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Geotechnical Engineering Report
SpEcial Inspections Construction Materials TEsting GEOtEchnical EnginEEring EnvironMEntal Sr=rvicEs Asbestos/lead Management Planning MATERIALS ATC TESTING & INSPECTION F,�, 4 p Ith e- rq g, C- Cquq rlitp, of Yov- CPMATERIALS TESTING & NSPECTION l Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GEOTECHNICAL ENGINEERING REPORT of Proposed Residential Subdivision 1235 McMillan Meridian, Idaho Prepared for: Covino Financial Group 13965 West Chinden Boulevard, Suite 100 Boise, Idaho 83713 MTI File Number 870810g 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CpMATERIALS TESTING & INSPECTION June 1, 2007 Page # 1 of 20 r:\boise\2007 reports\800-999\b708IOg\b708IOgeotech.doc -1 Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Mr. Ammon Covino Covino Financial Group 13965 West Chinden Boulevard, Suite 100 Boise, Idaho 83713 Re: Geotechnical Engineering Report Proposed Residential Subdivision 1235 McMillan Meridian, Idaho Gentlemen: In compliance with your instructions, we have conducted a soils exploration and foundation evaluation for the above referenced development. Fieldwork for this investigation was conducted on 30 May 2007. 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 one 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 would be pleased 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. 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. Respectfully Submitted, ���OFESSIOAI Materials Testing & Inspection, Inc. KEVIN L. 0 Ij SCFiROEDER f964 3' O Liz Brown Reviewed by: even r, P.G. OF 1DP�' Staff Engineer Geotechniervices Manager Reviewed by �" Cc: Ms. Sabrina Whitehead, Briggs Engineering, Inc. (2 copies) ivid O. Crarfi P.E!4�A7 -neral Manager Copyright © 2007 Materials "Nesting & Inspection. Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com cpMATERIALS TESTING & INSPECTION June 1, 2007 Page # 2 of 20 r:\boise\2007 repo rts\800-999\b70810g\b70810geotech.doc Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections ..W TABLE OF CONTENTS INTRODUCTION.................................................................................................................................................. 3 ProjectDescription.................................................................................................................................... 3 Authorization............................................................................................................................................. 3 Purpose...................................................................................................................................................... 3 Scopeof Investigation............................................................................................................................... 4 Warrantyand Limiting Conditions............................................................................................................4 SITEDESCRIPTION............................................................................................................................................. 5 SiteAccess.................................................................................................................................................5 RegionalGeology...................................................................................................................................... 5 Regional Site Climatology and Geochemistry...........................................................................................6 GeoseismicSetting.................................................................................................................................... 6 SOILSEXPLORATION..........................................................................................................................................6 Exploration and Sampling Procedures....................................................................................................... 6 LaboratoryTesting Program......................................................................................................................6 Soiland Sediment Profile.......................................................................................................................... 7 SoilsSurvey Review..................................................................................................................................7 VolatileOrganic Scan................................................................................................................................ 7 SITEHYDROLOGY.............................................................................................................................................. 8 Groundwater.............................................................................................................................................. 8 SoilInfiltration Rates................................................................................................................................. 8 InfiltrationTesting.....................................................................................................................................8 FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS.......................................................................9 Foundation Design Recommendations...................................................................................................... 