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Home My WebLink About21.09.17_Wildlands_Stormwater Design Report WILDLANDS DEVELOPMENT - STORMWATER DESIGN REPORT Project No. 21019 45 Architecture 1216 West Lincoln Street, Suite D Bozeman, MT 59715 September 17, 2021 Project No. 21019 STORMWATER DESIGN REPORT FOR WILDLANDS DEVELOPMENT PROJECT OVERVIEW & BACKGROUND The purpose of this drainage plan is to present a summary of calculations to quantify the stormwater runoff for the Wildlands project improvements. LOCATION The site is located at the corner of North Wallace Avenue and East Peach Street and is approximately 0.735 acres. EXISTING SITE CONDITIONS The existing project area is currently occupied by two buildings and associated parking lots. PROPOSED PROJECT Project improvements include expansion of the building currently occupied by Wild Crumb and Fink’s Delicatessen. New parking facilities will also be constructed and will include an underground stormwater infiltration chamber system. HYDROLOGY All design criteria and calculations are in accordance with The City of Bozeman Design Standards and Specifications Policy, dated March 2004. The site stormwater improvements have been designed with the intent to meet the current City of Bozeman drainage regulations for the entire site to the extent feasible. PRE-DEVELOPMENT Existing topography generally slopes southwest to northeast towards the alley. There are existing inlets located within the parking lots, but they are not connected to the city storm drain system. Pre- development runoff calculations for the existing site are provided in Appendix C. Existing site drainage is either captured by a surface pond and raised inlet in the northeast corner of the site, or runoff will sheet off the site to the public right-of-way. A Pre-development roof drainage exhibit is provided in Appendix G. P:21019_Stormwater_Design_Report 2 (09/17/21) CS/ed POST-DEVELOPMENT The Rational Method provided in The City of Bozeman Standard Specifications and Policy was used to calculate the runoff volumes for the 10-year and 25-year, 2-hour storm event. The rational drainage coefficient “C” was calculated for each contributing area using 0.9 for impervious areas and 0.20 for pervious areas. For the purposes of this report, the post-construction stormwater system will consist of two drainage basins (See Appendix A, Exhibit A Post-Developed Sub-Basins). A Post-development roof drainage exhibit is provided in Appendix G. The storage requirements for post development will be met using an ADS Stormtech (or approved equal) chamber system for basin 1 and a drywell for basin 2. Both systems will key into native gravels estimated to infiltrate at 6.8 in/hr per Infiltration Rates for USCS Soils Table for GP soils (Appendix B). For this design, an infiltration rate of 3.4 in/hr will be used, which is half of the estimated rate, to be conservative. The depth of the existing gravels was found to be at a depth of 3.8-5.6 feet based on the geotechnical investigation (See Appendix E, Geotechnical Investigation). The discharge rate for the chamber system is dependent upon the gravel footprint. Various iterations were calculated using the ADS Design Tool online design software. Runoff calculations for post-development conditions and ADS Design are shown in Appendix C. PIPES All storm drainage pipes were sized to handle peak flow resulting from a 25-year storm event. The Rational Method was used to calculate peak flow. The Manning Equation was used to determine the flow full capacity of each pipe. See Appendix D for pipe sizing calculations. Appendices Appendix A –Stormwater Basins Appendix B – Stormwater Chambers Design Details Appendix C – Pre & Post-Development Calculations Appendix D – Pipe Sizing Calculations Appendix E – Geotechnical Investigation Appendix F – Surface Improvements O&M Manual Appendix G – Pre & Post-Development Roof Drainage Exhibit APPENDIX A Stormwater Basins WILDLANDS DEVELOPMENT – STORMWATER DESIGN REPORT Project No. 21019 APPENDIX B Stormwater Chambers Design Details WILDLANDS DEVELOPMENT – STORMWATER DESIGN REPORT Project No. 21019 User Inputs Chamber Model: SC-740 Outlet Control Structure: No Project Name: Wildlands Engineer: Jacob Zwemke Project Location: Montana Measurement Type: Imperial Required Storage Volume: 900 cubic ft. Stone Porosity: 40% Stone Foundation Depth: 12 in. Stone Above Chambers: 6 in. Average Cover Over Chambers: 18 in. Design Constraint Dimensions:(20 ft. x 45 ft.) Results System Volume and Bed Size Installed Storage Volume: 1034.22 cubic ft. Storage Volume Per Chamber: 45.90 cubic ft. Number Of Chambers Required: 10 Number Of End Caps Required: 4 Chamber Rows: 2 Maximum Length:43.11 ft. Maximum Width: 11 ft. Approx. Bed Size Required: 474.26 square ft. System Components Amount Of Stone Required: 53.26 cubic yards Volume Of Excavation (Not Including Fill): 70.26 cubic yards 1002 cubic ft. H‐1 | Page This Section adds to the infiltration testing section of the Montana Post‐Construction Storm Water BMP Design Guidance Manual; however, this section shall take precedence over any discrepancies with the practices or results of the water quality Guidance Manual. One of the following methods should be used to determine the design infiltration rate.  Design Infiltration Rate Using the USCS Classification (non‐field measured – This method is only applicable to proposed infiltration systems with less than 5,000 square feet of infiltration area)  Encased Falling Head Test (field measured)  Pilot Infiltration Test (field measured)  Borehole Infiltration Test (field measured) Design Infiltration Rate Using the USCS Classification For infiltration systems with less than 5,000 square feet, a design infiltration rate can be selected from Table 1: Infiltration Rate Ranges for USCS Soils based on the least‐permeable soil layer encountered within 10 feet of the base of the proposed infiltration system. The design infiltration rates presented in Table 1: Infiltration Rate Ranges for USCS Soils represent the ranges of infiltration rates for each soil classification. The minimum infiltration rate shall be selected as the design infiltration rate. Table 1: Infiltration Rate Ranges for USCS Soils Soil Description USCS Range of Typical Infiltration Rates (inches/hour) min max* Well graded gravel, sandy gravel GW 1.30 137.00 Poorly graded gravel, sandy gravel GP 6.80 137.00 Well graded sand, gravelly sand SW 0.80 68.00 Poorly graded sand, gravelly sand SP 0.50 68.00 Silty gravel, silty sandy gravel GM 1.63 13.50 Clayey sands SC 0.05 0.78 Silty Sand SM 0.24 0.70 Clayey gravel, clayey sandy gravel GC 0.04 0.50 Inorganic Silts of low plasticity ML 0.04 0.14 Clay CL 0.00 0.01 Inorganic Silts of high plasticity MH 0.00 0.01 Inorganic clays of high plasticity CH 0.00 0.01 *If proposing to use maximum rates, a detailed explanation shall be provided why the maximum rates apply to development. APPENDIX C Pre & Post Development Calculations WILDLANDS DEVELOPMENT – STORMWATER DESIGN REPORT Project No. 21019 Design Storm Frequency =2 years Discharge Rate, d = cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 26389 0.61 0.95 1 0.95 0.95 0.58 5643 0.13 0.15 1 0.15 0.15 0.02 0.00 1 0.00 0.00 0.00 0 1 0.00 0.00 0.00 0 1 0.00 0.00 0.00 32032 0.7354 0.59 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.59 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 4.20 2.50 5 1.60 0.95 10 1.05 0.63 15 0.83 0.49 20 0.70 0.41 25 0.61 0.36 30 0.55 0.32 35 0.50 0.30 40 0.46 0.27 45 0.43 0.25 50 0.40 0.24 55 0.38 0.23 60 0.36 0.21 75 0.31 0.19 90 0.28 0.17 105 0.26 0.15 120 0.24 0.14 150 0.21 0.12 180 0.19 0.11 360 0.12 0.07 720 0.08 0.05 1440 0.05 1,017.41 ft3 0.79 (ft3/s) Impervious RATIONAL METHOD FOR RUNOFF CALCULATIONS Pre-Development Conditions Surface Type Pervious Totals = 0.8091 Cwd x Cf =0.81 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 149.91 0.00 149.91 285.37 0.00 285.37 376.55 0.00 376.55 442.85 0.00 442.85 496.86 0.00 496.86 543.25 0.00 543.25 584.35 0.00 584.35 621.52 0.00 621.52 655.61 0.00 655.61 687.24 0.00 687.24 716.82 0.00 716.82 744.68 0.00 744.68 771.05 0.00 771.05 