055-001 Material Description Atterberg Limits Coefficients Classification Remarks Location: Hole #1 Sample Number: A-23918 Depth: 7.5 - 9.0 ft Date: Client: Project: Project No:Figure SIEVE PERCENT SPEC. *PASS? SIZE FINER PERCENT (X=NO)PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 0.0 0.1 0.0 0.3 3.8 95.86 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report Tested By: WJC Checked By: 8-18-2021 12 (no specification provided) PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= * Clayey SAND with Gravel (Visual) 1.5" 1" 3/4" 1/2" 3/8" #4 #10 #20 #40 #60 #80 #100 #200 100.0 94.2 86.2 74.8 68.8 58.4 47.4 36.5 27.2 22.4 19.9 18.5 15.0 21.6304 18.3419 5.3764 2.4669 0.5336 0.0753 SC Report No. A-23922-206 Good Housing Project ANE - North 8th Improvements Bozeman, Montana B21-055-001 Material Description Atterberg Limits Coefficients Classification Remarks Location: Hole #1 Sample Number: A-23922 Depth: 20.0 - 21.5 ft Date: Client: Project: Project No:Figure SIEVE PERCENT SPEC. *PASS? SIZE FINER PERCENT (X=NO)PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 13.8 27.8 11.0 20.2 12.2 15.06 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report Tested By: WJC Checked By: 8-19-2021 13 (no specification provided) PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= * Lean CLAY with Sand (Visual) 3/4" 1/2" 3/8" #4 #10 #20 #40 #60 #80 #100 #200 100.0 97.7 97.4 95.4 94.4 93.6 92.6 91.1 88.8 86.3 72.8 0.2051 0.1382 CL Report No. A-23927-206 Good Housing Project ANE - North 8th Improvements Bozeman, Montana B21-055-001 Material Description Atterberg Limits Coefficients Classification Remarks Location: Hole #2 Sample Number: A-23927 Depth: 15.0 - 16.2 ft Date: Client: Project: Project No:Figure SIEVE PERCENT SPEC. *PASS? SIZE FINER PERCENT (X=NO)PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 0.0 4.6 1.0 1.8 19.8 72.86 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report Tested By: BS Checked By: 8-18-2021 14 (no specification provided) PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= * Clayey SAND with Gravel (Visual) 1.5" 1" 3/4" 1/2" 3/8" #4 #10 #20 #40 #60 #80 #100 #200 100.0 98.1 91.6 79.3 71.2 59.0 47.3 38.3 31.0 26.2 23.2 21.3 16.7 17.9916 15.2697 5.0878 2.4769 0.3811 SC Report No. A-23934/23935-206 Good Housing Project ANE - North 8th Improvements Bozeman, Montana B21-055-001 Material Description Atterberg Limits Coefficients Classification Remarks Location: Hole #3 Sample Number: A-23934/23935 Depth: 15.0 - 21.5 ft Date: Client: Project: Project No:Figure SIEVE PERCENT SPEC. *PASS? SIZE FINER PERCENT (X=NO)PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 8.4 32.6 11.7 16.3 14.3 16.76 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report Tested By: WJC Checked By: 8-11-2021 15 (no specification provided) PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= * Lean CLAY (Visual) #4 #10 #20 #40 #60 #80 #100 #200 100.0 100.0 100.0 99.9 99.7 99.4 99.1 96.7 CL