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Geotechnical Engineering Report
6 MATERIALS TESTING & INSPECTION ❑ Environmental Service:: J _,eotechnical Engineering 0 Construction Materials Testing ❑ Special Inspections GEOTECHNICAL ENGINEERING REPORT of Proposed Commercial/Retail Development Eagle Road and 'Victory Road Meridian, Idaho Prepared for: RECEIVEI j MAY 13 ?ppg 617y OF MERIDIAN CITY CLERK OFFICE DMG Real Estate Partners 350 N 9th, Suite 201 Boise, Idaho 83702 MTI File Number 871536g 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 - Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com 6 MATERIALS TESTING & INSPECTION 26 December 2007 Page # 1 ol' 29 rAboise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Services J geotechnical Engineering 0 Construction Materials Testing J Special Inspections Mr. Greg Goins DMG Real Estate Partners 350 N 91h Street, Suite 201 Boise, Idaho 83702 (208) 389-9900 Re: Geotechnical Engineering Report Proposed Commercial/Retail Development Eagle Road and Victory Road 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 November 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 three copies 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, Materials Testing & Inspection, Inc. > o awson Staff Geologist Q�pFESSlp�� KEVIN L. 0 SCHROEDER Z_G t 964 Y iC sT47Z7o>= Io�'�° Reviewed by: Kevin oeder, Geotechnical Services Manager At Z 0i Reviewed by: Colin J. Basye, P. Geotechnical Engineer +�7 f 1 Copyright ® 2007 Materia u��t d_Irisprc;:, c. Ir. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com MATERIALS lF������U���� �� TESTING . ""�=� �~ 26Douemher 2007 cVwioe\2007,em,ts\|400'1599\b7|536Q\b7|536&_800tech.dnc LJEnvironmental Services -J utech imd Engineering TABLE OF~.CONTENTS lmTnnnucTIOw ------------------------------------------------'3 ProjectDescription ...................................................... —_—_______________________ Authorization. un— ----�--— �' - Purpose.............................................................................. ........................... --------------3 Scopeof Investigation ............................................ —..................................................... --------� Warranty and Limiting Conditions .............................. --------------------------�4 SITE DsurRJPTION-----------------------------------------------� Site Aocea------------------- -----------------------------� Regional~Geology ...................................................................................................................................... 5 General Site Characteristics ..............................5 Regional Site Climatology and Geochemistry ---_--------_—_____—__________. Gooe6xodcGeuino-------------------------------_-------_—___�' SOILS EXPLORATION ...................... -------------------------------__—_--_ Exploration and 9�oocdum� —~~�^~� ----------------------------------�h Laboratory Testing Program ........................................................ ............................................................. �7 Soil and Sediment ^ ----------------------------------------'7 SoilsSurvey Review .................................................................................................................................. VolatileOrganic Scan ................................................................................................................................ 0 SITE HYDROLOGY ........ ------.--------______________________________ Groundwater.......... -------------------------------------------�8 Soil Infiltration Rates -------------------------------------------8 puuwoAnoN,SLAB, AND 9xvswcwTDmroSsx)wAND RECOMMENDATIONS ..................... -------_--9 Foundation Design Recommendations ——-------—. ---.--------'—� --—' p Floor3lah'nu'Grude .......................................... .......... ........................... --..................... ............. ..... |U Recommended Pavement Sections -----------------------------------.. F�x��Puvemcm3echono ' l0 ----------'---------------------' --�—'—' |0 CommonP�c�cm��o���u���mul�m� -----------------------------/| CONSTRUCTION CONSIDERATIONS -------------------------------------' 12 Earthwork.. ' -----------------------------------------------'}2 Dry Weather --------------------~--------------------------'l2 WetWeather __________________________________________---'—..l3 Soft Sub@radoSoils -------------------------------------------.. 13 Frozen 3u6gmdeSoih � '�'�������.'''..---.'--'.''.---.—'''---.----..'.'..'..'.'.—'...' 13 Structural Fill ------' ---------------------------------.14 8uckGU----------. ------� ---------------------------------------'|4 Ex----------------------------------------------------- 15 Groundwater Control ----' ________________________________ 15 bswsn^LCowmpmTx..... ........................................................................................................... _----'|6 REFERENCES...................................................................................................................................................... |7 APPENDICES --------- . _ __________________________________ .. 