843.04 0.00 843.04 906.82 0.00 906.82 964.50 0.00 964.50 1017.41 0.00 1017.41 1112.40 0.00 1112.40 1196.56 0.00 1196.56 1578.87 0.00 1578.87 2083.33 0.00 2083.33 2748.97 0.00 = Design Storm Frequency =50 years Unit Width (ft)Unit Length (ft) Infiltration Rate (in/hr) Infiltration Discharge Rate (cfs) Allowable Discharge (detention, cfs) Discharge Rate, d =0.00 cfs 0.00 0.00 0.00 0 Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 1100 0.03 0.9 1.2 1.08 1.00 0.03 0 0.00 0.15 1.2 0.18 0.18 0.00 0 1.2 0.00 0.00 0.00 0 1.2 0.00 0.00 0.00 0 1.2 0.00 0.00 0.00 1100 0.0253 0.03 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.03 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 13.72 0.35 5 4.74 0.12 10 3.00 0.08 15 2.30 0.06 20 1.90 0.05 25 1.64 0.04 30 1.45 0.04 35 1.31 0.03 40 1.20 0.03 45 1.11 0.03 50 1.04 0.03 55 0.97 0.02 60 0.92 0.02 75 0.79 0.02 90 0.70 0.02 105 0.64 0.02 120 0.58 0.01 150 0.50 0.01 180 0.45 0.01 360 0.28 0.01 720 0.18 0.00 1440 0.11 194.68 ft3 0.35 (ft3/s) 194.68 0.00 194.68 246.41 0.00 121.51 0.00 121.51 153.80 0.00 153.80 105.86 0.00 105.86 114.21 0.00 114.21 96.00 0.00 96.00 101.16 0.00 101.16 83.64 0.00 83.64 90.23 0.00 90.23 78.61 0.00 78.61 81.20 0.00 81.20 72.87 0.00 72.87 75.84 0.00 75.84 66.08 0.00 66.08 69.63 0.00 69.63 57.57 0.00 57.57 62.10 0.00 62.10 45.48 0.00 45.48 52.20 0.00 52.20 20.79 0.00 20.79 35.93 0.00 35.93 = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) = 0.9000 Cwd x Cf =1.00 Runoff Volume Discharge Volume Site Detention = Pervious Totals Impervious RATIONAL METHOD FOR RUNOFF CALCULATIONS Post-Development Conditions (EXISTING NW ROOF DRAIN #3) Surface Type = P:21019_Wildlands 1 (09/17/21) CS/TPR Basin 1 Post-development Total Area = 19,910ft2 = 0.4571 acres Post-development C = (0.9(0.4571 acres))/0.4571 acres = 0.9 Cf = 1.00 Tc = 5min (4 min Basin overland travel plus 1 min pipe travel) = I = Y=0.64X-0.65 = 0.64(5/60)-0.65 = 3.22 cfs A = 0.4571 acres = 0.9 ∗ 3.22 ℎ∗ 0.4571 Qpost = 1.32 cfs Chamber Type = SC-740 Gravel Footprint Area = 474.26ft2 (See ADS System Parameters) Infiltration Rate = 474.26ft2 * 3.4 in/hr * 1hr/3600sec * 1ft/12in = 0.0373 cfs The design will infiltrate into the native gravels with no discharge for the 10-year storm. This will treat the first 0.5 inches of precipitation. The maximum storage is calculated using the Modified Rational method with a 10-year storm and a Post-developed Tc of 5 minutes for Basin 1, and the required volume was found to be 1,002 cubic feet as shown on the following table. P:21019_Wildlands 2 (09/17/21) CS/TPR Basin 1 Storage Calculation with Infiltration Tc(min) 5 Detention Area (sf) 474.26 Post C 0.9 Perv Rate (in/hr) 3.4 Cf 1 Area(ac) 0.4571 Infiltration Rate 0.0373 cfs Duration Intensity Qp Incoming Outgoing (min) (in/hr) (cfs) Vol(cf) Vol (cf) 5 3.22 1.32 397.19 11.20 386.0 10 2.05 0.84 506.24 22.40 483.8 15 1.58 0.65 583.43 33.59 549.8 20 1.31 0.54 645.23 44.79 600.4 30 1.00 0.41 743.61 67.19 676.4 45 0.77 0.32 857.00 100.78 756.2 60 0.64 0.26 947.78 134.37 813.4 90 0.49 0.20 1092.30 201.56 890.7 120 0.41 0.17 1208.01 268.75 939.3 180 0.31 0.13 1392.20 403.12 989.0764 200 0.29 0.12 1444.49 447.91 996.5824 240 0.26 0.11 1539.68 537.49 1002.1814 241 0.26 0.11 1541.92 539.73 1002.1842 242 0.26 0.11 1544.15 541.97 1002.1809 243 0.26 0.11 1546.39 544.21 1002.1717 244 0.26 0.11 1548.61 546.45 1002.1564 245 0.26 0.11 1550.83 548.69 1002.1353 300 0.22 0.09 1664.75 671.87 992.8773 400 0.19 0.08 1841.10 895.82 945.2715 500 0.16 0.07 1990.65 1119.78 870.8696 The chamber system provides 1,034 cubic feet of storage (See ADS System Parameters), which exceeds the required volume of 1,002 cubic feet. Runoff from larger storm events will fill up the available storage and the excess will spill out of the inlets into an existing storm drain inlet located in the alley that is connected to the city storm drain system at East Cottonwood Street. P:21019_Wildlands 3 (09/17/21) CS/TPR Basin 2 Post-development Total Area = 3,138ft2 = 0.0720 acres Post-development C = (0.9(0.0720 acres))/0.0720 acres = 0.9 Cf = 1.00 Tc = 5min (4 min Basin overland travel plus 1 min pipe travel) = I = Y=0.64X-0.65 = 0.64(5/60)-0.65 = 3.22 cfs A = 0.0720 acres = 0.9 ∗ 3.22 ℎ∗ 0.0720 Qpost = 0.21 cfs Gravel Footprint Area = 66ft2 Infiltration Rate = 66ft2 * 3.4 in/hr * 1hr/3600sec * 1ft/12in = 0.0052 cfs Boulder Pit Volume Volume of Rock=LxWxH Void Ratio=0.38 Volume of Rock=6’x11’x8’=528cf Storage Volume=528cf*0.38=201cf The design will infiltrate into the native gravels with no discharge for the 10-year storm. This will treat the first 0.5 inches of precipitation. The maximum storage is calculated using the Modified Rational method with a 10-year storm and a Post-developed Tc of 5 minutes for Basin 1, and the required volume was found to be 169 cubic feet as shown on the following table. P:21019_Wildlands 4 (09/17/21) CS/TPR Basin 2 Storage Calculation with Infiltration Tc(min) 5 Detention Area (sf) 66 Post C 0.9 Perv Rate (in/hr) 3.4 Cf 1 Area(ac) 0.0720 Infiltration Rate 0.0052 cfs Duration Intensity Qp Incoming Outgoing (min) (in/hr) (cfs) Vol(cf) Vol (cf) 5 3.22 0.21 62.57 1.56 61.0 10 2.05 0.13 79.75 3.12 76.6 15 1.58 0.10 91.90 4.68 87.2 20 1.31 0.08 101.64 6.23 95.4 30 1.00 0.07 117.14 9.35 107.8 45 0.77 0.05 135.00 14.03 121.0 60 0.64 0.04 149.30 18.70 130.6 90 0.49 0.03 172.06 28.05 144.0 120 0.41 0.03 190.29 37.40 152.9 180 0.31 0.02 219.31 56.10 163.2057 200 0.29 0.02 227.54 62.33 165.2105 240 0.26 0.02 242.54 74.80 167.7373 290 0.23 0.01 259.15 90.38 168.7623 291 0.23 0.01 259.46 90.70 168.7630 292 0.23 0.01 259.77 91.01 168.7631 293 0.23 0.01 260.08 91.32 168.7624 294 0.23 0.01 260.39 91.63 168.7611 300 0.22 0.01 262.24 93.50 168.7388 400 0.19 0.01 290.02 124.67 165.3517 500 0.16 0.01 313.58 155.83 157.7436 The drywell and boulder pit provides 201 cubic feet of storage, which exceeds the required volume of 169 cubic feet. Runoff from larger storm events will fill up the available storage and the excess will spill out of the inlets into an existing storm drain inlet located in Peach Street. APPENDIX D Pipe Sizing Calculations WILDLANDS DEVELOPMENT – STORMWATER DESIGN REPORT Project No. 21019 P:21019_Wildlands 1 (09/17/21) CS/TPR Basin 1 Post-development Total Area = 19,910 ft2 = 0.4571 acres Post-development C = (0.9(0.4571 acres))/0.4571 acres = 0.9 Cf = 1.10 (25-year) Tc = 5min (4 min Basin overland travel plus 1 min pipe travel) = I = Y=0.78X-0.64 = 0.78(5/60)-0.64 = 3.83 cfs A = 0.4571 acres = 0.9 ∗ 3.83 ℎ∗ 0.4571 Qpost = 1.58 cfs 12-inch SDR 35 PVC pipe flowing full capacity: =1.49 ( /")$%/ n = 0.013 = & = 0.785ft2 ’ = 2&r = 3.14ft R=A/P=0.785ft2/3.14ft=0.25ft S=0.4% =1.49 0.013 0.785*+ (0.25*+ /")0.004%/ Q=2.26cfs All pipes are 12-inch with at least 0.4% slope, therefore they are adequate to handle the 25- year storm event. APPENDIX E Geotechnical Investigation WILDLANDS DEVELOPMENT – STORMWATER DESIGN REPORT Project No. 21019 MONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA JOB NO. B21-043-001 July 2021 REPORT OF GEOTECHNICAL INVESTIGATION CLIENT ENGINEER Outlaw Real Estate Partners, LLC PO Box 160250 Big Sky, MT 59716 Craig Nadeau, PE Craig.nadeau@tdhengineering.com REPORT OF GEOTECHNICAL INVESTIGATION PROJECT NAME PROJECT LOCATION 406.761.3010 tdhengineering.com 1800 River Drive Nor th Great Falls, MT 59401 WILDLANDS DEVELOPMENT BOZEMAN, MONTANA Wildlands Development 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 ................................................................................. 6 4.4 Foundation Walls.............................................................................................................. 7 4.5 Interior Building Slabs ...................................................................................................... 7 4.6 Exterior Concrete Flatwork .............................................................................................. 7 4.7 Pavements ....................................................................................................................... 8 5.0 RECOMMENDATIONS ........................................................................................................... 