Report No. A-23944-206 Good Housing Project ANE - North 8th Improvements Bozeman, Montana B21-055-001 Material Description Atterberg Limits Coefficients Classification Remarks Location: Hole #5 Sample Number: A-23944 Depth: 5.0 - 6.5 ft Date: Client: Project: Project No:Figure SIEVE PERCENT SPEC. *PASS? SIZE FINER PERCENT (X=NO)PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 0.0 0.0 0.0 0.1 3.2 96.76 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report Tested By: BS Checked By: 7-3-2021 16 (no specification provided) PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= * Lean CLAY #4 #10 #20 #40 #60 #80 #100 #200 100.0 100.0 99.9 99.8 99.5 99.1 98.8 95.4 23 36 13 CL A-6(13) Report No. A-23645/23646-206 Good Housing Partnership ANE - North 8th Improvements Bozeman, Montana B21-054 Material Description Atterberg Limits Coefficients Classification Remarks Location: TP #3 & TP #4 Sample Number: A-23645/23646 Depth: 2.5 - 3.0 ft Date: Client: Project: Project No:Figure SIEVE PERCENT SPEC. *PASS? SIZE FINER PERCENT (X=NO)PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 0.0 0.0 0.0 0.2 4.4 95.46 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report Tested By: WJC Checked By: LIQUID AND PLASTIC LIMITS TEST REPORT PLASTICITY INDEX0 10 20 30 40 50 60 LIQUID LIMIT 0 10 20 30 40 50 60 70 80 90 100 110 CL-ML C L o r O L C H o r O H ML or OL MH or OH Dashed line indicates the approximate upper limit boundary for natural soils 47 WATER CONTENT32.8 33.3 33.8 34.3 34.8 35.3 35.8 36.3 36.8 37.3 37.8 NUMBER OF BLOWS 5 6 7 8 9 10 20 25 30 40 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Project No. Client:Remarks: Project: Location: Hole #1 Sample Number: A-23917 Depth: 5.0 - 6.5 ft Figure Lean CLAY (Visual) 36 23 13 CL B21-055- Good Housing Project 17 Report No. A-23917-207 Date: 8-21-2021ANE - North 8th Improvements Bozeman, Montana Tested By: WJC Checked By: LIQUID AND PLASTIC LIMITS TEST REPORT PLASTICITY INDEX0 10 20 30 40 50 60 LIQUID LIMIT 0 10 20 30 40 50 60 70 80 90 100 110 CL-ML C L o r O L C H o r O H ML or OL MH or OH Dashed line indicates the approximate upper limit boundary for natural soils 47 WATER CONTENT47.5 48 48.5 49 49.5 50 50.5 51 51.5 52 52.5 NUMBER OF BLOWS 5 6 7 8 9 10 20 25 30 40 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Project No. Client:Remarks: Project: Location: Hole #2 Sample Number: A-23926 Depth: 10.0 - 11.5 ft Figure Lean CLAY (Visual) 50 22 28 CL B21-055- Good Housing Project 18 Report No. A-23926-207 Date: 8-21-2021ANE - North 8th Improvements Bozeman, Montana Tested By: WJC Checked By: LIQUID AND PLASTIC LIMITS TEST REPORT PLASTICITY INDEX0 10 20 30 40 50 60 LIQUID LIMIT 0 10 20 30 40 50 60 70 80 90 100 110 CL-ML C L o r O L C H o r O H ML or OL MH or OH Dashed line indicates the approximate upper limit boundary for natural soils 47 WATER CONTENT35 35.4 35.8 36.2 36.6 37 37.4 37.8 38.2 38.6 39 NUMBER OF BLOWS 5 6 7 8 9 10 20 25 30 40 