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HomeMy WebLinkAbout13 - Design Report - Norton Ranch Ph 2A - Street MORRISON L;iL MAIERLE, INC. An Employee-Owned Company STREET DESIGN REPORT NORTON RANCH EAST SUBDIVISION PHASE 2A BOZEMAN, MONTANA December 2013 Prepared For: DES R. NICKELSON Norton Properties, LLC 9063 P.E. 63020 NE Lower Meadow, Suite A � Bend, OR 97701 Prepared By: Morrison-Maierle, Inc. 2880 Technology Boulevard West Bozeman, Montana 59718 NA5149\007\Reports\Street Report.dou Introduction The Norton Ranch East Subdivision, Phase 2A is a portion of a project that was previously designed by Engineering, Inc. and approved in 2008 by the City of Bozeman under the project name of Norton Ranch East Subdivision, Phase 1. Since the approval in 2008, Engineering, Inc. separated a portion of the original Phase 1 into a new "Phase 1" project using the design work accomplished during the original Phase 1. In 2012 Morrison Maierle Inc. separated another portion "Phase 2" form the original Phase 1 designed by Engineering Inc. The design for Phase 2A uses the original approved Engineering, Inc. design as a basis and therefore this design report is limited to providing information to the specific components of Phase 2 and changes that are needed due to the changes in the City of Bozeman Design Standards. A copy of the approved design report by Engineering, Inc. dated January 2008, Revised 4/30/08 is attached to this report and is incorporated by reference and is referred to as the "approved design report" in this document. Phase 2 Description Phase 2A consists of 25 residential lots and a total area of 2.52 acres. It is located north and west of the platted Phase 1 and 2 and south of Phase 1. Phase 2A consists of extending West Babcock Street and Fallon Street both to the west and a portion of Laurel Parkway. The attached exhibit shows the location of Phase 2A relative to the overall Phase 1 project. Pavement Section The approved design report includes a design section of 3 inches of Asphalt, 6 inches of crushed base and 12 inches of pit run subbase. Based on constructability issues and our experience in the area our recommendation is to remove the lean clay material overlaying the poorly graded gravel and build the road section on pit run material above this material, and or geotextile fabric on subgrade. The boring logs completed for the project indicate that the total depth of top soil and lean clay is approximately 2.5 to 3 feet deep. Changes Required Due to Updated Design Standards Use Revised, April 2013, City of Bozeman Modifications to Montana Public Works Standard Specifications, 6 th Edition, Type "A" Crossings for pavement marking for pedestrian crossings. END N:\5149\007\Reports\Street Report.docx PRELIMINARY GEOTECHNICAL INVESTIGATION NORTON EAST RANCH SUBDIVISION RESIDENTIAL LOTS, UTILITIES AND STREETS BOZEMAN, MONTANA April 26, 2007 Project No.B-07-103-01 Prepared for: Big Sky Land Consulting, PLLC. 5530 Burnt Road Belgrade, Montana 59714 Prepared by: Rimrock Engineering, Inc. 5440 Holiday Avenue Billings, Montana 59101 �ENGINEERING, Ell— INC. Phone 406.294.8400 5440 Holiday Avenue • Billings, MT 59101 Fax 406.294.8405 April 26, 2007 Big Sky Land Consulting, PLLC 5530 Burnt Road Belgrade, MT 59714 Attention: Mr. Tom Henesh SUBJECT: Preliminary Geotechnica! Investigation Report Norton East Ranch Subdivision Residential Lots, Utilities and Streets Bozeman, Montana Dear Mr. Henesh: The attached report presents the results of our preliminary geotechnical investigation for the proposed Norton East Ranch Subdivision located in Bozeman, Montana. This investigation encompasses approximately 45 acres for future residential building lots and recommendations for construction of interior streets and utilities. Our work consisted of subsurface exploration, laboratory testing, engineering analyses, and preparation of this report. Based on our work completed to date, we have drawn the following general conclusions: • The 45 acre subdivision encompassed by this report is currently covered by 0.5 to 1.0 feet of topsoil and vegetation. The underlying soils consist of a layer of lean clay and sandy lean clay ranging in depth from 1.5 to 3.0 feet below the existing site grades. These fine grained soils are moderately compressible, have a low potential to swell, have a medium plasticity and were soft to medium stiff. Beneath the clay layer we encountered gravel with sand and cobbles to the depths explored of 14.5 below existing site grades. Groundwater was encountered in our boring and test pits at depths ranging from 3.2 to 5.5 feet below existing site grades during our exploration in March and April 2007. • Groundwater was encountered in the boring and all of the testpits. Due to the shallow groundwater elevations, dewatering for utilities and foundation construction will be required. Our scope of services did not include designing a dewatering system or the influence of dewatering on existing streets, utilities, or B-07-103-01 Page 1 of 2 April 26, 2007 Rimrock Engineering,Inc. I adjacent structures. A dewatering system should be designed by a competent engineer with experience with dewatering systems. • Conventional spread and continuous footings will support the structural loads for the anticipated buildings if founded in the medium dense to dense native gravels with sand and cobbles. These and other conclusions and recommendations, along with restrictions and limitations on these conclusions, are discussed in the attached report. We appreciate this opportunity to be of service to you, and look forward to future endeavors. If you have any questions regarding this report or need additional information or services, please feel free to call the undersigned. Sincerely, RIMROCK ENGINEERING, INC. y- X4 -07 Robert W. Kukes, P.E. QL Wade Reynolds Principal Staff Geologist Enclosures: Report (3 bound copies) B-07-103-01 Page 2 of 2 April 26,2007 Rimrcck Engineering,Inc. ' � ' TABLE {)FCONTENTS PAGE 1'0 INTRODUCTION AND SCOPE-^~~~^~'`'~ l 1] Project Description................................................................... 1.2 Purpose and Scope nf Work ........................ ...................... 2 13 Au�o�o�m ' -----------'---------------------.----% 1.4 References 2 2'0 METHODS OF STUDY--_--'.—.-.-----'---..--.-..^~'...~~-.'-----_-------'---^' 21 Field '---------------------------------'3 2.2 Lab oratory Testing......................................................................................................] 3J0 DISCUSSION^—'—'--^'----^ 4 3] Site Condhkonn-----------------.------------------.