10 CrawlSpace Recommendations................................................................................................................ 10 Floor, Patio, and Garage Slab -on Grade.................................................................................................... 11 CONSTRUCTION CONSIDERATIONS..................................................................................................................... 1 1 Earthwork.................................................................................................................................................. 12 DryWeather............................................................................................................................................... 12 WetWeather.............................................................................................................................................. 12 SoftSubgrade Soils.................................................................................................................................... 13 FrozenSubgrade Soils............................................................................................................................... 13 StructuralFill............................................................................................................................................. 13 Backfill...................................................................................................................................................... 14 Excavations................................................................................................................................................ 14 GroundwaterControl................................................................................................................................. 15 GENERALCOMMENTS........................................................................................................................................ 15 REFERENCES...................................................................................................................................................... 16 APPENDICES....................................................................................................................................................... 17 AcronymList............................................................................................................................................. 17 GeotechnicalGeneral Notes...................................................................................................................... 18 Geotechnical Investigation Test Pit Log.................................................................................................... 19 Copyright G 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CPMATERIALS TESTING & NSPECTION June 1, 2007 Page # 3 of 20 r:\boise\2007 reports\800-999\b708IOg\b708IOgeotech.doc Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Now, 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 storm water 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 foundation 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 north of the City of Meridian, Ada County, Idaho, and occupies a portion of the NE'/4 of Section 31, Township 4 North, Range 1 East, Boise Meridian. This project will consist of construction of approximately 21 residential structures to be developed on 5 acres. Total settlements are limited to 1 inch. Loads of up to 2,000 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 proposed grading. '--' Authorization Authorization to perform this exploration and analysis was given in the form of a verbal authorization to proceed from Ms. Sabrina Whitehead of Briggs Engineering, Inc., in care of Covino Financial Group, to Liz Brown of Materials Testing and Inspection, Inc. (MTI). Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between Covino Financial Group and MTI. Our scope of services for the proposed development has been provided in our proposal dated 14 May 2007 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 Copyright O 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CPMATERIALS TESTING & INSPECTION June 1, 2007 Page # 4 of 20 r:\boise\2007 reports\800-999\b708I0g\b708IOgeotech.doc -1 Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Scope of Investigation 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 of the site, field and laboratory testing of materials collected, and engineering analysis and evaluation of foundation materials. The scope of work did not include design recommendations specific to individual residences. 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 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. 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. 