18 AunugomL�t--------' ---'' ---------------------------------- 18 ueo�cbnou General Notes ----� -----------------------~-------' lQ Gno�cbn�u Tom9h�o0 ---- ���_=____ ___________________________ 20 Geo�cboua Test 9d�n� --- --�---- ' --------------------------.22 A8UHTOPavement 7h�k�u Dox��po��duz�o ---� _ ________________________---'2D Copyright 0zoo/Materials lemnumInspection, Inc. 27Q1South Victory View Way ^ Boise, /D8870S ^ MATERIALS TESTING & INSPECTION 26 December 2007 Page # 3 of 29 r\boise\2007 reports\1400-15991b71536g\b71536g geotech.doc ❑ Environmental Services J eotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections INTRODUCTION This report presents results of a geotechnical investigation and analysis in support of data utilized in design of structures as defined in the 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 southeast of the City of Meridian, Ada County, Idaho, and occupies a portion of the NW'/4NW'/4 of Section 28, Township 3 North, Range I East, Boise Meridian. This project will consist of construction of commercial structures to be developed on approximately 4.3 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 Mr. Greg Goins of DMG Real Estate Partners to Monica Saculles of Materials Testing and Inspection, Inc. (MTI), on 11 October 2007. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between DMG Real Estate Partners and MTI. Our scope of services for the proposed development has been provided in our proposal dated 10 October 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 light and heavy duty pavement section design requirements -- -_-_.. Copyright ® 2007 Materials Testing & Inspection, Inc 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mtiCmti-id.com • www.mti-id.com MATERIALS TESTING 6 INSPECTION 26 December 2007 Page # 4 of 29 r:\boise\2007 reports\1400-1599\b71536g\b71536g_ geotech.doc 0 Environmental Services -3 Geotechnical Engineering ❑ Construction Materials Testing 0 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. 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 DMG RE Partners 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'- 2007 Materials -1estitIg& Inspection, Inc 2791 South Victory View way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com MATERIALS 26 December 2007 TESTING Page # 5 of29 INSPECTION r:`,boise12007 reports\I400-1599\b71536g\b71536g_gcotech.doc ❑ Environmental Services _J ,eotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections SITE DESCRIPTION Site Access Access to the site may be gained via Interstate 84 to the Eagle Road exit. Proceed south on Eagle Road approximately 1.5 miles to its intersection with Victory Road. The site occupies the southeast corner of this intersection. Presently the site exists as a vacant residences with associated outbuildings and a farmed field. 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 Gowen Terrace" as mapped by Othberg and Stanford (1993). Sediments of the Gowen terrace consist of sandy pebble and cobble gravel. The Gowen terrace is the fourth terrace above modern Boise River floodplain, is thickest toward its eastern extent, and is mantled with 2-6 feet of loess. General Site Characteristics This proposed development consists of approximately 4.3 acres of gently sloping terrain. A majority of the site is sloping to the north, with the most southern approximately 0.5 acre along Eagle Road sloping to the south. Throughout the majority of the site, surficial soils consisted of fine-grained clay -silt mixtures. Vegetation consists primarily of lawn grass varieties and mature trees. Regional drainage is northwest 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) 322-65 15 mti@Mti-id.com - www.mti-id.com MATERIALS TESTING 6 INSPECTION 26 December 2007 Page # 6 of 29 r:lboise12007 reportsU400-15991b71536g1b71536g_geotech.doc ❑ Environmental Services J ;eotechnical 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 951 F with daily extremes ranging from -25' F to 111° F. Winds are generally from the northwest or southeast with an annual average wind speed of approximately 9 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. Copyright t�' 2007 Materials Testing & Inspection. Inc 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com MATERIALS TESTING & INSPECTION 26 December 2007 Page # 7 of 29 rAboise\2007 reports\ 1400-1599\b71536g\b71536g_geotech.doc 0 Environmental Services J otechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections Laboratory Testing Program Along with our field investigation, a supplemental laboratory testing program was conducted to determine additional pertinent engineering characteristics of subsurface materials necessary in 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. The laboratory testing program for this report included Atterberg Limits Tests - ASTM D 4318 and Grain Size Analysis - ASTM C I I7/C 136. Soil and Sediment Profile Test pits were advanced to depths of 10.7 to 18.2 feet below ground surface (bgs) across the site. Because of the areal extent of the studied parcel, the developed profile represents only a generalized case, and variations between test pit locations should be anticipated. Surficial soils were predominately lean clay silt mixtures. Silts and sandy silts were noted at excavation sites underlying surficial soils. Clays are often brown in color, but will vary from light to dark brown. Silts are more often a light to medium brown. These fine grained soils generally exhibit moisture contents of dry to slightly moist. Consistencies commonly range from stiff to hard, with many of these firmer soil horizons containing some degree of calcium carbonate cementation (hardpan). Organic materials were often noted to depths of roughly one foot, and disturbed materials, as a result of plowing activities, usually reached a depth of 1'/z feet, if present. In many of the more deeply developed soils, silty sand soils were encountered, and in a few cases poorly graded sands, poorly graded gravels, or silty gravels were present. Silty sands could most often be classified as light brown, slightly moist, and varied in relative density from medium dense to dense. Hardpan cementation also extended through portions of these horizons. The occurrence of poorly graded sands or gravels was limited, and they usually consisted of brown to yellow, dry, and medium dense to dense sand and gravel mixtures. Clasts found within some of the silty sands and a few of the gravels, consisted of basaltic and granitic cobbles. Competency of test pit walls varied across the site. In general, the fine grained soils remained stable while the more granular sediments sloughed. However, moisture contents will also affect wall competency, and saturated soils will have a tendency to readily slough when under load and unsupported. 