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Project No. Client:Remarks: Project: Location: Hole #5 Sample Number: A-23943 Depth: 2.5 - 4.0 ft Figure Lean CLAY (Visual) 38 23 15 CL B21-055- Good Housing Project 19 Report No. A-23943-207 Date: 8-21-2021ANE - North 8th Improvements Bozeman, Montana Tested By: WJC Checked By: LIQUID AND PLASTIC LIMITS TEST REPORT PLASTICITY INDEX0 10 20 30 40 50 60 LIQUID LIMIT 0 10 20 30 40 50 60 70 80 90 100 110 CL-ML C L o r O L C H o r O H ML or OL MH or OH Dashed line indicates the approximate upper limit boundary for natural soils 47 WATER CONTENT33.4 33.8 34.2 34.6 35 35.4 35.8 36.2 36.6 37 37.4 NUMBER OF BLOWS 5 6 7 8 9 10 20 25 30 40 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Project No. Client:Remarks: Project: Location: TP #3 & TP #4 Sample Number: A-23645/23646 Depth: 2.5 - 3.0 ft Figure Lean CLAY 36 23 13 99.8 95.4 CL B21-054 Good Housing Partnership 20 Report No. A-23645/23646-207 Date: 7-3-2021ANE - North 8th Improvements Bozeman, Montana Tested By: CRN Checked By: UNCONFINED COMPRESSION TEST Project No.: B21-055-001 Date Sampled: Remarks: Report No. A-23924-215 Figure 21 Client:Good Housing Project Project:ANE - North 8th Improvements Bozeman, Montana Location: Hole #2 Sample Number: A-23924 Depth: 4.0 - 6.0 ft Description: Lean CLAY (Visual) LL = PI = PL = Assumed GS= 2.7 Type: Shelby Tube Sample No. Unconfined strength, psf Undrained shear strength, psf Failure strain, % Strain rate, in./min. Water content, % Wet density, pcf Dry density, pcf Saturation, % Void ratio Specimen diameter, in. Specimen height, in. Height/diameter ratio 1 3548 1774 3.3 0.030 19.5 120.9 101.2 79.0 0.6649 2.85 5.59 1.96Compressive Stress, psf0 1000 2000 3000 4000 Axial Strain, % 0 1.5 3 4.5 6 1 Tested By: CRN Checked By: UNCONFINED COMPRESSION TEST Project No.: B21-055-001 Date Sampled: Remarks: Report No. A-23945-215 Figure 22 Client:Good Housing Project Project:ANE - North 8th Improvements Bozeman, Montana Location: Hole #5 Sample Number: A-23945 Depth: 7.5 - 9.5 ft Description: Lean CLAY (Visual) LL = PI = PL = Assumed GS= 2.7 Type: Shelby Tube Sample No. Unconfined strength, psf Undrained shear strength, psf Failure strain, % Strain rate, in./min. Water content, % Wet density, pcf Dry density, pcf Saturation, % Void ratio Specimen diameter, in. Specimen height, in. Height/diameter ratio 1 6884 3442 3.3 0.029 20.2 122.3 101.8 83.0 0.6561 2.87 5.60 1.95Compressive Stress, psf0 2500 5000 7500 10000 Axial Strain, % 0 1 2 3 4 1 Sat. Moist Project No.B21-055-001 Good Housing Partnership Remarks: Project:ANE - North 8th Improvements Report No. A-23924-219 Bozeman, Montana Location:B-2 Sample Depth (ft):4.0 - 6.0 23 Technician :CRN Reviewed By: Client: Figure CONSOLIDATION TEST REPORT AASHTO ----- USCS CL MATERIAL DESCRIPTION Lean CLAY (Visual) Natural Dry Density (pcf)LL PI Swell (%)eo Sp. Gr. Cs Swell Pressure (psf) ----- Overburden (psf) Pc (psf)Cc ----- 0.81946.9 14.2 92.4 N/A N/A 2.7 520 ~ 