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Geotechnical Engineering Report
MATERIAL TESTING & I NSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GEOTECHNICAL ENGINEERING REPORT of Black Cat Subdivision Black Cat & McMillan Roads MEridian, Idaho PrEparEd for: Pole CrEEI< PropErtiEs Inc. P.O. Box 190073 BOisE, Idaho 83719 MTI File NumbEr 1360513g 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 ftw E-Mail mti@mti-id.com • www.mti-id.com CrMATERIALS TESTING &� INSPECTION April 27, 2006 Page # I of 24 ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections _ Mr. Don Roberts Pole Creek Properties P.O. Box 190073 _ Boise, Idaho 83719 (208) 602-3800 ow Gentlemen: r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc Re: Geotechnical Engineering Report Black Cat Subdivision Black Cat & McMillian Roads Meridian, Idaho .. In compliance with your instructions, we have conducted a soils exploration and foundation evaluation for the above mentioned development. Field work for this investigation was conducted on 13 April 2006. Data have been analyzed to evaluate pertinent geotechnical conditions. Provided geotechnical, groundwater, and construction recommendations are listed in the Table of Contents. Results of this investigation, together with our recommendations, are to be found in the following report. Often, because of design and construction details that occur on a project, questions arise concerning soil conditions. We would be pleased to continue our role as geotechnical engineers during project implementation. MTI also has great interest in providing 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 be pleased to meet with you at your convenience. We appreciate this opportunity to be of service to you and we look forward to working with you in the future. If you have questions please call us at (208) 376-4748. Respectfully Submitted, Materials Testing & Inspection, Inc. Esther Miramontes Geotechnical Engineering Technician Reviewed by Michael G.Voodwo'rth, P.E. Senior G;otecical Engineer Foe Reviewed by Kevin L. Schroeder, P.G. Geotechnical Services Manager Copyright @ 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS April 27, 2006 ..., TESTING Fs... Page # 2 of 24 INSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing U Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc TABLE OF CONTENTS INTRODUCTION.....................................................................................................................3 ProjectDescription...............................................................................................3 _ Authorization........................................................................................................3 Purpose..................................................................................................................3 Scope......................................................................................................................3 Warranty And Limiting Conditions...................................................................4 General..................................................................................................................4 DESCRIPTION OF SITE.........................................................................................................5 SiteAccess.............................................................................................................5 General Geology Of Area....................................................................................5 Site Topography, Drainage And Vegetation......................................................5 Site Climatology And Geochemistry...................................................................6 GeoseismicSetting................................................................................................6 SOILSEXPLORATION............................................................................................................6 Exploration and Sampling Procedures...............................................................6 Laboratory Testing Program..............................................................................7 Soil And Sediment Profile...................................................................................7 SoilsSurvey Review..............................................................................................7 VolatileOrganic Scan...........................................................................................8 SITEHYDROLOGY................................................................................................................8 GeneralNotes........................................................................................................8 Groundwater.........................................................................................................8 Soil Infiltration Rates...........................................................................................8 -! FOUNDATION AND PAVEMENT DISCUSSION AND RECOMMENDATIONS .............................9 GeneralNotes........................................................................................................9 Foundation Design Recommendations...............................................................9 Crawl Space Recommendations..........................................................................9 Recommended Pavement Sections......................................................................10 CONSTRUCTION CONSIDERATIONS......................................................................................I I Earthwork.............................................................................................................11 DryWeather.........................................................................................................12 WetWeather.........................................................................................................12 SoftSubgrade Soils...............................................................................................12 