The URL can be used to link to this page

Home My WebLink AboutHARMONY TECHNOLOGY PARK RETAIL - Filed SEPD-SURFACE EXPLORATION/PAVEMENT DESIGN REPORT -TAGfAtEnkaR. Ke ton, P.E. aty0f City of Fort Collins lins Engineering Department 3 Exceptions as noted Attention: Roland Tremble Connell Resources, Inc. 7785 Highland Meadows Pkwy, Suite #100 Fort Collins, Co 80528 vV July 1, 2016 Subsurface Exploration, Pavement Thickness Design recommendations, Harmony Technology Park, Fort Collins, Colorado Job Number: 16-0584 This report summarizes results of our subsurface exploration program to develop geotechnical recommendations and pavement thickness designs for Timberwood Drive and Technology Parkway located in the Harmony Technology Park at the southwest corner of Harmony Road and Lady Moon Drive in Fort Collins, Colorado. The site grading and utility installations for these roadways have recently been completed. GROUND Engineering sampled the materials within these roadways as required by Larimer County Urban Street Standards to provide a final pavement design report for the subject roadways. A total of 7 test holes were advanced along the subject roadway alignments (at a frequency of at least 1 sample per 500 LF) to obtain samples for laboratory testing. The test holes were logged and sampled by a representative of GROUND Engineering. Locations of the test holes are shown on Figure 1, logs of the test holes on Figures 2 and 3, and the legend and notes provided on Figure 4. The sampled subgrade materials were tested in the laboratory to provide final subgrade characteristics of the site soils in addition to final pavement subgrade and section recommendations. The subgrade conditions along the roadway alignments appeared to be uniform and generally consisted of sandy clay materials with an AASHTO classification of A-6. During our field exploration it was determined that groundwater was encountered locally in test hole 2A at a depth of approximately 9 feet below subgrade and bedrock soils were not encountered to the depths explored of 10 feet and shouldn't impact the pavement section recommendations. LOVELAND OFFICE 2468 East 9th Street I Loveland, CO 80537 1 (970) 622-0800 www.groundeng.com ENGLEWOOD I COMMERCE CITY I LOVELAND I GRANBY GYPSUM Harmony Technology Park Pavement Thickness Fort Collins, Colorado Additional information was obtained from a geotechnical report for the site prepared by Terracon (Terracon Project # 20005198). This report is labeled Geotechnical Engineering Report, Harmony Technology Center Buildings C and E, Associated Parking Areas, Technology Parkway and Streets A and B South of Harmony Road, East of Celestica, Fort Collins, Colorado, prepared for Michael Barber Architecture, dated March 21, 2001. This report should be referenced for further site oeotechnical information in addition to recommendations concerning the placement of concrete materials on site soils. The laboratory test results for the samples taken at each test hole and composite sample are presented in the attached Table 1. Design Traffic: Traffic information was obtained from Table 10-1 / Chapter 10 of the Larimer County Urban Areas Street Standards (updated 2015). The City of Fort Collins will need to verify the following traffic information obtained from that standard. Based on the referenced table above and the project documents Technology Parkway will classify as an Industrial/Commercial Collector with an EDLA (Equivalent Daily Load Application) value of 100 and Timberwood Drive will classify as a major collector with an EDLA of 50. The EDLA values of 100 and 50 were converted to equivalent 18-kip single axle load ESAL) value of 730,000 and 365,000 respectively for 20-year design life. Pavement Section Thickness Recommendations The soil resilient modulus and the design ESAL values were used to determine the required design structural number for the proposed pavement. The required structural number was then used to develop recommended pavement sections. Pavement designs were based on the DARWinTM computer program that solves the 1993 AASHTO pavement design equation. Pavement design parameters and calculations are summarized in Appendix A. Structural coefficients of 0.44 and 0.11 were used for hot bituminous asphalt and high quality aggregate base course, respectively. A structural coeeficient of 