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 is underlain by Elijah Silt Loam, 2 to 4 percent slopes. Elijah silt soils occur on intermediate alluvial terraces. Specific soils characteristics, as defined by the USDA, include moderately slow penneability above the hardpan and very slow through fractures, medium runoff; and moderate erosion hazard. Copyright � 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • mti@mti-id.com . (208) 376-4748 •Fax (208) 322 6515 www.mti-id.com MATERIAL'S TESTING & INSPECTION 26 December 2007 Page # 8 of 29 rAboise12007 reports11400-15991b71536g1b71536g_geotech.doc O Environmental Services .1 ..eotechnical Engineering ❑ Construction Materials Testing 0 Special Inspections 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. SITE HYDROLOGY Existing surface drainage conditions are defined in the General Site Characteristics section. Information provided in this section is limited to observations made at the time of the investigation. Either regional or local ordinances may require information beyond the scope of this report. Groundwater During this field investigation, groundwater was not encountered in test pits advanced to depths of 18.2 feet. Additionally, soil moistures in the test pits were generally dry to slightly moist within surficial soils and underlying sediments. 1n the project site vicinity, groundwater levels are controlled in large part by residential and commercial irrigation activity and by canal leakage in the local area. Maximum groundwater elevations likely occur during the later portion of the irrigation season. Additionally, during previous investigations performed in April 2006 across Eagle Road from the project site, groundwater was not encountered to a depth of 12 feet bgs. Therefore, based on evidence of this investigation and background knowledge of the area, MTI estimates groundwater at depths greater than 18 feet bgs throughout the year. Soil Infiltration Rates Soil permeability, which was not tested in the field, is a measure of the ability of a soil to transmit a fluid. Given the absence of these measurements, for this report 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. Sandy silt soils will exhibit infiltration rates of commonly from 2 to 4 inches per hour. Silty sand soils usually display rates of 4 to 8 inches per hour. Poorly -graded gravel sediments typically exhibit infiltration values in excess of 12 inches per hour. Infiltration testing is generally not required within these sediments because of the free -draining nature. It is recommended that infiltration facilities constructed on the site be extended into native silty gravel sediments. Excavation depths of approximately 4 feet bgs should be anticipated to expose these silty gravel sediments. ASTM C 33 filter sand, or equivalent, should be incorporated into design of infiltration facilities. An infiltration rate of 4 inches per hour should be used in design. Copyright "' 2007 Materials Testing & Inspection. Inc - 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com MATERIALS TESTING & INSPECTION 26 December 2007 Page # 9 of 29 r:\bois62007 reports\1400-1599\b71536g\b71536g-geotech.doc 0 Environmental Services J Geotechnical Engineering J '�'onstruction Materials Testing 0 Special Inspections FOUNDATION, SLAB, AND PAVEMENT DISCtTSSION 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. Foundation Design Recommendations On the basis of data obtained from the site and test results from various laboratory tests performed, MTl recommends following guidelines be used for the net allowable soils bearing capacity: g Depth aou Ilseartng t apacity a— b `1`55 Subgrade Compaction Footings must bear on competent, native, cemented sandy silt soils or compacted structural fill. Existing plow zone and fill materials must be completely removed from below foundation elements.' Excavation depths ranging from 1 to 2 feet bgs should be anticipated to expose proper bearing soils. 'KATt ,-o,.,.,,,.,,o_a� .t,... - , Not Required for Native Soil 95% for Structural Fill Net Allowable Soil Bearing Capaci 2,500 lbs/ft` A 1/3 increase is allowable for short-term loading, which is defined by seismic events or designed wind VVLGVJuiIVal Gil tnCcr or en lneerin technlclan verif the bearin 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 % 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, MTl recommends continuous footings be suitably reinforced to make them as rigid as possible. For frost nrotection the bottom of external footings -..should be 30 inches below finished grade Copyright 112007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mtiOmti-id.com • www.mti-id.com MATERIALS ry TESTING & INSPECTION 26 December 2007 Page # 10 of 29 rAboise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Services J ,:; niera,,t ica! Fnninpering 0 Construction Materials Testing ❑ Special Inspections Floor Slab -on -Grade 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'/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. Recommended Pavement Sections