� 3`2 SubsurfeneConddiono ------ -------------------------� 3.3 Laboratory Test Results ...................................................................................--- 3.4 Analytical �e��� ' ---------------------------'-----'—j 4L0 CONCLUSIONS__~_______ 5 �iO RECOMMENDATIONS� ' ''---------~~---'-'~-----------'----'---'---'-~^-'—^-'-'.'.6 5.1 Site and ^=a ".y Preparation............ .......................................................................6 52 Earthwork� -----------^------''---'------'---'------.8 5.2.1 General Site Grading.......... ............ ~_______ _______ 5-2.2 Unconfined E:cavat�ns-------------------_6 5.2.3 Temporary Trench Excavation and BankfiU .................................................7 53 Foundations� ---------------^'------'---------------? 5/4 Compaction ReoukrenleOts-----------------------------.� 5.5 Concrete' --------'------------'--.�8 5.8 Pavement Sections.................. ................... -----------'---------8 5.7 Site Drainage .....................................---- ...... ........ .------�8 5DConcrete '.................. ................... ............. .......................................... —'8 G'U AOD[7K}NAJ- SERVICES-._.-. h1Bid� . .~,~.` -----.----.---------.------------.9 5.2 Construction Observation/Testing and Plan Review.................................................9 7.0 LIMITATIONS ' ^'-''^-~`''`^^--`~^~~-^'--~--^'^^^~'''^`'~—'-~~^'`--`--''``----^`~.-,`lO APPENDICES A Plates B Suggested Specifications for Earthwork C Application for Authorization toUse 8'07'183'01 nm`mo Engineering,Inc. Ap� 20. 2OO7 \ . . . / PRELIMINARY GEOTECHN|CAL INVESTIGATION REPDRT PROPOSED N{JRTON EAST RANCH SUBDIVISION RESIDENTIAL LOTS, UTILITIES AND STREETS BOZEM/\N, K8ONTANA 1.0 INTRODUCTION AND SCOPE This report presents the results of our preliminary gacdenhnica| investigation for the proposed Norton East Ranch Subdivision which includes residential lots, interior otnsets, and utilities shown on the site nnep. Appendix (Plate 2). The type of buildings anticipated to be in this subdivision were not known at the time of this report, but are anticipated to be one to two story wood frame construction. The project will also include construction of interior subdivision streets and associated utilities. � Structural loads were not available at the time of this report being issued and were estimated to have continuous »mU loads of2to 3 kips per lineal foot for long-term loading conditions for residential construction. Loads and the type of construction for the oonnnnarcia| buildings (if / ` applicable to this subdivision) were not available and should be designed when specific info/nnetionbenonneaavei|ab/o. Cuts and fills for building pad construction may beon the order of 3 to 4 feet with over excavation requirements in the footing in some locations. 1.2 Purpose and Scope of Work The purpose of this study is to evaluate the feasibility of the proposed development with respect to the observed subsurface condKions, and to provide our preliminary geotechn)oa| recommendations and opinions as outlined in our proposal dated February 15' 2007. summarized below. " General soil and groundwater conditions et the project site, with emphasis on how the conditions are expected io affect the proposed construction; , Suggested specifications for earthwork oonstruction, including site preparation reconnnnendotinno, o discussion of reuse of existing near surface soils as structural or non-structural fill, and a discussion of remedial earthwork recommendations, if warranted; ° Recommendations for temporary excavations and trench bonkfU; B'07-103-01 Page 1of12 April 2007 mm,ockEnoineexnn.|nc. ' • Preliminary conventional shallow spread foundation design including soil bearing values, minimum footing depth, resistance to lateral loads and estimated settlements; • Concrete reactivity potential of site soils; • Preliminary structural pavement sections for asphaltic concrete; • Subgrade preparation for slab-on-grade concrete. Our scope of services consisted of background review, site reconnaissance, field exploration, laboratory testing, engineering analyses, and preparation of this report. This study did not include evaluations of site seismicity, liquefaction, faulting, or other potential geologic or environmental hazards. 1.3 Authorization Authorization to proceed with our work on this project was provided on February 18, 2007. 1.4 References The following information was provided to Rimrock Engineering in the course of this study and serves as the basis of our understanding of the project type and scope. • Preliminary Site Plan of Norton East Ranch Subdivision. This map showing the proposed location of the interior subdivision streets was provided by Big Sky Land Consulting, PLLC and is the basis for the Site Map on Plate 2 of this report. • Google Earth Maps, Bozeman, Montana (2007)—Gallatin Co., (Satellite Image) This image was the basis for the Vicinity Map shown on Plate 1 of this report. 2.0 METHODS OF STUDY 2.1 Field Exploration E Our selection of field exploration locations was based on the an ticipated project layout and site access. The subsurface exploration consisted of drilling one (1) test boring and excavating seven (7) test pits in the proposed construction area using a drill rig equipped with hollow stem augers and a rubber tired backhoe. The test pits were completed in-lieu of borings due to B-07-103-01 Page 2 of 12 9 April 26,2007 Rimrock Engineering,Inc. 4 i the inclement weather and the inaccessibility of the site with a truck mounted drill rig. Boring depth was 14.5 feet below the existing ground surface. Test pits were excavated to 8 feet below existing site grades. Locations of the boring and test pits shown on the Site Map (Plate 2, Appendix A), were chosen by Rimrock Engineering, Inc. These locations should be considered accurate only to the degree implied by the method used. Soil conditions encountered are presented on the boring and test pit logs which are included as Plates 3 through 10, A description of the Unified Soil Classification System used to identify the site soils and a boring log legend are presented on Plates 11 and 12 (Appendix A). Field personnel logged the soil conditions exposed in the boring and excavations and collected bulk samples and driven penetration samples for laboratory testing. Soil samples were obtained by driving a 2-inch ID, Standard Penetration Sampler, into the bottom of the boring. The number of blows required to drive the last 12 inches of an 18-inch drive with a 140-pound hammer dropping 30 inches is recorded as the blows per foot (Blow Count) on the boring log. When the sampler was withdrawn from the boring, samples