0.05 was used for fly ash treated subgrade that is planned for use in the design. Pavement Section Table Minimum required navement cartinn thirlrnocc ronnmml,.,rl + Composite Pavement Assumed Minimum ESAL Asphalt / Base / Fly Ash Street I.D. Road Classification Traffic EDLA Values Treated Subgrade Values in. / in. / in. ) Technology Industrial/Commercial 100 730,000 6.5 / 9.0 / 12 Pkwy Collector Timbenvood Major Collector 50 365,000 5.5 / 8.0 / 12 Drive Job No. 16-0584 Page 2 of 6 Y Harmony Technology Park Pavement Thickness Fort Collins, Colorado It should be noted that per the Larimer County Urban Area Street Standards thickness credit for chemically treated subgrade shall be 2 inches less than the maximum specified tilling depth. Therefore the pavement design calculations only provide credit for 10 inches of Fly Ash subgrade treatment. Subgrade Preparation: The majority of the site soils classify as a sandy clay material. These materials generally consist of A-6 soils based on the AASHTO classification system and are anticipated to provide relatively poor pavement support characteristics. The swell potential measured from samples of undisturbed site soils ranged from approximately -0.9 to 1.1 percent when tested under a surcharge pressure of 150psf. Therefore no subgrade mitigation will be required. The contractor plans to utilize fly -ash subgrade treatment in the upper 12 inches to stabilize the subgrade materials prior to paving. Based on our experience with the subgrade materials present at this site and similar treated subgrades, a minimum of 12% Type C Fly Ash by dry unit weight shall be used. The following guidelines should be utilized in the construction of the fly ash stabilized section: Pavement Materials: Asphalt pavement should consist of a bituminous plant mix composed of a mixture of aggregate and bituminous material. Asphalt mixture(s) should meet the requirements of a job -mix formula established by a qualified engineer as well as applicable City of Fort Collins design requirements. Aggregate base material should meet the criteria of CDOT Class 5 or 6 aggregate base course. Base course should be placed in and compacted in accordance with the criteria in the Project Earthwork section of this report. WEATHER LIMITATION The Fly Ash shall not be mixed or compacted if the temperature of the treated soil is below 40°F. EQUIPMENT The equipment required shall include all equipment necessary to complete this item such as; grading and scarifying equipment, a spreader for the Fly Ash, mixing, pulverizing equipment or roto-miller, sheeps foot and pneumatic or vibrating rollers, grading equipment, sprinkling equipment and trucks as approved by the owner. Job No. 16-0584 Page 3 of 6 Harmony Technology Park Pavement Thickness Fort Collins, Colorado GENERAL CONSTRUCTION METHODS The contractor shall provide a completed subgrade containing a uniform Fly Ash mixture, free from loose or segregated areas, of uniform density and moisture content, well bound for its full depth and width; with a smooth surface suitable for placing subsequent courses. It shall be the responsibility of the Contractor to regulate the sequence of his/her work, to use the proper amount of Fly Ash, maintain the work, and rework the courses as necessary to meet the requirements. Prior to beginning any treatment the subgrade shall be constructed and finished to smooth and uniform surfaces conforming to the grades and typical sections specified. After the subgrade has been finished and approved as specified, the subgrade shall then be cut and pulverized by a cutting and pulverizing machine to the depth and width shown on the Drawings. The machine shall cut and pulverize uniformly to the specified depth and shall have cutters that plane the base of the cut and pulverized zone to a smooth surface over the entire width of the cut. The machine must give visible indication at all times that it is cutting to the proper depth. APPLICATION Fly Ash shall be spread only on that area where the mixing operations can be completed during the same working day. The distribution of Fly Ash shall be attained over a measured section of subgrade until the proper amount of Fly Ash has been spread. The amount of Fly Ash spread shall be the amount required for mixing to the specified depth which will result in the percentage