FrozenSubgrade Soils..........................................................................................13 StructuralFill........................................................................................................13 Backfill...................................................................................................................14 Excavations...........................................................................................................14 Groundwater Control 14 .......................................................................................... GENERALCOMMENTS..........................................................................................................15 REFERENCES........................................................................................................................16 APPENDIXLIST.....................................................................................................................17 Geotechnical General Notes.................................................................................18 Unified Soil Classification....................................................................................19 TestPit Logs..........................................................................................................20 Pavement Thickness Design.................................................................................23 Resistance R-Value Laboratory Test Data.........................................................24 Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIAL April 27, 2006 ,.� Page # 3 of 24 TESTING & ' INSPECTION U ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc INTRODUCTION This report presents results of a geotechnical investigation and analysis in support of data utilized in design of structures as defined in the 2003 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. Project Description: The proposed development is within the northwest portion of the City of Meridian, Ada County, Idaho, and occupies part of the NW'/4 SW'/4 of Section 27, Township 4 North, Range 1 West, Boise Meridian. The project will consist of development of approximately 24 to 26 single-family residential lots on an approximate 7.5-acre site. Roadways are anticipated to be included as part of the development. Proposed grading is presently undetermined. Authorization: Authorization to perform this exploration and analysis was given in the form of written authorization to proceed from Mr. Don Roberts to Liz Brown of Materials Testing and Inspection, Inc. (MTI), on 05 April 2006. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between Pole Creek Properties, Inc. and MTI. Our scope of services for the proposed development has been provided in our proposal dated 30 March 2006, and again below. Purpose: The purpose of this Geotechnical Engineering Report is to determine various soil profile components and their engineering characteristics for use by design engineers and/or architects in: • Preparing or verifying suitability of foundation design and placement, • Preparing site drainage designs, and • Indicating issues pertaining to earthwork construction. Scope: The scope of this investigation included review of geologic literature and existing available geotechnical studies of the area, review of available environmental reports, visual site reconnaissance of the immediate site, subsurface exploration, field and laboratory testing, and an engineering analysis and evaluation of foundation materials. The scope of work did not include design recommendations specific to individual residences. Copyright @ 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS April 27, 2006 TESTING & Page# 4of24 INSPECTION L ❑ Environmental Services J Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Lr:\boise\2006 reports\400-599\b60513g\b60513geotech.doc Warranty And Limiting Conditions: Field observations and research reported herein are considered sufficient in detail and scope to form a reasonable basis for the purposes cited above. MTI warrants that findings and conclusions contained herein have been promulgated in accordance with generally accepted professional engineering practice in 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 subject property within the scope cited above and are necessarily limited to conditions observed at the time of the site visit and research. The report is also limited to information available at the time it was prepared. In the event additional information is provided to MTI following the report, it will be forwarded to the client in the form received for evaluation by the client. There is a distinct possibility that conditions may exist which could not be identified within the scope of the investigation or which were not apparent during the site investigation. This report was prepared for the exclusive use of Pole Creek Properties, Inc. and their retained design consultants ("Client"). Conclusions and recommendations presented in this report are based upon agreed -upon scope of work outlined in the report and Contract for Professional Services between Client and Materials Testing and Inspection, Inc. ("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 •• whatever, known or unknown to Client or Consultant. Neither Client nor Consultant shall have liability to, or indemnifies or holds harmless third parties for losses incurred by actual or purported use or misuse of this report. No other warranties are implied or expressed. General: Revisions in plans and/or drawings for the proposed development from those enumerated in this report should be brought to the attention of the soils engineer to determine if changes in foundation recommendations are required. Deviations from noted subsurface conditions if encountered during construction, should also be brought to the attention of the soils engineer. Copyright @ 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS April 27, 2006 TESTING Page # 5 of 24 NSPECTION L ❑ Environmental Services J Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Lr:\boise\2006 