9 5.1 Site Grading and Excavations.......................................................................................... 9 5.2 Conventional Shallow Foundations ............................................................................... 10 5.3 Foundation Walls............................................................................................................ 11 5.4 Interior Building Slabs .................................................................................................... 12 5.5 Exterior Concrete Flatwork ............................................................................................ 13 5.6 Pavements ..................................................................................................................... 14 5.7 Continuing Services ....................................................................................................... 15 6.0 SUMMARY OF FIELD AND LABORATORY STUDIES ....................................................... 16 6.1 Field Explorations ........................................................................................................... 16 6.2 Laboratory Testing ......................................................................................................... 16 7.0 LIMITATIONS ........................................................................................................................ 18 Wildlands Development Appendix Bozeman, Montana ii APPENDIX  Boring Location Map (Figure 1)  Logs of Exploratory Borings (Figures 2 through 5)  Laboratory Test Data (Figures 6 through 15)  LTTPBind Online PG Asphalt Binder Analysis Summary  Construction Standard 02801-06C  Soil Classification and Sampling Terminology for Engineering Purposes  Classification of Soils for Engineering Purposes Wildlands Development Executive Summary Bozeman, Montana Page 1 GEOTECHNICAL REPORT WILDLANDS DEVELOPMENT BOZEMAN, MONTANA 1.0 EXECUTIVE SUMMARY The geotechnical investigation for the Wildlands Development to be located on the northeast corner of the intersection of East Peach Street and North Wallace Avenue in Bozeman, Montana, encountered limited thickness of native lean / fat clay beneath the existing asphalt surfacing and overlying the native gravels. 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 relatively soft, compressible, and expansive clay soils. Such materials are not considered suitable to remain beneath building foundations and interior slab systems and warrant removal and replacement with compacted structural fill. These clay soils are acceptable to remain beneath exterior parking lots and exterior flatwork provided some risk of vertical displacements is acceptable for these elements and that they are properly designed in accordance with our recommendations. The site is suitable for the use of conventional shallow foundation and interior slab-on-grade construction bearing on properly compacted structural fill extending to native gravel. A maximum allowable bearing pressure of 5,000 pounds per square foot (psf) is suitable for this site provided the recommendations included in this report are followed. Recommendations for exterior parking lots have been prepared assuming that clay soils will remain beneath the parking lot section. However, if preferred, the removal and replacement of the clay to native gravel will improve long-term performance by supporting the pavement section on a far superior subgrade material. Similar conventional construction of exterior flatwork has been recommended assuming some risk related to vertical movements can be tolerated in order to control the overall cost of building these elements. If no level of risk is acceptable for exterior flatwork or for specific elements which will be especially sensitive to vertical movements, the native clays should be completely removed and replaced with compacted structural fill. To ensure proper performance of subsurface storm water systems they should extend to the surface of the native gravel. The overlying clay soil is expected to have little or no permeability and is not suitable for on-site infiltration. Wildlands Development Introduction Bozeman, Montana Page 2 2.0 INTRODUCTION 2.1 Purpose and Scope This report presents the results of our geotechnical study for the proposed Wildlands Development to be located on the northeast corner of the intersection of East Peach Street and North Wallace Avenue in Bozeman, Montana. 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 structures 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 four soil borings across the proposed site. Samples were obtained from the borings 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. 2.2 Project Description It is our understanding that the proposed project consists of three new structures, two of which are to be connected to the existing Wild Crumb facility in the southwest corner of the site. The new construction is anticipated to be up to three stories, and portions may incorporate a basement configuration; however, the majority of the development is anticipated to utilize conventional slab- on-grade construction. One building is expected to incorporate indoor parking on the main level of the structure. The new construction is anticipated to utilize primarily steel construction and be supported on conventional shallow foundations. Structural loads had not been developed at the time of this report. However, for the purpose of our analysis, we have assumed that wall loads will be less than 6,000 pounds per lineal foot and column loads, if any, will be less than 150 kips. Site development will most likely include landscaping, exterior concrete flatwork, asphalt pavement for a single exterior parking lot, and subsurface retention systems. If the assumed design values presented above vary from the actual project parameters, the recommendations presented in this report should be reevaluated. Wildlands Development Site Conditions Bozeman, Montana Page 3 3.0 SITE CONDITIONS 3.1 Geology and Physiography The site is geologically characterized as alluvium consisting of mixtures of gravel, sand, silt, and clay typical of stream and river channels or floodplains. Based on our experience and available well logs in the area, similar gravel deposits generally extend to depths of more than 100 feet. 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 on the northeast corner of the intersection of East Peach Street and North Wallace Avenue in Bozeman, Montana. The area is heavily developed with nearly the entire property consisting of existing asphalt pavements, concrete flatwork, and buildings. A two- story structure being approximately 4,500 square feet in plan is located in the southwest portion of the project area and is currently occupied by various retail companies. Near the center of the property on the north side are three elevated tanks which are estimated to be ten to twelve feet in diameter and surrounded by concrete walls on the north, west, and south sides. The eastern portion of the property is a recently constructed parking lot which appears to be less than five years old. The far southeast corner contains another single-story building, being roughly 2,400 square- Approximate Site Location Wildlands Development Site Conditions Bozeman, Montana Page 4 feet in plan, which appears to be abandoned. Based on background information and site observations, the site is considered relatively flat with little grade change within its limits. 