required. COMPACTION Compaction of the Fly Ash/soil mixture shall begin immediately after final mixing with Fly Ash. The material shall be aerated or sprinkled as necessary to maintain the mixture within the specified moisture content limits during and following compaction. The field density for the compacted mixture shall be at least 95 percent of the maximum density of laboratory specimens prepared from samples taken from the treated soil material in place after curing and prior to compacting. The specimens shall be compacted and tested in accordance with ASTM D 698. The in -place field density shall be determined in accordance with ASTM D 2922. The optimum moisture content shall be determined in Job No. 16-0584 Page 4 of 6 J. Harmony Technology Park Pavement Thickness Fort Collins, Colorado accordance with ASTM D 698. It is recommended that the moisture content is between the optimum and 3 percent above the optimum at time of compaction. All compaction and compaction testing shall be completed within 2 hour of mixing the Fly Ash into the soil. Immediately prior to paving, the subgrade should be proof rolled with a heavily loaded, pneumatic tired vehicle. Areas that show excessive deflection during proof rolling should be excavated and replaced and/or re -stabilized. All subgrade preparation must ultimately comply with roadway inspection, testing, and construction procedures outlined by Larimer County Additional Observations: w The collection and diversion of surface drainage away from paved areas is extremely important to satisfactory performance of the pavements. The subsurface and surface drainage systems should be carefully designed to ensure removal of the water from paved areas and subgrade soils. Allowing surface waters to pond on pavements will cause premature pavement deterioration. Where topography, site constraints or other factors limit or preclude adequate surface drainage, pavements should be provided with edge drains to reduce loss of subgrade support. The long-term performance of the pavement also can be improved greatly by proper backfilling and compaction behind curbs, gutters, and sidewalks so that ponding is not permitted and water infiltration is reduced. Landscape irrigation adjacent to sidewalks and pavements has a detrimental effect on the subgrade soils by introducing significant amounts of water into the sidewalk and pavement subgrades. This effect should be carefully considered or differential heave and/or rutting of the nearby pavements and sidewalks will result. Drip irrigation systems are recommended for planters to reduce over - spray and water infiltration beyond the planters and distancing any landscaping a distance of at least five feet away from the pavement section and sidewalks will also aid in reducing infiltration. Subsurface drains running parallel to the sidewalk and/or pavement section should be required if irrigation or surface drainage is not controlled. GROUND's experience indicates that longitudinal cracking is common in asphalt - pavements generally parallel to the interface between the asphalt and concrete structures such as curbs, gutters or drain pans. Distress of this type is likely to occur even where the subgrade has been prepared properly and the asphalt has been compacted properly. Job No. 16-0584 Page 5 of 6 Harmony Technology Park Pavement Thickness Fort Collins, Colorado The design traffic loading does not include excess loading conditions imposed by heavy construction vehicles. Consequently, heavily loaded concrete, lumber, and building material trucks can have a detrimental effect on the pavement. In particular, significant distress will be observed in areas where water infiltration has elevated the subgrade moisture content and reduced the subgrade support properties. Construction traffic can displace the pavements where they are not adequately supported and induce premature cracking and settlements. GROUND recommends that an effective program of regular maintenance be developed and implemented to seal cracks, repair distressed areas, and perform thin overlays throughout the life of the pavements. If you have any questions, please contact this office. Sincerely, GROUND Engineering Consultants, Inc. Digitally signed by Joseph Zorack, P.E. Joseph DN: cn=Joseph Zorack, P.E., o=GROUND Engineering Consultants, nJ Fr Inc., ou, Zorack,emai1 