were removed, examined by the field engineer, labeled and sealed to preserve the natural moisture content for laboratory testing. After the boring and excavations were completed, they were checked for groundwater and backfilled with excavated soil using the equipment at hand. 2.2 Laboratory Testing Laboratory testing is useful for evaluating both index and engineering properties of soils. Typical index tests evaluate soil moisture content, soil particle gradation and plasticity characteristics. We have performed/will perform laboratory testing on selected soil samples to assess the following: • Soil Classification (ASTM D422, D1140, D4318, D2487, and D2488) • Unit Weight and Moisture Content(ASTM D2937 and D2216) • California Bearing Ratio (ASTM D1835) In addition, the following analytical tests were performed by Northern Analytical Laboratories. • Soluble Sulfate Content Individual laboratory test results can be found on the boring/excavation logs and on Plates 13 through 16, Appendix A, at the end of this report. B-07-103-01 Page 3 of 12 April 26, 2007 Rimrock Engineering,Inc. 3.0 DISCUSSION! 3.1 Site Conditions Access to the project site is provided by Huffine Lane and an existing non-paved road on adjacent property. The Norton East Ranch Subdivision covered by this investigation is surrounded by agricultural land and undeveloped residential/commercial property. The site is presently undeveloped agricultural land. The ground surface in the area of the proposed subdivision appears to slopes gradually to the north. A total relief of approximately ten feet is currently present at the entire project site. Drainage on the site consisted of sheet flow to the north. 3.2 Subsurface Conditions The following paragraphs summarize the results of our field exploration. The boring/testpit logs should be reviewed for a more detailed description of the subsurface conditions at the locations explored. • The 45 acre subdivision encompassed by this report is currently covered by 0.5 to 1.0 feet of topsoil and vegetation. The underlying soils consist of a layer of lean clay and sandy lean clay ranging in depth from 1.5 to 3.0 feet below the existing site grades. These fine grained soils are moderately compressible, have a low potential to swell, have a medium plasticity and were soft to medium stiff. Beneath the clay layer we encountered gravel with sand and cobbles to the depths explored of 14.5 below existing site grades. Groundwater was encountered in our boring and test pits at depths ranging from 3.2 to 5.5 feet below existing site grades during our exploration in March and April 2007. Fluctuations in the level of the groundwater and soil moisture conditions as noted in this report may occur due to variations in precipitation, land use, irrigation, and other factors. 3.3 Laboratory Test Results Laboratory testing was performed as previously discussed in Section 2.2. The test data were evaluated in combination with our field exploration information to assess the engineering properties of the predominant soil types. Atterberg limits tests indicated the sandy lean clay and lean with sand soils have a medium plasticity. The sulfate content test results indicated that the soils have a negligible potential for concrete reactivity. I I I i I B-07-103-01 Page 4 of 12 April 26, 2007 Rimrock Engineering,Inc. t i i t 3.4 Analytical Methods Field and laboratory data are useful when combined with engineering fundamentals to assess specific behavior such as bearing capacity, settlement, and other design parameters. The following approaches were used in developing the conclusions and recommendations presented in subsequent sections of this report. • Allowable bearing pressures were computed using Terzaghi's general bearing capacity formula. • Settlements were not computed at this time and will be provided when a design level report is completed. • Pavement sections were computed using the AASHTO Procedure for Design of Flexible Pavement Sections. 4.0 CONCLUSIONS The following conclusions are based on the data collected during this assessment and are subject to the limitations stated in this report. These conclusions may change if additional information becomes available. Based on the results of our study, no severe soil or groundwater constraints were observed which would preclude development, The following is a summary of our conclusions. • The 45 acre subdivision encompassed by this report is currently covered by 0.5 to 1.0 feet of topsoil and vegetation. The underlying soils consist of a layer of lean clay and sandy lean clay ranging in depth from 1.5 to 3.0 feet below the existing site grades. These fine grained soils are moderately compressible, have a low potential to swell, have a medium plasticity and were soft to medium stiff. Beneath the clay layer we encountered gravel with sand and cobbles to the depths explored of 14.5 below existing site grades. Groundwater was encountered in our boring and test pits at depths ranging from 3.2 to 5.5 feet below existing site grades during our exploration in March and April 2007. • Groundwater was encountered in the boring and testpits. Due to the shallow groundwater elevations, dewatering for utilities and foundation construction will be required. Our scope of services did not include designing a dewatering system or the influence of dewatering on existing streets, utilities, or adjacent structures. A B-07-103-01 Page 5 of 12 April 26, 2007 Rimrock Engineering,Inc. dewatering system should be designed by a competent engineer with experience with dewatering systems. Conventional spread and continuous footings will support the structural loads for the anticipated buildings if founded in the medium dense to dense native gravels with sand and cobbles. 5.0 RECOMMENDATIONS 5.1 Site Clearing and Preparation Prior to construction, surface soils and organic soils should be stripped and removed from the site or stockpiled for use in non-structural areas. It appears about 6 inches can be used as a reasonable estimate for average depth of stripping. Deeper stripping/grubbing of organic soils, tree roots, etc., may be required in localized areas. Tree root balls should be removed and the resulting voids backfilled with adequately compacted backfill soil. All man-made debris including dumped fills or trash should be removed from the site. The geotechnical engineer should be present during stripping and site preparation operations to observe stripping and grubbing depths, and to evaluate whether buried obstacles such as underground utilities, wells, and foundations are present. Excavations resulting from removal operations should be cleaned of all loose material and widened as necessary to permit access to compaction equipment. 