MTI has made assumptions for traffic loading variables based on the character of the proposed construction. The client should review these assumptions to make sure they reflect intended use and loading of pavements both now and in the future. Based on experience with soils in the region, a subgrade California Bearing Ratio (CBR) value of 8 has been assumed for near -surface soils on site. The following are minimum thickness requirements for assured pavement function. Depending on site conditions, additional work, e.g, soil preparation, may be required to support construction equipment. These have been listed within the Soft Subgrade Soils subsection. Flexible Pavement Sections The AASHTO design method has been used to calculate the following pavement sections. Calculation sheets provided in the Appendix indicate the soils constant, traffic loading, traffic projections, and material constants used to calculate the pavement sections. MTI recommends that materials used in the construction of asphaltic concrete pavements meet requirements of the State of Idaho Transportation Department (ITD) Standard Specification for Highway Construction. Construction of the pavement section should be in accordance with these specifications and should adhere to guidelines recommended in the section on Construction Considerations. Copyright a 2007 Materials I esttng & lnspecuon, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com MATERIALS j TESTING & INSPECTION 26 December 2007 Page # 11 of 29 rAboise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Serfices ❑ Gentechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections AASHTO Flexible Pavement Specifications 'p-awment Section Component Asphaltic Concrete Crushed Aggregate Base Structural Subbase Compacted Subgrade Driveways and Parking 2.5 Inches 4.0 Inches 6.0 Inches Not Required Driveways and 3.0 Inches 4.0 Inches 10.0 Inches Not Required *M'FI recommends that a qualified geotechnical engineer or engineering technician verify subgrade competent at t the time of construction. Asphaltic Concrete: Asphalt mix design shall meet the requirements of ITD Class III plant mix. Materials shall be placed in accordance with ITD Standard Specifications for Highway Construction. Aggregate Base: Material complying with ITD Standard Specifications for Highway Construction sections 303 and 703 for aggregates. Structural Subbase: Material should comply with the requirements detailed in the Structural Fill section of this report except that the maximum material diameter is no more than'/3 the component thickness. Common Pavement Section Construction Issues The subgrade upon which above pavement sections are to be constructed must be properly stripped, inspected, and proof -rolled. Proof rolling of subgrade soils should be accomplished using a heavy rubber - tired, fully loaded, tandem -axle dump truck or equivalent. Verification of subgrade competence by a qualified geotechnical engineer or engineering technician at the time of construction is recommended. Fill materials on the site must demonstrate the indicated compaction prior to placing material in support of the pavement section. MTI anticipates that pavement areas will be subjected to moderate traffic. MTI does not anticipate pumping material to become evident during compaction, but subgrade silts near and above optimum moisture contents may tend to pump. Pumping or soft areas must be removed and replaced with structural fill. Fill material and aggregates in support of the pavement section must be compacted to no less than 95 percent of the maximum dry density as determined by ASTM 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, then compaction of that material must be approved by observed proof rolling. Minor deflections from proof rolling for flexible pavements are allowable. Deflections from proof rolling of rigid pavement support courses should not be visually detectable. MTI recommends that rigid concrete pavement be provided for heavy garbage receptacles. This will eliminate damage caused by the considerable loading transferred through the small steel wheels onto asphaltic concrete. Rigid concrete pavement should consist of Portland Cement Concrete Pavement (PCCP) generally adhering to ITD specifications for Urban Concrete. PCCP should be 6 inches thick on a 4-inch drainage fill course (see Floor Slab -on -Grade section), and should be reinforced with welded wire fabric. Control joints must be on 12-foot centers or less. Copyright A 2007 Materials Testing & Inspection. Inc 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti®mti-id.com • www.mti-id.com MATERIALS TESTING & INSPECTION 26 December 2007 Page # 12 of 29 rAboiscQ007 reports\I400-1599\b71536g\b71536g geotech.doc ❑ Environmental Services J :eotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections CONSTRUCTION CONSIDERATIONS Recommendations in this report are based upon structural elements of the project being founded on competent cemented silt soils or compacted structural fill. Structural areas should be stripped to an elevation that exposes these soil types. Farthwork 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 I 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 (plow depths) or topsoil are removed prior to placement and compaction of structural fill materials. Exact removal depths should be detennined 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. Copyright @ 2007 Materials 'testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208 ) 376-4748 • Fax (208) 322 6515 mti@mti-id.com • www.mti-id.com MATERIALS TESTING & INSPECTION 26 December 2007 Page # 13 of 29 rAboise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Services