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Home My WebLink About12 - Design Report - Norton East Ranch Ph 2 - Street �i, LAMORRISON I iW MAIERLE, INC. An Employee-Owned Company STREET DESIGN REPORT NORTON RANCH EAST SUBDIVISION PHASE 2 BOZEMAN, MONTANA December 2012 Prepared For: Norton Properties, LLC 63020 NE Lower Meadow, Suite A Bend, OR 97701 �i ijy��i 4 MES R. , �-p NICKELSON }I % O 9063 P.E. Prepared By: , Morrison-Maierle, Inc. r�r,,�UN�A,��;•�` 2880 Technology Boulevard West Bozeman, Montana 59718 N:\5149\001\Design Docs\Reports\Street Report.docx Introduction The Norton Ranch East Subdivision, Phase 2 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. The design for Phase 2 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. The road section was designed by Rimrock Engineering, Inc. in a report dated April 26, 2007. Phase 2 Description Phase 2 consists of 30 residential lots and a total area of 6.66 acres. It is located directly-west of the platted Phase 1 and is bounded by May Fly Street on the south, Dragon Fly Street on the North and a park on the west. The attached exhibit shows the location of Phase 2 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. 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 No changes in the design are needed to meet the updated design standards. END NA5149\001\Design Docs\Reports\Street Report.docx PRELIMINARY GEOTECHNICAL INVESTIGATION NORTON EAST RANCH SUBDIVISION RESI DENTIAL-ttYT-S,—UTI LITI ES-AND-STREETS- BOZEMAN, MONTANA April 26, 2007 Project No.13-07-103-01 Prepared for: Big Sky Land Consulting, PLLC. 5530 Burnt Road Belgrade, Montana 59714 Prepared by: ,y Rimrock Engineering, Inc. 5440 Holiday Avenue Y' Billings, Montana 59101 . V Y � A 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. M .:..,ai - • fir_;. . 'E -v 7 P ALA Robert W. Kukes, P.E. QZ Wade.Reynolds Principal Staff Geologist Enclosures: Report (3 bound copies) B-07-103-01 Page 2 of 2 April 26, 2007 Rimrock Engineering, Inc. PRELIMINARY GEOTECHNICAL INVESTIGATION REPORT PROPOSED NORTON EAST RANCH SUBDIVISION RESIDENTIAL LOTS, UTILITIES AND STREETS BOZEMAN, MONTANA 1.0 INTRODUCTION AND SCOPE 1.1 Proiect Description This report presents the results of our preliminary geotechnical investigation for the proposed Norton East Ranch Subdivision which includes residential lots, interior streets, and utilities shown on the site map, Appendix A (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 wall loads of 2 to 3 kips per lineal foot for long-term loading conditions for residential construction. Loads and the type of construction for the commercial buildings (if I applicable to this subdivision) were not available and should be designed when specific information becomes available. Cuts and fills for building pad construction may be on 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 conditions, and to provide our preliminary geotechnical recommendations and opinions as outlined in our proposal dated February 15, 2007, summarized below. • General soil and groundwater conditions at the project site, with emphasis on how the conditions are expected to affect the proposed construction; • Suggested specifications for earthwork construction, including site preparation recommendations, a 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 backfill; t B-07-103-01 Page 1 of 12 April 26, 2007 Rimrock Engineering, Inc. 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 i 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. 3.4 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 subiect 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. 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 backfill 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 backfill 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. 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 Sections ��,�y.�-�_��•f" V� 5i� t / 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 Traffic Condition Redomme:nded 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. 6.2 Construction Observation/Testing and Plan 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. APPENDIX A Plates Geotechnical Investigation Report Norton East Ranch Subdivision EXISTING R CITY BOUNDARY \ o `rie.ry sr:Y rs.¢ I / TP-3 CRTP-4 T -2 O TP-7 O O O TP-5 - N; JA V�.M fZ.MLMPRIIt PROPOSED _ �1Si1�D EXTERIORLQ4Y<yC• ' Y BOUNDARY � BOUNDARY vFIVLC.Ec0."