5.2 Earthwork 5.2.1 General Site Grading Site preparation and grading should conform to the requirements contained in this report and in the suggested specifications which are provided as Appendix B of this report. We anticipate that site grading can be performed with conventional earthmoving equipment. Prior to fill placement, the exposed native soils should be scarified to a minimum depth of six inches, moisture conditioned as necessary, and compacted to a minimum of 95% relative compaction in accordance with the ASTM D698 compaction test method. Where fill is necessary, it should meet the requirements for structural fill found in Appendix B. It appears that the existing near surface soils are not generally capable of meeting recommended requirements for structural fill. Fill placement and compaction requirements presented in Appendix B should be followed. B-07-103-01 Page 6 of 12 April 26,2007 Rimrock Engineering,Inc. i i 5.2.2 Temporary Unconfined Excavations The contractor is ultimately responsible for the safety of workers and should strictly observe federal and local OSHA requirements for excavation shoring and safety. All temporary slopes should comply with OSHA requirements for Type A soils near the surface and Type C below approximately three feet. During wet weather, runoff water should be prevented from entering excavations. 5.2.3 Temporary Trench Excavation and Backfill It appears that excavation for footings and utility trenches can be readily made with either a conventional backhoe or excavator in the native soil. We expect the walls of the footing trenches in the near surface fine grained soils to stand near vertically without significant sloughing. If trenches are extended deeper than three feet into the native gravel with sand or are allowed to dry out, the excavations may become unstable and should be evaluated to verify their stability prior to occupation by construction personnel. Shoring or sloping of any deep trench walls may be necessary to protect personnel and provide temporary stability. All excavations should comply with current OSHA safety requirements for Type A soils near the surface and Type C below three feet. (Federal Register 29 CFR, Part 1926). Backfills for trenches or other excavations within pavement areas should be compacted in six to eight inch layers with mechanical tampers. Jetting and flooding should not be permitted. We recommend all backfil) be compacted to a minimum compaction of 97% of the maximum dry density as determined by ASTM D698. The moisture content of compacted backfill soils should be within 2% of the optimum. Poor compaction in utility trench Backfill may cause excessive settlements resulting in damage to the pavement structural section or other overlying improvements. Compaction of trench backfil) outside of improvement areas should be a minimum of 90% relative compaction 5.3 Foundations Shallow spread footing foundations may be founded directly on the native gravel with sand and cobbles. Foundations on the native gravel with sand and cobbles may use an allowable bearing capacity of 4,000 pounds per square foot. Settlements have not been computed at this time. Foundations founded in the native gravel may require dewatering during construction. If structures with concrete basements are anticipated, they will require a permanent dewatering system. Exterior foundations should be embedded a minimum of 4 feet below lowest adjacent exterior finish grade for frost protection and confinement. Interior footings should be bottomed at least 12 inches below lowest adjacent finish grade for confinement. Wall foundation dimensions should satisfy the requirements listed in the latest edition of the International Residential Code. Reinforcing steel requirements for foundations should be provided by the design engineer. B-07-103-01 Page 7 of 12 April 26, 2007 Rimrock Engineering,Inc. The allowable bearing pressures, indicated above, are net values, therefore, the weight of the foundation and backfill may be neglected when computing dead loads. Allowable bearing pressures may be increased by one-third for short-term loading such as wind or seismic. Resistance to lateral loads in the upper lean clay and sandy soils may be calculated using an allowable passive equivalent fluid unit weight of 350 pounds per cubic foot and an allowable coefficient of friction of 0..45 applied to vertical dead loads. Both passive and frictional resistances may be assumed to act concurrently. An allowable active equivalent fluid pressure of 36 pounds per cubic foot may be used. The International Building Code Site Class for this project is Class C. 5.4 Compaction Requirements The following table lists the compaction requirements for the different types of fill recommended in this report. TABLE I COMPACTION REQUIREMENTS Structural Fill Beneath Foundations 981%, of ASTM D698 Backfill Against Foundations 95% of ASTM D698 Utility Trench Backfill q]EE97% of ASTM D698 5.5 Concrete Slab-on-Grade Construction Prior to constructing concrete slabs, the upper six inches of slab subgrade should be scarified, moisture conditioned to within 2% of optimum, and uniformly compacted to at least 95% of maximum dry density as determined by ASTM D698. Scarification and compaction will not be required if floor slabs are to be paced directly on undisturbed compacted structural fill. All concrete floor slabs should have a minimum thickness of four inches. Slab thickness and structural reinforcing requirements within the slab should be determined by the design engineer. At least four inches of crushed base aggregate should be placed beneath slab-on-grade floors to provide uniform support. The aggregate base should be compacted to a minimum of 95% relative compaction. We recommend that the base course be placed within three to five days (depending on the time of year) after moisture conditioning and compaction of the subgrade soil. The subgrade should be protected against drying until the concrete slab is placed. I i B-07-103-01 Page 8 of 12 April 26, 2007 Rimrock Engineering,Inc. In floor slab areas where moisture sensitive floor coverings are planned, an impermeable membrane (e.g. 10-mil thick polyethylene) should be placed over the base course to reduce the migration of moisture vapor through the concrete slabs. The impermeable membrane should be protected by two inches of fine, moist sand placed both above and below the membrane. The sand cover will provide protection for the membrane and will promote uniform curing of the concrete slab. The sand cover should be moistened and tamped prior to slab placement. 