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Home My WebLink AboutHARMONY TECHNOLOGY PARK-CELESTICA - PDP - 12-97A - SUBMITTAL DOCUMENTS - ROUND 2 - GEOTECHNICAL (SOILS) REPORT1 1 i 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 J BM NE BONNET BOLT FH=ELEV. 4933.02 HARMONY ROAD L=IK. NG020� NO.1 O NO.6 N0.2 77 PARKING fDETENTION NO.21 POND B 0— NO.4 1$�N0.7 � NO.8 Y NO.9 N0.1 �. N0.1 NO.1 O LOADING '$NO 17 Q' DOCK N0.18 N0.24 0 NO.27 C= NO.14. NO.1 19 0.5 0 � oz NO.10 a NO.23 a L NO.16 PARKING LEGEND NO.1-19-0 APPROXIMATE LOCATION OF SOIL BORING DRILLED B-29 & 9-2.3-97 NO.20-30-($� APPROXIMATE LOCATION OF SOIL BORING DRILLED 9-15-97 N0.30 FIGURE 2: SITE PLAN CELESTICA—HP TECHNOLOGY PARK FORT COLLINS, COLORADO TCW INC. PROJECT No. 20975066 DETENTION POND A -ONO.28 N SCALE 1" = 200' Irerracon CONSULTANTS WESTERN. INC. EMPIRE DIVISION Z �i nVnOelVUln 29511 HUAM 1 1 4 862 i Collindale 0 TM�ourse i zll"J �32 ---49'. --- ---------- 33 41, rProject Si te J; --- ---- c 99 7 X 0 �q so 9 ullcw f SCALE 1:24000 1/2 0 1 MILE 1�000 20�0 1000 0 3000 4000 5000 6000 7000 FEET 1 .5 CONTOUR INTERVAL 10 FEET NATIONAL GEODETIC VERTICAL DATUM OF 1929 FIGURE 1: VICINITY MAP CELESTICA—HP TECHNOLOGY PARK FORT COLLINS, COLORADO PROJECT NUMBER 20975066 DRAWN, SEPTEMBER, 1997 DRAWN BY, IES.lrerracon j CONSULTANTS Whi'Ftatl. 1M. EMPIRE DIVISION ' Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 This report has been prepared for the exclusive use of our client for specific application to ' the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. In the event that changes in the nature, design, or location of the project as outlined in this report, are planned, the conclusions and recommendations contained in this report shall not be considered valid. unless Terracon reviews the changes, and either ' verifies or modifies the conclusions of this report in writing. 1 I 7 L II 15 i ' Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 All underground piping within or near the proposed structure should be designed ' with flexible couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts in grade beams should be oversized to accommodate differential movements. ' Corrosion Protection ' Results of soluble sulfate testing indicate that ASTM Type 1-11 Portland cement is suitable for all concrete on or below grade. Foundation concrete should be designed ' in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. Laboratory test results indicate that on -site soils have resistivities ranging from 1200 ' to 2400 ohm -centimeters, pH values ranging from 8.0 to 8.1 and oxidation-reduction potentials of 63 to 105 millivolts along with trace sulfides. These values should be used to determine potential corrosive characteristics of the on -site soils with respect ' to contact with the various underground materials which will be used for project construction. ' GENERAL COMMENTS Terracon Consultants Western, Inc. should be retained to review the final design plans and ' specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should ' be retained to provide testing and observation during excavation, grading, and construction phases of the project. In the event that any changes of the proposed project are planned, the conclusions and recommendations contained in this report should be reviewed and the ' report modified or supplemented as necessary The analyses and recommendations in this report are based in part upon data obtained ' from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations which may occur between borings or across the site. The nature and extent of such variations may not become evident until construction. If variations appear, it will be necessary to reevaluate the recommendations of this report. ' The scope of services for this project does not include either specifically or by implication any environmental assessment of the site or identification of contaminated or hazardous ' materials or conditions. If the owner is concerned about the potential for such contamination, other studies should be undertaken. 1 14 ' Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 Drainage ' Surface Drainage: 1. Positive drainage should be provided during construction and maintained throughout the life of the proposed facility. Infiltration of water into utility excavations must be prevented during construction. Planters and other surface ' features which could retain water in areas adjacent to pavements should be sealed or eliminated. 2. Backfill against utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration. ' Additional Design and Construction Considerations Exterior Slab Design and Construction Exterior slabs -on -grade, exterior architectural features, and utilities founded on, or in ' backfill may experience some movement due to the volume change of the backfill. Potential movement could be reduced by: ' minimizing moisture increases in the backfill • controlling moisture -density during placement of backfill • using designs which allow vertical movement between the exterior features and adjoining structural elements • placing effective control joints on relatively close centers • allowing vertical movements in utility connections Underground Utility Systems All piping should be adequately bedded for proper load distribution. It is suggested ' that clean, graded gravel compacted to 75 percent of Relative Density ASTM D4253 be used as bedding. Where utilities are excavated below groundwater, temporary ' dewatering will be required during excavation, pipe placement and backfilling operations for proper construction. Utility trenches should be excavated on safe and stable slopes in accordance with OSHA regulations as discussed above. Backfill ' should consist of the on -site soils or existing bedrock. If bedrock is used, all plus 6- inch material should be removed from it prior to its use. The pipe backfill should be compacted to a minimum of 95 percent of Standard Proctor Density ASTM D698. 