reports\400-599\b60513g\b60513geotech.doc DESCRIPTION OF SITE Site Access: Access to the site may be gained via Chinden Boulevard. Proceed south on Black Cat Road approximately 0.7 mile. The site is located east of Black Cat Road, just north of the Black Cat Road & Daphne Street intersection. Presently the site exists as undeveloped agricultural land with one residence and associated .. outbuildings located fronting Black Cat Road. Site location is depicted in map plates included in Appendix. General Geology Of Area: The subject site is located within the Boise Valley which is directly underlain by a thick sequence of alluvial sands and gravels typically deposited on basalt formations. These sediments are loosely named the Boise River Gravels and were deposited as river floodplain and stream overwash from the Boise River. These gravel deposits tend to have imbricated well-rounded clasts, poor sorting, and crude stratification of beds of gravel and lenses of cross -bedded sand suggesting deposition in braided channels. The Boise River Gravels consist of unconsolidated clay, silt, sand, gravel, and cobbles. These gravels have been subdivided into smaller units based on their age and are exposed as distinct alluvial terraces. Five of these terraces are well exposed in the Boise area and range in age from Middle Pleistocene to Holocene (Recent) (0 - 0.9 million years ago). The site lies on the Whitney Terrace, the second terrace above the currently defined floodplain. Geologic data published for the area indicated that bedrock is typically encountered at a depth of approximately 100 feet beneath the soil surface (Othberg and Stanford, 1992). Site Topography, Drainage And Vegetation: The proposed development consists of approximately 7.5 acres of relatively flat irrigated pasture, with a residence located in the western portion of the property. The surface exhibits fine-grained soils throughout the majority of the site. The parcel is bounded on the north, south, and east by existing rural residential development and agricultural land, and on the west by Black Cat Road. Regional drainage is north and west toward the Boise River. Stormwater drainage for the site is achieved by percolation through surficial soils. No stormwater drainage facilities are located in the vicinity of the site and the area does not receive significant off -site drainage. Vegetation throughout the area consists primarily of irrigated pasture grasses. Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS �./ April 27, 2006 TESTING & Page # 6 of 24 INSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections rAboise\2006 reports\400-599\b60513g\b60513geotech.doc Site Climatology And Geochemistry: Average precipitation for the region is on the order of 10 to 12 inches per year. Annual average temperature range from 20' F to 91' F with extremes ranging from -4° F to 102' F. Average wind speed range to 11 miles per hour in spring with a prevailing direction from the southeast. Soil in the area is primarily derived from siliceous materials and exhibits low electro-chemical potential for corrosion of metals or concretes. Local aggregates are generally appropriate for Portland Cement and Lime Cement mixtures. The State Transportation Department has adopted anionic asphalt cements. The H of surface water, p p ,groundwater, and soil in the region typically range from 7 to 9. No indication of abnormal geochemical conditions was noted on -site. Nominal frost penetration is typically on the order of 6 inches, with extremes ranging to 3 feet. Geoseismic Setting: Soils on -site are classed as Site Class D in accordance with Chapter 16 of the 2003 edition of the IBC. Building structures on this project should be designed as per the IBC requirement for such a seismic classification. Our investigation did not reveal potential hazards resulting from earthquake motions: slope instability, liquefaction, and surface rupture because of faulting or lateral spreading. Incidence and anticipated acceleration of seismic activity in the area is low. SOILS EXPLORATION WW Exploration And Sampling Procedures: The field exploration to determine engineering characteristics of subsurface materials included a reconnaissance of the project site and investigation by test pit. Test pit sites were located in the field by means of normal taping procedures from known locations and are presumed to be accurate to within a few feet. Upon completion of investigation each test pit was backfilled in with loose excavated materials. These loose areas need to be re -excavated and compacted prior to constructing structures over them. Samples were obtained from representative soil strata encountered in test pits. Samples obtained have been visually classified in the field by an engineering technician, identified according to test pit number and depth, placed in sealed containers, and transported to our laboratory for additional testing. These materials have been further described in detail on logs provided in the Appendix. Results of field and laboratory tests are also presented on these logs. It is recommended that these logs not be used for estimating quantities because of highly interpretive results. Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com LMATERIALS April 27, 2006 TESTING & Page # 7 of 24 r I j INSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Lr:\boise\2006 reports\400-599\b60513g\b60513geotech.doc Laboratory Testing Program: Along with the field investigation, a supplemental laboratory testing program was conducted to determine _ additional pertinent engineering characteristics of subsurface materials necessary in analyzing the behavior of the proposed structures. Laboratory tests were conducted according to 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 Tests — ASTM designation D 4318, Grain Size Analysis — ASTM designation C 117, C 136, and Resistance R-Value and Expansion Pressure of Compacted Soils — ASTM designation D 2844. Soil And Sediment Profile: Three test pits were advanced to depths of 6.9 to 8.0 feet across the site, terminating within saturated poorly graded gravel sediments. Groundwater was encountered between 6.6 and 6.7 feet within test pits explored. The developed soil profile represents only a generalized case and variations between test pits should be anticipated across the site. The following soils represent a hypothesized profile as compiled from observations in the three test pits advanced: Dark brown, slightly moist, medium stiff to very stiff, fine-grained sandy lean clay (CL) is present at ground surface across the site. Organic material was noted to depths of 1.2 to 1.6 feet in test pits advanced. Sandy lean clay extended from 1.6 to 2.0 feet in depth. Underlying sandy lean clay is brown, slightly moist, soft to •• very stiff, fine-grained sandy silt (ML). Sandy silt is present to depths of 3.9 to 5.1 feet. Brown to reddish - brown, moist to saturated, medium dense, poorly graded gravel (GP) with fine to coarse -grained sand was observed below silty sand soils and extends beyond termination depths of test pits advanced. Walls of each test pit were stable with the exception of those through native granular soils. Excavations through granular soils, particularly after penetration of the water table, will have a propensity for sloughing or caving. Soils Survey Review: A review of the United States Department of Agriculture, Soil Conservation Service, Soil Survey of Ada County Area, Idaho, 1980, indicated the site can be characterized by the Abo silt loam and the Purdam silt loam. Specific soils characteristics are as follow: • Abo silt loam: Soils are well -drained with moderately slow permeability, slow runoff, and slight hazard of erosion. The seasonal water table limits this soil for uses of septic absorption fields. Basements are affected by the water table unless drainage is provided. • Purdam silt loam, 0 to 2 percent slopes: Soils are well -drained with moderately slow permeability, slow runoff, and slight to no hazard of erosion. Digging and trenching in this soil may be hampered by hardpan. The low strength, frost action potential, and high shrink -swell potential limit construction of roads and streets; however, suitable sub -grade material can offset these limitations. Copyright © 2006 Materials Testing & Inspection, Inc 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS TESTING INSPECTION April 27, 2006 Page # 8 of 24 ❑ Environmental Services .J Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc 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 contamination. Groundwater encountered did not exhibit indications of contamination. SITE HYDROLOGY General Notes: Existing surface drainage conditions are defined in the Description of Site. Information provided in this section is limited to observations made at the time of the investigation. Regional and/or local ordinances may require information beyond the scope of this report. Groundwater: Groundwater was encountered between 6.6 and 6.7 feet within test pits explored. Soil moistures in test pits �. were generally slightly moist within surficial fine-grained soils, grading from slightly moist to saturated as groundwater table was approached and penetrated. Groundwater levels in the site vicinity are controlled in large part by residential and agricultural irrigation activity and canal leakage in the local area and are likely at maximum elevations during irrigation season. Based on evidence of this investigation and background 1 knowledge of the area, during a typical season, groundwater is anticipated to remain at depths of greater than 2 to 4 feet below ground surface throughout the year. Estimation of seasonal groundwater fluctuation is problematic without regular monitoring. If desired, given estimated depths to groundwater may be confirmed following periodic monitoring performed by MTI. Soil Infiltration Rates: Soil permeability is a measure of the ability of a liquid to move through a soil and was not tested in the field. However, a pipe for possible percolation testing were installed in test pit 1. In this report this parameter is approximated by soil type and gradation. Of soils comprising the generalized soil profile for this study, lean clay and silt soils generally offer little permeability, with typical infiltration rates less than 2 inches per hour. Poorly graded gravel sediments typically exhibit infiltration values in excess of 24 inches per hour, and percolation testing is typically not required as a result of the free -draining nature of the gravel sediment. All infiltration facilities constructed on -site should be extended into native poorly graded gravel sediments. Excavation depths of approximately 4 to 5 feet should be anticipated to expose these sediments. In addition, because of the high permeability, ASTM C 33 filter sand, or equivalent, should be incorporated into design of infiltration facilities. MTI recommends that an infiltration rate of 8 inches per hour be used for design. r.. Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com 006 MATERIALS April 2f24 � Page # 9 of 24 TESTING & INSPECTION ❑ Environmental Services J Caeotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc FOUNDATION AND PAVEMENT DISCUSSION AND RECOMMENDATIONS General Notes: Presently, approximately 24 to 26 lots are proposed for the project site. Considering typical residential construction, and subsurface conditions, it is recommended that the structures be founded upon conventional spread footings and continuous wall footings. 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: On the basis of data obtained from the site and test results from various laboratory tests performed, MTI recommends following guidelines be used for the net allowable soils bearing capacity. Footing Depth ASTM D 1557 Subgrade Compaction Net Allowable Soils Bearing Capacity Footings should bear on competent, native, sandy silt present at depths of 1.6 to 2.0 feet across the site. Not required for native soil All surficial lean clay soils must be removed from 1,500lbs/ft2 below footings.' 