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. Upon commencement of construction, such conditions may be identified that required corrective actions; and these required corrective actions may impact the project budget. This report was prepared for exclusive use of Covino Financial Group 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, 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 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. Copyright O 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com 0 www.mti-id.com CoMATERIALS TESTING & NSPECTION June 1, 2007 Page # 5 of 20 r:\boise\2007 reports\800-999\b70810g\b708IOgeotech.doc -1 Environmental Services ❑ Geotechnical Engineering ❑ construction Materials Testing ❑ Special Inspections SITE DESCRIPTION Site Access Access to the site may be gained via Interstate 84 to the Meridian Road exit. Proceed north on Meridian Road approximately 3.75 miles to its intersection with McMillan Road. From this intersection, proceed east 0.75 mile to the site location. The site is located on the south side of McMillan Road at 1235 McMillan. Presently the site exists as a rural residence with associated outbuildings fronting McMillan Road. The location is depicted in 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. General Site Characteristic This proposed development consists of approximately 5 acres of relatively flat land. Throughout the majority of the site, surficial soils consisted of fine-grained clay -sand mixtures. Vegetation consists primarily of bunchgrass, and other native grass varieties typical of and to semi -arid environments. Regional drainage is north toward the Boise River. Storm water drainage for the site is achieved by percolation through surficial soils. Storm water drainage collection and retention systems are not in place on the project site; however, they are proposed as part of the development. Additionally, storm water drainage collection systems do not currently exist within the vicinity of the project site. Copyright © 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com crMATERIALS TESTING & INSPECTION June 1, 2007 Page # 6 of 20 r:\boise\2007 reports\800-999\b70810g\b708 I Ogeotech.doc Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Regional Site Climatology and Geochemistry According to the Western Regional Climate Center (WRCC; 2006) the average precipitation for 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 I I V F. Winds are generally from the northwest or southeast with an annual average wind speed is approximately 9 mph with 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, and local aggregates are generally appropriate for Portland cement and lime cement mixtures. Surface waters, groundwaters, and soils in the region typically have pH levels ranging from 7.2 to 8.2 (USGS 2006). No indication of abnormal geochemical conditions were noted on site. Geoseismic Setting Soils on site are classed as Site Class D in accordance with Chapter 16 of the 2003 edition of the IBC. Structures constructed on this site should be designed per IBC requirements 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 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 located in the field by means of visual approximation from on -site features or known locations and are presumed to be accurate to within a few feet. Upon completion of investigation, each test pit was backfilled with loose excavated materials. These loose areas need to be re -excavated and compacted prior to constructing structures over them. 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 on these logs. It is recommended that these logs not be used for estimating quantities because of highly interpretive results. 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 analyzing the anticipated 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. Copyright © 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CPMATERIALS TESTING & NSPECTION June 1, 2007 Page # 7 of 20 rAboise\2007 reports\800-999\b70810g\b70810geotech.doc Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections The laboratory testing program for this report included: Atterberg Limits Tests - ASTM D 4318 and Grain Size Analysis - ASTM C 117, C 136, and Resistance Value (R-Value) and Expansion Pressure of Compacted Soils - Idaho T-8. As to date, the R-Value test results have not been received and therefore have not been included within this report. MTI will forward the results in the form of an addendum once the R-Value test results have been received. Soil and Sediment Profile Test pits were advanced to depths of 10.3 to 17.2 feet below ground surface (bgs) across the site. The developed profile represents only a generalized case, and variations between test pit locations should be anticipated. Lean Clay (CL) — Brown, dry, hard, lean clay soils were encountered at ground surface. Fine-grained sand was observed throughout the clay soils, and organic material was present generally to depths of 0.8 to 0.9 foot bgs. Lean clay soils were noted at the surface and extended to depths of 3.1 to 4.3 feet bgs. Cemented Sandy Silt (ML) — Underlying lean clay, brown to light brown, dry, weakly cemented, sandy silt was observed in each test pit. Cemented sandy silt soils were noted to depths of 6.1 to 6.8 feet bgs. Poorly Graded Sandy Gravel (GP) — Light brown, dry, medium dense to dense, poorly graded sandy gravel sediments were observed in each test pit under the cemented sandy silt horizon. Fine grained sand and cobbles of up to 8 inches in diameter were present within this sediment. Cementation was noted within the upper 12 inches of this material. Poorly -graded gravel sediments extended beyond termination depths of each test pit. Test pit walls were generally stable. Excavations through granular sediments will have a propensity for sloughing or caving. Soils Survey Review Review of the United States Department of Agriculture (USDA) Soil Conservation Service, Soil Survey of Ada County Area, Idaho, 1980, indicates that the site includes Power silt loam soil type. Power silt loam soils occur on low alluvial terraces and basalt plains. Specific soils characteristics, as defined by the USDA, include moderately slow permeability, slow runoff, and slight hazard of erosion. 