2,000 0.075 0.009 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 100 1000 10000Percent StrainApplied Pressure - psf Sat. Moist Project No.B21-055-001 Good Housing Partnership Remarks: Project:ANE - North 8th Improvements Report No. A-23945-219 Bozeman, Montana Location:B-5 Sample Depth (ft):7.5 - 9.5 24 Technician :CRN Reviewed By: Client: Figure CONSOLIDATION TEST REPORT AASHTO ----- USCS CL MATERIAL DESCRIPTION Lean CLAY (Visual) Natural Dry Density (pcf)LL PI Swell (%)eo Sp. Gr. Cs Swell Pressure (psf) ----- Overburden (psf) Pc (psf)Cc ----- 0.94453.1 18.6 86.4 N/A N/A 2.7 870 ~ 2,000 0.24 0.02 0.00 2.00 4.00 6.00 8.00 10.00 12.00 100 1000 10000Percent StrainApplied Pressure - psf Tested By: TF Checked By: Moisture-Density Test Report Dry density, pcf96 98 100 102 104 106 Water content, % 14 16 18 20 22 24 26 18.1%, 103.5 pcf ZAV for Sp.G. = 2.65 Test specification:ASTM D 698-12 Method A Standard 2.5 - 3.0 ft CL A-6(13) 2.65 36 13 0.0 95.4 Lean CLAY B21-054 Good Housing Partnership Report No. A-23645/23646-204 Date: 7-3-2021 25 Elev/ Classification Nat.Sp.G. LL PI % > % < Depth USCS AASHTO Moist.#4 No.200 TEST RESULTS MATERIAL DESCRIPTION Project No. Client:Remarks: Project: Location: TP #3 & TP #4 Sample Number: A-23645/23646 Figure Maximum dry density = 103.5 pcf Optimum moisture = 18.1 % ANE - North 8th Improvements Bozeman, Montana BEARING RATIO TEST REPORT ASTM D1883-16 Project No: B21-054 Project: ANE - North 8th Improvements Bozeman, Montana Location: TP #3 & TP #4 Sample Number: A-23645/23646 Depth: 2.5 - 3.0 ft Date: 7-3-2021 Lean CLAY Test Description/Remarks: ASTM D698 with 6-inch Mold 96-hour soak prior to testing Report No. A-23645/23646-210 Date: 7-16-2021 Figure 26 103.5 18.1 36 13CL Material Description USCS Max. Dens. (pcf) Optimum Moisture (%) LL PI Molded Density (pcf) Percent of Max. Dens. Moisture (%) Soaked Density (pcf) Percent of Max. Dens. Moisture (%) CBR (%) 0.10 in. 0.20 in. Linearity Correction (in.) Surcharge (lbs.) Max. Swell (%) 1 89.4 86.4 18.9 88.7 85.7 27.9 3.3 2.8 0.000 10 0.8 2 98.9 95.6 19.2 98.3 95 23.0 3.8 4.9 0.048 10 0.6 3 104.7 101.2 19.1 103.6 100.1 20.8 7.0 6.4 0.006 10 1Penetration Resistance (psi)0 40 80 120 160 200 Penetration Depth (in.) 0 0.1 0.2 0.3 0.4 0.5 Swell (%)0 0.4 0.8 1.2 1.6 2 Elapsed Time (hrs) 0 24 48 72 96CBR (%)1 3 5 7 9 Molded Density (pcf) 85 90 95 100 105 110 10 blows 20 blows 64 blows CBR at 95% Max. Density = 3.7% for 0.10 in. Penetration PROJECT:ANE JOB NO.: B21-055 TEST DATE:9/10/2021 TEST CASING: TEST REFERENCE POINT: DISTANCE FROM REFERANCE POINT TO BOTTOM OF CASING: PRESOAK START TIME & DATE:9/10/21 @ 09:46 PRESOAK END TIME & DATE:9/10/21 @ 13:46 START TIME END TIME START DEPTH (ft)END DEPTH (ft)INFIL RATE (in/hr) 13:46 14:06 7.22 7.22 0.00 14:06 14:26 7.22 7.22 0.00 14:26 14:46 7.22 7.22 0.00 NOTES:Infiltration rate steady at 0.00 in/hr after 4-hour presoak. TEST PERFORMED BY:Timothy R. Blystone Monitoring well west of U-Haul Top of