5.6 Pavement SectionsSC The recommended pavement structural sections for the project presented in Table 2 were calculated using the AASHTO pavement design procedure. Traffic loading was not available at the time of this preliminary report and was assumed by Rimrock Engineering, Inc. based on experience with similar projects. Final pavement sections will be calculated when traffic volume information is available. In our analysis, we used an ADT of 1200 vehicles per day which results in a traffic loading condition of 118,573 18-kip equivalent single axle load (18-kip ESAL) was used for interior subdivision streets for the lifetime of the pavement. A CBR value of 5.5 was used for design of the pavement sections. TABLE 2 PAVEMENT STRUCTURAL SECTIONS I Traffic Condition Recommended Minimum Structural Section* Interior Subdivision Streets 3 inches Asphaltic Concrete, 6-inches of 1 1/2 inch Crushed Base Course and 12 inches of pit run subbase " Aggregate base course thickness may be reduced in each pavement structural section by approximately 20%with the use of a recommended geotextile fabric. Placement and compaction procedures for materials and construction should conform to the suggested specifications contained in Appendix B of this report. The sections presented in Table 2 are based on CBR tests performed on selected samples obtained during our investigation and should be considered preliminary in nature. We recommend verification of soil conditions as construction progresses so that appropriate revisions can be made if necessary. Aggregate base course thickness may be reduced in each alternate pavement structural section by approximately 20% with the use of Amoco 4553 or 2002 geotextile fabric or comparable geotextile fabric meeting AASHTO M 288-2000 class 1 requirements. If this alternative is selected, we can provide addition pavement structural sections. The asphalt pavement structural sections presented in Table 2 are designed for the assumed traffic loadings. However, based on our experience in the area, environmental aspects such as freeze-thaw cycles and thermal cracking will probably govern the life of AC pavements in light traffic areas. Thermal cracking of the asphalt pavements allows more water to enter the pavement section which promotes deterioration and increases maintenance costs. B-07-103-01 Page 9 of 12 April 26,2007 Rimrock Engineering,Inc. It should be noted that the subgrade soils are likely to be prone to frost action during the winter and saturation during the wet spring months. The primary impact of frost action and subgrade saturation is the loss of subgrade and aggregate base strength. Pavement life will be increased if efforts are made to reduce the accumulation of excess moisture in the subgrade soils. Consideration should be given to installing subdrainage in the form of trench drains in low areas, which are daylighted or tied to the storm drain system. 5.7 Site Drainage Final elevations at the site should be planned so that drainage is directed away from all foundations. Parking areas should be sloped and drainage gradients maintained to carry all surface water off the site. In parking lot areas, curbs adjacent to landscaping should be deepened to act as a cutoff, or a sub-drain system should be constructed to collect excessive water from landscaping irrigation. 5.8 Concrete Reactivity Analytical testing of selected soil samples was performed to assess the potential for adverse reactivity with concrete. Soluble sulfate tests were performed to evaluate potential sulfate attack against Portland Cement Concrete. Soluble sulfate contents were observed to be less than 0.10%. Therefore, the potential for sulfate attack appears to be negligible and conventional Type 11 cement may be used according to Table 1904.3 of the 2003 International Building Code. 6.0 ADDITIONAL SERVICES 6.1 Proiect Bid Documents It has been our experience during the bidding process, that contractors often contact us to discuss the geotechnical aspects of the project. Informal contacts between Rimrock Engineering and an individual contractor could result in incorrect or incomplete information being provided to the contractor. Therefore, we recommend a pre-bid meeting be held to answer any questions about the report prior to submittal of bids. If this is not possible, questions or clarifications regarding this report should be directed to the project Owner or his designated representative. After consultation with Rimrock Engineering, the project Owner (or his representative) should provide clarifications or additional information to all contractors bidding the job. B-07-103-01 Page 10 of 12 April 26,2007 Rimrock Engineering,Inc. i 6.2 Construction Observation/Testing and Flan Review The recommendations made in this report are based on the assumption that an adequate program of tests and observations will be made during construction to verify compliance with these recommendations. These tests and observations should include, but not necessarily be limited to, the following: • Observations and testing during site preparation and earthwork. • Observation of footing trench excavations. • Observation and testing of construction materials. • Consultation as may be required during construction. We also recommend that project plans and specifications be reviewed by us to verify compatibility with our conclusions and recommendations. Additional information concerning the scope and cost of these services can be obtained from our office. The review of plans and specifications and the field observation and testing by Rimrock Engineering are an integral part of the conclusions and recommendations made in this report. If we are not retained for these services, the Client agrees to assume Rimrock Engineering's responsibility for any potential claims that may arise during construction. 7.0 LIMITATIONS Recommendations contained in this report are based on our field explorations, laboratory tests, and our understanding of the proposed construction. The study was performed using a mutually agreed upon scope of work. It is our opinion that this study was a cost-effective method to evaluate the subject site and evaluate some of the potential geotechnical concerns. More detailed, focused, and/or thorough investigations can be conducted. Further studies will tend to increase the level of assurance, however, such efforts will result in increased costs. If the Client wishes to reduce the uncertainties beyond the level associated with this study, Rimrock Engineering should be contacted for additional consultation. The soils data used in the preparation of this report were obtained from boring/testpits made for this investigation. It is possible that variations in soils exist between the points explored. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at this site which are different from those described in this report, our firm should be immediately notified so that we may make any necessary revisions to our B-07-103-01 Page 11 of 12 April 26,2007 Rimrock Engineering,Inc. recommendations. In addition, if the scope of the proposed project, locations of structures, or building loads change from the description given in this report, our firm should be notified. This report has been prepared for design purposes for specific application to the Norton East Ranch Subdivision project in accordance with the generally accepted standards of practice at the time the report was written. No warranty, express or implied, is made. Other standards or documents referenced in any given standard cited in this report, or otherwise relied upon by the authors of this report, are only mentioned in the given standard; they are not incorporated into it or"included by reference," as that latter term is used relative to contracts or other matters of law. This report may be used only by the Client and for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both on- and off-site), or other factors including advances in man's understanding of applied science may change over time and could materially affect our findings_ Therefore, this report should not be relied upon after 36 months from its issue. Rimrock Engineering should be notified if the project is delayed by more than 24 months from the date of this report so that a review of site conditions can be made, and recommendations revised if appropriate. It is the Client's responsibility to see that all parties to the project including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety. The use of information contained in this report for bidding purposes should be done at the Contractor's option and risk. Any party other than the Client who wishes to use this report shall notify Rimrock Engineering of such intended use by executing the "Application for Authorization to Use" which follows this document as an appendix. Based on the intended use of the report, Rimrock Engineering may require that additional work be performed and that an updated report be issued. Non-compliance with any of these requirements by the Client or anyone else will release Rimrock Engineering from any liability resulting from the use of this report by any unauthorized party. I !I I i i B-07-103-01 Page 12 of 12 9 April 26, 2007 Rimrock Engineering,Inc, j i I i APPENDIX Plates M• 1mmi . , i ! •,M- A li Ov ff IIA ON— M`" �' �� & •• ,IDS Ys t�,r t x k,i +<* # Sw '�` �'. tiG17 ��� � �, 4. tf A "t '1 � � x�+�- �+`�...n �y'a"�`tea, �_ ct• r 4e- c14 s c L . � k r s Mj�AM 4 d x v % rn ;� 5 r s " j � � a = 3 L4 ` linage �207 DiglialC3iabE+ x ? 1e m r ..�.......::. .- • :• • Geotechnical Investigation-Report Norton East Ranch Subdivision EXIST440 c",DOUKIDARY •p TP-3 T?-4 TP-1 T 0 0 TP-7 0 0 0 T'p-5 \N RO-OSSO -8 p ExisnNG NOARY EXTERIOR ZCM4a- SCUNQARY r'TY U 77 CLU.S. Hn'tw'y SW40ARY SITE MAP PLATE L2±��Rimrock Engineering,Inc. ­NO� RTON EAST RANCH SUBDIVISION Page I of 1 5440 Holiday Avenue Bozeman,Montana Billings,MT 59101 Tel. (406)294-8400 Big Sky Land Consulting,PLLC 2 PROJECT NO.B-07-103-01 Date Completed: 4/20/2007 Logged By: .1 Frank Boring Location: See Site Map,Plate 2 Driller: Duneman Construction Drilling MethodlSize: Backhoe Elev.Top of Hole: 100 Total Depth: 8 Groundwater Depth:I S. 3,2 F - 1.8 a x � w rn w `w w EL > DESCRIPTION NOTES w n ¢ ccoZ mp W Of FU 0 Ve etated To soil Lean Clay,Light Brown,Moist, f1 e ium Stiff Medium Plasticity Lean Clay with Sand Light Brown,Moist,Soft/Medium MC=29.6% i edam Alas icr y,(CL) Minus#200=83% Plastic Index=21.8 PoorI Graded Gravel with Sand Grey,Wet a(� •;::. ens. . wm Dense, rams ar on-Plastic,(G`P-SP) C oC 0 95 5 O O 0 O End of Test Pit 90 10 0 85 15 v a t7 4 0 m L} � 7 LOG OF TEST PIT TP-1 PLATE Ii Norton East Ranch Subdivision N Rimrock Engineering Bozeman, Montana 1 of 1 o Drafted By: R_Kukes Project No.: B-07-103-01 Big Sky Land Consulting, PLLC 3 Date: 4/25/2007 File Number: Rirt..k E,4n-4 g Date Completed: 4/20/2007 Logged By: •f Frank Boring Location: See Site Map,Plate 2 Driller: Duneman Construction Drilling Method/Size: E3ackhoe Elev.Top of Hole: 100 Total Depth: 8 Groundwater Depth:l-7 4'5 F V 4.5 °W- x o Z Fr m W o O o! a ¢ = J J W DESCRIPTION NOTES F a am a �E 2 L 00 C) p n W 0 0) W Z m LL 0 W 0 Ve etated To soil Lean to Fat Clay,Grey,Moist,Stiff, me +um ig asOcity Lean Cla with Sand Grey,Moist,Stiff,Low/Medium MC=30.5% as ici y,(CL)—-- Minus#200=83.7% X 0 Plastic Index=24.1 Poo" Graded Gravel with Sand Grey,Moist/Wet,Dense, o a 9T,n,I on- as ic, ut-b ) Ga '.•'.'•': o ` 0 0 O End of Test Pit 90 10 0 85 15 v a 0 9 m O O J o LOG OF TEST PIT TP-2 PLATE o L Rimrock Ep ineerin Norton East Ranch Subdivision 1 of 1 g g Bozeman, Montana Y o Drafted By: R.Kukes Project No.: B 07-103 01 Big Sky Land Consulting, PLLC 4 Fr I Date: 4/25/2007 File Number: R —h E da eMg Date Completed: 4/20/2007 Logged By: .1 Frank Boring Location: See Site Map Plate 2 Driller: Duneman Construction Drilling Method/Size: Backhoe Elev.Top of Hole: 100 Total Depth: 8 Groundwater Depth:l 4.8 F V 3.2 a x O F}- m a o o DESCRIPTION = a a m > NOTES � W Q Q� 0p O m W U) cn Z -0 a Cl) Ve etated Topsoil Lean Ciay,Light Brown,Moist,Stiff, :_�;•+;':;,� TvTe !um t1laslicity Lean Clay Light Brown,Moist,Stiff,Medium Plasticity, Poorl Graded Gravel with Sand Grey,Moist to Wet, Mn s-e°C, ..=;::: — , rams arNon-Plastic,(GP SP) 0 0 95 5- 0 O End of Test Pit 9a 10 0 85 t5 w` N a' o j 0 O m U' O J LOG OF TEST PIT TP-3 PLATE a Rimrock Engineering Norton East Ranch Subdivision 1 of 1 y Bozeman, Montana Y 0 Drafted By: R.Kukes Project No.: B-07-103-01 Big Sky Land Consulting, PLLC Date: 4l25l2007 File Number: Rimrock Engineering 1 Date Completed: 4/20/2007 Logged By: .I Frank Boring Location: See Site Map Plate 2 Driller: Dune an Construction Drilling Method/Size: Backhoe Elev.Top of Hole: 100 Total Depth: 8 Groundwater Depth:l 3.5 F1 2.5 o �� a j Imo- a a m > o DESCRIPTION NOTES t O s w n co WZ m0 Ve etate-d Topsoil Lean Clay,Light Brown,Moist to Wet, e lum tiff,McMum Plasticity Lean cla Light Brown,Moist to Wet,Medium Stiff, e lum asticity,(CL) Poorl Graded Gravel with Sand Grey,Wet, Dens Q :';.:'• e,ran-ar — O 95 $ U C� O 0 Q O End of Test Pit 90 10 0 85 i5 N P a' q 0 0 m O LOG OF TEST PIT TP-4 PLATE � Rimr©ck Engineering N°'�°n East Ranch subdivision Bozeman, Montana 1 of X Drafted By; R.Kukes Project No.: 8-07-103-01 gig Sky Land Consulting PLLC Date: 4/25/2007 File Number: RIM=k Enyme*V Date Completed: 4/20/2007 Logged By:- .1 Frank Boring Location: See Site Map,Plate 2 Driller: Duneman Construction Drilling Method/Size: Backhoe Elev.Top of Hole: 100 Total Depth: 8 Groundwater Depth:I�Z 5.5 F V 4.5 W x d� W >- m w J w W DESCRIPTION NOTES j Of 0 a a m 3 t— O J-_ w a 00 U ❑ a 12 W ❑ (n U)Z mQ of 0D Ve etated To soil Lean Clay,Dark Brown,Moist to Wet, Lean Cla ark Brown,Mois to Wet,Medium Stiff, Medium Plasticity,(CL) Poorl Graded Gravel with Sand Light Brown,Moist to e, e ium Dense,G rams ar Non-Plastic,(GP-SP) 0 0 o 6 Q O O End of Test Pit 90 10 0 85 15 `n N 4 a 4 I 0 0 0 LOG OF TEST PIT TP-5 PLATE —"` Norton East Ranch Subdivision Rimrock Engineering Bozeman, Montana 1 of t Y -7 Drafted By: R.Kukes Project No.: B-07-103-01 gig Sky Land Consulting, PLLC Date: 4/25/2007 File Number: Ri.