1 13 I� n 11 Geotechnical Engineering Exploration Young+Wright Architects Inc. Project No. 20975066 Material On -site soils: Terracon Estimated Shrink(-) Swell (+) Based on ASTM D698 Clays.................................................................................15 to -20% ' Compliance Performance of pavement elements supported on compacted fills or prepared ' subgrade depend upon compliance with "Earthwork" recommendations. To assess compliance, observation and testing should be performed under the direction of the geotechnical engineer. ' Excavation and Trench Construction ' Excavations into the on -site soils will encounter a variety of conditions. Excavations into the clays and bedrock can be expected to stand on relatively steep temporary slopes during construction. However, caving soils and/or groundwater may also be encountered. The individual contractor(s) should be made responsible for designing and constructing stable, temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. The soils to be penetrated by the proposed excavations may vary significantly across the site. The preliminary soil classifications are based solely on the materials ' encountered in widely spaced exploratory test borings. The contractor should verify that similar conditions exist throughout the proposed area of excavation. If different ' subsurface conditions are encountered at the time of construction, the actual conditions should be evaluated to determine any excavation modifications necessary to maintain safe conditions. ' As a safety measure, it is recommended that all vehicles and soil piles be kept to a minimum lateral distance from the crest of the slope equal to no less than the slope ' height. The exposed slope face should be protected against the elements. 1 12 Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 Placement and Compaction: ' 1. Place and compact fill in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. 1 2. No fill should be placed over frozen ground. ' 3. Materials should be compacted to the following: Minimum Percent Compaction Material ASTM D698) ' Subgrade soils beneath fill areas................................................................... 95 On -site soils or approved imported fill: Beneath pavements....................................................................... 95 Utilities............................................................................................ 95 ' Miscellaneous backfill.....................................................................90 ' 4. Clay soils placed beneath pavement should be compacted within a moisture content range of 2 percent below to 2 percent above optimum. 5. Granular soils should be compacted within a moisture content range of 3 percent below to 3 percent above optimum unless modified by the project geotechnical engineer. 6. If a well defined maximum density curve cannot be generated by impact compaction in the laboratory for any fill type, engineered fill should be compacted to a minimum of 80 percent relative density as determined by ASTM D4253 D4254. Shrinkage ' For balancing grading plans, estimated shrink of soils and bedrock when used as compacted fill following recommendations in this report are as follows: ' Geotechnical Engineering Exploration Young+Wright Architects Inc. Project No. 20975066 Excavation: Terracon 1. It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. 2. Depending upon depth of excavation and seasonal conditions, groundwater may be encountered in excavations on the site. Pumping from sumps may be utilized to control water within excavations. Well points may be required for significant groundwater flow or where excavations penetrate groundwater to a significant depth. 3. On -site clay soils in proposed pavement areas may pump or become unstable or unworkable at high water contents. Workability may be improved by scarifying and drying. Overexcavation of wet zones and replacement with granular materials may be necessary. Lightweight excavation equipment may be required to reduce subgrade pumping. Minimizing construction traffic on -site is recommended. Use of lime, fly ash, kiln dust, cement or geotextiles could also be considered as a stabilization technique. Laboratory evaluation is recommended to determine the effect of chemical stabilization on subgrade soils prior to construction. Proof -rolling of the subgrade may be required to determine stability prior to paving. 