3.3 Subsurface Conditions 3.3.1 Soils The subsurface soil conditions appear to be relatively consistent based on our exploratory drilling and soil sampling. In general, the subsurface soil conditions encountered within the borings consist of an existing asphalt pavement section ranging in total thickness from 15 to 21 inches and underlain by native clay. The clay extends to depths of 3.8 to 5.6 feet below existing site grade and are underlain by native gravel. The native gravels extend to depths of at least 21.5 feet, the maximum depth investigated. The subsurface soils are described in detail on the enclosed boring 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. EXISTING PAVEMENT Existing pavement sections across the property are generally consistent. The section appears to be comprised of approximately three inches of surfacing asphalt underlain by 12 to 18 inches of base course gravel. A woven separation geotextile was observed in the recently constructed eastern parking area between the base course gravel and the clay subgrade. A geotextile was not observed in the western portion of the existing asphalt. LEAN / FAT CLAY Lean / fat clay was encountered in all four borings beneath the surfacing section and extend to depths of 3.8 to 5.6 feet. The clay soil is generally considered soft to stiff as indicated by penetration resistance N-values of 4 and 10 blows per foot (bpf). This material is moderately to highly compressible and moderately expansive as indicated by the consolidation-swell test results shown on Figures 12 and 13. Two samples of the clay exhibited liquid limits of 46 and 51 percent and plasticity indices of 23 and 31 percent. The natural moisture contents varied from 21 to 27 percent. A bulk sample of this material was obtained for laboratory testing; however, due to the limited thickness of the clay deposit, the sample was heavily contaminated with sand and gravel from the overlying base course layer. Thus, the sample classified as clayey sand and is not representative of actual field conditions. This sample did result in a maximum dry density of 115.5 pounds per cubic foot, optimum moisture content of 13.6 percent, and CBR of 5.7 percent. The maximum dry density and CBR are likely higher than is typical for the uncontaminated lean clay, and the optimum moisture is lower. Wildlands Development Site Conditions Bozeman, Montana Page 5 NATIVE GRAVEL Native gravel was encountered in all four borings beneath the clay at depths of 3.8 to 5.6 feet and extending to depths of at least 21.5 feet. The gravels are medium dense to very dense as indicated by penetration resistance values which ranged from 27 to greater than 100 bpf and averaged 74 bpf. A single bulk sample of this material obtained from auger spoils contained 69.3 percent gravel, 22.1 percent sand, and 8.6 percent fines (clay and silt). The same sample exhibited a liquid limit of 22 percent and a plasticity index of 6 percent resulting in a classification of poorly-graded gravel with clay and sand. The actual gradation of on-site material is expected to be much coarser than indicated by this test due to the impacts of drilling resulting in fractured rocks and some segregation of material. The natural moisture contents varied from 2 to 18 percent and averaged 7.5 percent. 3.3.2 Ground Water Ground water was encountered in all four borings performed on this site and was relatively consistent with depths ranging from 11.0 to 11.9 feet below ground surface. A single boring (B-2) was completed as a monitoring well; however, no ground water measurements have been collected since the completion of our investigation. 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. Wildlands Development Engineering Analysis Bozeman, Montana Page 6 4.0 ENGINEERING ANALYSIS 4.1 Introduction The primary geotechnical concern regarding this project is the presence of relatively soft, compressible, and expansive clay soil across the site which poses a risk of settlement and heave to infrastructure constructed over it. However, the clay soil is generally thin, and the majority of footings are anticipated to bear on native gravels or in close proximity to the native gravels depending on final site grading. The remaining clay beneath foundations and interior building slabs can be removed and replaced fairly economically. Exterior concrete does not require the complete removal and replacement of the native clays and can utilize conventional construction provided some risk of vertical movement related to construction over this material can be tolerated for the project. The clay soil is highly compressible, frost susceptible, and expansive, which can have adverse impacts on similar concrete elements, especially those directly adjacent to irrigated landscaping. 4.2 Site Grading and Excavations The ground surface at the proposed site is nearly level with little grade change evident during our investigation. Based on our field work, existing pavement materials, native clay soils, and native gravel will be encountered in foundation and utility excavations to the depths anticipated. Based on the borings, ground water may be encountered depending on the overall depth of the excavation and time of year. Water levels at the time of our investigation were measured approximately eleven feet below existing grade but may fluctuate seasonally. A ground water monitoring well has been installed on the property; however, long term data collection from this well is not planned as part of our scope of work for this project. 4.3 Conventional Shallow Foundations Considering the subsurface conditions encountered and the nature of the proposed construction, the structures can be supported on conventional shallow foundation bearing directly on properly compacted native gravel or on compacted structural fill extending to native gravel. Footings should not be constructed over any thickness of the native clay due to the potential settlements associated with this stratum. Based on our experience, the theory of elasticity, and using an allowable bearing pressure of 5,000 psf, we estimate the total settlement for footings will be less than ¾-inch. Differential settlement within individual structures should be on the order of one-half this magnitude. 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 Wildlands Development Engineering Analysis Bozeman, Montana Page 7 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 Walls When basement configurations are utilized, foundation walls 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 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 Interior Building Slabs The natural on-site soils are highly compressible, frost susceptible, and exhibit expansive properties making them unsuitable to support interior building slabs which would require extensive financial and disruption to the completed structures if excessive movements were to occur. Thus, to mitigate the risk associated with these materials, all native clay should be completely removed and replaced with properly compacted structural fill within the limits of interior building slabs. 4.6 Exterior Concrete Flatwork As noted previously, the natural on-site clay soil is highly compressible, frost susceptible, and exhibit expansive properties. However, most exterior flatwork applications can tolerate a higher level of movement without adversely impacting their function. Additionally, exterior concrete flatwork can be repaired or replaced much more economically and with less impact to the facility compared to interior building slabs. For these reasons, we believe the use of conventional slab-on- grade construction consisting of a thin leveling course of granular fill, typically four to six inches, directly beneath the concrete slab and overlying compacted native clay is permissible for exterior concrete applications provided a higher level of risk and increased potential for repair and/or replacement can be tolerated for the project. Wildlands Development Engineering Analysis Bozeman, Montana Page 8 If the increased risk and potential for repair and/or replacement are not acceptable for this project or specific exterior elements within the project, then the complete removal and replacement of the clay soils from beneath the exterior concrete is warranted. 