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PZ - Geotechnical Engineering ReportMATERIALS TESTING S INSPECTION AN ATLAS COMPANY Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GEOTECHNICAL ENGINEERING REPORT of Vogel Property 3610 North Linder Road Meridian, ID Prepared for: CI7 Development 4824 West Fairview Avenue Boise, ID 83706 MTI File Number B190770g 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mtiAmti-id.com MATERIALS TESTING S INSPECTION AN ATLAS COMPANY 14 May 2019 Page # 1 of 27 b190770g_geotech ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Mr. Laren Bailey C17 Development 4824 West Fairview Avenue Boise, ID 83706 (208) 366-5355 Re: Geotechnical Engineering Report Vogel Property 3610 North Linder Road Meridian, ID Dear Mr. Bailey: In compliance with your instructions, MTI has conducted a soils exploration and foundation evaluation for the above referenced development. Fieldwork for this investigation was conducted on 30 April 2019. Data have been analyzed to evaluate pertinent geotechnical conditions. Results of this investigation, together with our recommendations, are to be found in the following report. We have provided a PDF copy for your review and distribution. Often, questions arise concerning soil conditions because of design and construction details that occur on a project. MTI would be pleased to continue our role as geotechnical engineers during project implementation. Additionally, MTI can provide materials testing and special inspection services during construction of this project. If you will advise us of the appropriate time to discuss these engineering services, we will meet with you at your convenience. MTI appreciates this opportunity to be of service to you and looks forward to working with you in the future. If you have questions, please call (208) 376-4748. o�SS�O NA L FNc Respectfully Submitted, \cENs Materials Testing & Inspection Q 14898 5/14/2019 Maren Tanberg, E.I.T., G.I.T. Reviewed by: Elizabeth Brown, P.E. ET VA Staff Engineer and Geologist Geotechnical Services Manager 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mti(o)mti-id.com Copyrightm g&Inspection Testing MATERIALS TESTING & INSPECTION 14 May 2019 Page # 2 of 27 b190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing Ll Special Inspections TABLE OF CONTENTS INTRODUCTION...............................................................................................................................................................3 ProjectDescription.................................................................................................................................................3 Authorization..........................................................................................................................................................3 Purpose...................................................................................................................................................................3 Scopeof Investigation............................................................................................................................................3 Warrantyand Limiting Conditions.........................................................................................................................4 SITEDESCRIPTION..........................................................................................................................................................5 SiteAccess..............................................................................................................................................................5 RegionalGeology...................................................................................................................................................5 GeneralSite Characteristics....................................................................................................................................6 Regional Site Climatology and Geochemistry........................................................................................................ SEISMICSITE EVALUATION............................................................................................................................................6 GeoseismicSetting.................................................................................................................................................6 SeismicDesign Parameter Values..........................................................................................................................6 SOILSEXPLORATION......................................................................................................................................................7 Explorationand Sampling Procedures....................................................................................................................7 LaboratoryTesting Program...................................................................................................................................8 Soiland Sediment Profile.......................................................................................................................................8 VolatileOrganic Scan.............................................................................................................................................8 SITEHYDROLOGY...........................................................................................................................................................8 Groundwater...........................................................................................................................................................9 SoilInfiltration Rates..............................................................................................................................................9 FOUNDATION, SLAB, AND PAVEMENT DISCUSSION AND RECOMMENDATIONS ...............................................................9 FoundationDesign Recommendations.................................................................................................................10 CrawlSpace Recommendations...........................................................................................................................11 Floor, Patio, and Garage Slab-on-Grade...............................................................................................................1 l RecommendedPavement Sections.......................................................................................................................12 FlexiblePavement Section...................................................................................................................................12 PavementSubgrade Preparation...........................................................................................................................13 Common Pavement Section Construction Issues.................................................................................................13 CONSTRUCTIONCONSIDERATIONS...............................................................................................................................13 Earthwork.............................................................................................................................................................13 DryWeather.........................................................................................................................................................14 WetWeather.........................................................................................................................................................14 SoftSubgrade Soils..............................................................................................................................................14 FrozenSubgrade Soils..........................................................................................................................................15 StructuralFill........................................................................................................................................................15 Backfillof Walls...................................................................................................................................................16 Excavations...........................................................................................................................................................17 GroundwaterControl............................................................................................................................................17 GENERALCOMMENTS..................................................................................................................................................17 REFERENCES.................................................................................................................................................................18 APPENDICES.................................................................................................................................................................19 