4. Due to the plastic nature of the subsoils and shallow depth to groundwater, roadway subgrade stabilization is anticipated. With properly designed stabilization, reductions in the pavement section may be possible. Fill Materials: 1. Clean on -site soils or approved imported materials may be used as fill material for the following: • general site grading exterior slab areas • detention ponds pavement areas 10 ' Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 be given to use of a synthetic liner and pressure relief valves to protect the pond from high ' groundwater. Earthwork Site Clearing and Subgrade Preparation: t 1. Strip and remove existing vegetation, debris, and other deleterious materials from proposed pavement and detention pond areas. All exposed surfaces ' should be free of mounds and depressions which could prevent uniform compaction. 2. If unexpected fills or underground facilities are encountered during site clearing, such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction. All excavations should be observed by the geotechnical engineer prior to backfill placement. 3. Stripped materials consisting of vegetation and organic materials should be wasted from the site or used to revegetate exposed slopes after completion of grading operations. If it is necessary to dispose of organic materials on -site, they should be placed in non-structural areas and in fill sections not exceeding 5 ' feet in height. 4. Sloping areas steeper than 3:1 (horizontal:vertical) should be benched to reduce the potential for slippage between existing slopes and fills. Benches should be level and wide enough to accommodate compaction and earth ' moving equipment. 5. The site should be initially graded to create a relatively level surface to receive fill, and to provide for a relatively uniform thickness of fill beneath proposed building structures. 6. All exposed areas which will receive fill and/or pavement, once properly cleared and benched where necessary, should be scarified to a minimum depth of 8 ' inches, conditioned to near optimum moisture content, and compacted. 7. Finished subgrade below paved areas should be placed a minimum of 3 feet ' above groundwater after grading is complete, or area drains should be constructed to lower groundwater levels at the site. 1 9 Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 • Site grading at a minimum 2% grade away from the pavements; • Compaction of any utility trenches for landscaped areas to the same criteria as the pavement subgrade; • Sealing all landscaped areas in or adjacent to pavements to minimize or prevent moisture migration to subgrade soils; and, • Placing compacted backfill against the exterior side of curb and gutter. Preventative maintenance should be planned and provided for an on -going pavement management program in order to enhance future pavement performance. Preventative maintenance activities are intended to slow the rate of pavement deterioration and to preserve the pavement investment. Preventative maintenance consists of both localized maintenance (e.g. crack sealing and patching) and global maintenance (e.g. surface sealing). Preventative maintenance is ' usually the first priority when implementing a planned pavement maintenance program and provides the highest return on investment for pavements. Recommended preventative maintenance policies for asphalt and jointed concrete ' pavements, based upon type and severity of distress, are provided in Appendix D. Prior to ' implementing any maintenance, additional engineering observation is recommended to determine the type and extent of preventative maintenance. Detention Ponds In view of the shallow depth to groundwater, the bottom of the detention ponds may be at or near existing groundwater in the southern and southeastern portions of the site. Temporary dewatering may be required during construction to adequately construct the detention ponds. Lining of the ponds will be required to separate detention water from the groundwater. It is recommended the ponds be lined with a minimum of one foot of the on - site lean clay with sand or sandy lean clay. The liner should be placed on the wetted perimeter of the ponds. The upper 8 to 12 inches of the wetted perimeter of the pond including the bottom of the pond and cut slopes of the pond should be scarified and recompacted plus or minus 2 percent of optimum moisture to a minimum of 95 percent of Standard Proctor Density ASTM D698. Embankments constructed to form the ponds should consist of the on -site clays compacted in uniform 6 to 8 inch lifts and mechanically compacted to the required moisture and density. Detention pond cut and fill slopes should be constructed on grades of 3:1 or flatter. The ponds should be designed to maintain a minimum amount of water to resist hydrostatic uplift, or the bottom pond elevation should be raised to protect the pond lining should water levels rise at the site. Consideration may W I Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 • Modulus of Rupture @ 28 days .................................................. 600 psi minimum ' Strength Requirements.........................................................................ASTM C94 • Minimum Cement Content............................................................6.5 sacks/cu. yd. ' Cement Type................................................................................. Type I Portland • Entrained Air Content................................................................................. 