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 traffic conditions. Traffic information was not available at the time of this report. We have assumed that traffic for the exterior parking lot will be limited to primarily passenger-type vehicles with occasional mid-size truck traffic associated with deliveries, trash collection, etc. We have assumed that traffic conditions will not result in a total equivalent single axle loading (ESAL) exceeding 50,000 over a typical 20-year design interval. The potential worst case subgrade material is high plasticity lean / fat clay encountered on site which is classified as an A-7-6 soil in accordance with the American Association of State Highway and Transportation Officials (AASHTO) classification. AASHTO considers this soil type to be a relatively poor subgrade medium due to its moisture sensitivity, poor drainage property, and reduced strength when wetted. Typical California Bearing Ratio (CBR) values for this type of soil range from 3 to 5 percent when properly compacted. However, natural moisture contents found in samples at the time of our investigation were higher than the typical optimum moisture content for the material, which will restrict the ability to compact the clay subgrade without considerable moisture processing. Thus, the subgrade at the time of construction is likely to exhibit a lower CBR value because of low compaction levels. During construction, the subgrade should be cleared of all loose soil debris and rolled smooth using static methods. Vibration should be limited, especially if the subgrade exhibits signs of instability such as pumping. All subsequent 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 prepared clay subgrade. The recommended geotextile will prevent the upward migration of fines and the loss of aggregate into the subgrade while adding strength to the overall pavement section to account for the weak clay subgrade. These benefits will prolong the structural integrity and performance of the pavement section. The pavement section presented in this report is based on an assumed CBR value of two 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. Wildlands Development Recommendations Bozeman, Montana Page 9 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. The on-site soils, exclusive of topsoil and construction debris, are suitable for use as backfill and general site grading fill on this project. 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 moisture conditioned to near the optimum moisture content and 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) Native Gravel and Structural Fill Below Foundations ................. 98% b) Native Gravel and Structural Fill Below Building Slabs .............. 98% c) Beneath Exterior Concrete & Exterior Foundation Wall Backfill . 95% d) Below Streets, Parking Lots, or Other Paved Areas ................... 95% e) General Landscaping or Nonstructural Areas ............................. 92% 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 are not incurred due to laboratory processing times or rush processing fees. 3. Imported structural fill should be non-expansive, free of organics and debris, and conform to the material requirements outlined in Section 02234 of the Montana Public Works Standard Specifications (MPWSS). All gradations outlined in this standard are acceptable for use on this project; however, conventional proctor methods (outlined in ASTM D698) shall not be used for any materials containing less than 70 percent passing the ¾-inch sieve. Conventional proctor methods are Wildlands Development Recommendations Bozeman, Montana Page 10 not suitable for these types of materials, and the field compaction value must be determined using a relative density test outlined in ASTM D4253-4254. Native gravels excavated from other areas of the project site are permissible for use in structural fill applications provided they do not contain any organics, construction debris, or other deleterious material. 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. The final site grading shall conform to the grading plan, prepared by others, to satisfy the minimum requirements of the applicable building codes. 5. 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 borings are considered Type B for the native clay and Type C for the existing base course gravel and native gravel. 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. 5.2 Conventional Shallow Foundations The design and construction criteria below should be observed for a conventional shallow foundation system. The construction details should be considered when preparing the project documents. 6. Both interior and exterior footings should bear on properly compacted native gravel or compacted structural fill (Item 3) extending to native gravel and should be designed for a maximum allowable soil bearing pressure of 5,000 psf provided settlements as outlined in the Engineering Analysis are acceptable. The limits of over-excavation and replacement with compacted structural fill should extend at least two feet beyond the out limits of the foundation in all directions. 7. Soils disturbed below the planned depths of footing excavations should be re- compacted in accordance with the requirements of Item 2 above. 8. Footings shall be sized to satisfy the minimum requirements of the applicable building codes while not exceeding the maximum allowable bearing pressure provided in Item 6 above. Wildlands Development Recommendations Bozeman, Montana Page 11 9. Exterior footings and footings beneath unheated areas should be placed at least 48 inches below finished exterior grade for frost protection. 10. The bottom of the footing excavations should be free of cobbles and boulders to avoid stress concentrations acting on the base of the footings. If the base of the footing excavation cannot be rolled smooth due to protruding cobbles or boulders, the inclusion of a thin leveling course should be considered. Leveling course materials should conform to the materials requirements of MPWSS Section 02235 and be compacted to the requirements of Item 2a. 11. 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 friction coefficient of 0.45 and a lateral resistance pressure of 150 psf per foot of depth are appropriate for footing bearing on properly compacted native gravel or structural fill and backfilled with compacted native clay soils. An increased lateral resistance pressure of 350 psf per foot of depth should be utilized if project specifications will require native gravel or structural fill to be used as backfill within four feet of the foundation wall. 12. 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 to verify compliance with the subgrade preparation and compaction recommendations outlined above. 5.3 Foundation Walls The design and construction criteria presented below should be observed for foundation walls where basement configurations are considered as part of the final design. The construction details should be considered when preparing the project documents. 13. Basement walls and other retaining walls which are laterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of 60 pcf for backfill consisting of properly compacted native gravels or structural fill. For consideration of seismic forces, a seismic equivalent fluid unit weight of 75 pcf is appropriate for the increased lateral forces associated with earthquake motions for similar backfill conditions. 14. 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. Wildlands Development Recommendations Bozeman, Montana Page 12 15. Exterior footing drains are required by the applicable building codes for all portions of the new construction which will incorporate a basement or other below grade space to remove ground water seepage and infiltrated surface runoff away from foundation soils. Drains should consist of a minimum 3-inch diameter, geotextile- wrapped, flexible, slotted pipe (ADS) or perforated, SDR 35, 4-inch diameter, PVC drain tile in poorly-graded gravel with geotextile placed at or below exterior footing grade. Drains shall be covered by at least 12 inches of free-draining, open-graded, granular material. The open-graded granular material should be enveloped in a geotextile to prevent the migration of fines. Use of a single piece of geotextile with a full-width lap at the top is preferred; however, two separate pieces of fabric may be used provided a minimum overlap distance of 12 inches is maintained at all joints. Drains should be sloped to an interior sump or a storm water system. A typical perimeter foundation drain is shown on Construction Standard No. 02801-06C. At the time of our investigation, ground water was below the anticipated depth of basement construction; however, seasonal fluctuations are expected, and the magnitude of these has not yet been determined. It is advised that ground water measurements be performed during the spring months of 2022 when ground water will be near its seasonal high to evaluate if foundation waterproofing systems would need to be utilized to help control ground water at the basement elevation. 