95% for structural fill 'Verification of bearing soils for each residence by a qualified geotechnical engineer, engineering technician, or building official at the time of construction is recommended. Footings should be proportioned to meet the stated bearing capacity and/or the IBC 2003 minimum requirements. Total settlement should be limited to about 1 inch with differential settlement of approximately 1/2 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 at footing subgrade will require over -excavation and backfilling with structural fill. To minimize effects of slight differential movement that may occur because of variations in character of supporting soils, and in 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. Crawl Space Recommendations: Considering the presence of shallow cemented soils across the site, all residences constructed with crawl spaces should be designed in a manner that will inhibit water in the crawl spaces. Therefore, proper grading should be considered to be critical. MTI recommends that roof drains carry storm water at least 5 feet away from each residence, and grades should be greater than 5% 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. Copyright @ 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 �— E-Mail mti@mti-id.com 9 www.mti-id.com M ATE R IAlS, April 2006 Page # 10 of 24 TESTING & INSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections rAboise\2006 reports\400-599\b60513g\b60513geotech.doc Recommended Pavement Sections: MTI collected a sample of near -surface soils for R-value testing representative of soils to depths of 0.5-1.0 foot below existing ground surface. A bulk sample collected from the eastern portion of the site, consisted of sandy lean clay (CL) soil with fine-grained sand. This sample yielded an R value of less than 5. MTI has used a traffic index of 6 to determine necessary pavement cross -sections for the site. Additionally, MTI has made other 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. Flexible Pavement Sections The Idaho Method as defined in Idaho Department of Transportation's Materials Manual (section 500) was _ used to develop the pavement section. Ada County Highway District (ACHD) parameters for traffic index and substitution ratios were also used in the design, and were obtained from ACHD's Development Policy Manual. Calculation sheets provided in the Appendix indicate the soils values, traffic loading, and material ratios used to calculate the pavement sections. MTI recommends that all materials used in the construction of Asphaltic Concrete Pavements meet the requirements of the Idaho Standards for Public Works Construction (ISPWC) specifications. Construction of the pavement section should be in accordance with these specifications. The following thicknesses are MINIMUM THICKNESSES for assured pavement function. a Pavement Section Com onent Drivewa s and Parking, Residential Streets Asphaltic Concrete 2.5 Inches Untreated Aggregate Base 6.0 Inches Granular Borrow 12.0 Inches Compacted Subgrade Not Required .. Aggregate Base Material complying with ISPWC Standards for Crushed Aggregate Materials. Structural Subbase Any material complying with the requirement for granular structural fill (uncrushed) as defined in ISPWC. Common Pavement Section Construction Issues The subgrade upon which above pavement sections are to be constructed must be properly stripped, compacted (if indicated), inspected, and proof rolled. Proof rolling of subgrade soils should be accomplished with a heavy rubber -tired fully loaded tandem axle dump truck or equivalent. MTI anticipates that pavement areas will be subject to moderate traffic. It should be noted that surficial clay and silt soils near to and above optimum moisture contents may tend to pump. Pumping or soft areas must be removed and replaced with structural fill. I i Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 •Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS TESTING & INSPECTION April 27, 2006 Page # 11 of 24 ❑ Environmental Services -J Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc Fill material and compacted native subgrade soils (if required) in support of the pavement section as well as aggregates comprising the pavement section must be compacted to not less than 95% of maximum dry density indicated by ASTM D 698 for flexible pavements and by ASTM D 1557 for rigid pavements. If a material placed as a pavement section component cannot be tested by usual compaction testing methods, compaction of that material shall 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 Earthwork: Recommendations in this report are based upon structural elements of the project being founded on competent native silt -sand mixtures or compacted structural fill. Structural areas should be stripped to an elevation that exposes these soil types. Excessively organic soils, deleterious materials, and/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. Mature trees, brush, and thick grasses with associated root systems were noted at the time of our investigation. It is recommended that organic soils be removed to depths of 1 foot (minimum) and wasted or stockpiled for later use. Stripping depths should be adjusted in the field to assure that the entire root zone and/or topsoil is removed prior to placement and compaction of structural fill materials. Exact removal depths should be determined during grading operations by a qualified geotechnical representative, and shall be based upon subgrade soil type, composition, and firmness or soil stability. If underground storage tanks (UST), below surface utilities, wells, or septic systems are identified, they must be decommissioned, removed, or abandoned as deemed necessary by governing Federal, State, and local agencies. Excavations developed as the result of such removal must be backfilled with structural fill materials as defined below. After existing subgrade soils are excavated to design grade, proper control of subgrade conditions (i.e., moisture content) and placement and compaction of new fill (if required) should be overseen by a representative of the soils