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. No groundwater was encountered. Copyright © 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CyMATERIALS TESTING & INSPECTION June 1, 2007 Page # 8 of 20 r:\boise\2007 reports\800-999\b70810g\b70810geotech.doc t Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections SITE HYDROLOGY Existing surface drainage conditions are defined in the Site Topography, Drainage, and Vegetation 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. Groundwater Groundwater was not encountered within the depths explored during this field investigation. Soil moistures in the test pits were generally dry. Groundwater levels in the site vicinity are controlled in large part by residential and agricultural irrigation activity and canal leakage in the local area. Maximum groundwater elevations likely occur during irrigation season. Estimating seasonal groundwater level fluctuation is problematic without regular monitoring. However, during previous explorations performed in September 2005 and June 2006, each within approximately 0.5 mile of the project site, no evidence of groundwater was noted within numerous test pits advanced to depths of between 6.8 and 15.8 feet bgs. Therefore, based on evidence of this investigation and background knowledge of the area, MTI anticipates groundwater depths to remain greater than 15 feet bgs throughout the year. This depth is an estimate. Soil Infiltration Rates Soil permeability is a measure of the ability of a soil to transmit a fluid. An estimation of fluid transport is presented using generally recognized values for each 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 hydraulic infiltration rates of less than 2 inches per hour; though calcium carbonate cementation encountered within cemented silt soils may reduce this value to near zero. Poorly graded sandy gravel sediments typically exhibit infiltration values in excess of 24 inches per hour. Infiltration testing is generally not required within these sediments as a result of the free -draining nature. Infiltration Testing Infiltration testing was conducted on poorly graded sandy gravel sediments encountered at depth across the site. Testing procedures as specified in the IDEQ Technical Guidance Manual were followed. Tests were conducted using 4-inch diameter PVC pipe installed in the poorly graded sandy gravels at a depth of 10.3 feet bgs in test pit 2. The test apparatus was filled with approximately 5 gallons of water on 30 May 2007 and allowed to pre-soak until the entire 5 gallons of water had drained prior to testing. Pre-soaking increases soil moistures, which allows the tested soils to reach a saturated condition more readily during testing. Saturation of the tested soils is desirable in order to isolate the vertical component of infiltration by inhibiting horizontal seepage during testing. Copyright © 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CFMATERIALS TESTING & INSPECTION June 1, 2007 Page # 9 of 20 rAboise\2007 reports\800-99%70810g\b708IOgeotech.doc Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Test procedures, as described in the above referenced design manual, specify that 6 inches of water should be added to the apparatus followed by monitoring of water level decline for '/2 hour or until the water is completely drained. During testing on 30 May 2007, the rate of water level decline within each test apparatus was monitored for successive intervals. For safety considerations, soils surrounding each test apparatus were completely replaced to original surface elevation. However, these areas will need to be re -excavated and compacted prior to construction of structures that will be sensitive to settlement. The results of the infiltration testing are as follows: fnfllfro+inn Too+i D .,I Test Location Test Interval Infiltration Time Minutes Observed Infiltration Inches Infiltration Rate Inches/Hour Test Pit 2 — 10.3 Feet 1 2 24 >50 2 2 24 >50 3 2 24 >50 4 2 24 >50 These data suggest that the native, non -cemented, poorly -graded gravel, present at depths of approximately 7.1 to 7.8 feet below existing grade are sufficiently permeable to permit rapid drainage of storm water. However, in accordance with IDEQ regulations, the incorporation of filter sand in seepage bed design should be anticipated because soil permeability is in excess of 8 inches per hour. The sand filter should consist of ASTM C 33 filter sand, or equivalent, and should be extended from the base of the seepage beds through the cemented sandy soils to ensure that cementation does not inhibit drainage. Excavation depths of 7.1 to 7.8 feet below existing grade should be anticipated to expose free draining soils. FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS Various foundation types have been considered for support of the proposed building structures. Two requirements must be fulfilled 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. Considering subsurface conditions and the proposed construction, it is recommended that the structures 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 approximately 21 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. Copyright O 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CYMATERIALS TESTING & NSPECTION June 1, 2007 Page # 10 of 20 r:\boise\2007 repo rts\800-999\b708]0g\b708IOgeotech.doc Environmental Services ❑ Geotechnical Engineering 0 Construction Materials Testing ��. 