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HomeMy WebLinkAboutREGISTRY RIDGE SEVENTH FILING - Filed SEPD-SURFACE EXPLORATION/PAVEMENT DESIGN REPORT - 2018-05-21TABLE OF CONTENTS PURPOSE ......................................................................................................................... 1 FIELD EXPLORATION ........................................................................................................ 1 LABORATORY TESTING ..................................................................................................... 2 SUBGRADE DESCRIPTION ................................................................................................. 2 WATER SOLUBLE SULFATES .............................................................................................. 3 EXPANSIVE SUBGRADE CONDITIONS ................................................................................. 3 SUBGRADE SUPPORT ........................................................................................................ 4 TRAFFIC CONSIDERATIONS .............................................................................................. 5 PAVEMENT THICKNESS RECOMMENDATIONS ..................................................................... 5 PAVEMENT SELECTION PROCESS ...................................................................................... 7 GENERAL DISCUSSION ..................................................................................................... 7 DRAINAGE ....................................................................................................................... 8 CONSTRUCTION RECOMMENDATIONS ............................................................................... 8 Subgrade .............................................................................................................. 8 Aggregate Base Course .........................................................................................10 Asphalt Concrete Surface .......................................................................................10 LIMITATIONS ..................................................................................................................11 ATTACHMENTS SITE PLAN AND VICINITY MAP .............................................................................. FIGURE 1 PAVEMENT THICKNESS RECOMMENDATIONS ....................................................... FIGURE 1A TEST BORING LOGS ................................................................................. FIGURES 2 AND 3 LEGEND AND NOTES ............................................................................................ FIGURE 4 GRADATION AND ATTERBERG TEST RESULTS .................................... FIGURES 5 THROUGH 8 SWELL-CONSOLIDATION TEST RESULTS .......................................... FIGURES 9 THROUGH 11 R-VALUE TEST RESULTS ..................................................................................... FIGURE 12 DARWin PAVEMENT THICKNESS CALCULATIONS ............................ FIGURES 13 THROUGH 15 SUMMARY OF LABORATORY TEST RESULTS .............................................................. TABLE I PAVEMENT MAINTENANCE ................................................................................... APPENDIX _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 1 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 PAVEMENT STUDY Registry Ridge, Seventh Filing Fort Collins, Colorado April 26, 2018 PURPOSE The purpose of this study was to provide pavement thickness recommendations for the subject site in general conformance with City of Fort Collins, which were adopted from the "Larimer County Urban Area Street Standards (LCUASS)" ("Manual"). This report presents the analysis of approximately 1,000 and 800 feet of local residential and private roadways, respectively. Factual data gathered during the field and laboratory work and our analyses are summarized on Figures 1 through 15 and Table I. Our opinions and recommendations presented in this report are based on the data generated during this field exploration, laboratory testing, and our experience with similar projects. FIELD EXPLORATION The subgrade soils were sampled by drilling seven test borings within the proposed roadway alignments approximately 250 lineal feet apart (see Figure 1). The test borings were drilled after the installation of the water line and sanitary sewer using a 4-inch diameter continuous flight auger powered by a truck-mounted drill rig. The test borings were drilled to depths of approximately 5 or 10 feet with disturbed bulk samples collected in the upper 5 feet of rough subgrade elevation. Samples of the subsurface materials were obtained using a Modified California sampler which was driven into the soil by dropping a 140-pound hammer through a _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 2 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 free fall of 30 inches. The Modified California sampler is a 2.5-inch outside diameter by 2-inch inside diameter device. The number of blows required for the sampler to penetrate 12 inches and/or the number of inches that the sampler is driven by 50 blows gives an indication of the consistency or relative density of the subsurface materials encountered. Results of the penetration tests are presented on the "Test Boring Logs", Figures 2 and 3. Ground water was not encountered at the time of drilling. LABORATORY TESTING The samples obtained during drilling were returned to the laboratory where they were visually classified by a geotechnical engineer. Laboratory testing was then assigned to determine the soil classification, swell-consolidation potential, water soluble sulfate concentration, and subgrade support properties of the soils collected at the site. Based on the results of these tests, the subsurface materials exhibiting the "poorest" pavement support characteristics were selected to estimate the subgrade support strength. The Atterberg limits and gradation test results are presented on Figures 5 through 8. The swell- consolidation test results are presented on Figures 9 through 11. The bulk sample from Test Boring No. 7 (0-5’) was tested to determine the R-value. The results of the R-value test are presented on Figure 12. A summary of the laboratory tests conducted is presented on Table I. SUBGRADE DESCRIPTION The subgrade soils encountered consisted of sandy clay fill and sandy to very sandy clay. According to the AASHTO Soil Classification system, the soils from the bulk samples collected classified as A-6 (5) to A-6 (15). Based upon field observations, fill was encountered in five of _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 3 