16 Foundation walls should de damp-proofed in accordance with the applicable sections of the International Building Code (IBC) unless future ground water monitoring indicates that seasonal ground water will rise to or above the planned footing elevation. If high ground water is possible, the use of water-proofing on foundation walls is warranted. 5.4 Interior Building Slabs 17. Based on the compressibility, frost susceptibility, and expansive potential of the native clay soils they are not considered suitable to remain beneath interior slab systems where the financial and disruption impacts of future repairs are considered excessive. All interior building slabs should be supported on properly compacted structural fill (Item 3) extending to native gravel. 18. An optional cushion course consisting of material conforming to the requirements outlined in Section 02235 of the Montana Public Works Standard Specifications (MPWSS) can be placed beneath interior slabs depending on the gradation of structural fill utilized. Alternatively, clean washed chips exhibiting a high fracture percentage exceeding 70 percent single face may be utilized as a cushion material provided the overall thickness does not exceed 6 inches. This layer should be compacted using a Wildlands Development Recommendations Bozeman, Montana Page 13 minimum of four passes with a smooth vibratory plate compactor following installation. 19. Concrete floor slabs constructed as described above should be designed using a modulus of vertical subgrade reaction no greater than 400 pci when designed and constructed as recommended above. 20. Geotechnically, an underslab vapor barrier is not required for this project for conventional slab-on-grade construction near the ground surface. The incorporation of a vapor barrier beneath any basement portions is recommended due to fluctuations in the ground water table. 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 Concrete Flatwork 21. For normally loaded, exterior concrete flatwork, a typical cushion course consisting of free-draining, crushed gravel may be placed beneath the concrete and compacted to the requirements of Item 2 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 clay soil present on site. In most cases, the cost to repair and/or replace exterior flatwork when excessive movements occur is far more economical than efforts to mitigate these movements. However, if conventional construction is utilized it is assumed that the Owner is willing to accept the potential reduced concrete performance and increased maintenance time and expense. 22. Cushion course materials utilized beneath exterior slab-on-grade applications should conform to the requirements outlined in Section 02235 of the Montana Public Works Standard Specifications (MPWSS). All gradation outlined in this specification are acceptable for this application. Prior to placing the cushion course, the upper six inches of subgrade should be compacted per Item 2. 23. If no acceptable risk can be assumed by the Owner, the only positive method to control potential slab movements is to completely remove and replace the clay soils with compacted structural fill (Item 3) extending to the surface of the native gravel. Such improvements should be implemented beneath any portions of the exterior concrete in which higher levels of performance are expected or those which will be especially difficult or expensive to replace should movements be considered excessive. Wildlands Development Recommendations Bozeman, Montana Page 14 5.6 Pavements 24. The following flexible asphalt pavement section or an approved equivalent section should be selected in accordance with the discussions in the Engineering Analysis for use in exterior parking applications. Pavement Component Component Thickness Asphaltic Concrete Pavement 3” Crushed Base Course 6” Crushed Subbase Course 9” Total 18” 25. Crushed base courses 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 courses shall conform to material properties outlined in Section 02234 of the MPWSS. All gradations outlined in this specification are acceptable for this application based on local availability and contractor preference. 26. 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 2 above. 27. 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 as well as to reinforce the pavement structure. A Mirafi RS380i has been assumed in our design section and should not be substituted without our prior review and modification (if necessary) of the overall pavement section. 28. 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. Wildlands Development Recommendations Bozeman, Montana Page 15 Reliability Min. High Temp Rating Min. Low Temp Rating Ideal Oil Grade 50% 35.6 -23.6 PG 58-28 98% 39.5 -32.5 PG 52-34 For most low volume parking lot applications, a 50 percent reliability is considered sufficient. For this reliability level, a PG 58-28 grade oil is recommended as this is a commonly available product which will provide suitable low temperature resistance to thermal cracking. 5.7 Continuing Services Three additional elements of geotechnical engineering service are important to the successful completion of this project. 29. 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. 30. 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. 31. 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 experienced 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 be used: 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 Wildlands Development Summary of Field & Laboratory Studies Bozeman, Montana Page 16 6.0 SUMMARY OF FIELD AND LABORATORY STUDIES 6.1 Field Explorations The field exploration program was conducted on May 27, 2021. A total of four borings were drilled to depths ranging from 20.3 to 21.5 feet at the approximate locations shown on Figure 1 to observe subsurface soil and ground water conditions. The borings were advanced through the subsurface soils using a truck-mounted Mobile B-61 drill rig equipped with 4.25-inch I.D. hollowstem augers. The subsurface exploration and sampling methods used are indicated on the attached boring logs. The borings were logged by Mr. Craig Nadeau, PE of TD&H Engineering. The location of the borings as shown on Figure 1 were estimated based on proximity to existing surface features. No survey was performed to verify these locations or to determine surface elevations at the drilling locations. 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, which include soil descriptions, sample depths, and penetration resistance values, are presented on the Figures 2 through 5. Measurements to determine the presence and depth of ground water were made in the borings using a weighted tape measure through the open auger when free water was first observed on drilling equipment and soil samples. The depths or elevations of the water levels measured, if encountered, and the date of measurement are shown on the boring logs. 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. Wildlands Development Summary of Field & Laboratory Studies Bozeman, Montana Page 17 Grain-Size Distribution Particle size distribution of soil constituents describing the percentages of clay/silt, sand and gravel. 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. 