_�.J , HIGHINAY 101 ry'` BOUNDARY �I SITE MAP PLATE Rimrock Engineering, Inc. NORTON EAST RANCH SUBDIVISION Page 1 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: 1Erank 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 Q 4.5 F 1 4.5 u x CL Z O o: } o) u1 w W>r a W DESCRIPTION NOTES Q = J —J W U o_ a COw a � L� 00 OU O w 0 co 0z mU � � c 0 �_r•'• Ve elated To soil Lean to Fat Clay,Grey,Moist,Stiff, 'g,Plasticity Lean Cla with Sand Grey,Moist,Stiff,Low/Medium MC=30.5% as is y, Minus#200=83.7% Plastic Index=24.1 Poorl Graded Gravel with Sand Grey,MoisWJet,Dense, ° :'• rams ar on- as ic, )o 0 ss— 5— ° 0 �0 b 0 �0 0 End of Test Pit 90— 10 r 85— 15— a N O a C7 0 m 0 r= 0 m C9 O LOG OF TEST PIT TP-2 PLATE L03 Rimrock EngineeringNorton East Ranch Subdivision 1 of 1 s Bozeman, Montana LO o Drafted By: R. Kukes Project No.: B-07-103-01 Big Sky Land Consulting, PLLC 4 Date: 4/25/2007 File Number: Rimrock Englneering Date Completed: 4/20/2007 Logged By: .I 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 Q 35 FY- 2-5 d X r } o Q F m a Q = w w w j J DESCRIPTION NOTES I— d o-C° w a 2 �2 00 OV ❑ La w ❑ u U)Z m� Ve etated Topsoil Lean Clay, Light Brown,Moist to Wet, Medium i e ium Plasticity Lean Clay Light Brown,Moist to Wet,Medium Stiff, e ium asticity, (CL) Poo, ly Graded Gravel with Sand Grey,Wet, Dense, o ranu ar on- as ic, - �o 0 `. 95 5 0 �0 0 r ,O End of Test Pit go 1a ro 8s 75 N N V 'a 0 m 0 0 ai 0 O J LOG OF TEST PIT TP-4 PLATE o Rimrock En ineerin Norton East Ranch Subdivision 1 of 1 g 9 Bozeman, Montana Y 6 o Drafted By: R. Kukes Project No.: B-07-103-01 � Big Sky Land Consulting, PLLC Date: 4/25/2007 File Number: Rimrock Engineedng Date Completed: 4/20/2007 Logged By: J 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:1 Q 4.4 F 3.6 a x m o� m w O $ Ld m a w � DESCRIPTION NOTES da >a m Cw < a 0uJ o nz m CL u '• Ve etated To soil Lean Clay, Light Brown/Grey,Moist, e ium as icity Lean Clay Light Brown/Grey,Moist,Stiff,Medium as is y, L) AnNPoorl Graded Gravel with Silt and Sand Grey,Moist to ° e, erase, Granular on- as ic, ) 0 Q Wet @3.5ft MC= 13% ° Minus 4200=5.4% o Plastic Index=GNP 95— 5 0 °L o O Q o Q Q End of Test Pit 90 10 0 85 15— CV P a c� 0 m 0 r 0 m 0 O J LOG OF TEST PIT TP-6 PLATE o Rimrock En ineerin Norton East Ranch Subdivision 1 of 1 g g Bozeman, Montana o Q Drafted By: R. Kukes Project No.: B-07-103-01 Big Sky Land Consulting, PLLC v E2 Date: 4/25/2007 File Number: Rimrock Engineering Date Completed: 3/20/2007 Logged By: R R 1.1 F Boring Location: See Site Map, Plate 2 Driller: Rimrock Engineering Inc. Drilling Method/Size: 3 25"1D -Hollow Stem Auger Elev.Top of Hole: .100 Total Depth. 14.5 Groundwater Depth:l 5 2 F Z 2.5 W X Z m W rn W W o w DESCRIPTION NOTES Q = J J W Y) > U m w o :.'i :�2 oo ° o a W O Cn U)Z m U � (7 Vo stated To soil Lean Clay,Dark Brown/Black,Moist, •. .:• Medium Plasticity IFNLean Clay Brown,Moist,Medium Plasticity,(CL) PoorI Graded Gravel with Sand Brown,Moist to Wet, oose, rams ar on- as ic, SP) 0 �O 95 5 °Q 52 A O 7 O O 0 ,O °b O JQ U 90— 10 B ;:. 0 ,O o Q O o Q J O o Q - O ro 85 15 N End of Boring a 0 m o_ r 0 m 0 _ PLATE LOG OF TEST PIT B-8 Rimrock Engineering Norton East Ranch Subdivision 1 of 1 s g g Bozeman, Montana 0 Drafted By: R. Kukes Project No.: B-07-103-01 gig Sky Land Consulting, PLLC 10 2 Date: 4/25/2007 File Number: LOG SYMBOLS PERCENT FINER THANVN BULK BAG SAMPLE 4 (ASTMTHE Test Meth dIEVE C 136) PERCENT FINER MODIFIED CALIFORNIA SAMPLER -200 THAN THE NO.200 SIEVE (2-1/2 inch outside diameter) (ASTM Test Method C 117) CALIFORNIA SAMPLER LL LIQUID LIMIT (3 inch outside diameter) (ASTM Test Method D 4318) STANDARD PENETRATION PLASTICITY INDEX SPLIT SPOON SAMPLER Pi. (ASTM Test Method D 4318) (2 inch outside diameter) El EXPANSION INDEX GEOPROBE (UBC STANDARD 29-2) COL COLLAPSE POTENTIAL ROCK CORE I WATER LEVEL UC UNCONFINED COMPRESSION (level where first encountered) (ASTM Test Method D 2166) V WATER LEVEL (level after completion) SEEPAGE MC MOISTURE CONTENT (ASTM Test Method D 2216) GENERAL NOTES 1. Lines separating strata on the logs represent approximate boundaries only. Actual transitions may be gradual. 2. No warranty is provided as to the continuity of soil conditions between individual sample locations, 3.Logs represent general soil conditions observed at the point of exploration on the date indicated. 