AcronymList........................................................................................................................................................19 GeotechnicalGeneral Notes.................................................................................................................................20 Geotechnical Investigation Test Pit Log...............................................................................................................21 Gravel Equivalent Method — Pavement Thickness Design Procedures................................................................24 R -Value Laboratory Test Data..............................................................................................................................25 Plate1: Vicinity Map............................................................................................................................................26 Plate2: Site Map...................................................................................................................................................27 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mti(a)mti-id.com Copyright®2019 spedi is Testlng &Inspection MATERIALS 14 May 2019 TESTING Fr Page # 3 of 27 INSPECTION b190770g_geotecb AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections INTRODUCTION This report presents results of a geotechnical investigation and analysis in support of data utilized in design of structures as defined in the 2015 International Building Code (IBC). Information in support of groundwater and stormwater issues pertinent to the practice of Civil Engineering is included. Observations and recommendations relevant to the earthwork phase of the project are also presented. Revisions in plans or drawings for the proposed development from those enumerated in this report should be brought to the attention of the soils engineer to determine whether changes in the provided recommendations are required. Deviations from noted subsurface conditions, if encountered during construction, should also be brought to the attention of the soils engineer. Project Description The proposed development is in the northern portion of the City of Meridian, Ada County, ID, and occupies a portion of the SW'/4SW1/4 of Section 36, Township 4 North, Range 1 West, Boise Meridian. This project will consist of the development of approximately 13.5 acres of agricultural land into a residential subdivision. Total settlements are limited to 1 inch. Loads of up to 4,000 pounds per lineal foot for wall footings, and column loads of up to 50,000 pounds were assumed for settlement calculations. Additionally, assumptions have been made for traffic loading of pavements. Retaining walls are not anticipated as part of the project. MTI has not been informed of the proposed grading plan. Authorization Authorization to perform this exploration and analysis was given in the form of a written authorization to proceed from Mr. Laren Bailey of C17 Development to Maren Tanberg of Materials Testing and Inspection (MTI), on 23 April 2019. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between C 17 Development and MTI. Our scope of services for the proposed development has been provided in our proposal dated 18 April 2019 and repeated below. Purpose The purpose of this Geotechnical Engineering Report is to determine various soil profile components and their engineering characteristics for use by either design engineers or architects in: • Preparing or verifying suitability of foundation design and placement • Preparing site drainage designs • Indicating issues pertaining to earthwork construction • Preparing residential pavement section design requirements Scope of Investigation The scope of this investigation included review of geologic literature and existing available geotechnical studies of the area, visual site reconnaissance of the immediate site, subsurface exploration of the site, field and laboratory testing of materials collected, and engineering analysis and evaluation of foundation materials. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 als www.mti-id.com • mtiOmti-id.com Copy fight®g&I Inspection Testing &Inspection MATERIALS 14 May 2019 Page # 4 of 27 TESTING INSPECTION b190770g_geotecb AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Warranty and Limiting Conditions MTI warrants that findings and conclusions contained herein have been formulated in accordance with generally accepted professional engineering practice in the fields of foundation engineering, soil mechanics, and engineering geology only for the site and project described in this report. These engineering methods have been developed to provide the client with information regarding apparent or potential engineering conditions relating to the site within the scope cited above and are necessarily limited to conditions observed at the time of the site visit and research. Field observations and research reported herein are considered sufficient in detail and scope to form a reasonable basis for the purposes cited above. Exclusive Use This report was prepared for exclusive use of the property owner(s), at the time of the report, and their retained design consultants ("Client"). Conclusions and recommendations presented in this report are based on the agreed-upon scope of work outlined in this report together with the Contract for Professional Services between the Client and Materials Testing and Inspection ("Consultant"). Use or misuse of this report, or reliance upon findings hereof, by parties other than the Client is at their own risk. Neither Client nor Consultant make representation of warranty to such other parties as to accuracy or completeness of this report or suitability of its use by such other parties for purposes whatsoever, known or unknown, to Client or Consultant. Neither Client nor Consultant shall have liability to indemnify or hold harmless third parties for losses incurred by actual or purported use or misuse of this report. No other warranties are implied or expressed. Report Recommendations are Limited and Subiect to Misinterpretation There is a distinct possibility that conditions may exist that could not be identified within the scope of the investigation or that were not apparent during our site investigation. Findings of this report are limited to data collected from noted explorations advanced and do not account for unidentified fill zones, unsuitable soil types or conditions, and variability in soil moisture and groundwater conditions. To avoid possible misinterpretations of findings, conclusions, and implications of this report, MTI should be retained to explain the report contents to other design professionals as well as construction professionals. Since actual subsurface conditions on the site can only be verified by earthwork, note that construction recommendations are based on general assumptions from selective observations and selective field exploratory sampling. Upon commencement of construction, such conditions may be identified that require corrective actions, and these required corrective actions may impact the project budget. Therefore, construction recommendations in this report should be considered preliminary, and MTI should be retained to observe actual subsurface conditions during earthwork construction activities to provide additional construction recommendations as needed. Since geotechnical reports are subject to misinterpretation, do not separate the soil logs from the report. Rather, provide a copy of, or authorize for their use, the complete report to other design professionals or contractors. Locations of exploratory sites referenced within this report should be considered approximate locations only. For more accurate locations, services of a professional land surveyor are recommended. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 Copyright ®2019 Materials w ww.mti-id.com • mflAwIti-id.com Testing 8Inspection MATERIALS TESTING & INSPECTION 14 May 2019 Page # 5 of 27 b 190770g_geotech AN ATLAS COMPANY El Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections This report is also limited to information available at the time it was prepared. In the event additional information is provided to MTI following publication of our report, it will be forwarded to the client for evaluation in the form received. Environmental Concerns Comments in this report concerning either onsite conditions or observations, including soil appearances and odors, are provided as general information. These comments are not intended to describe, quantify, or evaluate environmental concerns or situations. Since personnel, skills, procedures, standards, and equipment differ, a geotechnical investigation report is not intended to substitute for a geoenvironmental investigation or a Phase II/III Environmental Site Assessment. If environmental services are needed, MTI can provide, via a separate contract, those personnel who are trained to investigate and delineate soil and water contamination. SITE DESCRIPTION Site Access Access to the site may be gained via Interstate 84 to the Ten Mile Road exit. Proceed north on Ten Mile Road approximately 2.8 miles to its intersection with Ustick Road. From this intersection, proceed east 1.0 mile to Linder Road. Drive north on Linder Road for 0.21 mile. The site is east of Linder Road. Presently the site exists as a residence with various outbuildings and an agricultural field. The location is depicted on site map plates included in the Appendix. Regional Geology The project site is located within the western Snake River Plain of southwestern Idaho and eastern Oregon. The plain is a northwest trending rift basin, about 45 miles wide and 200 miles long, that developed about 14 million years ago (Ma) and has since been occupied sporadically by large inland lakes. Geologic materials found within and along the plain's margins reflect volcanic and fluvial/lacustrine sedimentary processes that have led to an accumulation of approximately 1 to 2 km of interbedded volcanic and sedimentary deposits within the plain. Along the margins of the plain, streams that drained the highlands to the north and south provided coarse to fine-grained sediments eroded from granitic and volcanic rocks, respectively. About 2 million years ago the last of the lakes was drained and since that time fluvial erosion and deposition has dominated the evolution of the landscape. The project site is underlain by the "Gravel of Whitney Terrace" as mapped by Othberg and Stanford (1993). Sediments of the Whitney terrace consist of sandy pebble and cobble gravel. The Whitney terrace is the second terrace above modern Boise River floodplain, is thickest toward its eastern extent, and is mantled with 2-6 feet of loess. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mtKi)mti-id.com Copynght02019 Testing 8lnspectispection MATERIALS TESTING 6 INSPECTION 14 May 2019 Page # 6 of 27 b190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections General Site Characteristics This proposed development consists of approximately 13.5 acres of relatively flat terrain. A residence with various outbuildings is located in the northern portion of the site. The rest of the site consists of an agricultural field. Throughout the majority of the site, surficial soils consist of fat clays. Vegetation primarily consists of mature trees around the existing residence and remnant agricultural crops, bunchgrass, and other native grass varieties typical of and to semi -arid environments throughout the remainder of the site. Regional drainage is north and west toward the Boise River. Stormwater drainage for the site is achieved by percolation through surficial soils. The site is situated so that it is unlikely that it will receive any stormwater drainage from off-site sources. Stormwater drainage collection and retention systems are not in place on the project site and do not currently exist within the vicinity of the project site. Regional Site Climatology and Geochemistry According to the Western Regional Climate Center, the average precipitation for the Treasure Valley is on the order of 10 to 12 inches per year, with an annual snowfall of approximately 20 inches and a range from 3 to 49 inches. The monthly mean daily temperatures range from 21'F to 95°F, with daily extremes ranging from - 25°F to 111°F. Winds are generally from the northwest or southeast with an annual average wind speed of approximately 9 miles per hour (mph) and a maximum of 62 mph. Soils and sediments in the area are primarily derived from siliceous materials and exhibit low electro -chemical potential for corrosion of metals or concretes. Local aggregates are generally appropriate for Portland cement and lime cement mixtures. Surface water, groundwater, and soils in the region typically have pH levels ranging from 7.2 to 8.2. SEISMIC SITE EVALUATION Geoseismic Setting Soils on site are classed as Site Class D in accordance with Chapter 20 of the American Society of Civil Engineers (ASCE) publication ASCE/SEI 7-10. Structures constructed on this site should be designed per IBC requirements for such a seismic classification. Our investigation did not reveal hazards resulting from potential earthquake motions including: slope instability, liquefaction, and surface rupture caused by faulting or lateral spreading. Incidence and anticipated acceleration of seismic activity in the area is low. Seismic Design Parameter Values The United States Geological Survey National Seismic Hazard Maps (2008), includes a peak ground acceleration map. The map for 2% probability of exceedance in 50 years in the Western United States in standard gravity (g) indicates that a peak ground acceleration of 0.199 is appropriate for the project site based on a Site Class D. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 CopyA9ht ®2019 Materials www.mti-id.com • mtifaZmti-id.com Testing & Inspection MATERIALS —TESTING £s INSPECTION 14 May 2019 Page # 7 of 27 b190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections The following section provides an assessment of the earthquake -induced earthquake loads for the site based on the Risk -Targeted Maximum Considered Earthquake (MCER). The MCER spectral response acceleration for short periods, S,us, and at 1 -second period, SMI, are adjusted for site class effects as required by the 2015 IBC. Design spectral response acceleration parameters as presented in the 2015 IBC are defined as a 5% damped design spectral response acceleration at short periods, SDs, and at 1 -second period, SDI. The USGS National Seismic Hazards Mapping Project includes a program that provides values for ground motion at a selected site based on the same data that were used to prepare the USGS ground motion maps. The maps were developed using attenuation relationships for soft rock sites; the source model, assumptions, and empirical relationships used in preparation of the maps are described in Petersen and others (1996). Seismic Desien Values Seismic Design Parameter Design Value Site Class D "Stiff Soil" SS 0.293 (g) Si 0.103 (g) Fa 1.566 F'v 2.388 Sms 0.458 SM1 0.429 SDs 0.306 SDI 0.164 SOILS EXPLORATION Exploration and Sampling Procedures Field exploration conducted to determine engineering characteristics of subsurface materials included a reconnaissance of the project site and investigation by test pit. Test pit sites were selected by C 17 Development and provided to MTI via a site map. The test pits were located in the field by means of a Global Positioning System (GPS) device and are reportedly accurate to within fifteen feet. Upon completion of investigation, each test pit was backfilled with loose excavated materials. Re -excavation and compaction of these test pit areas are required prior to construction of overlying structures. In addition, samples were obtained from representative soil strata encountered. Samples obtained have been visually classified in the field by professional staff, identified according to test pit number and depth, placed in sealed containers, and transported to our laboratory for additional testing. Subsurface materials have been described in detail on logs provided in the Appendix. Results of field and laboratory tests are also presented in the Appendix. MTI recommends that these logs not be used to estimate fill material quantities. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mti(6amti-id.com Copyright®Tesgng&I2019 Materials lnspecgon MATERIALS 14 May 2019 TESTING £r Page # 8 of 27 INSPECTION b190770g_geoteeh AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Laboratory Testing Program Along with our field investigation, a supplemental laboratory testing program was conducted to determine additional pertinent engineering characteristics of subsurface materials necessary in an analysis of anticipated behavior of the proposed structures. Laboratory tests were conducted in accordance with current applicable American Society for Testing and Materials (ASTM) specifications, and results of these tests are to be found on the accompanying logs located in the Appendix. The laboratory testing program for this report included: Atterberg Limits Testing—ASTM D4318, Grain Size Analysis —ASTM C117/C136, and Resistance Value (R - value) and Expansion Pressure of Compacted Soils — Idaho T-8. Soil and Sediment Profile The profile below represents a generalized interpretation for the project site. Note that on site soils strata, encountered between test pit locations, may vary from the individual soil profiles presented in the logs, which can be found in the Appendix. The materials encountered during exploration were quite typical for the geologic area mapped as Gravel of Whitney Terrace. At ground surface, fat clay was noted. The fat clay was brown, slightly moist to moist, stiff to very stiff. Organics were noted to depths up to 3 feet bgs. Underlying the fat clay was silty clay with sand. Silty clays with sand were brown, slightly moist to wet, medium stiff to stiff, and contained fine to medium - grained sand. At depth, poorly graded gravel with silt and sand was noted. The poorly graded gravel with silt and sand was brown, dry to saturated, medium dense to very dense, and contained fine to coarse-grained sand, fine to coarse gravel, and 10 -inch -minus cobbles. Competency of test pit sidewalls varied little across the site. In general, fine grained soils remained stable while more granular sediments readily sloughed. However, moisture contents will also affect wall competency with saturated soils having a tendency to readily slough when under load and unsupported. Volatile Organic Scan No environmental concerns were identified prior to commencement of the investigation. Therefore, soils obtained during on-site activities were not assessed for volatile organic compounds by portable photoionization detector. Samples obtained during our exploration activities exhibited no odors or discoloration typically associated with this type of contamination. Groundwater encountered did not exhibit obvious signs of contamination. SITE HYDROLOGY Existing surface drainage conditions are defined in the General Site Characteristics section. Information provided in this section is limited to observations made at the time of the investigation. Either regional or local ordinances may require information beyond the scope of this report. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 aterials www.mti-id.com • mti(C7mm ti-id.coCopyright02019 Testing &Inspeedosspection MATERIALS TESTING & INSPECTION 14 May 2019 Page # 9 of 27 b190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Groundwater During this field investigation, groundwater was encountered in test pits at depths ranging from 6.9 to 8.7 feet bgs. Soil moistures in the test pits were generally dry to moist within surficial soils. Within the poorly graded gravels with silt and sand, soil moistures graded from dry to saturated as the water table was approached and penetrated. In the vicinity of the project site, groundwater levels are controlled in large part by residential and agricultural irrigation activity and leakage from nearby canals. Maximum groundwater elevations likely occur during the later portion of the irrigation season. During previous investigations performed in January 2006 and July 2015 within approximately 1/4 -mile to the east and southeast of the project site, groundwater was encountered in test pits at depths ranging from 3.5 to 7.9 feet bgs. Long term groundwater monitoring performed by MTI for these sites revealed groundwater depths ranging between 3.0 and 6.7 feet bgs throughout the year. For construction purposes groundwater depth can be assumed to remain greater than 3.0 feet bgs throughout the year. Since this is an estimated depth and seasonal groundwater levels fluctuate actual levels should be confirmed by periodic groundwater data collected from piezometers installed in the test pits. If desired, MTI is available to perform this monitoring. Soil Infiltration Rates Soil permeability, which is a measure of the ability of a soil to transmit a fluid, was not tested in the field. Given the absence of direct measurements, for this report an estimation of infiltration is presented using generally recognized values for each soil type and gradation. Of soils comprising the generalized soil profile for this study, fat clay and silty clay with sand soils generally offer little permeability, with typical hydraulic infiltration rates of less than 2 inches per hour. Poorly graded gravel with silt and sand sediments typically exhibit infiltration of 8 to 12 inches per hour. Due to shallow groundwater and heavy irrigation influences, MTI recommends infiltration testing to determine site-specific infiltration rates for drainage design once proposed locations of infiltration facilities are determined. FOUNDATION, SLAB, AND PAVEMENT DISCUSSION AND RECOMMENDATIONS Various foundation types have been considered for support of the proposed development. Two requirements must be met in the design of foundations. First, the applied bearing stress must be less than the ultimate bearing capacity of foundation soils to maintain stability. Second, total and differential settlement must not exceed an amount that will produce an adverse behavior of the superstructure. Allowable settlement is usually exceeded before bearing capacity considerations become important; thus, allowable bearing pressure is normally controlled by settlement considerations. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 Copyright ®2019 Materials www.mti-id.com • mtiti)mti-ld.com Tesgng&Inspecgon MATERIALS TESTING 6 � INSPECTION AN ATLAS COMPANY 14 May 2019 Page # 10 of 27 b190770g_geotech ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Considering subsurface conditions and the proposed construction, it is recommended that the development be founded upon conventional spread footings and continuous wall footings. Total settlements should not exceed 1 inch if the following design and construction recommendations are observed. Presently, there are an unknown number of lots proposed for the project site. The following recommendations are not specific to the individual structures but rather should be viewed as guidelines for the subdivision — wide development. Foundation Design Recommendations Based on data obtained from the site and test results from various laboratory tests performed, MTI recommends the following guidelines for the net allowable soil bearing capacity: Soil Bearin2 Capacity Footing Depth FSub ASTM D1557 rade Com action Net Allowable Soil Bearing Capacity Footings must bear on competent, undisturbed, 1,500 lbs/ft2 native silty clay with sand soils or compacted Not Required for Native structural fill. Existing fat clay soils and organic Soil , A /3 increase is allowable materials must be completely removed from below for short-term loading, foundation elements.' Excavation depths ranging 95% for Structural Fill which is defined by seismic from roughly 1.3 to 3.0 feet bgs should be events or designed wind anticipated to expose proper bearing soils.2 speeds. 'It will be required for MTI personnel to verify the bearing soil suitability for each structure at the time of construction. 'Depending on the time of year construction takes place the subgrade soils may be unstable because of high moisture contents If unstable conditions are encountered over -excavation and replacement with granular structural fill and/or use of geotextiles may be required. The following sliding frictional coefficient values should be used: 1) 0.35 for footings bearing on native silty clay with sand soils and 2) 0.45 for footings bearing on granular structural fill. A passive lateral earth pressure of 297 pounds per square foot per foot (psf/ft) should be used for silty clay soils. For compacted sandy gravel fill, a passive lateral earth pressure of 496 psf/ft should be used. Footings should be proportioned to meet either the stated soil bearing capacity or the 2015 IBC minimum requirements. Total settlement should be limited to approximately 1 inch, and differential settlement should be limited to approximately %2 inch. Objectionable soil types encountered at the bottom of footing excavations should be removed and replaced with structural fill. Excessively loose or soft areas that are encountered in the footings subgrade will require over -excavation and backfilling with structural fill. To minimize the effects of slight differential movement that may occur because of variations in the character of supporting soils and seasonal moisture content, MTI recommends continuous footings be suitably reinforced to make them as rigid as possible. For frost protection, the bottom of external footings should be 24 inches below finished grade. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 Copyright ®2079 Materials www.mti-id.com • mtiOrriti-id.com Testing Mnspedon J1 CMATERIALS TESTING & INSPECTION AN ATLAS COMPANY 14 May 2019 Page # 11 of 27 b 190770g_geotech ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Crawl Space Recommendations Considering the presence of shallow groundwater across the site, all residences constructed with crawl spaces should be designed in a manner that will inhibit water in the crawl spaces. Bottom of crawl spaces must be elevated at least 2 feet above seasonal high groundwater elevation. MTI recommends that roof drains carry stormwater at least 10 feet away from each residence. Grades should be at least 5 percent for a distance of 10 feet away from all residences. In addition, rain gutters should be placed around all sides of residences, and backfill around stem walls should be placed and compacted in a controlled manner. Floor, Patio, and Garage Slab -on -Grade Native clay soils are moderately plastic and will be susceptible to shrink/swell movements associated with moisture changes. Areas of the site within the proposed structures should be excavated to sufficient depths to expose clay soils. The clay soils should be scarified to a depth of 6 inches and compacted between 92 to 98 percent of the maximum dry density as determined by ASTM D698. The moisture content should be within 2 percent of optimum. Structural fill should be placed as soon as possible after compaction of clay soils in order to limit moisture loss within the upper clays. Ground surfaces should be sloped away from structures at a minimum of 5 percent for a distance of 10 feet to provide positive drainage of surface