c=U51—,oe.zorack@groundeng.com, Date: 2016.07.06 13:03:36 -06'00' Joseph Zorack, P.E. Job No. 16-0584 Page 6 of 6 r 1 Indicates test hole number and approximate location i Not to Scale) Test Hole Test Hole Test Hole Test Hole Test Hole 1 2A 213 3A 36 0 7K7' 12/12 10/12 12/12 6/12Y^'' 5 D<X 5/12 Q 0 10 GROUND ENSONEERING CONSULTRNTS LOGS OF TEST HOLES JOB NO.: 16-0584 FIGURE: 2 CADFILE NAME:0584Log.01 Test Hole Test Hole Test Hole Test Hole Test Hole 4A 413 5 6 7 0 r\11vr 7/12 r 7/12 14/12 9/12 C 5 8/12 10 OROUNIO E:9N4GfINr=ER1N5 CONSULTRNTS LOGS OF TEST HOLES JOB NO.:16-0584 FIGURE: 3 CADFILE NAME:0584Log.02 LEGEND: Clay: Sandy, fine to medium grained, medium plastic medium stiff to stiff, moist to very moist, and tan to11brownincolor. Fill: Sandy, fine to medium grained, medium plastic, relatively compact (medium stiff to stiff), moist, and tan to brown in color. Drive sample, 2-inch I.D. California liner sample kSmall disturbed sample 0 Depth to water level and number of days after drilling that measurement was taken. NOTES: 1) Test holes were drilled on 06/22/16 with 4-inch diameter continuous flight augers. 2) Locations of the test holes were measured approximately by pacing from features shown on the site plan provided. 3) Elevations of the test holes were not measured and the logs of the test holes are drawn to depth. 4) The test hole locations and elevations should be considered accurate only to the degree implied by the method used. 5) The lines between materials shown on the test hole logs represent the approximate boundaries between material types and the transitions may be gradual. 6) Groundwater level readings shown on the logs were made at the time and under the conditions indicated. Fluctuations in the water level may occur with time. 7) The material descriptions on this legend are for general classification purposes only. See the full text of this report for descriptions of the site materials and related information. 8) All test holes were immediately backfilled upon completion of drilling, unless otherwise specified in this report. U) F- LU w F— Ln W z F- a: x Ln 0 O J ~ OzaoF— W J Z_ LO LL z OW Q D aD a m m U U U U U U 0 p C O 0 0 0 a 0 Ct) Cf) U) Cl) U) cf) U) U) m C.4 Ln R M v co L) Q Q Q Q Q Q Q Q Vl O J J J J J J J J in U U U U U U U U u U a C CL r= OL U) c) R o 0 0 0 Z3 U t N L 3 u, Ln Ln Ln r Fo a ( a) r r v v v cn CL ooo U x J cm a E M 00 COY= O•._ M M M M M M M M Q J O C O d d N > O N CO r r d) N d a)R O cn w r co 00 00 00 a n. z 0 f9 r Ln 00 O) d: ao 7 N U Ln N M Ln Q Q O CD r CD r CD r CDO r r V Z p r U Q O w O Ln M a0 N 00 M i r co m I— co O f6 o O Z U o d t O M M Ln q- M M O p U O J r d O o M m Ln coEoo m~ zrN Mo= L— L L V- co 0 6 r O Z O Appendix A 1993 AASHTO Pavement Design DARWin Pavement Design and Analysis System A Proprietary AASHTOWare Computer Software Product Network Administrator Flexible Structural Design Module Harmony Technology Park Technology Parkway - Industrial / Commercial Collector Composite Section with Fly Ash 18-kip ESALs Over Initial Performance Period Initial Serviceability Terminal Serviceability Reliability Level Overall Standard Deviation Roadbed Soil Resilient Modulus Stage Construction Calculated Design Structural Number Flexible Structural Design 730,000 4.5 2.3 85 % 0.44 3,025 psi 1 4.14 in Specified Layer Design Struct Drain Coef. Coef. Thickness Width Calculated Laver Material Description Ai Mi Di in ft) SN in 1 HMA 0.44 1 6.5 1 2.86 2 Base Course 0.11 1 9 1 0.99 3 12" of Fly Ash Treated Subgrade 0.05 1 10 1 0.50 Total 25.50 4.35 Page 1 1993 AASHTO Pavement Design DARWin Pavement Design and Analysis System A Proprietary AASHTOWare Computer Software Product Network Administrator Flexible Structural Design Module Harmony Technology Park Timberwood Drive Composite Section with Fly Ash Flexible Structural Design 18-kip ESALs Over Initial Performance Period 365,000 Initial Serviceability 4.5 Terminal Serviceability 2.3 Reliability Level 75 Overall Standard Deviation 0.44 Roadbed Soil Resilient Modulus 3,025 psi Stage Construction I Calculated Design Structural Number 3.55 in Specified Layer Design Struct Drain Coef. Coef Thickness Width Calculated Laver Material Description Ai Mi Di in SN in 1 HMA 0.44 1 5.5 1 2.42 2 Base Course 0.11 1 8 1 0.88 3 12" of Fly Ash Treated Subgrade 0.05 1 10 1 0.50 Total 23.50 3.80 Page 1