6 to 8% ' Concrete Aggregate........................................ASTM C33 and CDOT Section 703 Aggregate Size............................................................................ 1 inch maximum • Maximum Water Content........................................................ 0.49 lb/lb of cement • Maximum Allowable Slump.......................................................................4 inches Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 ' minutes from the time the water is added to the mix. Other specifications outlined by the Colorado Department of Transportation should be followed. Longitudinal and transverse joints should be provided as needed in concrete pavements for expansion/contraction and isolation. The location and extent of joints should be based ' upon the final pavement geometry and should be placed (in feet) at.roughly twice the slab thickness (in inches) on center in either direction. Sawed joints should be cut within 24- hours of concrete placement, and should be a minimum of 25% of slab thickness plus 1/4 inch. All joints should be sealed to prevent entry of foreign material and dowelled where necessary for load transfer. Future performance of pavements constructed on the clay soils at this site will be dependent upon several factors, including: ' maintaining stable moisture content of the subgrade soils and • providing for a planned program of preventative maintenance. Since the clay soils on the site have shrink/swell characteristics, pavements could crack in the future primarily because of expansion of the soils when subjected to an increase in ' moisture content to the subgrade. The cracking, while not desirable, does not necessarily constitute structural failure of the pavement. ' The performance of all pavements can be enhanced by minimizing excess moisture which can reach the subgrade soils. The following recommendations should be considered at minimum: t 1 ' Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 1 I 1 i 11 Traffic Area Alter Recommended m Paveent Thicknesses (Inches) native WWI Asphalt Aggregate Plaht Mixed <i Portland Total:. z Concrete Base Bituminous Cement Surface Course;i f3ase Concrete Automobile Parking IA 3 7 10 B 2 3Y2 5'/2 C 5 5 Main Traffic Corridors A 3 10 13 & Truck Loading Areas B 2 4 6 C 6 6 Each alternative should be investigated with respect to current material availability and economic conditions. Aggregate base course (if used on the site) should consist of a blend of sand and gravel which meets strict specifications for quality and gradation. Use of materials meeting Colorado Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for base course. Aggregate base course should be placed in lifts not exceeding six inches and should be compacted to a minimum of 95% Standard Proctor Density (ASTM D698). Asphalt concrete and/or plant -mixed bituminous base course should be composed of a mixture of aggregate, filler and additives, if required, and approved bituminous material. The bituminous base and/or asphalt concrete should conform to approved mix designs stating the Hveem properties, optimum asphalt content, job mix formula and recommended mixing and placing temperatures. Aggregate used in plant -mixed bituminous base course and/or asphalt concrete should meet particular gradations. Material meeting Colorado Department of Transportation Grading C or CX specification is recommended for asphalt concrete. Aggregate meeting Colorado Department of Transportation Grading G or C specifications is recommended for plant -mixed bituminous base course. Mix designs should be submitted prior to construction to verify their adequacy. Asphalt material should be placed in maximum 3-inch lifts and should be compacted to a minimum of 95% Hveem density (ASTM D1560) (ASTM D1561). Where rigid pavements are used, the concrete should be obtained from an approved mix design with the following minimum properties: 2 Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 Highway and Transportation Officials (AASHTO). Areas within proposed pavements on ' the site will be divided into two categories based upon anticipated traffic and usage. Traffic criteria provided for pavement thickness designs include equivalent 18-kip single ' axle loads (ESAL's) of 36,500 for automobile parking, and 73,000 for drive and truck access. ' Based upon AASHTO criteria, Colorado is located within Climatic Region VI of the United States. This region is characterized as being dry, with hard ground freeze and spring thaw. ' The spring thaw condition typically results in saturated or near -saturated subgrade soil moisture conditions. The AASHTO criteria suggests that these moisture conditions are prevalent for approximately. 