J .,eotechnical Engineering 0 Construction Materials Testin ❑ Special Inspections Wet Weather If construction is to be conducted during wet seasonal conditions (commonly from mid -November through May), problems associated with soft soils must be considered as part of the construction plan. During this time of year, fine-grained soils such as silts and clays will become unstable with increased moisture content, and eventually deform or rut. Additionally, constant low temperatures reduce the possibility of drying soils to near optimum conditions. Soft Subgrade Soils Shallow fine-grained subgrade soils that are high in moisture content should be expected to pump and rut under construction traffic. During periods of wet weather, construction may become very difficult if not impossible. The following recommendations and options have been included for dealing with 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 % 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. Copyright ® 2007 Materials Testing& Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com 0 www.mti-id.com MATERIALS TESTING & INSPECTION 26 December 2007 Page # 14 of 29 r.,boise\2007 reports11400-l599\b7l536g\b7l536g_geotech.doc ❑ Environmental Storvices J aeotechnical Engineering 0 Construction Materials Testing 0 Special Inspections 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, use of silty soils (GM SM and MLA structural fill below footings is prohibited. Excessive heavy loading prohibits use of silty soils for structural fill below footings. 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, and SP, should consist of a 6 inch minus select, clean, granular soil with no more than 50 percent oversize (greater than'/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 1/4-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 III -place density test results indicate a drop (or no increase) in the dry density, defined as the maxitnui» 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. Copyright 2007 Materials resting & InspectUon, Inc 2791 South Victory View Way - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-6515 mti@mti-id.com 0 www.mti-id.com MATERIALS TESTING b INSPECTION 26 December 2007 Page # 15 of 29 r.\boise12007 reports\1400-15991b71536g1b71536g_geotech.doc ❑ Environmental Services J Fngineering J "" onstruction Materials Testing ❑ Special Inspections Excavations Shallow excavations that do not exceed 4 feet in depth may be constructed with side slopes approaching vertical. Below this depth, it is recommended that slopes be constructed in accordance with Occupational Safety and Health Administration (OSHA) regulations, section 1926, subpart P. Based on these regulations, on -site soils are classified as type "D" soil, and as such, excavations within these soils should be constructed at a maximum slope of 1 %2 foot horizontal to 1 foot vertical (1'/2H: l 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 During our subsurface exploration, test pit sidewalls generally exhibited little indication of collapse; however, sloughing of native granular sediments from test pit sidewalls was observed. 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. Shallow soil cementation (caliche) was observed throughout much of the site and may cause difficulties during foundation development and utility placement. Cemented soils should be anticipated throughout the site at depths of 2 to 5 feet bgs. Groundwater Control Groundwater was not encountered in the investigation and is anticipated to be below the depth of most construction. Excavations below the water table will require a dewatering program. Dewatering will be required prior to placement of fill materials; however, placement of concrete can be accomplished through water by the use of a treme. It may be possible to discharge dewatering effluent to remote portions of the site, to a sump, or to a pit. This will essentially recycle effluent, thus eliminating the need to enter into agreements with local drainage authorities. Should the scope of the proposed project change, MTI should be contacted to provide more detailed groundwater control measures. Special precautions may be required for control of surface runoff and subsurface seepage. It is recommended that runoff caused by wet weather be directed away from open excavations. Silty or 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. Copyright 2007 Materials 'I estmg x Inspection. Inc 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti®mti-id.com • www.mti-id.com MATERIALS 26 December 2007 TESTING & Page# 16of29 INSPECTION rAboise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc U Environmental Services J Geotechnical Engineering ❑ Construction Materials Testis 0-Special Inspections GENERAL COMMENTS When plans and specifications are complete, or if significant changes are made in the character or location of the proposed structures, 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'- 2007 Materials Testing & Inspection, Inc, 2791 South Victory View Way - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-6515 mti@mti-id.com - www.mti-id.com 6 MATERIALS TESTING & INSPECTION 26 December 2007 Page # 17 of 29 r:\boise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Services .J Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections .REFERENCES American Society for Testing and Materials (ASTM) (1999). Standard Test Method for Materials Finer than 75-µm (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 Agates: ASTM C 136 96a. West Conshohocken, PA: AS'lA4 American Society for Testing and Materials (ASTM) (2006). Standard Practice for Classification of Soils for EngineeringPuu poses (Unified Soil Classification System) D2487-06. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (1999). Standard Test Methods for Liquid 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: <b=://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 (1992). Geologic Map 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, Natiunal 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. (1986)". [Online] Available: < www.osha.gov> (2007). U. S. Geological Survey. (2006). National Water Information System: Web Interface. [Online] Available: <http:;iwaterdata.usgs.gov/nwis> (2007). ('opyrighj - 20(17 Materials Icwnp & In.pccnon hi, 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com 6 MATERIALS TESTING 6 INSPECTION 26 December 2007 Page # 18 of 29 r:\boise\2007 reports\ 1400-1599\b7 l 536g\b7 1536g _geotech.doc ❑ Environmental Service: U Geotechnical Engineering J 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 MSL: mean sea level 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 mti@mti-id.com • www.mti-id.com - 6MATERIALS TESTING & INSPECTION 26 December 2007 Page # 19 of 29 r:\boise\2007 reports11400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Services 0 Geotechnical Engineering :3 Construrtion Materials Testing ❑ Special Inspections GEOTECHNICAL GENERAL NOTES Coarse -Grained Soils SPT Blow Counts Fine -Grained Soils SPT Blow Counts N Very Loose: <4 Very Soft: <2 Loose: 4-10 Soft: 2-4 Medium Dense: 10-30 Medium Stiff- 4-8 Dense: 30-50 Stiff: Very Stiff. 8-15 15-30 V'e Dense: >50 Hard: >30 Boulders: >12 in. Cobbles: 12 to 3 in. Gravel: 3 in. to 5 min Coarse -Grained Sand: Medium -Grained Sand Fine -Grained Sand: 5 to 0.6 mm 0.6 to 0.2 mm 0.2 to 0.075 mm Silts: 0.075 to 0.005 mm Clays: <0.005 mm L NIFIED SC?ID_CMA 1716 TIQ _-YSTENI iliajpr Divisio'� Gravel & Gravelly Soils <50% coarse fraction passes No.4 sieve yutEaol..... GW oil Descriptions_ Coarse -Grained Soils <50% passes No.200 sieve Well -graded gravels; gravel/sand mixtures with little or no fines GP Poorly -graded gravels; gravel/sand mixtures with little or no fines GM Silty gravels; poorly -graded gravel/sand/silt mixtures GC Clayey gravels; poorly -graded gravel/sand/clay mixtures Sand & Sandy Soils >50% coarse fraction passes No.4 sieve SW Well -graded sands; gravelly sands with little or no fines SP Poorly -graded sands; gravelly sands with little or no fines SM — - Silty sands; poorly -graded sand/gravel/silt mixtures SC Clayey sands; poorly -graded sand/gravel/clay mixtures Fine Grained Soils >50% passes No.200 sieve Highly Organic Silts &Clays LL < 50 ML Inorganic silts; sandy, gravelly or clayey silts CL Lean clays; inorganic, gravelly, sandy, or silty, low to medium -plasticity clays OL Organic, low -plasticity clays and silts Silts & Clays LL > 50 MH Inorganic, elastic silts; sandy, gravelly or clayey elastic silts CH Fat clays; high -plasticity, inorganic clays OH PT Organic, medium to high -plasticity clays and silts Peat, humus, hydric soils with high organic content Soils Copyright ' 2007 Materials Testing & hsspection, tnc 2791 South Victory View Way - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-6515 mti@mti-id.com - www.mti-id.com MATERIALS TESTING & INSPECTION 26 December 2007 Page # 20 of 29 r:\boise\2007 reports\I400-1599\b71536g\b71536g_geotech.doc 0 Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing 0 Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-1 Date Advanced: 10/30/07 Logged by: Kory Dawson Excavated by: Bob Camp Excavation Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 17.2 Feet bgs Depth Field Description and Sample Sample Depth Field Lab (Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) TestMethod Test Ill Borderline Lean Clay/Sandy Silt (CL/ML): Qp 0.0-1.8 Brown to dark brown, dry, very stiff, with fine- 2.75-3.0 grained sand. Torvane --Organic material throughout. 0.5-2.5 Sandy Silt (ML): Light brown, dry, hard, with Qp 1.8-3.9 fine-grained sand. 4.5+ --Weak, intermittent, calcium carbonate Torvane cementation throughout. 3.5-4.5 Silty Gravel (GM): Light brown, drt% to 3.9-7.3 slightly moist, dense, with fine-grained sand and 4-inch minus basaltic cobbles. --Sand coarsening with depth. Silty Sand (SM): Brown, slightly moist, 7.3-11.7 medium dense to dense, containing fine- I rained sand. Poorly -Graded Sand (SP): Yellow -brown, dry, 11.7-15.0 medium dense to dense, with medium to coarse- rained sand. 15.0-17.2 Silty Sand (SM): Brown, slightly moist, dense, containin ine to coarse -grained sand. Copyright ® 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-6515 mti®mti-id.com - www.mti-id.com 6 MATERIALS TESTING fr INSPECTION 26 December 2007 Page # 21 of 29 r:\boise\2007 reports\1400-1599\b71536g\b7l536g_geotech.doc Environmental Services ❑ Geotechnical Engineering 0 Construction Materials Testing ❑ Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-2 Date Advanced: 10/30/07 Logged by: Kory Dawson Excavated by: Bob Camp Excavation Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 16.3 Feet bgs Depth Field Description and Sample Sample Depth Field Test Lab (Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Method Test ID Borderline Lean Clay/Sandy Silt (CL/ML): Qp Brown to dark brown, dry, very stiff, with fine- 2.75-3.0 0.0-1.3 grained sand. Torvane --Organic material throughout. 0.5-2.5 Sandy Silt (ML): Light brown, dry, hard, with Qp fine-grained sand. 4.5+ 1.3-3.6 --Weak, intermittent, calcium carbonate Torvane cementation throughout. 2.0-3.5 Silty Gravel (GM): Light brown, dry to slightly moist, with fine-grained sand and 3.6-7.6 4-inch minus basaltic cobbles. --Sand coarsening with depth. Silty Sand (SM): Brown, slightly moist, 7.6-16.3 medium dense to dense, containing fine - rained sand. Copyright 0 2007 Materials Testing & Inspection. Inc. 2791 South Victory View Way • Boise.. ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com MATERIALS TESTING fr w�pFr-nnn� 26 December 2007 Page # 22 of 29 r:\boise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Services J Geotechnical Engineering ❑ Constr«rtion Materials Testing ❑ Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-3 Date Advanced: 10/30/07 Logged by: Kory Dawson Excavated by: Bob Camp Excavation Location. See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 10.7 Feet bgs Depth Field Description and Sample Sample Depth Field Test Lab ( Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Method Test ID Borderline Lean Clay/Sandy Silt (CL/ML): Qp Brown to dark brown, dry, very soft, with fine- <0.25 0.0-0.8 grained sand. Torvane --Organic material throughout. 2.0-3.0 Sandy Silt (ML): Light brown, dry, hard, with Qp fine-grained sand. 4.5+ 0.8-3.4 --Moderate, calcium carbonate cementation Torvane throughout. _ 2.0-3.0 Silty Gravel (GM): Light brown, dry to 3.4-8.0 slightly moist, dense, with fine-grained sand and 4-inch minus basaltic gravels. Silty Sand (SM): Brown, slightly moist, 8.0-10.7 medium dense to dense, containing fine- grained sand. Copyright ° 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-6515 mti®mti-id.com - www.mti-id.com MATERIALS TESTING 6 11U4r.Pr—rT1nKj 26 December 2007 Page # 23 of 29 r:\boise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Services J Geotechnical Engineering ❑ rtion Materials Testing ❑ Special Inspectinns GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-4 Date Advanced: 10/30/07 Logged by: Kory Dawson Excavated by: Bob Camp Excavation Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 11.3 Feet bgs Depth Field Description and Sample Sample Depth Field TestMethod Lab (Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Test ID Borderline Lean Clay/Sandy Silt (CL/ML): Qp 0.0-1.3 Brown to dark brown, dry, stiff, with fine- GS 0.5-0.75 1.0-2.0 A grained sand. Torvane --Organic material throughout. 2.5-3.0 Sandy Silt (ML): Light brown, dry, hard, with Qp fine-grained sand. 4.0-4.5+ 1 3-8 7 --Weak, intermittent, calcium carbonate Torvane cementation throughout. 2.0-2•5 Silty Sand (SM): Brown, slightly moist, 8.7-11.3 medium dense to dense, containing fine- grained sand. Lab Test ID M LL PI Sieve Analysis - % - - #4 #10 #40 #100 #200 A 8.6 37 10 95 91 81 74 66 Copyright ® 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way • Boise, ID 83709 (208) 376-4748 - Fax (208) 322-6515 mti@mti-id.com - www.mti-id.com CMATERIALS TESTING & iKjczPt=rTInKI 26 December 2007 Page # 24 of 29 r.\boise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Services tl Geotechnical Engineering ❑ Construction Materials Testing ❑ Special inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-5 Date Advanced: 10/30/07 Logged by: Kory Dawson Excavated by: Bob Camp Excavation Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 18.2 Feet bgs Depth Field Description and Sample Sample Depth Field Test Lab ( Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Method Test ID Borderline Lean Clay/Sandy Silt (CUML): Qp Brown to dark brown, dry, stiff, with fine- 1.0-2.0 0.0-1.6 grained sand. Torvane --Organic material throughout. 1.0-1.5 Sandy Silt (ML): Light brown, dry, hard, with Qp fine-grained sand. 4.5+ 1.6-11.1 --Moderate calcium carbonate cementation Torvane throughout. 3.5-4.5 Silty Sand (SM): Brown, slightly moist, medium dense to dense, containing fine to 11.1-13.4 coarse -grained sand and occasional 6-inch minus cobbles. Poorly -Graded Sandy Gravel (GP): Yellow- brown, dry, medium dense to dense, 13.4-18.2 containing fine to medium -grained sand and 6- inch minus cobbles. Copyright ® 2007 Materials Testing & Inspection. Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti®mti-id.com • www.mti-id.com CMATERIALS TESTING 6 iniCI—pFrTin 26 December 2007 Page # 25 of 29 rlboise12007 reportsU400-15991b71536g1b71536g_geotech.doc 0 Environmental Services 0 Geotechnical Engineering 0 Construction Materials Testing ❑ Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-6 Date Advanced: 10/30/07 Logged by: Kory Dawson Excavated by: Bob Camp Excavation Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 17.2 Feet bgs Depth Field Description and Sample Sample Depth Field Test Lab (Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Method Test ID Borderline Lean Clay/Sandy Silt (CL/ML): Qp Brown to dark brown, dry, stiff to very stiff, 1.5-3.0 0.0-1.6 with fine-grained sand. Torvane --Organic material throughout. 2.5-4.0 Sandy Silt (ML): Light brown, dry, hard, with Qp fine-grained sand. 4.5+ 1.6-8.1 --Moderate calcium carbonate cementation Torvane throughout. 3.5-4.5 Silty Sand (SM): Brown, slightly moist, 8.1-15.4 medium dense to dense, containing fine - rained sand. Poorly -Graded Sand (SP): Yellow -brown, dry, 15.4-11.2 medium dense, containing fine-grained sand. Copyright Q 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com MATERIALS TESTING & ir%jc_-r3r_r'riniq 26 December 2007 Page # 26 of 29 r:\boise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Service, ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-7 Date Advanced: 10/30/07 Logged by: Kory Dawson Excavated by: Bob Camp Excavation Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 16.6 Feet bgs Depth Field Description and Sample Sample Depth Field Test Lab (Feet bgs) USCS Soil and Sediment Classification "Type (Feet bgs) Method Test ID Borderline Lean Clay/Sandy Silt (CL/ML): Qp Brown to dark brown, dry, stiff to very stiff, 1.5-3.0 0.0-1.3 with fine-grained sand. Torvane --Organic material throughout. 