engineer (MTI). Recommendations for structural fill presented within this report can be used to minimize volume changes and differential settlements that are detrimental to 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. Copyright© 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS P ger#12of024 TESTING & INSPECTION ❑ Environmental Services J 3eotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc Dry Weather: If construction is to be conducted during what is considered "Dry" seasonal conditions, problems associated with soft soils may be avoided. However, shallow groundwater conditions, related to springtime runoff and/or late summer/early fall irrigation, may induce rutting subgrade soils. Problems may also arise because of lack of moisture in native and fill soils at time of placement. This will require addition of water to achieve near optimum moisture levels. Low cohesive 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 what is considered "Wet" seasonal conditions (commonly from mid -November to April), 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 moderate to high in moisture content can be expected to pump and rut under construction traffic. The following recommendations and/or options have been included for dealing with anticipated subgrade conditions: • Track -mounted vehicles should be used to strip subgrade of root matter and other deleterious debris. Heavy rubber -tired equipment should be prohibited from operating directly on native subgrades, and in structural areas such as roadways and foundations. Construction traffic can be restricted to designated .. roadways that do not cross, or cross on a limited basis, proposed roadway or parking subgrades. • During periods of wet weather, construction on -site may become very difficult if not impossible. To ensure constructability, access/haul roads should be constructed with a minimum of 2 feet of structural fill material. Fill material should consist of relatively large cobble (4 to 6 inch in diameter) with sufficient fines to fill voids. • Instead of structural fill placement, scarification and aeration of subgrade soils can be employed to •• reduce the moisture content. After stripping is complete, the exposed subgrade should be ripped and/or disked to a depth of 1.5 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. Alternate recommendations can be provided involving cement stabilization or use of geotextiles, upon request. Copyright @ 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com %W .. two CPMATERIALS TESTING & NSPECTION April 27, 2006 Page # 13 of 24 ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b605l3g\b60513geotech.doc Frozen Subgrade Soils: Frozen subgrade soils must be allowed to thaw, or may be stripped prior to placement of structural fill materials or foundation elements. Frozen soils must be removed to depths that expose non -frozen soils and wasted or stockpiled for later use. These soils must be allowed to thaw and return to near optimum conditions prior to use as structural fill. Structural Fill: Soils regarded as suitable for use as structural fill are those classified as GW, GP, GM, SW, SP, SM, and ML, in accordance with the Unified Soil Classification System (USCS) (ASTM D 2487). The use of silty soils (USCS designation of GM, SM, and ML) as fill may be acceptable. However, these materials require very high moisture contents for compaction and require a long time to dry out if natural moisture contents are too high. 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. Recommended granular structural fill materials, those classified as GW, GP, SW, SP, should consist of a 6 inch minus select, clean, granular soil with no more than 30% oversize (greater than 3/4 inch) material and no more than 12% fines (less than #200) and placed in layers not to exceed 9 inches in 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 footing for a distance equal to the thickness of fill between the bottom of foundation and underlying soils, or 5 feet, whichever is less. Each layer of structural fill must be compacted to a minimum density of 95% of maximum dry density as determined by ASTM D 1557 (for rigid structures) or D 698 (for flexible pavements). The ASTM D 1557 and D 698 test methods shall be used for samples containing up to 40% oversize particles (greater than 3/4 inch). If material contains more than 40% but less than 50% oversize particles, compaction of fill shall be confirmed by proof -rolling each lift with a 10-ton vibratory roller (or equivalent) until the maximum density has been achieved. Density testing shall 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 the maximum density or "break over" point. The number of required passes shall be used as the requirement on the remainder of fill placement. Material shall contain sufficient fines to fill all void spaces, and shall not contain more than 50% oversize particles. Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 ►— E-Mail mti@mti-id.com • www.mti-id.com 2006 MATERIALS Page # 1Ap # 14 of 24 TESTING & INSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc Backfill: Backfill materials shall ascribe to the requirements of structural fill except that the maximum material size shall be 4 inches. In no case shall material greater than 2 inches in diameter bear directly on structural elements. Placing oversized material against rigid surfaces interferes with proper compaction. Backfill should be compacted in accordance with 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. 