12-1/2% of the annual moisture variation cycle. ' Local drainage characteristics of proposed pavement areas are considered to vary from fair to good depending upon location on the site. For purposes of this design analysis, fair ' drainage characteristics are considered to control the design. These characteristics, coupled with the approximate duration of saturated subgrade conditions, results in a design drainage coefficient of 1.0 when applying the AASHTO criteria for design. ' For flexible pavement design, a terminal serviceability index of 2.0 was utilized along with ' an inherent reliability of 70% and a design life of 20 years. Using the correlated design average R-value of 7, appropriate ESAL/day, environmental criteria and other factors, the structural numbers (SN) of the pavement sections were determined on the basis of the ' 1986 AASHTO design equation. In addition to the flexible pavement design analyses, a rigid pavement design analysis was ' completed, based upon AASHTO design procedures. Rigid pavement design is based on an evaluation of the Modulus of Subgrade Reaction of the soils (K-value), the Modulus of Rupture of the concrete, and other factors previously outlined. The design K-value of 100 ' for the subgrade soil was determined by correlation to the laboratory tests results. A modulus of rupture of 600 psi (working stress 450 psi) was used for pavement concrete. ' The rigid pavement thicknesses for each traffic category were determined on the basis of the AASHTO design equation. ' Recommended alternatives for flexible and rigid pavements, summarized for each traffic area, are as follows: 1 1 5 Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 SUBSURFACE CONDITIONS Soil and Bedrock Conditions The site is overlain by a 6-inch layer of cultivated silty topsoil. The topsoil has been penetrated by root growth and organic matter. A layer of sandy clay which varies to a lean clay with sand underlies the topsoil and extends to the silty sand with gravel stratum below, the depths explored and/or the bedrock below. The silty sand with gravel was encountered in Boring 28 at a depth of 14%2 feet. Siltstone-claystone bedrock was encountered in Borings 24, 26 and 29 at depths of 9 to 9'/z feet. Field and Laboratory Test Results Field and laboratory test results indicate that the clay soils are moderately plastic and exhibit low subgrade strength characteristics. Groundwater Conditions Groundwater was encountered Borings 23 and 25 through 28 at approximate depths of 5% to 8 feet at the time of field exploration. The remaining borings were dry to the depths explored. When checked one day after drilling, groundwater was measured at ' approximate depths of 4% to 8'/2 feet in all borings. These observations represent only current groundwater conditions, and may not be indicative of other times, or at other ' locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions and irrigation demands on the site. Water levels may lower several feet in the area after site development is complete and crop irrigation is eliminated. ' CONCLUSIONS AND RECOMMENDATIONS Based on the subsurface conditions encountered, it is our opinion that pavement construction at the site is feasible. The pavement may consist of asphalt concrete and aggregate base course, full -depth asphalt and nonreinforced concrete. On -site clay soils ' are suitable to line the proposed ponds. Construction of the detention ponds may be require temporary dewatering and a permanent water level in the ponds may be needed to ' maintain the integrity of the liner in the proposed detention ponds. Pavement Design and Construction Design of pavements for the project have been based on the procedures outlined in the 1986 Guideline for Design of Pavement Structures by the American Association of State 1 4 ■ �I I 1 [1 1 Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 resistance value is a useful index to the consistency, relative density or hardness of the materials encountered. Groundwater measurements were made in each boring at the time of site exploration, and one day after drilling. Laboratory Testing All samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer, and were classified in accordance with the Unified Soil Classification System described in Appendix C. Samples of bedrock were classified in accordance with the general notes for Bedrock Classification. At that time, the field descriptions were confirmed or modified as necessary and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Boring logs were prepared and are presented in Appendix A. Selected soil and bedrock samples were tested for the following engineering properties: • Water content Resistivity • Plasticity index pH • R-Value Oxidation-reduction potential • Water soluble sulfate content Sulfides The significance and purpose of each laboratory test is described in Appendix C. Laboratory test results are presented in Appendix B, and were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. All laboratory tests were performed in general accordance with the applicable ASTM, local or other accepted standards. SITE CONDITIONS The area of the additional investigation is located south of the proposed building. The site consists of an irrigated corn field that has been recently cut. The site is relatively flat and has minor drainage to the south and east. The property is bordered on the north by Harmony Road, on the east and south by farm fields, and on the west by County Road 9. 