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 22 moisture-visual analyses, two sieve (grain-size distribution) analyses, and four Atterberg Limits analyses. The results of the water content analyses are presented on the boring logs, Figures 2 through 5. The grain-size distribution curves and Atterberg limits are presented on Figures 6 through 11. In addition, two consolidation tests, one proctor (moisture-density) test, and one California Bearing Ratio (CBR) test were performed. The results of these tests are shown on Figures 12 through 15. Wildlands Development Limitations Bozeman, Montana Page 18 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 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 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 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. Our geotechnical engineers are available upon request 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. This service was not included in the original scope of the project and will require additional fees for the time required for specification and plan document review and comment. 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. Wildlands Development Limitations Bozeman, Montana Page 19 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 logs and presented in discussions of subsurface conditions included in this report. Prepared by: Reviewed by: Craig Nadeau PE & Principal Peter Klevberg PE Geotechnical Manager Sr. Geotechnical Engineer TD&H ENGINEERING TD&H ENGINEERING WILDLANDS DEVELOPMENT BOZEMAN, MONTANA BORING LOCATION MAP FIGURE 1 VICINITY MAP E PEACH ST. N WALLACE AVE B-1 B-2 B-3 B-4 NOTE: BORING LOCATIONS ARE APPROXIMATE BASED ON PROXIMITY TO EXISTING SURFACE FEATURES. BORING LOCATIONS WERE NOT SURVEYED TO OBTAIN ACCURATE LOCATIONS OR ELEVATIONS. 0 3.25 6.5 9.75 13 16.25 19.5 22.75 ASPHALT Pavement, fair to good condition Poorly-Graded GRAVEL with Sand, relatively dense, light brown, moist, woven geotextile at bottom Lean CLAY, soft, dark brown, moist, high plasticity - Tube Crushed on Gravel Poorly-Graded GRAVEL with Clay and Sand, medium dense to very dense, light brown, slightly moist to wet - Six inches of heave in augers prior to sampling. Bottom of Boring 0.3 1.3 5.6 21.5 3-2-2 PUSH 14-30- 31 10-15- 12 15-18- 24 14-23- 26 20-41- 40 T 61 81 LEGEND LOG OF SOIL BORING B-1SPT blows per foot Atterberg Limits Field Moisture content Wildlands Development Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted Mobile B-61 with 4.25-inch ID 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. May 27, 2021 B21-043-001 No sample recovery Figure No. 2 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Asphalt Pavement SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 1 of 1 0 3.25 6.5 9.75 13 16.25 19.5 22.75 ASPHALT Pavement, fair to good condition Poorly-Graded GRAVEL with Sand, relatively dense, light brown, moist, woven geotextile at bottom Lean CLAY, relatively firm, brown, moist, high plasticity - See Figures 14 and 15 for proctor and CBR test results. Sample contained contamination from overlying base course and does not accurately reflect the properties of the lean clay. - See Figure 12 for consolidation test result. Poorly-Graded GRAVEL with Clay and Sand, dense to very dense, light brown, slightly moist to wet Bottom of Boring - Completed as Monitoring Well - Screened Interval 10.0 - 20.0 ft BGS - Sand 8.5 - 20.0 ft BGS - Bentonite 0.5 - 8.5 ft BGS - Concrete Well Cover 0.0 - 0.5 ft BGS 0.3 1.8 3.8 20.3 BULK PUSH 19-26- 50/2" 31-50/ 6" BULK 29-30- 27 10-17- 24 50/3" G T G 76/8" 50/6" 57 50/3" LEGEND LOG OF SOIL BORING B-2SPT blows per foot Atterberg Limits Field Moisture content Wildlands Development Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted Mobile B-61 with 4.25-inch ID 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. May 27, 2021 B21-043-001 No sample recovery Figure No. 3 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Asphalt Pavement SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 1 of 1 0 3.25 6.5 9.75 13 16.25 19.5 22.75 ASPHALT Pavement, fair to good condition Poorly-Graded GRAVEL with Sand, relatively dense, light brown, moist Lean CLAY, relatively firm, brown, moist - See Figure 13 for consolidation test result. Poorly-Graded GRAVEL with Clay and Sand, very dense, light brown, slightly moist to wet Bottom of Boring 0.3 1.8 3.8 21.3 PUSH 17-25- 34 34-50/ 6" 28-28- 24 17-45- 50/3" 15-33- 50/4" T 59 50/6" 52 95/9" 83/10" LEGEND LOG OF SOIL BORING B-3SPT blows per foot Atterberg Limits Field Moisture content Wildlands Development Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted Mobile B-61 with 4.25-inch ID 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. May 27, 2021 B21-043-001 No sample recovery Figure No. 4 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Asphalt Pavement SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 1 of 1 0 3.25 6.5 9.75 13 16.25 19.5 22.75 ASPHALT Pavement, fair to good condition Poorly-Graded GRAVEL with Sand, relatively dense, light brown, moist Fat CLAY, firm to stiff, brown, moist Poorly-Graded GRAVEL with Clay and Sand, dense to very dense, light brown, slightly moist to wet - No Sample Recovered - Rock Chips Bottom of Boring 0.3 1.8 4.0 20.4 3-4-6 15-36- 41 50/1" 50/2" 13-19- 20 50/5" 51 77 50/1" 50/2" 50/5" LEGEND LOG OF SOIL BORING B-4SPT blows per foot Atterberg Limits Field Moisture content Wildlands Development Bozeman, MontanaGroundwater Level Grab/composite sample 1-3/8-inch I.D. split spoon Logged by:Craig Nadeau, PE 2-1/2-inch I.D. split spoon Drilled by:O'Keefe Drilling Truck-mounted Mobile B-61 with 4.25-inch ID 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. May 27, 2021 B21-043-001 No sample recovery Figure No. 5 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Asphalt Pavement SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSPT BLOWCOUNTSSAMPLEDEPTH (FT)PENETRATION RESISTANCE/MOISTURE CONTENT 0 10 20 30 40 50 = BLOWS PER FOOT = MOISTURE CONTENT 1 of 1 Tested By: TF Checked By: 6-3-2021 6 (no specification provided) PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= * Clayey SAND #4 #10 #20 #40 #60 #80 #100 #200 100.0 86.5 77.3 67.4 60.0 55.4 52.8 45.5 16 31 15 2.5902 1.7650 0.2497 0.1195 SC A-6(3) Report No. A-23414-206 Contains mixed in sand from the overlying base course and does not accurately reflect the lean clay subgrade. Outlaw Real Estate Partners, LLC Wildlands Development Bozeman, Montana B21-043-001 Material Description Atterberg Limits Coefficients Classification Remarks Location: B-2 Sample Number: A-23414 Depth: 2.5 - 3.5 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 13.5 19.1 21.9 45.56 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: TF Checked By: 6-3-2021 7 (no specification provided) PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= * Poorly-Graded GRAVEL with Clay and Sand 2" 1.5" 1" 3/4" 1/2" 3/8" #4 #10 #20 #40 #60 #80 #100 #200 100.0 98.3 91.6 82.7 65.6 53.3 30.7 21.2 16.9 14.1 12.3 11.2 10.5 8.6 16 22 6 23.8904 20.3311 11.1693 8.7631 4.5897 0.5485 0.1288 86.70 14.64 GP-GC A-1-a Report No. A-23417-206 Outlaw Real Estate Partners, LLC Wildlands Development Bozeman, Montana B21-043-001 Material Description Atterberg Limits Coefficients Classification Remarks Location: B-2 Sample Number: A-23417 Depth: 7.5 - 12.5 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 17.3 52.0 9.5 7.1 5.5 8.66 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: MS 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 CONTENT43.5 44 44.5 45 45.5 46 46.5 47 47.5 48 48.5 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: B-1 Sample Number: A-23406 Depth: 2.5 - 4.0 ft Figure Lean CLAY 46 23 23 CL B21-043- Outlaw Real Estate Partners, LLC 8 Report No. A-23406-207 Date: 6-3-2021Wildlands Development Bozeman, Montana Tested By: BS/MS 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 CONTENT30 30.4 30.8 31.2 31.6 32 32.4 32.8 33.2 33.6 34 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: B-2 Sample Number: A-23414 Depth: 2.5 - 3.5 ft Figure Clayey SAND 31 16 15 67.4 45.5 SC B21-043- Outlaw Real Estate Partners, LLC 9 Report No. A-23414-207 Date: 6-4-2021Wildlands Development 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 CONTENT21.4 21.6 21.8 22 22.2 22.4 22.6 22.8 23 23.2 23.4 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: B-2 Sample Number: A-23417 Depth: 7.5 - 12.5 ft Figure Poorly-Graded GRAVEL with Clay and Sand 22 16 6 14.1 8.6 