water away from buildings. Grading must be provided and maintained following construction. Organic, loose, or obviously compressive materials must be removed prior to placement of concrete floors or floor -supporting fill. In addition, the remaining subgrade should be treated in accordance with guidelines presented in the Earthwork section. Areas of excessive yielding should be excavated and backfilled with structural fill. Fill used to increase the elevation of the floor slab should meet requirements detailed in the Structural Fill section. Fill materials must be compacted to a minimum 95 percent of the maximum dry density as determined by ASTM D1557. A free -draining granular mat (drainage fill course) should be provided below slabs -on -grade. This should be a minimum of 4 inches in thickness and properly compacted. The mat should consist of a sand and gravel mixture, complying with Idaho Standards for Public Works Construction (ISPWC) specifications for 3/4 -inch (Type 1) crushed aggregate. The granular mat should be compacted to no less than 95 percent of the maximum dry density as determined by ASTM D1557. A moisture -retarder should be placed beneath floor slabs to minimize potential ground moisture effects on moisture -sensitive floor coverings. The moisture -retarder should be at least 15 -mil in thickness and have a permeance of less than 0.01 US perms as determined by ASTM E96. Placement of the moisture -retarder will require special consideration with regard to effects on the slab -on -grade and should adhere to recommendations outlined in the ACI 302.1R and ASTM E1745 publications. Upon request, MTI can provide further consultation regarding installation. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 Copyright ®2079 Materials www.mti-id.com • mtaZm titi-id.com Testing alnspection MATERIALS TESTING & INSPECTION AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Enginee Recommended Pavement Sections ❑ Construction Materials Testi 14 May 2019 Page # 12 of 27 b 190770g_geotech ❑ Special Inspections As required by Ada County Highway District (ACHD), MTI has used a traffic index of 6 to determine the necessary pavement cross-section for the site. MTI has made assumptions for traffic loading variables based on the character of the proposed construction. The Client should review these assumptions to make sure they reflect intended use and loading of pavements both now and in the future. MTI collected a sample of near - surface soils for Resistance Value (R -value) testing representative of soils to depths of 3.0 feet below existing ground surface. This sample, consisting of fat clay collected from test pit 2, yielded an R -value of less than 5. A R -value of 4 was used for design calculations. The following are minimum thickness requirements for assured pavement function. Depending on site conditions, additional work, e.g. soil preparation, may be required to support construction equipment. These have been listed within the Soft Subgrade Soils section. Results of the test are graphically depicted in the Appendix. Flexible Pavement Section The Gravel Equivalent Method, as defined in Section 500 of the State of Idaho Department of Transportation (ITD) Materials Manual, was used to develop the pavement section. ACHD parameters for traffic index and substitution ratios, which were obtained from the ACHD Policy Manual, were also used in the design. A calculation sheet provided in the Appendix indicate the soils constant, traffic loading, traffic projections, and material constants used to calculate the pavement section. MTI recommends that materials used in the construction of asphaltic concrete pavements meet the requirements of the ISPWC Standard Specification for Highway Construction. Construction of the pavement section should be in accordance with these specifications and should adhere to guidelines recommended in the section on Construction Considerations. (Travel Eauivalent Method Flexible Pavement Specifications Pavement Section Component' Roadway Section Asphaltic Concrete 2.5 Inches Crushed Aggregate Base 4.0 Inches Structural Subbase 14.0 Inches Compacted Subgrade See Pavement Subgrade Preparation Section 1It will be required for MTI personnel to verify subgrade competency at the time of construction. Asphaltic Concrete: Asphalt mix design shall meet the requirements of ISPWC, Section 810 Class III plant mix. Materials shall be placed in accordance with ISPWC Standard Specifications for Highway Construction. Aggregate Base: Material complying with ISPWC Standards for Crushed Aggregate Materials. Structural Subbase: Material complying with requirements for granular structural fill (uncrushed) as defined in ISPWC. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 Copyright ®2019 Materials www.mti-id.com • mOntiti-id.com Testing &Inspection MATERIALS 14 May 2019 _ TESTING &Page # 13 of 27 INSPECTION b190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Pavement Subgrade Preparation Native clay soils are moderately plastic and will be susceptible to shrink/swell movements associated with moisture changes. Areas of the site within the proposed pavement sections should be excavated to sufficient depths to expose clay soils. The clay soils should be scarified to a depth of 6 inches and compacted between 92 to 98 percent of the maximum dry density as determined by ASTM D698. The moisture content should be within 2 percent of optimum. Structural fill should be placed as soon as possible after compaction of clay soils in order to limit moisture loss within the upper clays. Common Pavement Section Construction Issues The subgrade upon which above pavement sections are to be constructed must be properly stripped, inspected, and proof -rolled. Proof rolling of subgrade soils should be accomplished using a heavy rubber -tired, fully loaded, tandem -axle dump truck or equivalent. Verification of subgrade competence by MTI personnel at the time of construction is required. Fill materials on the site must demonstrate the indicated compaction prior to placing material in support of the pavement section. MTI anticipated that pavement areas will be subjected to moderate traffic. Subgrade clays near and above optimum moisture contents may pump during compaction. Pumping or soft areas must be removed and replaced with structural fill. Fill material and aggregates, in support of the pavement section must be compacted to no less than 95 percent of the maximum dry density as determined by ASTM D698 for flexible pavements and by ASTM D1557 for rigid pavements. If a material placed as a pavement section component cannot be tested by usual compaction testing methods, then compaction of that material must be approved by observed proof rolling. Minor deflections from proof rolling for flexible pavements are allowable. Deflections from proof rolling of rigid pavement support courses should not be visually detectable. CONSTRUCTION CONSIDERATIONS Recommendations in this report are based upon structural elements of the project being founded on competent, native silty clay with sand soils or compacted structural fill. Structural areas should be stripped to an elevation that exposes these soil types. Earthwork Excessively organic soils, deleterious materials, or disturbed soils generally undergo high volume changes when subjected to loads, which is detrimental to subgrade behavior in the area of pavements, floor slabs, structural fills, and foundations. Agricultural crop remnants, mature trees, brush, and thick grasses with associated root systems were noted at the time of our investigation. It is recommended that organic or disturbed soils, if encountered, be removed, and wasted or stockpiled for later use. However, in areas where trees are/were present, deeper excavation depths should be anticipated. Stripping depths should be adjusted in the field to assure that the entire root zone or disturbed zone or topsoil are removed prior to placement and compaction of structural fill materials. Exact removal depths should be determined during grading operations by MTI personnel, and should be based upon subgrade soil type, composition, and firmness or soil stability. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mti(Wmti-id.com Copyright Testing ng W19 Materiels $ Inspecflon MATERIALS TESTING & INSPECTION AN ATLAS COMPANY 14 May 2019 Page # 14 of 27 b 190770g_geotech ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections If underground storage tanks, underground utilities, wells, or septic systems are discovered during construction activities, they must be decommissioned then removed or abandoned in accordance with governing Federal, State, and local agencies. Excavations developed as the result of such removal must be backfilled with structural fill materials as defined in the Structural Fill section. MTI should oversee subgrade conditions (i.e., moisture content) as well as placement and compaction of new fill (if required) after native soils are excavated to design grade. Recommendations for structural fill presented in this report can be used to minimize volume changes and differential settlements that are detrimental to the behavior of footings, pavements, and floor slabs. Sufficient density tests should be performed to properly monitor compaction. For structural fill beneath building structures, one in-place density test per lift for every 5,000 square feet is recommended. In parking and driveway areas, this can be decreased to one test per lift for every 10,000 square feet. Dry Weather If construction is to be conducted during dry seasonal conditions, many problems associated with soft soils may be avoided. However, some rutting of subgrade soils may be induced by shallow groundwater conditions related to springtime runoff or irrigation activities during late summer through early fall. Solutions to problems associated with soft subgrade soils are outlined in the Soft Subgrade Soils section. Problems may also arise because of lack of moisture in native and fill soils at time of placement. This will require the addition of water to achieve near -optimum moisture levels. Low -cohesion soils exposed in excavations may become friable, increasing chances of sloughing or caving. Measures to control excessive dust should be considered as part of the overall health and safety management plan. Wet Weather If construction is to be conducted during wet seasonal conditions (commonly from mid-November through May), problems associated with soft soils must be considered as part of the construction plan. During this time of year, fine-grained soils such as silts and clays will become unstable with increased moisture content, and eventually deform or rut. Additionally, constant low temperatures reduce the possibility of drying soils to near optimum conditions. Soft Subgrade Soils Shallow fine-grained subgrade soils that are high in moisture content should be expected to pump and rut under construction traffic. During periods of wet weather, construction may become very difficult if not impossible. The following recommendations and options have been included for dealing with soft subgrade conditions: • Track -mounted vehicles should be used to strip the subgrade of root matter and other deleterious debris. Heavy rubber -tired equipment should be prohibited from operating directly on the native subgrade and areas in which structural fill materials have been placed. Construction traffic should be restricted to designated roadways that do not cross, or cross on a limited basis, proposed roadway or parking areas. • Soft areas can be over -excavated and replaced with granular structural fill. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mTesting tiOrriti-id.com Copyright®g&I2019 nspection j MATERIALS TESTING £r INSPECTION 14 May 2019 Page # 15 of 27 b 190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Construction roadways on soft subgrade soils should consist of a minimum 2 -foot thickness of large cobbles of 4 to 6 inches in diameter with sufficient sand and fines to fill voids. Construction entrances should consist of a 6 -inch thickness of clean, 2 -inch minimum, angular drain -rock and must be a minimum of 10 feet wide and 30 to 50 feet long. During the construction process, top dressing of the entrance may be required for maintenance. Scarification and aeration of subgrade soils can be employed to reduce the moisture content of wet subgrade soils. After stripping is complete, the exposed subgrade should be ripped or disked to a depth of 1'/2 feet and allowed to air dry for 2 to 4 weeks. Further disking should be performed on a weekly basis to aid the aeration process. Alternative soil stabilization methods include use of geotextiles, lime, and cement stabilization. MTI is available to provide recommendations and guidelines at your request. Frozen Subgrade Soils Prior to placement of structural fill materials or foundation elements, frozen subgrade soils must either be allowed to thaw or be stripped to depths that expose non -frozen soils and wasted or stockpiled for later use. Stockpiled materials must be allowed to thaw and return to near -optimal conditions prior to use as structural fill. The onsite, shallow clayey soils are susceptible to frost heave during freezing temperatures. For exterior flatwork and other structural elements, adequate drainage away from subgrades is critical. Compaction and use of structural fill will also help to mitigate the potential for frost heave. Complete removal of frost susceptible soils for the full frost depth, followed by replacement with a non -frost susceptible structural fill, can also be used to mitigate the potential for frost heave. MTI is available to provide further guidance/assistance upon request. Structural Fill Soils recommended for use as structural fill are those classified as GW, GP, SW, and SP in accordance with the Unified Soil Classification System (USCS) (ASTM D2487). Use of silty soils (USCS designation of GM, SM, and ML) as structural fill may be acceptable. However, use of silt soils oils (GM SM, and ML) as structural fill below footings is prohibited. These materials require very high moisture contents for compaction and require a long time to dry out if natural moisture contents are too high and may also be susceptible to frost heave under certain conditions. Therefore, these materials can be quite difficult to work with as moisture content, lift thickness, and compactive effort becomes difficult to control. If silty soil is used for structural fill, lift thicknesses should not exceed 6 inches (loose) and fill material moisture must be closely monitored at both the working elevation and the elevations of materials already placed. Following placement, silty soils must be protected from degradation resulting from construction traffic or subsequent construction. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mti(cDmti-id.com Copy fight®Materials Tesgng & & Inspection MATERIALS TESTING 6 INSPECTION 14 May 2019 Page # 16 of 27 b190770g_geotech AN ATLAS COMPANY ❑ Environmental Services L1 Geotechnical Engineering ❑ Construction Materials Testing U Special Inspections Recommended granular structural fill materials, those classified as GW, GP, SW, and SP, should consist of a 6 -inch minus select, clean, granular soil with no more than 50 percent oversize (greater than %-inch) material and no more than 12 percent fines (passing No. 200 sieve). These fill materials should be placed in layers not to exceed 12 inches in loose thickness. Prior to placement of structural fill materials, surfaces must be prepared as outlined in the Construction Considerations section. Structural fill material should be moisture -conditioned to achieve optimum moisture content prior to compaction. For structural fill below footings, areas of compacted backfill must extend outside the perimeter of the footings for a distance equal to the thickness of fill between the bottom of foundation and underlying soils, or 5 feet, whichever is less. All fill materials must be monitored during placement and tested to confirm compaction requirements, outlined below, have been achieved. Each layer of structural fill must be compacted, as outlined below: Below Structures and Rigid Pavements: A minimum of 95 percent of the maximum dry density as determined by ASTM D 1557. Below Flexible Pavements: A minimum of 92 percent of the maximum dry density as determined by ASTM D1557 or 95 percent of the maximum dry density as determined by ASTM D698. The ASTM D1557 test method must be used for samples containing up to 40 percent oversize (greater than %- inch) particles. If material contains more than 40 percent but less than 50 percent oversize particles, compaction of fill must be confirmed by proof rolling each lift with a 10 -ton vibratory roller (or equivalent) until the maximum density has been achieved. Density testing must be performed after each proof rolling pass until the in-place density test results indicate a drop (or no increase) in the dry density, defined as maximum density or "break over" point. The number of required passes should be used as the requirements on the remainder of fill placement. Material should contain sufficient fines to fill void spaces, and must not contain more than 50 percent oversize particles. Backfill of Walls Backfill materials must conform to the requirements of structural fill, as defined in this report. For wall heights greater than 2.5 feet, the maximum material size should not exceed 4 inches in diameter. Placing oversized material against rigid surfaces interferes with proper compaction, and can induce excessive point loads on walls. Backfill shall not commence until the wall has gained sufficient strength to resist placement and compaction forces. Further, retaining walls above 2.5 feet in height shall be backfilled in a manner that will limit the potential for damage from compaction methods and/or equipment. It is recommended that only small hand - operated compaction equipment be used for compaction of backfill within a horizontal distance equal to the height of the wall, measured from the back face of the wall. Backfill should be compacted in accordance with the specifications for structural fill, except in those areas where it is determined that future settlement is not a concern, such as planter areas. In nonstructural areas, backfill must be compacted to a firm and unyielding condition. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mti(ZDmti-id.com Copyright®&IMaterials TTestinggInspection MATERIALS TESTING £s INSPECTION 14 May 2019 Page # 17 of 27 b190770g_geotech AN ATLAS COMPANY Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Excavations Shallow excavations that do not exceed 4 feet in depth may be constructed with side slopes approaching vertical. Below this depth, it is recommended that slopes be constructed in accordance with Occupational Safety and Health Administration (OSHA) regulations, Section 1926, Subpart P. Based on these regulations, on-site soils are classified as type "C" soil, and as such, excavations within these soils should be constructed at a maximum slope of 1 %2 feet horizontal to 1 foot vertical (I V2:1) for excavations up to 20 feet in height. Excavations in excess of 20 feet will require additional analysis. Note that these slope angles are considered stable for short- term conditions only, and will not be stable for long-term conditions. During the subsurface exploration, test pit sidewalls generally exhibited little indication of collapse; however, sloughing of native granular sediments from test pit sidewalls was observed, particularly after penetration of the water table. For deep excavations, native granular sediments cannot be expected to remain in position. These materials are prone to failure and may collapse, thereby undermining upper soil layers. This is especially true when excavations approach depths near the water table. Care must be taken to ensure that excavations are properly backfilled in accordance with procedures outlined in this report. Groundwater Control Groundwater was encountered during the investigation but is anticipated to be below the depth of most construction. Excavations below the water table will require a dewatering program. Dewatering will be required prior to placement of fill materials. Placement of concrete can be accomplished through water by the use of a treme. It may be possible to discharge dewatering effluent to remote portions of the site, to a sump, or to a pit. This will essentially recycle effluent, thus eliminating the need to enter into agreements with local drainage authorities. Should the scope of the proposed project change, MTI should be contacted to provide more detailed groundwater control measures. Special precautions may be required for control of surface runoff and subsurface seepage. It is recommended that runoff be directed away from open excavations. Clayey soils may become soft and pump if subjected to excessive traffic during time of surface runoff. Ponded water in construction areas should be drained through methods such as trenching, sloping, crowning grades, nightly smooth drum rolling, or installing a French drain system. Additionally, temporary or permanent driveway sections should be constructed if extended wet weather is forecasted. GENERAL COMMENTS Based on the subsurface conditions encountered during this investigation and available information regarding the proposed development, the site is adequate for the planned construction. When plans and specifications are complete and if significant changes are made in the character or location of the proposed structure, consultation with MTI must be arranged as supplementary recommendations may be required. Suitability of subgrade soils and compaction of structural fill materials must be verified by MTI personnel prior to placement of structural elements. Additionally, monitoring and testing should be performed to verify that suitable materials are used for structural fill and that proper placement and compaction techniques are utilized. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 als www.mti-id.com • mt0)mti-id.com Copynght02019 Inspection Testing 8lnspection MATERIALS TESTING & INSPECTION AN ATLAS COMPANY 14 May 2019 Page # 18 of 27 b 190770g_geotech ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections REFERENCES American Concrete Institute (ACI) (2015). Guide for Concrete Floor and Slab Construction: ACI 302.111. Farmington Hills, ME ACI. American Society of Civil Engineers (ASCE) (2013). Minimum Design Loads for Buildings and Other Structures: ASCE/SEI 7-10. Reston, VA: ASCE. American Society for Testing and Materials (ASTM) (2013). Standard Test Method for Materials Finer than 75-µm (No. 200) Sieve in Mineral Aggregates by Washing: ASTM C117. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2014). Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates: ASTM C136. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2012). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort: ASTM D698. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2012). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort: ASTM D1557. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2013). Standard Test Methods for Resistance Value (R -Value) and Expansion Pressure of Compacted Soils: ASTM D2844. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2011). Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System): ASTM D2487. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2010). Standard Test Methods for Liquid Limit Plastic Limit, and Plasticity Index of Soils: ASTM D4318. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2011). Standard Specification for Plastic Water Vapor Retarders Used in Contact with Soil or Granular Fill Under Concrete Slabs: ASTM E1745. West Conshohocken, PA: ASTM. Desert Research Institute. Western Regional Climate Center. [Online] Available: <http://www.wrcc.dri.edu/> (2019). International Building Code Council (2015). International Building Code, 2015. Country Club Hills, IL: Author. Local Highway Technical Assistance Council (LHTAC) (2017). Idaho Standards for Public Works Construction, 2017. Boise, ID: Author. Othberg, K. L. and Stanford, L. A., Idaho Geologic Society (1992). Geologic Map of the Boise Valley and Adjoining Area, Western Snake River Plain, Idaho. (scale 1:100,000). Boise, ID: Joslyn and Morris. U.S. Department of Labor, Occupational Safety and Health Administration. CFR 29 Part 1926 Subpart P: Safety and Health Regulations for Construction, Excavations (1986). [Online] Available: <www.osha.gov> (2019). U.S. Geological Survey (2019). National Water Information System: Web Interface. [Online] Available: <http://-vvaterdata.usgs.gov/nwis> (2019). U.S. Geological Survey. (2011). U.S. Seismic Design Maps: Web Interface. [Online] Available: <https://earthquake.usgs.gov/designmaps/us/application.php> (2019). 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 Copyright ®2019 Materials www.mti-id.com • mtl(almtl-Id.com Testing&Inspection MATERIALS j TESTING & INSPECTION AN ATLAS COMPANY Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing APPENDICES ACRONYM LIST AASHTO: American Association of State Highway and Transportation Officials ACHD: Ada County Highway District ACI American Concrete Institute ASCE American Society of Civil Engineers ASTM: American Society for Testing and Materials bgs: below ground surface CBR: California Bearing Ratio D: natural dry unit weight, pcf ESAL Equivalent Single Axle Load GS: grab sample IBC: International Building Code ISPWC: Idaho Standards for Public Works Construction ITD: Idaho Transportation Department LL: Liquid Limit M: water content MSL: mean sea level N: Standard "N" penetration: blows per foot, Standard Penetration Test NP: nonplastic OSHA Occupational Safety and Health Administration PCCP: Portland Cement Concrete Pavement PERM: vapor permeability PI: Plasticity Index PID: photoionization detector PVC: polyvinyl chloride Qe: cone penetrometer value, unconfined compressive strength, psi Qp: Penetrometer value, unconfined compressive strength, tsf Qu: Unconfined compressive strength, tsf RMR Rock Mass Rating RQD Rock Quality Designation R -Value Resistance Value SPT: Standard Penetration Test (140:pound hammer falling 30 in. on a 2:in. split spoon) USCS: Unified Soil Classification System USDA: United States Department of Agriculture UST: underground storage tank V: vane value, ultimate shearing strength, tsf 14 May 2019 Page # 19 of 27 b190770g_geotech ❑ Special Inspections 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 Copyright ©2019 Materials www.mti-id.com • mtiamti-id.com Testing & Inspection MATERIALS TESTING & INSPECTION AN ATLAS COMPANY 14 May 2019 Page # 20 of 27 b 190770g_geotech ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GEOTECHNICAL GENERAL NOTES Moisture Content RELATIVE DENSITY AND CONSISTENCY CLASSIFICATION Field Test Coarse -Grained Soils SPT Blow Counts (N) Fine -Grained Soils SPT Blow Counts (N) Very Loose: < 4 Very Soft: < 2 Loose: 4-10 Soft: 2-4 Medium Dense: 10-30 Medium Stiff: 4-8 Dense: 30-50 Stiff.. 8-15 Very Dense: >50 Very Stiff. 