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 excavations within these soil should be constructed at a maximum slope of 1'/2 foot horizontal to 1 foot vertical (1'/2H:1 V) 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. For deep excavations, native granular soils cannot be expected to remain in position. These materials are prone to failure and may collapse, thereby undermining upper soils layers. During our subsurface exploration, test pit sidewalls generally exhibited moderate indication of collapse, especially after penetration of the water table. Proper care must be taken so that excavations are properly backfilled in accordance with procedures outlined in this report to protect personnel and equipment. Water and loose debris should be removed from these excavations, prior to placement of fill soils or concrete. Groundwater Control: .. Groundwater was encountered in the investigation between 6.6 and 6.7 feet in depth. Excavations below the water table will require a dewatering program. It may be possible to discharge dewatering effluent to remote portions of the site or to a strategically located sump or 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 in general. It is recommended that runoff caused by wet weather be directed away from open excavations. On -site silty or clayey soils can be expected to become soft and pump if subjected to excessive traffic following periods of wet weather. Ponded surface water areas should be drained to allow construction to take place through methods such as trenching, sloping, crowning grades, nightly smooth drum rolling, or installation of a :.. French -drain system. Additionally, temporary or permanent driveway sections may be constructed should wet weather be forecast. Copyright © 2006 Materials Testing & Inspection, Inc. j 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 r• E-Mail mti@mti-id.com 9 www.mti-id.com il MATERIALS Pager# 15 o0224 TESTING & NSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b605l3g\b605l3geotech.doc GENERAL COMMENTS When plans and specifications are complete, or if significant changes are made in the character or location of the proposed development, consultation should be arranged as supplementary recommendations may be required. It is recommended that the service of a qualified geotechnical engineering firm be engaged to test and evaluate soils in footing excavations before placement of concrete to determine if soils meet compaction requirements. Monitoring and testing should also be performed to verify that suitable materials are used for structural fill and that proper placement and compaction is performed. L L L Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 �.. E-Mail mti@mti-id.com • www.mti-id.com L April 27, 2006 MATERIALS `J „� _ Page # 16 of 24 TESTING & NSPGCTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections rAboise\2006reports\400-599\b60513g\b60513geotech.doc REFERENCES American Society for Testing Materials, 1999, Standard Test Method for Materials Finer than 75-µm (No. 200) Sieve in Mineral Aggregates by Washing: C 117 - 95, 3 p. American Society for Testing Materials, 1999, Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates: C 136 - 96a, 5 p. American Society for Testing Materials, 1999, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils, ASTM Designation: D 4318 - 86, 11 p. Collett, R.A., 1980, Soil Survey of Ada County Area, Idaho: US Department of Agriculture, Soil Conservation Service, 327 p. Othberg, K.L. and Stanford, L.A., 1992, Geologic Map of the Boise Valley and adjoining area, Ada and Canyon Counties, Idaho: Idaho Geologic Map Series, scale 1:100,000. Copyright @ 2006 Materials Testing & Inspection, Inc. L 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS April 27, 2006 TESTING & ... .-J Page # 17 of 24 INSPECTION ❑ Environmental Services J Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r.\boise\2006 reports\400-599\b60513g\b60513geotech.doc APPENDIX GEOTECHNICAL GENERAL NOTES UNIFIED SOIL CLASSIFICATION SYSTEM GEOTECHNICAL TEST PIT LOGS PAVEMENT THICKNESS DESIGN RESISTANCE R-VALUE LABORATORY TEST DATA SITE MAP PLATES 4 L Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-6515 i_ E-Mail mti@mti-id.com - www.mti-id.com v April 27, 2006 MATERIALS — Page# 18of24 TESTING & INSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc L GEOTECHNICAL GENERAL NOTES SOIL PROPERTY SYMBOLS N: Standard "N" penetration: Blows per foot of a 140 pound hammer falling 30" on a 2" O.D. SS. Qu: Unconfined compressive strength, tons/ft2 Qp: Penetrometer value, unconfined compressive strength, tons/ft2 Qc: Cone Penetrometer value, unconfined compressive strength, pounds/in 2 V: Vane value, ultimate shearing strength, tons/ft2 I too M: Water content, % LL: Liquid Limit PI: Plasticity Index .. NP: Non -Plastic D: Natural dry density, lbs/ft3 WT: Apparent groundwater level (at time noted after completion). DRILLING AND SAMPLING SYMBOLS L L L SS: Split -Spoon - 1 3/8" I.D., 2" O.D., except where noted. ST: Shelby Tube - 3" O.D., except where noted. AU: Auger Sample. DB: Diamond Bit. CB: Carbide Bit. GS: Grab Sample. RELATIVE DENSITY AND CONSISTENCY CLASSIFICATION Non -Cohesive Soils Very Loose Loose Medium Dense Dense Very Dense Standard Penetration Resistance Cohesive Soils Standard Penetration Resistance <4 Very Soft <2 4-10 Soft 2-4 10-30 Firm Medium Stiff) 4-8 30-50 Stiff 8-15 >50 Very Stiff 15-30 Hard >30 PARTICLE SIZE Boulders 12 in. + Coarse Sand 5 mm to 0.6 mm Silts 0.074 mm to 0.005 mm Cobbles 12 in. to 3 in. Medium Sand 0.6 mm to 0.2 mm Clays 0.005 mm & Smaller Gravel 3 in. to 5 mm Fine Sand 0.2 mm to 0.074 mm Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com .4 �Nw April 27, 2006 MATERIALS Page# 19of24 TESTING & INSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc Unified Soil Classification System Major Symbol Soil Descriptions Divisions Well -graded gravels, gravel -sand mixtures, little or no fines Gravel and GW Poorly -graded gravels, gravel -sand mixtures, little or no fines Gravelly Soils GP Silty gravels, Poorly -graded gravel -sand -silt mixtures <50% coarse fraction GM Clayey gravels, Poorly -graded gravel -sand -clay mixtures passes #4 sieve GC Coarse Well -graded sands, gravelly sands, little or no fines Grained Soils Sand and SW Poorly -graded sands, gravelly sands, little or no fines <50% passes Sandy Soils SP Silty sands, Poorly -graded sand -gravel -silt mixtures #200 sieve >50% coarse fraction SM Clayey sands, Poorly -graded sand -gravel -clay mixtures passes #4 sieve SC Inorganic silts & very fine sands, silty or clayey fine sands, Fine Silts and Clays LL < 50 