=k Engh..dng j I Date Completed: 4/20/2007 Logged By: 1 Frank Boring Location: See Site Map,Plate 2 Driller: Duneman Construction Drilling Method/Size: Bagkhoe Elev.Top of Hole: 100 Total Depth: 8 Groundwater Depth: FY 3.5 CL x O I— m¢ nw. W o z w w o DESCRIPTION NOTES �w to W Q Q� -Jp w w O v> rq Z M u- p[ 0, 0 Ve stated Togsoiill Lean Clay,Light Brown/Grey,Moist, e3ium Plasticity Lean CI Light Brown/Grey,Moist,Stiff,Medium as iG y, CL) Poori Graded Gravel with Silt and Sand Grey,Moist to e, ense, rams ar on- as ic, ) O Wet @3.5ft MC=13% ° Minus#200=5.4% O Plastic Index=GNP 95 5-1 O O O Q O Q End of Test Pit 80 10 $ 85 15 e a 4 o_ n 4 m 0 0 J LOG OF TEST PIT TP-6 PLATE o �Rirnrock Engineering Norton East Ranch Subdivision 1 of 1 Bozeman, Montana Y CffDrafted By: R. Kukes Project No.: B-07-103-01 Big Sky Land Consulting, PLLC i8 FrDate: 4/25/2007 File Number: Rimrod Er gi-6,g Date Completed: 4/20/2007 Logged By:_ .1 Frank Boring Location: See Site Map, Plate 2 Driller: Duneman Construction Drilling Method/Size: Backhoe Elev.Top of Hole: 100 Total Depth: 8 Groundwater Depth: F_Y 2LE d X Z O w O r F m Lu o Q m � _J w > o DESCRIPTION NOTES w o- 2 0 0 O CL w o Zo viz m0 w Cam! m Vie eettateed TTVsoil Lean Clay,Light Brown,Moist, Medium Stiff,Me I J Plasticity Lean Cla Light Brown,Moist,Medium Stiff,Medium FIAT yf , Lj Poori Graded Gravel with Sand Grey, Wet,Dense, o .'• rams ar on- as ic,(UP---uF) O as :.'..•. D 95 5 b o _ O d O End of Test Pit 90 10 0 85 15 a a 0 m 0 r 0 O 7 LOG OF TEST PIT TP-7 PLATE Rimrock Engineering Norton East Ranch Subdivision 1 of 1 Bozeman, Montana Y Drafted By: R.Kukes Project No.: B 07-103-01 Big Sky Land Consulting, PLLC Date: 4/25/2007 File Number: K6 _X Enpbtear APPENDIX i ^ SUGGESTED SPECIFICATIONS FOR EARTHWORK AND PAVEMENT CONSTRUCTION | NORTON EAST RANCH SUBDIVISION BOZEMAN' MONTANA 1.0 GENERAL 1'1 Scope - The work done under these specifications shall include cleahng, stripping, removal of unsuitable material, excavation, preparation of natural sui|a, placement and rorDpoc1ion of on-site and imported structural fill nuetSh8[ and placement and compaction of pavement materials. 1.2 - /\ geoteohnioa| investigation was performed for the project by Rinnrock Engineering dated April 28, 2007. The Contractor shall attentively examine the site in such a manner that he can confirm existing surface conditions with those presented in the geotenhnica) report. He shall satisfy himself that the quality and quantity of exposed materials and subsurface soil or rock deposits have been satisfactory represented by the Geoteohnioa| ( Engineer's report and Civil Engineers drawings. Any discrepancy that may buof prior knowledge to the Contractor or that is nsw»a)ed through his investigations shall be made available to the Owner. It is the Contractor's responsibility to nsV|nvv the attached report prior to construction. The selection of equipment for use on the project and the order ofwork will similarly be his responsibility such that the requirements included in following sections have been met. 1.3 Geotechnical Engineer - The work covered by these specifications shall be � observed and bested by the GeotechOice) Engineer, F{innnook Engineering. who � shall be hired by the Owner. The GaVLachnioa| Engineer will be present during the site preparation and grading to observe the work and toperform the tests necessary to evaluate material quality and compaction. The Geoteohn|ca| Engineer shall submit report to the Owner, including o tabulation of all tests performed. The costs of retesting of unsuitable work performed by the Contractor shall be deducted from the payments to the Contractor. 1.4 Standard Specifications - VVhero referred to in these specifications, "Standard Specifications" oheU mean the current Montana Public Works Standard Specifications dated March 2003. ( B'07'103'01 Page 1of6 Aph|26. 2007 Rimm,*Engineering,Inc. 1.5 Compaction Test Method - Where referred to herein, relative compaction shall mean the in-place dry density of soil expressed as a percentage of the maximum dry density of the same material, as determined by ASTM D698 Compaction Test Procedure. Optimum moisture content shall mean the moisture content at maximum dry density as determined above. 2.0 SITE PREPARATION 2.1 Clearing -Areas to be graded shall be cleared and grubbed of all vegetation and debris. These materials shall be removed from the site by the Contractor. 2.2 Stripping - Surface soils containing roots and organic matter shall be stripped from areas to be graded and stockpiled or discarded as directed by the Owner. In general, the depth of stripping of the topsoil will be approximately six inches. Deeper stripping, where required to remove weak soils or accumulations or organic matter, shall be performed when determined by the Geotechnical Engineer. Strippings shall be removed from the site or stockpiled at a location designated by the Owner. 2.3 Removal of Existing Fill - Existing fill soils, trash, and debris in the areas to be graded shall be removed prior to the placing of any compacted fill. Portions of any existing fills that are suitable for use in compacted fill may be stockpiled for future use. All organic material, topsoil, expansive soils, oversize material or other unsuitable material shall be removed from the site by the Contractor or disposed of at a location on site, if so designated by the Owner. 