casing 9.92' SOIL INFILTRATION TEST (FROM DEQ-8 APPENDIX C) Figure 27 Great Falls, Kalispell, Bozeman, Montana Spokane, Washington, Lewiston, Idaho THOMAS, DEAN & HOSKINSEngineering Consultants SOIL CLASSIFICATION AND SAMPLING TERMINOLOGY FOR ENGINEERING PURPOSES 12" 3" 3/4" No.4 No.10 No.40 No.200 <No.200 SILTS & CLAYSBOULDERSCOBBLESGRAVELSSANDS PARTICLE SIZE RANGE (Distinguished By Atterberg Limits)FineCoarse FineMediumCoarse Sieve Openings (Inches)Standard Sieve Sizes CL - Lean CLAY ML - SILT OL - Organic SILT/CLAY CH - Fat CLAY MH - Elastic SILT OH - Organic SILT/CLAY SW - Well-graded SAND SP - Poorly-graded SAND SM - Silty SAND SC - Clayey SAND GW - Well-graded GRAVEL GP - Poorly-graded GRAVEL GM - Silty GRAVEL GC - Clayey GRAVEL * Based on Sampler-Hammer Ratio of 8.929 E-06 ft/lbf and 4.185 E-05 ft^2/lbf for granular and cohesive soils, respectively (Terzaghi) STANDARD PENETRATION TEST (ASTM D1586) RELATIVE DENSITY*RELATIVE CONSISTENCY* Granular, Noncohesive (Gravels, Sands, & Silts)Fine-Grained, Cohesive (Clays) Very Loose Loose Medium Dense Dense Very Dense Very Soft Soft Firm Stiff Very Stiff Hard 0-2 3-4 5-8 9-15 15-30 +30 0-4 5-10 11-30 31-50 +50 Standard Penetration Test (blows/foot) Standard Penetration Test (blows/foot) PLASTICITY CHART 0 10 16 20 30 40 50 60 70 80 90 100 110 60 50 40 30 20 107 4 C L or O LC H or O H ML or OL MH or OH CL-ML "U - LIN E""A - LIN E"LIQUID LIMIT (LL)PLASTICITY INDEX (PI)For classification of fine-grained soils and thefine-grained fraction of coarse-grained soils. Equation of "A"-line Horizontal at PI = 4 to LL = 25.5, then PI = 0.73 (LL-20) Equation of "U"-line Vertical at LL = 16 to PI = 7, then PI = 0.9 (LL-8) Great Falls, Kalispell, Bozeman, Montana Spokane, Washington, Lewiston, Idaho THOMAS, DEAN & HOSKINSEngineering Consultants ASTM D2487 CLASSIFICATION OF SOILS FOR ENGINEERING PURPOSES Flow Chart For Classifying Coarse-Grained Soils (More Than 50 % Retained On The No. 200 Sieve) Flow Chart For Classifying Fine-Grained Soils ( 50 % Or More Passes The No. 200 Sieve) <5% fines 5-12% fines >12% fines <5% fines 5-12% fines >12% fines Well-graded GRAVELWell-graded GRAVEL with sandPoorly-graded GRAVELPoorly-graded GRAVEL with sand Well-graded GRAVEL with silt Well-graded GRAVEL with silt and sandWell-graded GRAVEL with clay (or silty clay)Well-graded GRAVEL with clay and sand (or silty clay and sand) Poorly-graded GRAVEL with silt Poorly-graded GRAVEL with silt and sand Poorly-graded GRAVEL with clay (or silty clay)Poorly-graded GRAVEL with clay and sand (or silty clay and sand) Silty GRAVELSilty GRAVEL with sandClayey GRAVELClayey GRAVEL with sandSilty, clayey GRAVEL Silty, clayey GRAVEL with sand Well-graded SAND Well-graded SAND with gravel Poorly-graded SANDPoorly-graded SAND with gravel Well-graded SAND with silt Well-graded SAND with silt and gravel Well-graded SAND with clay (or silty clay)Well-graded SAND with clay and gravel (or silty clay and gravel) Poorly-graded