3 ' Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 Parkway. Detention ponds are planned in the northeast, southeast and south-central ' portions of the site. Improvements are to be made to County Road 9 and Harmony Road and Technology Parkway is to be constructed on the east edge of the project area. Field investigations for off -site improvements to County Road 9, Harmony Road and the ' construction of Technology Parkway have not been completed at this time since this work cannot be performed in accordance with City of Fort Collins requirements until such time as the street subgrade has been constructed. Additional investigations will be required for the off -site improvements after site grading has been completed. Based on the grading plan prepared by The Sear -Brown Group, site grading will include fills of between 1 and 4 feet for site grading and cuts of between 1 and 4 feet for the proposed detention ponds. SITE EXPLORATION The scope of the services performed for this project included site reconnaissance by an engineering geologist, a subsurface exploration program, laboratory testing and engineering analysis. Field Exploration Eleven additional test borings were drilled on September 15, 1997 to depths of 10 to 15 feet at the locations shown on the Site Plan, Figure 2. Nineteen borings were drilled on the site on August 26 and September 2 and 3, 1997 for the proposed building. The additional borings were drilled in the areas of proposed pavements and detention pond areas. All borings were advanced with a truck -mounted drilling rig, utilizing 4- and 6-inch diameter solid stem augers. The borings were located in the field by pacing from property lines and/or existing site features. Elevations were taken at each boring location by measurements with an engineer's level from a bench mark (BM) shown on the Site Plan. The accuracy of boring locations and elevations should only be assumed to the level implied by the methods used. Continuous lithologic logs of each boring were recorded by the engineering geologist during the drilling operations. At selected intervals, samples of the subsurface materials were taken by driving split -spoon samplers. Representative bulk samples of subsurface materials were obtained from pavement borings. Penetration resistance measurements were obtained by driving the split -spoon into the subsurface materials with a 140-pound hammer falling 30 inches. The penetration 2 ' Terracon ADDENDUM TO GEOTECHNICAL ENGINEERING REPORT PROPOSED CELESTICA FACILITY SITE IMPROVEMENTS HP TECHNOLOGY PARK ' HARMONY ROAD AND COUNTY ROAD 9 FORT COLLINS, COLORADO Project No. 20975066 September 22, 1997 INTRODUCTION This addendum contains the results of our geotechnical engineering exploration for the proposed site work for the Celestica facility to be located on County Road 9 and Harmony Road in Fort Collins, Colorado. The site is located in the . Northwest 1/4 of Section 4, ' Township 6 North, Range 68 West of the 6th Principal Meridian. A Vicinity Map showing the project location is included as Figure 1 of this report. The purpose of these services is to provide information and geotechnical engineering recommendations relative to: • additional subsurface soil and bedrock conditions • groundwater conditions • pavement design and construction • detention pond construction • earthwork • drainage The conclusions and recommendations contained in this report are based upon the results of field and laboratory testing, engineering analyses, our experience with similar soil conditions and structures and our understanding of the proposed project. PROPOSED CONSTRUCTION ' Based on information provided by The Sear -Brown Group, parking and drive areas are planned adjacent to the west, north and east sides of the proposed Celestica facility, and ' entrance roads are planned adjacent to County Road 9 and the proposed Technology Geotechnical Engineering Exploration Young+Wright Architects Inc. Project No. 20975066 TABLE OF CONTENTS (cont'd) APPENDIX A Vicinity Map Site Plan and Boring Location Diagram Logs of Borings APPENDIX B Laboratory Test Results APPENDIX C General Notes APPENDIX D Pavement Notes iv Terracon TABLE OF CONTENTS Terracon Page No. Letterof Transmittal.............................................................................................................ii INTRODUCTION.................................................................................................................1 PROPOSEDCONSTRUCTION..........................................................................................1 SITEEXPLORATION..........................................................................................................2 FieldExploration......................................................................................................2 LaboratoryTesting.................................................................................................. 3 SITECONDITIONS.............................................................................................................3 SUBSURFACE CONDITIONS............................................................................................4 Soil and Bedrock Conditions................................................................................... 4 Field and Laboratory Test Results...........................................................................4 GroundwaterConditions.......................................................................................... 4 CONCLUSIONS AND RECOMMENDATIONS....................................................................4 Pavement Design and Construction........................................................................ 