9 ❑Special Inspections 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: Soil Bearing Cavaci Footing Depth Footings must bear on competent, native, cemented sandy silt soils or compacted structural fill. Existing lean clay soils must be completely removed from below foundation elements.' Excavation depths ranging from 3.1 to 4.3 feet bgs should be anticipated to expose proper bearing soils. Su ASTM D 1557 Not Required for Native Soil 95% for Structural Fill Net Allowable II Soil Bearing Canacity 2,000 lbs/ft2 A '13 increase is allowable for short-term loading, which is defined by seismic events or designed wind s eeas. 'MTI recommends that a qualified geotechnical en ineer or engineering technician verify the bearing soil suitability for each structure at the time of construction Footings should be proportioned to meet either the stated soil bearing capacity or the 2003 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 footing 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 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 fine grained 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 U 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CPMATERIALS TESTING & INSPECTION June 1, 2007 Page # 11 of 20 r:\boise\2007 reports\800-999\008IOg\b708I Ogeotech.doc l Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections 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 lean clay. The clay soils should be scarified to a depth of 6 inches and re -compacted to a minimum of " 92 percent and a maximum of 98 percent of the maximum density as determined by ASTM D 698. The moisture content should range from 1 to 4 percentage points above optimum. Structural fill should be placed as soon as possible after re -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 fora 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 maximum density as determined by ASTM D 1557. 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. 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 10-mil in thickness and have a permeance of less than 0.3 US perms as determined by ASTM E 96. Placement of the moisture -retarder will require special consideration with regard to effects on the slab -on -grade. Use of a blotter sand over the moisture -retarder or placement of the moisture -retarder directly below the slab should be considered. Upon request, MTI can provide further consultation regarding installation. The granular mat should be compacted to no less than 95 percent of maximum density as determined by ASTM D 1557. CONSTRUCTION CONSIDERATIONS Recommendations in this report are based upon structural elements of the project being founded on competent, native, cemented sandy silt soils or compacted structural fill. Structural areas should be stripped to an elevation that exposes these soil types. Copyright © 2007 Materials Testing & Inspection, Inc, 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com ".4 _w, MATERIALS TESTING & INSPECTION June 1, 2007 Page # 12 of 20 r:\boise\2007 reports\800-999\b708IOg\b708I Ogeotech.doc 7 Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing g ❑Special Inspections 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. 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 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 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 a qualified geotechnical representative, and should be based upon subgrade soil type, composition, and firmness or soil stability. If underground storage tanks (USTs), 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 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. Copyright O 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CRMATERIALS TESTING & INSPECTION June 1, 2007 Page # 13 of 20 rAboise\2007 reports\800-999\b70810g\b708IOgeotech.doc Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections 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 anticipated 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. • 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. 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 D 2487). Use of silty soils (USCS designation of GM, SM, and ML) as structural 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. Copyright O 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com erMATERIALS TESTING & INSPECTION June 1, 2007 Page # 14 of 20 r:\boise\2007 reports\800-999\b708IOg\b708IOgeotech.doc ` Environmental Services ❑ Geotechnical En .", 9meerin 9 ❑ Construction Materials Testing ❑ 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 3/4-inch) material and no more than 12 percent fines (passing No.200 sieve) and 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 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 percent 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 must be used for samples containing up to 40 percent oversize (greater than 3/4-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 the maximum density or "break over" point. The number of required passes should be used as the requirement 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 Backfill materials must ascribe to the requirements of structural fill except that the maximum material size should be 4 inches. In no case should 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 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. 