0 4. In general, Unified Soil Classification System designations presented on the logs were evaluated by visual methods only. N Therefore,actual designations(based on laboratory tests)may vary. a o_ o J 4 LOG KEY PLATE t Norton East Ranch Subdivision ' Rimrock Engineering Bozeman, Montana 12 Drafted By: R.Rexford Project No.: B-07-103-01 v Big Sky Land Consulting, PLLC Date: 4/25/2007 File Number: Copyrighl Rimrock Englneering,Inc 2003 60 70 80 90 10 60 GROUP UNIFIED SOIL CLASSIFICATION / SYMBOL FINE GRAINED SOIL GROUPS / OL Organic silts and organic silty Z clays of low plasticity / 0 Inorganic clayey silts to very // U LINE /A-LINE Qfine sands of slight plasticity 5 / — __ 50 Q CL Inorganic clays of low / to moderate plasticity / J / OH Organic clays of moderate to high / CH x plasticity,organic silts / Inorganic silts and F-1 _ 40 — clayey slits / CH Inorganic clays of d high plasticlty / X LU / Z 3 / 30 / C1 M r Q / J 2 // • a / CL 10 - — — 10 / f I_ML L r OL I ' 0 10 20 30 40 50 60 70 80 90 100 LIQUID LIMIT(LL) LEGEND: SOURCE DEPTH LL PL PI DESCRIPTION • TP-1 2.0 43 21 22 LEAN CLAY with SAND(CL) m TP-2 1.5 46 22 24 LEAN CLAY with SAND(CL) A TP-6 4.5 NP NP NP POORLY GRADED GRAVEL with SILT and SAND(GP-GM) 0 N V a c7 0 M 0 r; 4 m r PLASTICITY CHART PLATE W Norton East Ranch Subdivision Rimrock Engineering Bozeman, Montana 1 of 1 Y14 o Drafted By: R.Rexford Project No.: B-07-103-01 Big Sky Land Consulting, PLLC ml Date: 4/25/2007 File Number: r.—Mhl Rim-1,Fnnlnanrinn Inr.2003 PHYSICAL PROPERTIES OF SOIL/AGGREGATE Client Name: Big Sky Land Consulting,PLLC Project No: B-07-103-01 Address: 5530 Burnt Road Date of Report: 04/24/07 Belgrade,Montana 59714 Project Name: Norton East Ranch Subdivision Sample No: Composite,TP1-B8, 1-4ft. Project Location: Bozeman, Montana Date Sampled: 04/20/07 Sampled By: Rimrock Engineering, Inc. Type of Soil/Aggregate: Existing Subgrade Submitted By: Rimrock Engineering, Inc. Source of Sample: Composite,TP1-68, 1-4ft. CALIFORNIA BEARING RATIO LABORATORY BEARING RATIO(CBR) 120 I I l I 100 l I I I , i I i t i ! — I I n - 60 0 IJ I i 40 ! 1 I I I i_ I 20 ) i I I 1 I I 0 0.000 0.100 0.200 0.300 0 400 0.500 Penetration,Inches %CBR@0.1" 5.5 California Bearing Ratio-CBR Plate Rimrock Engineering, Inc. Norton East Ranch Subdivision page 1 of 1 5440 Holiday Avenue Belgrade, Montana Wlln.p,Montana 59101 Tel (4D6)294-6400 Project No.B-07-102-01 Big Sky Land Consulting, PLLC 16 APPENDIX B 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 clearing, stripping, removal of unsuitable material, excavation, preparation of natural soils, placement and compaction of on-site and imported structural fill material, and placement and compaction of pavement materials. 1.2 _Contractor's Responsibility - A geotechnical investigation was performed for the project by Rimrock Engineering dated April 26, 2007. The Contractor shall attentively examine the site in such a manner that he can confirm existing surface conditions with those presented in the geotechnical 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 Geotechnical t Engineer's report and Civil Engineer's drawings. Any discrepancy that may be of prior knowledge to the Contractor or that is revealed through his.investigations shall be made available to the Owner. It is the Contractor's responsibility to review the attached report prior to construction. The selection of equipment for use on the project and the order of work 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 tested by the Geotechnical Engineer, Rimrock Engineering, who shall be hired by the Owner. The Geotechnical Engineer will be present during the site preparation and grading to observe the work and to perform the tests necessary to evaluate material quality and compaction. The Geotechnical Engineer shall submit a report to the Owner, including a 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 - Where referred to in these specifications, "Standard Specifications" shall mean the current Montana Public Works Standard Specifications dated March 2003. t B-07-103-01 Page 1 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 - ! ill 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. 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. APPENDIX C Application for Authorization to Use