2.0-3.5 _. Sandy Silt (ML): Light brown, dry, very stiff Qp to hard, with fine-grained sand. 3.0-4.5+ 1.3-5.2 --Weak, intermittent calcium carbonate Torvane cementation throughout. 3.5-4.5 Silty Gravel (GM): Light brown, dry to slightly moist, with fine-grained sand and fl- 5.2-6.9 inch minus basaltic gravels. y --Sand coarsening with depth. Poorly -Graded Sandy Gravel (GP): Yellow - brown, dry, medium dense to dense, I containing fine to coarse -grained sand and 4- inch minus cobbles. Silty Sand (SM): Brown, slightly moist, 10.1-16.6 medium dense to dense, containing fine- grained sand. Copyright 2007 Materials Testing & Inspection. Inc. 2791 South Victory View Way • Boise, ID 83709 • (208) 376-4748 • Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com 6 MATERIALS TESTING £r w�aFrr�n 26 December 2007 Page # 27 of 29 r:\boise\2007 reports\1400-1599\b71536g\b71536g_geotech.doc 0 Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing J Special Inspections GEOTECHNICAL INVESTIGATION `NEST PIT LOG Test Pit Log #: TP-8 Date Advanced: 10/30/07 Logged by: Kory Dawson Excavated by: Bob Camp Excavation Location: See Site Map Plates Depth to Water Table: Not Encountered Total Depth: 10.6 Feet bgs Depth Field Description and Sample Sample Depth Field 'rest Lab (Feet bgs) USCS Soil and Sediment Classification Type (Feet bgs) Method Test ID Borderline Lean Clay/Sandy Silt (CL/ML). Qp 0.0-1.5 Brown to dark brown, dry, stiff to hard, with GS 0.75-1.0 2.5-4.5+ B fine-grained sand. --Organic material throughout. Sandy Silt (ML): Light brown, dry, very stiff Qp 1.5-4.9 to hard, with fine-grained sand. 3.0-4.5+ --Strong calcium carbonate cementation 3.5- 4.9 eet bgs. Silty Gravel (GM): Light brown, dry, containing f ne-grained sand and 4-inch minus 4.9-6.2 basaltic gravels. --Sand coarsening with depth. Silty Sand (SM): Brown, slightly moist, 6.2-10.6 medium dense to dense, containing fine- grained sand. Lab Test ID M LL PI Sieve Analysis _ % - - #4 #10 #40 #100 #200 B 8.9 41 16 100 99 94 90 84 Copyright '� 2007 Materials Testing & Inspection. Inc. 2791 South Victory View Way - Boise, ID 83709 - (208) 376-4748 - Fax (208) 322-6515 mti@mti-id.com - www.mti-id.com MATERIALS TESTING it iiuc;Pr-rT1nKJ 26 December 2007 Page # 28 of 29 Oboise\2007 reports1I400-1599\b71536g\b71536g_geotech.doc © Environmental Services 0 Geotechnicai Engineering ❑ Construction Materials Testing ❑ Special Inspections AASHTO PAVEMENT THICKNESS DESIGN PROCEDURES Pavement Section Design Location: Proposed commercial Retail Development, No Truck Access Average Daily Traffic Count: 170 All Lanes & Both Directions Design Life: 20 Years Percent of Traffic in Design Lane: 100% Terminal Seviceability Index (Pt): 2 5 Level of Reliability: 9� Subgrade CBR Value: 8 Subgrade Mr: 12,000 Calculation of Design-18 kip ESALs Daily Growth Load Design Traffic Rate Factors ESALs Passenger Cars: 70 2.0% 0.0008 497 Buses: 2 2.0% 0.6806 12,072 Panel & Pickup Trucks: 10 2.0% 0.0122 1,082 2-Axle, 6-Tire Trucks: 3 2.0% 0.1890 5,028 Concrete Trucks: 1.0 2.0% 4.4800 39,731 Dump Trucks: 0 2.0% 3.6300 0 Tractor Semi Trailer Trucks: 0 2.0% 2.3719 0 Double Trailer Trucks 0 2.0% 2.3187 0 Heavy Tractor Trailer Combo Trucks: 0 2.0% 2.9760 0 Average Daily Traffic in Design Lane: 86 Total Design Life 18-kip ESALs: 58,410 Actual Log (ESALs): 4.766 Trial SN: 2.00 Trial Log (ESALs): 4.870 This number must be equal to or greater than the Actual Log. Pavement Section Design SN: 2.21 This number must be equal to or greater than the I rial SN. Design Depth Structural Drainage Inches Coefficient Coefficient Asphaltic Concrete: 2.50 0.42 n/a Asphalt -Treated Base: 0.00 0.25 n/a Cement -Treated Base: 0.00 0.17 n/a Crushed Aggregate Base: 4.00 0.14 1.0 Pit Run Aggregate Subgrade: 6.00 0.10 1.0 Special Aggregate Subgrade: 0.00 0.09 0.9 Copyright 2007 Materials I esung & inspection. Inc. 2791 South Victory View Way a Boise. ID 83709 - (208) 376-4748 - Fax (208) 322-6515 mti@mti-id.com • www.mti-id.com tMATERIALS TESTING & �nicocr-nnn 26 December 2007 Page # 29 of 29 r:\boise\2007 reports\I400-1599\b71536g\b71536g_geotech.doc ❑ Environmental Services 0 Geote:;hnical Engineering ❑ Construction Materials Testing ❑ Sr ecial Inspections AASHTO PAVEMENT THICKNESS DESIGN PROCEDURES Pavement Section Design Location: Proposed Commerciat/Retail Development, Truck Access Average Daily Traffic Count: 180 All Lanes & Both Directions Design Life: 20 Years Percent of Traffic in Design Lane: 100% Terminal Seviceability Index (Pt): 2.5 Level of Reliability: 95 Subgrade CBR Value: 8 Subgrade Mr: 12,000 Calculation of Design-18 kip ESALs Daily Growth Load Design Traffic Rate Factors FSALs Passenger Cars: 50 2.0% 0.0008 355 Buses: 7 2.0% 0.6806 42.251 Panel & Pickup Trucks: 15 2.0% 0.0122 1,623 2-Axle, 6-Tire Trucks: 10 2.0% 0.1890 16,762 Concrete Trucks: 2.0 2.0% 4,4800 79,462 Dump Trucks: 2 2.0% 3.6300 64,386 Tractor Semi Trailer Trucks: 2 2.0% 2.3719 42,071 Double Trailer Trucks 2 2.0% 2.3187 41,127 Heavy Tractor Trailer Combo Trucks: 0 2.0°/o 2.9760 0 Average Daily Traffic in Design Lane: 90 Total Design Life 18-kip ESALs: 288,036 Actual Log (ESALs): 5,459 Trial SN: 2.52 Trial Log (ESALs): 5.468 Pavement Section Design SN: 2.82 Design Depth Structural Drainage Inches Coefficient Coefficient Asphaltic Concrete: 3.00 0.42 n/a Asphalt -Treated Base: 0.00 0.25 n/a Cement -Treated Base: 0.00 0.17 n/a Crushed Aggregate Base: 4.00 0.14 1.0 Pit Run Aggregate Subgrade: 10.00 0.10 1.0 Special Aggregate Subgrade: 0.00 0.09 0.9 Copyright ° 2007 Materials Testing & Inspection, Inc. 2791 South Victory View Way Boise. 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