SAND with siltPoorly-graded SAND with silt and gravelPoorly-graded SAND with clay (or silty clay) Poorly-graded SAND with clay and gravel (or silty clay and gravel) Silty SANDSilty SAND with gravelClayey SAND Clayey SAND with gravel Silty, clayey SAND Silty, clayey SAND with gravel <15% sand>15% sand <15% sand >15% sand <15% sand>15% sand <15% sand >15% sand <15% sand>15% sand<15% sand>15% sand <15% sand>15% sand<15% sand>15% sand<15% sand >15% sand <15% gravel >15% gravel <15% gravel>15% gravel <15% gravel>15% gravel<15% gravel>15% gravel <15% gravel >15% gravel<15% gravel>15% gravel <15% gravel >15% gravel<15% gravel>15% gravel<15% gravel>15% gravel Lean CLAYLean CLAY with sandLean CLAY with gravelSandy lean CLAY Sandy lean CLAY with gravel Gravelly lean CLAY Gravelly lean CLAY with sand Silty CLAY Silty CLAY with sand Silty CLAY with gravel Sandy silty CLAYSandy silty CLAY with gravelGravelly silty CLAYGravelly silty CLAY with sand SILT SILT with sandSILT with gravelSandy SILTSandy SILT with gravel Gravelly SILT Gravelly SILT with sand Fat CLAYFat CLAY with sand Fat CLAY with gravel Sandy fat CLAYSandy fat CLAY with gravelGravelly fat CLAYGravelly fat CLAY with sand Elastic SILT Elastic SILT with sand Elastic SILT with gravelSandy elastic SILTSandy elastic SILT with gravelGravelly elastic SILT Gravelly elastic SILT with sand %sand > %gravel %sand < %gravel <15% gravel>15% gravel<15% sand>15% sand %sand > %gravel %sand < %gravel<15% gravel>15% gravel<15% sand >15% sand %sand > %gravel%sand < %gravel <15% gravel>15% gravel<15% sand>15% sand %sand > %gravel%sand < %gravel<15% gravel>15% gravel<15% sand >15% sand %sand > %gravel %sand < %gravel <15% gravel>15% gravel<15% sand>15% sand fines=ML or MH fines=CL or CH (or CL-ML) fines=ML or MH fines=CL or CH (or CL-ML) fines=ML or MH fines=CL or CH fines=CL-ML fines=ML or MH fines=CL or CH (or CL-ML) fines=ML or MH fines=CL or CH (or CL-ML) fines= ML or MH fines=CL or CH fines=CL-ML <30% plus No. 200 >30% plus No. 200 <30% plus No. 200 >30% plus No. 200 <30% plus No. 200 >30% plus No. 200 <30% plus No. 200 >30% plus No.200 <30% plus No. 200 >30% plus No. 200 Cu>4 and 1<Cc<3 Cu<4 and/or 1>Cc>3 Cu>4 and 1<Cc<3 Cu<4 and/or 1>Cc>3 Cu>6 and 1<Cc<3 Cu<6 and/or 1>Cc>3 Cu>6 and 1<Cc<3 Cu<6 and/or 1>Cc>3 CL CL-ML ML CH MH PI>7 and plotson or above"A" - line 4<PI<7 andplots on or above"A" - line PI<4 or plotsbelow "A" - line PI plots on orabove "A" - line PI plots below"A" - line GRAVEL%gravel > %sand SAND%sand >%gravel LL>50(inorganic) LL<50(inorganic) GW GP GW-GM GW-GC GP-GM GP-GC GM GC GC-GM SW SP SW-SM SW-SC SP-SM SP-SC SM SC SC-SM <15% plus No. 20015-29% plus No. 200 %sand > %gravel %sand < %gravel <15% plus No. 200 15-29% plus No. 200 %sand > %gravel %sand < %gravel <15% plus No. 200 15-29% plus No. 200 %sand > %gravel %sand < %gravel <15% plus No. 20015-29% plus No. 200 %sand > %gravel %sand < %gravel <15% plus No. 20015-29% plus No. 200 %sand > %gravel %sand < %gravel