4 DetentionPonds.............................................................................................:........8 Earthwork................................................................................................................ 9 Site Clearing and Subgrade Preparation..................................................... 9 Excavation...................................................................................................10 FillMaterials.................................................................................................10 Placement and Compaction.........................................................................11 Shrinkage.....................................................................................................11 Compliance..................................................................................................12 Excavation and Trench Construction ........ :.................................................. 12 Drainage..................................................................................................................13 SurfaceDrainage.........................................................................................13 Additional Design and Construction Considerations................................................13 Exterior Slab Design and Construction........................................................13 Underground Utility Systems........................................................................13 CorrosionProtection....................................................................................14 GENERALCOMMENTS.....................................................................................................14 1 1 1 1 Geotechnical Engineering Exploration Young+Wright Architects Inc. Terracon Project No. 20975066 Terracon site, lining of the proposed ponds may be required. Further details are provided in this report. We appreciate the opportunity to be of service to you on this phase of your project. If you have any questions concerning this report,' or if we may be of further service to you, please do not hesitate to contact us. Sincerely, TERRACON CONSULTANTS V)/;EST I INC. Empire Division .tit •' °'q^;�'' Prepared by/r, I 4117i' ! 2575 ��`• '':reviewed by: AJPG Neil R. Sherrod �qF�! A. SHOX, Senior Engineering Geologist P"�`rs8:011P Copies to: Addressee (2) The Sear -Brown Group, Inc. (3) Larry G. Dell, P.E. Division Manaqer I 1 1 1 September 22, 1997 1 Young+Wright Architects Inc. 1 172 St. George Street Toronto, Ontario Canada M5R 2M7 1 Attn: Mr. Robert D. Macpherson Re: Addendum to Geotechnical Engineering Report 1 Proposed Celestica Facility Site Improvements HP Technology Park 1 Harmony Road and County Road 9 Fort Collins, Colorado Project No. 20975066 Irerracon CONSULTANTS WESTERN, INC. P.O. Box 503. 301 N. Howes Fart Collins, Colorado 80522 (970)484-0359 Fax: (970) 484-0454 Larry G. O'Dell, P.E. William J. Attwooll, P.E. Neil R. Sherrod, C.P.G. 1 Terracon Consultants Western, Inc. has completed the addendum to our geotechnical engineering exploration for the proposed site improvements for the Celestica Facility to be 1 located at the southeast comer of Harmony Road and County Road 9, Fort Collins, Colorado. This study was performed in general accordance with our proposal number D2097093 dated April 30, 1997 and Schedule A Pricing Detail. 1 The purpose of the addendum is to provide recommendations regarding site improvements adjacent to the proposed Celestica facility. The results of our engineering study, including 1 the boring location diagram, laboratory test results, test boring records, and the geotechnical recommendations needed to aid in the design and construction of paved areas, detention ponds and other earth connected phases of this project are attached. 1 The subsoils at the site consist of sandy lean clay and lean clay with sand underlain by silty 1 sand with gravel and siltstone-claystone bedrock. Groundwater was encountered at relatively shallow depths of 4% to 8'/2 feet below the surface. The subsoil conditions at the site are such that the proposed site improvements are feasible. Pavement sections may 1 consist of asphaltic concrete underlain by aggregate base course, full -depth asphalt and nonreinforced concrete. Due to the shallow depth to groundwater and the plastic nature of the subsoils, stabilization of portions of the subgrade below pavement is anticipated. 1 Finished subgrade below paved areas should be placed a minimum of 3 feet above seasonal high groundwater. In view of the shallow depth to groundwater encountered at the 1 Offices of The Terracon Companies, Inc. Geotechnical, Environmental and Materials Engineers 1 Arizona ■ Arkansas ■ Colorado ■ Idaho ■ Illinois ■ Iowa ■ Kansas ■ Minnesota ■ Missouri ■ Montana Nebraska ■ Nevada ■ North Dakota ■ Oklahoma ■ Tennessee ■ Texas ■ Utah ■ Wyoming QUALITY ENGINEERING SINCE 1965 ADDENDUM TO GEOTECHNICAL ENGINEERING REPORT PROPOSED CELESTICA FACILITY SITE IMPROVEMENTS HP TECHNOLOGY PARK HARMONY ROAD AND COUNTY ROAD 9 FORT COLLINS, COLORADO PROJECT NO. 20975066 September 22, 1997 Prepared for. YOUNG+WRIGHT ARCHITECTS INC. 172 ST. GEORGE STREET TORONTO, ONTARIO CANADA M5R 2M7 ATTN: MR. ROBERT D. MACPHERSON Prepared by: Terracon Consultants Western, Inc. Empire Division 301 North Howes Street Fort Collins, Colorado 80521 Irerracon