ML clayey silts CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays Organic silts and organic silt -clays of low plasticity Grained Soils OL Inorganic silts, micaceous or diatomaceous fine sand or silt >50% passes Silts and MH Inorganic clays of high plasticity, fat clays #200 sieve Clays LL > 50 CH Organic silts and clays of medium -to -high plasticity OH Highly Organic Soils Peat, humus, hydric soils with high organic content PT i Copyright ©2006 Materials Testing &Inspection, Inc. 7446 W. Lemhi St. - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-6515 E-Mail mti@mti-id.com - www.mti-id.com .. April 27, 2006 MATERIALS Page # 20 of 24 CPTESTING & NSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-1 Date Advanced: 4/13/06 Logged By: Liz Brown Excavated By: Circle H Construction Location: See Later Site Map Plates Depth to Water Table: 6.6 Feet Depth to Bottom Of Hole: 8.0 Feet Depth Field Description, w/USCS Soil Sample Sample Depth Qp Lab Test (Feet) and Sediment Classification Type (From -To) ID Sandy Lean Clay (CL): Dark 0.0-2.0 brown to brown, slightly moist, very 2.3-2.5 stiff, with fine-grained sand. - Organic material to 1.6 feet. Sandy Silt (ML): Brown, slightly 0.5-1.0 2.0-5.1 moist to moist, soft to stiff, with fine- rained sand. Poorly Graded Sandy Gravel 5.1-8.0 (GP): Brown to reddish -brown, moist to saturated, medium dense, with 6-inch minus cobbles. Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS — April 27, 2006 �..• TESTING Page # 21 of 24 ' INSPECTION v ❑ Environmental Services ❑ aeotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r jawr:\boise\2006 reports\400-599\b60513g\b605l3geotech.doc GEOTECHNICAL INVESTIGATION .. TEST PIT LOG Test Pit Log #: TP-2 Date Advanced: 4/13/06 Logged By: Liz Brown Excavated By: Circle H Construction Location: See Later Site Map Plates Depth to Water Table: 6.6 Feet Depth to Bottom Of Hole: 6.9 Feet Depth Field Description, w/USCS Soil Sample Sample Depth Qp Lab Test (Feet) and Sediment Classification Type From -To ID Sandy Lean Clay (CL): Dark 0.0-1.8 brown, slightly moist, stiff to very 1.8-2.8 stiff, with fine-grained sand. - Organic material to 1.4 feet. Sandy Silt (ML): Brown, slightly 1.8-3.9 moist, medium stiff to stiff, with fine- 1.0-1.5 rained sand. Poorly Graded Sandy Gravel 3.9-6.9 (GP): Brown to reddish -brown, moist to saturated, medium dense, with 6-inch minus cobbles. Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com M ATE R IALS April 27, 2006 _ TESTING & Page # 22 of 24 INSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-3 Date Advanced: 4/13/06 Logged By: Liz Brown Excavated By: Circle H Construction Location: See Later Site Map Plates Depth to Water Table: 6.7 Feet Depth to Bottom Of Hole: 7.1 Feet Depth Field Description, w/USCS Soil Sample Sample Depth Qp Lab Test (Feet) and Sediment Classification Type (From -To) ID Sandy Lean Clay (CL): Dark 0.0-1.6 brown, slightly moist, medium stiff to stiff, with fine-grained sand and Bulk 0.5-1.0 0.7-1.0 A occasional 2 inch minus cobbles. Or anic material to 1.2 eet. Sandy Silt (ML): Brown, slightly 1.6-4.0 moist, stiff to very stiff, with fine- 1.5-2.5 rained sand. Poorly Graded Sandy Gravel 4.0-7.1 (GP): Brown to reddish -brown, moist to saturated, medium dense, with 8-inch minus cobbles. Lab Test ID M LL PI Sieve Anal sis - % - - #4 #10 #40 #100 #200 A 16.2 40 17 86 82 66 51 43.0 Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 — E-Mail mti@mti-id.com • www.mti-id.com yMATERIALS April 27, 2006 TESTING & Page # 23 of 24 INSPECTION ❑ Environmental Services J 3eotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections EI r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc I IDAHO METHOD - PAVEMENT THICKNESS (USING ADA COUNTY HIGHWAY DISTRICT SUBSTITUTION RATIOS) Pavement Section Design Location: Proposed Black Cat Subdivision Average Daily Traffic Count: All Lanes & Both Directions Design Life: 20 Years Traffic Index: 6.00 Climate Factor: 1 R-Value of Subgrade: Subgrade CBR Value: -- Subgrade Mr: R-Value of Aggregate Base: 80 R-Value of Granular Borrow: 60 Subgrade R-Value: 3 Expansion Pressure of Subgrade: 0.33 Unit Weight of Base Materials: 130 3.00 Total Design Life 18 kip ESAL's: 33,131 ASPHALTIC CONCRETE: Gravel Equivalent, Calculated: 0.384 Feet Thickness: 0.196923077 Use = 0.208 Feet Gravel Equivalent, ACTUAL: 0.41 CRUSHED AGGREGATE BASE: Gravel Equivalent (Ballast): 0.768 (if only aggregate base is to be considered change B 14 to B 15) Thickness: 0.329 Use = 0.5 Feet Gravel Equivalent, ACTUAL: 0.956 GRANULAR BORROW: Gravel Equivalent (Ballast): 1.862 Thickness: 0.907 Use = 1 Feet Gravel Equivalent, ACTUAL: 1.956 TOTAL Thickness: 1.708 Thickness Required by Exp. Pressure: 0.366 This number must be less than TOTAL Thickness Design (ACHD Values) Depth Substitution Inches Ratios Asphaltic Concrete (at least 2.5): 2.50 1.95 (ACHD minimums: 2.5 for local & 3 for art./collector) Asphalt Treated Base (at least 4.2): 0.00 Cement Treated Base (at least 4.2): 0.00 Untreated Aggregate Base (at least 4.2): 6.00 1.10 Granular Borrow (at least 4.2): 12.00 1.00 Copyright @ 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com 006 MATERIALS April 27, 2 Page # 24 of 24 TESTING & .-0' INSPECTION ❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections r:\boise\2006 reports\400-599\b60513g\b60513geotech.doc WW RESISTANCE R-VALUE LABORATORY TEST DATA Source and Description: TP-3, 0.5'-1.0' —Clay Date Obtained: Aril 13, 2006 Sample ID: 4924 Sampling and Preparation: ASTM D75: AASHTO T2: X AASHTO T87: X ASTM D421: Test Standard: I ASTM D2844: AASHTO T190: Idaho T8: X Sample A B C Dry Density lb/ft 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** ** 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 10.0 8.0 6.0 4.0 2.0 0.0 300 250 200 150 100 Exudation Pressure (psi) Copyright © 2006 Materials Testing & Inspection, Inc. 7446 W. Lemhi St. • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 `-' E-Mail mti@mti-id.com • www.mti-id.com u N Im(1) cv a O Ay > N O2 N H m s co e N.. O Z L aco~ W c 3 Q 3 Z J fn m O N O � O W Z W aIL WVI I_ Z