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'/z foot horizontal to I foot vertical (1'/ZH:IV) for excavations up to 20 feet in height. Excavations in excess of 20 feet will require additional analysis. Note that these sloe angles are considered stable for short-term conditions onlv, and will not hi- ctnii- , i--- During our subsurface exploration, test pit sidewalls generally exhibited little indication of collapse. 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 soils layers. This is especially true when working at depths near the water table. Additionally, care must be taken so that excavations are properly backfilled in accordance with procedures outlined in this report. Copyright © 2007 Materials Testing & Inspection. Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • E-Mail mti@mti-id.com • Fax (208) 322 6515 www. mti-id. com crMATERIALS TESTING & INSPECTION June 1, 2007 Page # 15 of 20 r:\boise\2007 reports\800-999\b70810g\b708I0geotech.doc ' Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Groundwater Control Groundwater was not encountered in the investigation and is anticipated to be below the depth of most construction. However, special precautions may be required for control of surface runoff and subsurface seepage. It is recommended that runoff caused by wet weather be directed away from open excavations. Silty and clayey soils may become soft and pump if subjected to excessive traffic following periods of wet weather. 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 When plans and specifications are complete, or if significant changes are made in the character or location of the proposed development, consultation with MTI should be arranged as supplementary recommendations may be required. It is recommended that suitability of subgrade soils and compaction of structural fill materials be verified 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. Copyright O 2007 Materials Testing & Inspection. Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com MATERIALS TESTING & INSPECTION June 1, 2007 Page # 16 of 20 Environmental Services ❑ Geotechnical En r:\boise\2007 reports\800-999\b708IOg\b708IOgeotech.doc ` Engineering 9 ❑Construction Materials Testing ❑ Special Inspections REFERENCES American Society for Testing and Materials (ASTM) (1999). Standard Test Method for Materials Finer than 75- m No. 200 Sieve in Mineral Aggregates by Washing: ASTM C 117 — 95. West Conshohocken, PA: ASTM, American Society for Testing and Materials (ASTM) (1999). Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates' ASTM C 136 96a. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2002). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort D1557 02e1. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (1999). Standard Test Methods for Resistance Value R-Value and Exaansion Pressure of Compacted Soils ASTM D 2844. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2006). Standard Practice for Classification of Soils for Engineering Pu oses (Unified Soil Classification System) D2487 06. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (1999). Standard Test Methods for Li uid Limit Plastic Limit and Plasticity Index of Soils: ASTM D 4318 — 86. West Conshohocken, PA: ASTM. Collett, R. A., U. S. Department of Agriculture, Soil Conservation Service. (1980). Soil Survey of Ada County Area Idaho Washington, DC: U. S. Government Printing Office. Desert Research Institute. Western Regional Climate Center. [Online] Available: <htM://www wrcc dri edu/> (2007). International Building Code Council (2002). International Building Code, 2003 Country Club Hills, IL: Author. Local Highway Technical Assistance Council (LHTAC) (2005). Idaho Standards for Public Works Construction 2005. Boise, ID: Author. Othberg, K. L. and Stanford, L. A., Idaho Geologic Society 0992). Geologic Mao of the Boise Valley and Adjoining Area, Western Snake River Plan Idaho (scale 1.100 000). Boise, Idaho: Joslyn and Morris. State of Idaho, Department of Health and Welfare, Division of Environmental Quality. (April 2000). Technical Guidance Manual For Individual and Subsurface Sewage Disposal Systems. Boise, Idaho: Author. U. S. Department of Agriculture, Natural Resource Conservation Service. Web Soil Survey. [Online] Available: <http://websoilsurvey.nres.usda.gov/app/> (2007). U. S. Department of Commerce, National Oceanic and Atmospheric Administration and Desert Research Institute. Western Regional Climate Center. [Online] Available: <http://www.wrcc.dri.edu/> (2007). U. S. Dept. of Labor, Occupational Safety and Health Administration. "CFR 29 Part 1926 subpart P: Safety and Health Regulations for Construction Excavations. 