2.4 Ground Surface - The ground surface exposed by stripping shall be scarified to a depth of six inches, moisture conditioned to the proper moisture content for compaction, and compacted as required for compacted fill. Recompaction shall be approved by the Geotechnical Engineer prior to placing fill. 3.0 EXCAVATION 3.1 General - Excavations shall be performed to the lines and grades indicated on the plans. The data presented in the geotechnical investigation report is for information and only the Contractor shall make his own interpretation with regard to the methods and equipment necessary to perform the excavation and to obtain material suitable for fill. 3.2 Materials - Soils which are removed and are unsuitable for fill should be placed in non-structural areas of the project. When necessary, these soils may be placed in deeper fills if approved by the Geotechnical Engineer. B-07-103 01 Page 2 of 5 April 26, 2007 Rimrock Engineering,Inc. 3.3 Treatment of Exposed Surface - The ground surface exposed by excavation shall be scarified to a depth of six inches, moisture conditioned to the proper moisture content for compaction, and compacted as required for compacted fill. Recompaction shall be approved by the Geotechnical Engineer prior to placing fill. 4.0 STRUCTURAL FILL 4.1 Limits — Structural fill, if required for fill beneath foundations should be medium dense to dense gravel with sand. 4.2 Material—We recommend the gradation for structural fill be 100% passing the 3- inch sieve, 25 to 65% passing the No. 4 sieve, and no more than 20% minus No. 200 sized material. The structural fill should have a liquid limit less than 25 and a plasticity index less than 15. 4.3 Placement - All fill materials shall be placed in layers of eight inches or less in loose thickness and uniformly moisture conditioned. The lift should then be compacted with approved compaction equipment to achieve at least 98% relative compaction in areas under structure foundations. No fill material shall be placed, spread, or rolled while it is frozen or thawing, or during unfavorable weather I conditions. 4.4 Benching - Fill placed on slopes steeper than 5 horizontal to 1 vertical shall be keyed into firm, native soils or rock by a series of benches. Benching can be conducted simultaneously with placement of fill. However, the method and extent of benching shall be checked by the Geotechnical Engineer. 4.5 Compaction Equipment - The Contractor shall provide and use sufficient equipment of a type and weight suitable for the conditions encountered in the field. The equipment shall be capable of obtaining the required compaction in all areas, including those that are inaccessible to ordinary rolling equipment. 4.6 Recompaction - When, in the judgment of the Geotechnical Engineer, sufficient compaction effort has not been used, or where the field density tests indicate that the required compaction or moisture content has not been obtained, or if "pumping" or other indications of instability are noted, the fill shall be reworked and recompacted as needed to obtain a stable fill at the required density and moisture content prior to placing additional fill materials. 4.6 Responsibility - The Contractor shall be responsible for the maintenance and protection of all embankments and fills made during the contract period and shall B-07-103-01 Page 3 of 5 April 26,2007 Rimrock Engineering,Inc. bear the expense of replacing any portion which has become displaced due to carelessness, negligent work, or failure to take proper precautions. 5.0 UTILITY TRENCH BEDDING AND BACKPILL 5.1 Material - Pipe bedding shall be defined as all material within six inches of the perimeter of the pipe. Backfill shall be classified as all material within the remainder of the trench. Material for use as bedding shall consist of clean, granular materials, and shall conform to requirements for bedding material listed in the Standard Specifications. 5.2 Placement and Compaction - Pipe bedding shall be placed in thin layers not exceeding eight inches in loose thickness, and conditioned to the proper moisture content for compaction. All other trench backfill shall be placed in thin layers not exceeding eight inches in loose thickness, conditioned to the proper moisture content, and compacted as required for adjacent fill. If not specified, backfill should be compacted to at least 97% relative compaction in areas under structures, utilities, roadways, parking areas, concrete flatwork, and to 90% relative compaction in undeveloped areas. 6.0 AGGREGATE BASE FOR CONCRETE SLABS 6.1 Material -Aggregate base for concrete slabs shall consist of crushed base rock conforming to requirements of the Standard Specifications. 6.2 Placement-Aggregate base shall be compacted and kept moist until placement of concrete. Compaction shall be by suitable vibrating compactors. Aggregate base shall be placed in layers not exceeding eight inches in thickness. Each layer shall be compacted by at least four passes of the vibratory compaction equipment or until 95% relative compaction has been obtained. 7.0 SUBGRADE AND AGGREGATE BASE FOR PAVED AREAS 7.1 Subgrade Preparation -After completion of the utility trench backfill and prior to placement of aggregate base, the upper six inches of subgrade soil shall be uniformly compacted to at least 95% relative compaction. This may require scarifying, moisture conditioning, and compacting in both cut and fill areas. 7.2 Aggregate Base - Aggregate materials shall meet the requirements of the appropriate sections of the "Standard Specifications" for 1 !2 Minus Crushed B-07-103-01 Page 4 of 5 April 26,2007 Rimrock Engineering,inc. Base Rock. The aggregate base materials must be approved by the Geotechnical Engineer prior to use. After the subgrade is properly prepared, the aggregate base shall be placed in layers, moisture conditioned as necessary, and compacted by rolling to at least 95% relative compaction. The compaction thickness of aggregate base shall be as shown on the approved plans. 8.0 ASPHALT CONCRETE PAVEMENT 8.1 Thickness - The compacted thickness of asphalt concrete shall be shown on the approved plans. 8.2 Materials - Aggregate materials for asphalt concrete shall conform to the requirements listed for Type B or Type S-3 bituminous aggregates in Section 02503-2.2.3 of the "Standard Specifications."Asphalt concrete mixes shall utilize asphalt cement meeting the requirements of Section 02510 of "Standard Specifications". The Contractor shall submit a proposed asphalt concrete mix design to the Owner for review and approval prior to paving. The mix design shall be based on the Marshall Method. 8.3 Placement and Compaction - The asphalt concrete material and placement procedures shall conform to appropriate sections of the "Standard Specifications." The asphalt concrete material shall be compacted to a minimum of 92% of the Theoretical Maximum Rice Specific Gravity, B-07-103-01 Page 5 of 5 April 26,2007 Rimrock Engineering,Inc.