GP-GC B21-043- Outlaw Real Estate Partners, LLC 10 Report No. A-23417-207 Date: 6-4-2021Wildlands Development Bozeman, Montana Tested By: BS 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 CONTENT49.4 49.8 50.2 50.6 51 51.4 51.8 52.2 52.6 53 53.4 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: B-4 Sample Number: A-23427 Depth: 2.5 - 4.0 ft Figure Fat CLAY 51 20 31 CH B21-043- Outlaw Real Estate Partners, LLC 11 Report No. A-23427-207 Date: 6-3-2021Wildlands Development Bozeman, Montana Sat. Moist Project No.B21-043-001 Outlaw Real Estate Partners, LLC Remarks: Project:Wildlands Development Report No. A-23413-219 Bozeman, MT Location:B-2 Sample Depth (ft):2.5 - 3.8 ft 12 Technician :CRN Reviewed By: Client: Figure CONSOLIDATION TEST REPORT AASHTO ----- USCS CL MATERIAL DESCRIPTION Lean CLAY Natural Dry Density (pcf)LL PI Swell (%)eo Sp. Gr. Overburden (psf) Pc (psf)Cc 0.118 0.015 Cs Swell Pressure (psf) 250 1.24 0.79191.1 26.7 93.8 ----- ----- 2.7 350 ~ 2,000 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 100 1000 10000Percent StrainApplied Pressure - psf WATER ADDED Sat. Moist Project No.B21-043-001 Outlaw Real Estate Partners, LLC Remarks: Project:Wildlands Development Report No. A-23421-219 Bozeman, MT Location:B-3 Sample Depth (ft):2.5 - 3.8 ft 13 Technician :CRN Reviewed By: Client: Figure CONSOLIDATION TEST REPORT AASHTO ----- USCS CH MATERIAL DESCRIPTION Fat CLAY Natural Dry Density (pcf)LL PI Swell (%)eo Sp. Gr. Overburden (psf) Pc (psf)Cc 0.072 0.01 Cs Swell Pressure (psf) 250 2.95 0.71391.9 24.3 98.1 ----- ----- 2.7 360 ~ 1,500 -0.50 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 100 1000 10000Percent StrainApplied Pressure - psf WATER ADDED Tested By: TF Checked By: Moisture-Density Test Report Dry density, pcf100 105 110 115 120 125 Water content, % 7 9 11 13 15 17 19 13.6%, 115.5 pcf ZAV for Sp.G. = 2.65 Test specification:ASTM D 698-12 Method A Standard 2.5 - 3.5 ft SC A-6(3) 2.65 31 15 0.0 45.5 Clayey SAND B21-043- Outlaw Real Estate Partners, LLC Report No. A-23414-204 Date: 6-3-2021 14 Elev/ Classification Nat.Sp.G. LL PI % > % < Depth USCS AASHTO Moist.#4 No.200 TEST RESULTS MATERIAL DESCRIPTION Project No. Client:Remarks: Project: Location: B-2 Sample Number: A-23414 Figure Maximum dry density = 115.5 pcf Optimum moisture = 13.6 % Wildlands Development Bozeman, Montana BEARING RATIO TEST REPORT AASHTO T 193-13 Project No: B21-043-001 Project: Wildlands Development Bozeman, Montana Location: B-2 Sample Number: A-23414 Depth: 2.5 - 3.5 ft Date: 6-3-2021 Clayey SAND Test Description/Remarks: ASTM D698 with 6-inch mold 144-hour soak prior to testing Report No. A-23414-210 date: 6-15-2021 Figure 15 115.5 13.6 31 15SC 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 (%) 1 104.5 90.5 13.6 104.1 90.1 17.9 3.8 3.3 0.000 10 0.4 2 112.8 97.7 13.0 112.3 97.2 15.1 6.7 8.0 0.011 10 0.4 3 119.1 103.1 13.3 118.6 102.7 13.2 8.6 8.0 0.000 10 0.4Penetration Resistance (psi)0 70 140 210 280 350 Penetration Depth (in.) 0 0.1 0.2 0.3 0.4 0.5 Swell (%)0 0.1 0.2 0.3 0.4 0.5 Elapsed Time (hrs) 0 24 48 72 96 120 144CBR (%)3 5 7 9 11 Molded Density (pcf) 100 105 110 115 120 125 10 blows 20 blows 64 blows CBR at 95% Max. Density = 5.7% for 0.10 in. Penetration General Project Information Project Number: B21-043-001 Project Title: Wildlands Development Project Description: Climatic Data Source (MERRA) Latitude, Degree: 45.68591 Longitude, Degree: -111.02771 Climatic Data Lowest Yearly Air Temperature, ºC: -31.23 Low Air Temp Standard Deviation, ºC: 5.23 Yearly Degree-Days > 10 Deg. ºC: 1643.75 High Air Temperature of high 7 days: 29.23 Standard Dev. of the high 7 days: 2.05 Low Pavement Temperature 50%: -30.50 Low Pavement Temperature 98%: -39.40 High Avg Pavement Temperature of 7 Days 50%: 51.16 High Avg Pavement Temperature of 7 Days 98%: 55.38 Target Rut Depth Target Rut Depth (mm): 16.5 Temperature Adjustments Depth of Layer, mm: 0 Base HT PG: 52 Traffic Adjustments Traffic loading Cumulative ESAL for the Design Period, Millions: 0.1 Traffic Speed (Fast: >70 km/h, Slow: 20-70 km/h, Standing: < 20 km/h): Standing Performance Grade AASHTO M323-13 Performance-Graded Asphalt Binder PG Temperature High Low Performance Grade Temperature at 50% Reliability 35.6 -23.6 Performance Grade Temperature at 98% Reliability 39.5 -32.5 Adjustment for Traffic (AASHTO M323-13)2.8 Adjustment for Depth 0.0 -0.0 Adjusted Performance Grade Temperature 42.3 -32.5 Selected PG Grade 52 -34 PG Grade M323, PG 52-34 AASHTO M 332-14 Performance-Grade Asphalt Binder using Multiple Stress Creep Recovery (MSCR) Test PG Temperature High Low Performance Grade Temperature at 50% Reliability 35.6 -23.6 Performance Grade Temperature at 98% Reliability 39.5 -32.5 Designation for traffic loading V Selected PG Grade 46 -34 PG Grade M332, PG 46V-34 Temperature Report Lowest Yearly Air Temperature, ºC:-31.23 Low Air Temp Standard Deviation, ºC:5.23 Yearly Degree-Days > 10 Deg. ºC:1643.75 High Air Temperature of high 7 days:29.23 Standard Dev. of the high 7 days:2.05 Low Pavement Temperature 50%:-30.50 Low Pavement Temperature 98%:-39.40 High Avg Pavement Temperature of 7 Days 50%:51.16 High Avg Pavement Temperature of 7 Days 98%:55.38 QUALITY CHECK: DESIGNED BY: DRAWN BY: CAD NO. JOB NO. DATE: 02801-06C Engineering tdhengineering.com CONSTRUCTION STANDARD NO. 02801-06C PERIMETER FOUNDATION DRAIN RESIDENTIAL CONSTRUCTION RLT CRN MMJ 5/21/15 FIGURE TD&H Engineering Consultants Great Falls, Kalispell, Bozeman, MT Spokane, WA; Lewiston, ID, Watford City, ND TD&H Engineering Consultants Great Falls, Kalispell, Bozeman, MT Spokane, WA; Lewiston, ID, Watford City, ND APPENDIX F Surface Improvements O & M Manual WILDLANDS DEVELOPMENT – STORMWATER DESIGN REPORT Project No. 21019 September 17, 2021 Project No. 21019 STORM DRAINAGE FACILITY MAINTENANCE PLAN FOR WILDLANDS DEVELOPMENT, LOTS 24-32, BLOCK 106, PLAT C-23 BOZEMAN, MONTANA 59715 OVERVIEW NARRATIVE The purpose of this maintenance plan is to outline the necessary details related to ownership, responsibility and cleaning schedule for the storm drainage facilities for Wildlands. This plan has been completed in accordance with The City of Bozeman Design Standards and Specifications Policy, dated March 2004. The site stormwater improvements have been designed with the intent to meet the current City of Bozeman drainage regulations for the entire site to the extent feasible. Specific site information and criteria are described below: I. Ownership of Facilities Wildlands Development Wildlands Development will own all stormwater facilities which includes the storm chambers, inlets, and piping within the site boundary. II. Inspection Thresholds for Cleaning Infiltration Chamber If sediment in the Isolator Row exceeds 3 inches or grate is more than 25% clogged with debris, clean grate and/or structure and vacuum Isolator Row. Structures Inspect structures and inlet grates for debris and sediment. III. Cleaning Infiltration Chamber To clean grate of structure, remove and dispose of debris clogging the grate. To clean structure, use catch basin vacuum to remove sediment and debris. To clean Isolator Row use JetVac. P:21019_Wildlands 2 (09/17/21) CS/TPR Structures Remove trash, obstructions, debris, sediment and vegetation to prevent clogging of the grate or pipes. Clean out if sediment fills 60% of sump or comes within 6-inches of a pipe. IV. Schedule Infiltration Chamber Inspection: Every 6 months or after a storm event larger than 0.5-inches of precipitation. Vacuum Isolator Row: Every 5 years or as needed based on inspection. Structures Inspection: Every 6 months or after a storm event larger than 0.5-inches of precipitation. V. Responsible Party Wildlands Development Wildlands Development will be responsible for the inspection and maintenance of all stormwater facilities located within the project limits. I agree to the above operation, maintenance and replacement schedule detailed above. Signature: __________________________________________ Wildlands Development Representative APPENDIX G Pre & Post Development Roof Drainage Exhibit WILDLANDS DEVELOPMENT – STORMWATER DESIGN REPORT Project No. 21019