0 986)". [Online] Available: < www,osha.gov> (2007). U. S. Geological Survey. (2006). National Water Information System: Web Interface. [Online] Available: <htti):Hwaterdata.us_gs.gov/nwis> (2007). Copyright ©2007 Materials Testing & Inspection. Inc. 2791 South Victory View Way •Boise, ID 83709 •------------ E-Mail mti@Mti-id.com . w(376-4748 •Fax (208) 322-6515 ww-w. mti-id.com crMATERIALS TESTING & INSPECTION June 1, 2007 Page # 17 of 20 r:\boise\2007 reports\800-999\b708IOg\b708I Ogeotech.doc ` Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections APPENDICES ACRONYM LIST AASHTO: American Association of State Highway and Transportation Officials ACCP: Asphalt Cement Concrete Pavement ACHD: Ada County Highway District ASTM: American Society for Testing and Materials AU: Auger sample bgs: below ground surface CB: Carbide bit CBR: California Bearing Ratio D: natural dry unit weight, pcf DB: diamond bit DM: Dames & Moore sampling tube GS: grab sample IBC: International Building Code ISPWC: Idaho Standards for Public Works Construction ITD: Idaho Transportation Department LL: Liquid Limit M: water content N: Standard "N" penetration: blows per foot, Standard Penetration Test NP: nonplastic PCCP: Portland Cement Concrete Pavement PERM: vapor permeability PI: Plasticity Index PID: photoionization detector PVC: polyvinyl chloride QC: cone penetrometer value, unconfined compressive strength, psi Qp: Penetrometer value, unconfined compressive strength, tsf Qu: Unconfined compressive strength, tsf SPT: Standard Penetration Test (140:pound hammer falling 30 in. on a 2:in. split spoon) SS: split spoon (13/8:in. inside diameter, 2:in. outside diameter, except where noted) ST: shelby tube (3:in. outside diameter, except where noted) USCS: Unified Soil Classification System USDA: United States Department of Agriculture UST: underground storage tank V: vane value, ultimate shearing strength, tsf WT: apparent groundwater level Copyright © 2007 Materials Testing & Inspection. Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CoMATERIALS TESTING & INSPECTION June 1, 2007 Page # 18 of 20 r:\boise\2007 reports\800-999\b70810g\b70810geotech.doc Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing 9 ❑Special Inspections GEOTECHNICAL GENERAL NOTES RELATIVE Coarse -Grained Soils DENSITY AND CONSISTENCY CLASSIFICATION SPT Blow Counts (N) Fine -Grained Soils SPT Blow Counts <2 Very Loose: <4 Ve Soft: Loose: 4-10 Soft: 2-4 Medium Dense: 10-30 Medium Stiff. 4-8 8-15 Dense: 30-50 Stiff. -Very Dense: >50 Very Stiff. 15-30 Hard: >30 PARTICLE SIZE Boulders: >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 Cla s: <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 Gravel & Gravelly Soils GW Well -graded gravels; gravel/sand mixtures with little or no fines Coarse -Grained <50% GP Poorly -graded gravels; gravel/sand mixtures with little or no fines Soils coarse fraction GM Silty gravels; poorly -graded gravel/sand/silt mixtures <50% passes No.4 sieve GC Clayey gravels; poorly -graded gravel/sand/clay mixtures passes No.200 Sand & Sandy SW Well -graded sands; gravelly sands with little or no fines sieve Soils >50% SP Poorly -graded sands; gravelly sands with little or no fines coarse fraction SM Silty sands; poorly -graded sand/gravel/silt mixtures asses No.4 sieve SC Clayey sands; poorly -graded sand/gravel/clay mixtures ML ilts; sandy, gravelly or clayey silts Fine Grained Silts & 50Clays ean clays; inorganic, gravelly, sandy, or silty, low to medium -plasticity Soils >50% ,j1norgamc' a s passes No.200 rganic, low -plasticity clays and silts sieve Silts & Clays MH , elastic silts; sandy, gravellyor clayeyelastic silts A�clays; LL > 50 CH igh-plasticity, inorganic clays OH Organic, medium to high -plasticity clays and silts Highly Organic Soils PT Peat, humus, hydric soils with high organic content Copyright OO 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CrMATERIALS TESTING & NSPECTION June 1, 2007 Page # 19 of 20 r:\boise\2007 reports\800-999\b708IOg\b708IOgeotech.doc Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-1 Date Advanced: 5/30/2007 Logged by: Liz Brown Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 17.2 Feet bgs Depth Field Description and Sample Sample Depth Lab Feet b s USCS Soil and Sediment Classification Type Feet b s Qp Test ID 0.0-4.3 Lean Clay (CL): Brown, dry, hard, with fine rained sand and organic material to 0.8 oot. 4.5 Cemented Sandy Silt (ML): Brown to light 4.3-6.1 brown, dry, hard, weak calcium carbonate 4.5 cementation, with fine grained sand. Poorly Graded Sandy Gravel (GP): Light 6.1- l 7.2 brown, dry, medium dense to dense, with fine grained sand and 8 inch minus cobbles. Cemented in the upper 12 inches. Copyright © 2007 Materials Testing & Inspection. Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com CYMATERIALS TESTING & INSPECTION June 1, 2007 Page # 20 of 20 r:\boise\2007reports\800-999\b708IOg\b708IOgeotech.doc Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing � 9 ❑Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-2 Date 5/30/2007 Logged by: Liz Brown Advanced: Excavated by: Struckman's Backhoe Service Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 10.3 Feet bgs Notes: Pipe installed to 10.3 feet bgs for percolation testing. Depth (Feet b s Field Description and USCS Soil and Sediment Classification Sample T e Sample Depth Feet b s Qp Lab Test ID 0.0-3.1 Lean Clay (CL): Brown, dry, hard, with fine rained sand and organic material to 0.9 foot. GS BULK 0.2-0.5 0.2-0.5 4.5 A R-Value 3.1-6.8 Cemented Sandy Silt (ML): Brown to light brown, dry, hard, weak calcium carbonate cementation, with me grained sand. 4.5 6.8-10.3 Poorly Graded Sandy Gravel (GP): Light brown, dty, medium dense to dense, with fine grained sand and 8 inch minus cobbles. Cemented in the upper 12 inches. Lab Test ID M LL PI Sieve Anal si�Q� #4 #10 #40 ##200 100 100 95 73 - % - A 11.7 36 17 Copyright O 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 E-Mail mti@mti-id.com • www.mti-id.com i gym® JLbo � Z U LL �N E C C BZ O 11 N @J O `0 O Q W 0. 0 y o � Ul --� J � M F- oN ONmrL C 1�-P�irig �`�iIMPrnp� O N O] 09