15-30 MH Inorganic, elastic silts; sandy, gravelly or clayey elastic silts Hard: >30 Moisture Content Description Field Test Dry Absence of moisture, dusty, dry to touch Moist Damp but not visible moisture Wet Visible free water, usually soil is below water table PARTICLE SIZE Boulders T >12 in Coarse -Grained Sand: 5 to 0.6 mm Silts: 0.075 to 0.005 mm Cobbles: 12 to 3 in. Medium -Grained Sand: 0.6 to 0.2 mm Clays: <0.005 mm Gravel: 3 in. to 5 mm Fine -Grained Sand: 0.2 to 0.075 mm UNIFIED SOIL CLASSIFICATION SYSTEM Cementation Description Field Test Weakly Crumbles or breaks with handling or GW Well -graded gravels; gravel/sand mixtures with little or no fines slight finger pressure Moderately Crumbles or beaks with considerable Sand & Sandy Soils >50% coarse fraction passes No.4 sieve finger pressure Strongly Will not crumble or break with finger SC Clayey sands; poorly -graded sand/gravel/clay mixtures pressure PARTICLE SIZE Boulders T >12 in Coarse -Grained Sand: 5 to 0.6 mm Silts: 0.075 to 0.005 mm Cobbles: 12 to 3 in. Medium -Grained Sand: 0.6 to 0.2 mm Clays: <0.005 mm Gravel: 3 in. to 5 mm Fine -Grained Sand: 0.2 to 0.075 mm UNIFIED SOIL CLASSIFICATION SYSTEM Major Divisions Symbol Soil Descriptions Coarse -Grained Soils <50% passes No.200 sieve Gravel & Gravelly Soils <50% coarse fraction passes No.4 sieve GW Well -graded gravels; gravel/sand mixtures with little or no fines GP Poorly -graded gravels; gravel/sand mixtures with little or no fines GM Siltyravels; poorly -graded raded ravel/sand/silt mixtures g y -g g GC Clayey gravels; poorly -graded gravel/sand/clay mixtures Sand & Sandy Soils >50% coarse fraction passes No.4 sieve SW Well -graded sands; gravelly sands with little or no fines SP Poorly -graded sands; gravelly sands with little or no fines SM Silty sands; poorly -graded sand/gravel/silt mixtures SC Clayey sands; poorly -graded sand/gravel/clay mixtures Fine Grained Soils >50% passes No.200 sieve Silts & Clays LL < 50 ML Inorganic silts; sandy, gravelly or clayey silts CL Lean clays; inorganic, gravelly, sandy, or silty, low to medium -plasticity clays OL Organic, low -plasticity clays and silts Silts & Clays LL> 50 MH Inorganic, elastic silts; sandy, gravelly or clayey elastic silts CH Fat clays; high -plasticity, inorganic clays OH Organic, medium to high -plasticity clays and silts Highly Organic Soils PT Peat, humus, hydric soils with high organic content 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mtiCa anti-id.com Copyright ® Testing g & Inspection I CMATERIALS IFTESTING & INSPECTION 14 May 2019 Page # 21 of 27 b190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP -1 Date Advanced: 30 April 2019 Logged by: Maren Tanberg, E.I.T., G.I.T, Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Latitude: 43.636351 Longitude: -116.412297 Depth to Water Table: 8.7 Feet bgs Total Depth: 10.2 Feet bgs Notes: Piezometer installed to 10.2 feet bgs. Depth Field Description and USCS Soil and Sample Sample Depth QP Lab (Feet bgs) Sediment Classification Type (Feet bgs) Test ID Fat Clay (CH): Broivn, slightly moist, very 0.0-1.3 stiff. 2.5-6.75 --Organics noted throughout. Silty Clay with Sand (CL -ML): Broivn, moist to ivet, medium stiff to stiff, with fine to 1.3-4.1 medizan-grained sand. GS 3.0-3.5 0.75-1.5 A --Color change to light brown noted fi-om 1.6 to 3.0 feet bgs. --Sand content increased with depth. Poorly Graded Gravel with Silt and Sand (GP -GM): Broivn, dry to saturated, dense to 4.1-10.2 veiry dense, with fine to coarse-grained sand, fine to coarse gravel, and 4-Inch-7ninits cobbles. Lab Test ID M LL PI Sieve Anal Ysis (% passing) - - #4 #10 #40 #100 #200 A 30.0 26 5 100 1 99 91 83 77.2 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mti(a�Testing mti-id.com Copyright®g&I2019 nspection MATERIALS TESTING & INSPECTION 14 May 2019 Page # 22 of 27 b 190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP -2 Date Advanced: 30 April 2019 Excavated by: Struckman's Backhoe Service Latitude: 43.635138 Depth to Water Table: 6.9 Feet bgs Notes: Piezometer installed to 7.5 feet bgs. Logged by: Maren Tanberg, E.I.T., G.I.T, Location: See Site Map Plates Longitude: -116.411486 Total Depth: 7.5 Feet bgs Depth Field Description and USCS Soil and Sample Sample Depth=QPTest Lab (Feet bgs) Sediment Classification Type (Feet b s) ID Fat Clay (CH): Broivn, slightly moist to GS 0.0-3.0 moist, stiff to very stiff. Bulk 2.1 3.0 R -value --Organics noted throughout. Silty Clay with Sand (CL -ML): Brown, moist to wet, medium stiff to stiff, with fine to 3.0-5.2 medium grained sand. --Sand content increased with depth. Poorly Graded Gravel with Silt and Sand (GP -GM): Brown, slightly moist to saturated, 5.2-7.5 medium dense to dense, with fine to coarse- grained sand, fine to coarse gravel, and 6 - inch -minus cobbles. Lab Test ID M LL PI Sieve Anal ysis (% assin % #4 #10 #40 #100 #200 B 27.9±A7E-J6�100 100 98 95 91.8 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mtiCalmTesting ti-id.com Copyrig 9 Materials Blnspection 0 C MATERIALS IFTESTING £s INSPECTION 14 May 2019 Page # 23 of 27 b190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP -3 Date Advanced: 30 April 2019 Logged by: Maren Tanberg, E.I.T., G.I.T, Excavated by: Struckrnan's Backhoe Service Location: See Site Map Plates Latitude: 43.635783 Longitude: -116.413306 Depth to Water Table: 8.0 Feet bgs Total Depth: 8.8 Feet bgs Notes: Piezometer installed to 8.8 feet bgs. Depth Field Description and USCS Soil and Sample Sample DepthLab ()p (Feet bgs) Sediment Classification Type (Feet bgs) Test ID Fat Clay (CH): BroTvn, slightly moist, stiff to 0.0-2.7 very stiff. 1.5-2.0 --Organics noted to 1.4_feet bgs. Silty Clay with Sand (CL -ML): Brown, 2.7-4.0 slightly moist to wet, medium stiff to stiff, ivith 1.0-1.75 fine to medium grained sand. Poorly Graded Gravel with Silt and Sand (GP -GM): Brown, slightly moist to saturated, 4.0-8.8 dense, ivith fine to coarse-grained sand, fine to coarse gravel, and 10 -inch -minus cobbles. 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mtVD.mti-id.com Copyright®Testingg&Inspection 0 C MATERIALS IFTESTING & INSPECTION AN ATLAS COMPANY 14 May 2019 Page # 24 of 27 b 190770g_geotech ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GRAVEL EQUIVALENT METHOD — PAVEMENT THICKNESS DESIGN PROCEDURES Pavement Section Design Location: Vogel Residence, Residential Roadway Average Daily Traffic Count: All Lanes & Both Directions Design Life: 20 Years Traffic Index: 6.00 Climate Tactor: 1 R -Value of Subgrade: 4.00 Subgrade CBR Value: 2 Subgrade Nor: 3,000 R -Value of Aggregate Base: 80 R -Value of Granular Borrow: 60 Subgrade R -Value: 4 Expansion Pressure of Subgrade: 1.40 Unit Weight of Base Materials: 130 Total Design Life 18 ldp ESAL's: 33,131 ASPHALTIC CONCRETE: Depth Substitution Gravel Equivalent, Calculated: 0.384 Thickness: 0.196923077 Use= 2.5 Inches Gravel Equivalent, ACTUAL: 0.41 CRUSHED AGGREGATE BASE: 0.00 Gravel Equivalent (Ballast): 0.768 Thickness: 0.329 Use = 4 Inches Gravel Equivalent, ACTUAL: 0.773 SUBBASE: Gravel Equivalent (Ballast): 1.843 Thickness: 1.070 Use = 14 hiches Gravel Equivalent, ACTUAL: 1.940 TOTAL Thickness: 1.708 Thickness Required by Exp. Pressure: 1.551 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mti(a�mti-id.com copyright (Materials Teestingsting &Inspection Design ACHD Depth Substitution Inches Ratios Asphaltic Concrete (at least 2.5): 2.50 1.95 Asphalt Treated Base (at least 4.2): 0.00 Cement Treated Base (at least 4.2): 0.00 Crushed Aggregate Base (at least 4.2): 4.00 1.10 Subbase (at least 4.2): 14.00 1.00 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mti(a�mti-id.com copyright (Materials Teestingsting &Inspection MATERIALS TESTING 6 INSPECTION 14 May 2019 Page # 25 of 27 b190770g_geotech AN ATLAS COMPANY ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections R -VALUE LABORATORY TEST DATA Source and Description: TP -2: 2.1'-3.0', Fat Clay Date Obtained: 30 April 2019 Sample ID: 19-7275 Sampling and Preparation: ASTM D75: Moisture Content (%) AASHTO T2: X ASTM D421: Expansion Pressure (psi) AASHTO T87: X Test Standard: ASTM D2844: NA AASHTO T190: NA Idaho T8: X NA Sample A B C Dry Density (lb/ft3) NA NA NA Moisture Content (%) NA NA NA Expansion Pressure (psi) NA NA NA Exudation Pressure (psi) NA NA NA R -Value NA NA NA R -Value @ 200 psi Exudation Pressure = Less than 5* -Y ** ASTM D2844 Note 2: Occasionally, material from very plastic clay -test specimens will extrude from under the mold and around the follower ram during the loading operation. If this occurs when the 800 -psi point is reached and fewer than five lights are lighted, the soil should be reported as less than 5 R -value. R -Value @ Exudation Pressure 90.0 88.0 86.0 84.0 IT 82.0 80.0 400 350 300 250 200 150 100 50 Exudation Pressure (psi) 2791 S Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 www.mti-id.com • mtKDmti-id.com Copyright®20Testing 8lnspeUnspe19 rials dion m ASN�,v 1 , 1 Doil ■ Iwo ink � IIAtF•i �"'�'�i�:ffjj ��i� , ., Site Map Plate 2 NOTES: H H • Not to Scale —� LEGEND Approximate Site — — — — Fii I Boundary Approximate MTI Test 1 Pit Location I with Piezometer EIEP I South Slogh — • • — 1 TP -1 1 � I 1 Residential Area I 1 TP -3l FiI I N I TP -2 I 8Vog 0 I el Pro e rtv 3610 North Linder Road 36 Z J — — — Meridian, ID I I Drawn by: MJT 9 May 2019 Drawing: B190770g ...... _ I I MATERIALS TESTING Fr —USTICK ROAD— — — — — — — — — — INSPECTION AN ATLAS COMPANY Residential Area I 2791 S. Victory Vim ay Phone: 208 Boise, t 8 37092835 Fax: 208322-65`1548 Ewell: m8'@md-id.com