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 the seven test borings to depths ranging from approximately 4½ to 10 feet below rough subgrade elevation. Clay was encountered in three of the test borings at depths ranging from approximately zero to 9½ feet. Neither ground water nor bedrock were encountered to the depths drilled. WATER SOLUBLE SULFATES The Colorado Department of Transportation (CDOT) stipulates requirements for the risk of sulfate exposure on concrete structures based on Table 601-2 of the "Standard Specifications for Road and Bridge Construction". The water soluble sulfate concentration of the samples tested resulted in less than 100 parts per million (ppm) (<0.01% by soil mass). Based on these results, the sulfate concentration of the samples tested represents a Class 0 risk of sulfate exposure. We recommend concrete structures bearing upon onsite materials meet the requirements stipulated in Section 601.04 of the CDOT "Standard Specifications for Road and Bridge Construction". EXPANSIVE SUBGRADE CONDITIONS The "Manual" stipulates subgrade soils requiring expansive subgrade mitigation should be addressed in the pavement design. Swell-consolidation tests were conducted to determine expansion potential under a surcharge load of 150 pounds per square foot (psf). These test results ranged from 0.8% to 3.1%. Based on these test results, expansive subgrade mitigation per the "Manual" is required. Expansive subgrade mitigation may be determined based upon the Plasticity Index (PI) of the subgrade soils. Table 4.8, "Treatment of Expansive Soils", in the CDOT "Pavement Design _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 4 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 Manual", indicates soils with PI’s of 10 to 20 require moisture treatment to a depth of at least 2 feet below proposed pavement subgrade elevation. Our laboratory tests indicated the subgrade soils encountered exhibited an average PI of 17. Based upon Table 4.8, moisture treatment to a depth of at least 2 feet is recommended. The fill should be placed in maximum 8-inch loose lifts and compacted to at least 95% of Standard Proctor (ASTM D698) maximum dry density at optimum to +3.0% of optimum moisture content for compaction of A-6 soils. We recommend the moisture treatment extend to at least 1-foot beyond the proposed back of curb for detached sidewalks or 1-foot beyond back of walk for attached sidewalks. The soil type encountered in our test borings may be used as the replacement fill. Lokal Homes, LLC requested an alternate approach to moisture treatment. Additional aggregate base course may be placed on prepared subgrade in lieu of moisture treatment. This approach will need approval from the municipality prior to construction. The aggregate base course should be placed as indicated in the "Aggregate Base Course" section of this report. SUBGRADE SUPPORT The pavement subgrade support strength of soils is based on the resilient modulus (MR). The resilient modulus is a measure of the elastic property of soil, which is dependent upon moisture content, density, and the applied stress level. Based on our laboratory testing, the soils encountered at the site are considered to possess poor subgrade support characteristics. It is our experience these soils generally exhibit low design resilient moduli values. The CDOT "Pavement Design Manual" utilizes two equations to approximate the resilient modulus based upon the R-value. The A-6 (15) soils from Test Boring No. 7 (0–5′) were tested for R-value and _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 5 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 exhibited an R-value of 18 (see Figure 12). The following equations were used to approximate the resilient modulus: MR = 10 ^ [S1 +18.72 6.24 ] where S1 = [R-value -5 11.29 ] + 3 MR = 4,627 psi Based on the subgrade soils encountered at this site, the resilient modulus of 4,627 psi was adjusted for seasonal variation (see Figure 13). This adjustment yielded an effective resilient modulus of 3,829 psi, which was used in the pavement design. TRAFFIC CONSIDERATIONS Based on the "Manual" and the plans, the roadways at the site classify as local residential roadways and private drives. A traffic study was not available during this study. However, the "Manual" stipulates default traffic values for the various roadway classifications based on a 20- year design period. We found these values to be reasonable given the intended roadway applications. The following table summarizes the traffic design criteria. Roadway Classification ESALs Reliability (%) Serviceability Index Local Residential 73,000 80 2.0 Private Drives 73,000 80 2.0 ESAL = Equivalent Single Axle Load (18-kip) PAVEMENT THICKNESS RECOMMENDATIONS The pavement thickness recommendations have been calculated using the 1993 AASHTO Pavement Design, DARWin Pavement Design and Analysis System computer program. Pavement _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 6 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 thicknesses less than the minimum allowed per the "Manual" were calculated for local residential and private drives (see Figures 13 and 14). We recommend utilizing the minimum pavement thickness stipulated on Table 10-1 of the "Manual". The minimum pavement thicknesses are provided in the table below and on Figure 1A. Roadway Alternate ACS (in.) ABC (in.) Total (in.) Local Residential and Private Drives (ESAL = 73,000; MR = 3,829 psi) A 6.5 — 6.5 B 4.5 6.0 10.5 C 5.5 12.0 17.0 ACS = Asphalt Concrete Surface ABC = Aggregate Base Course Note: Alternate A is allowed only if approved by the City Engineer according to the "Manual". Alternates A and B require moisture treatment to a depth of at least 2 feet (see "Expansive Subgrade Conditions). Alternate C requires approval of the municipality because this section contains additional of aggregate base course in lieu of moisture treatment (see design structural number on Figure 15). This section contains approximately 8.5 inches of additional aggregate base course for expansive subgrade mitigation. This base course will add strength to the pavement, a transition zone between pavement layers and aid in reducing future heave potential. Proper and timely maintenance will be required during the lifetime of the pavement to reach the designed service life. Pavement maintenance recommendations are provided in the Appendix. Based on the construction plans, concrete pavers are anticipated on Cabot Court west of Nimitz Drive. The design of concrete pavers is typically provided by the supplier. The design of the concrete pavers is presented in Detail 2/C902 of the approved construction plans. AGW makes no inference that this pavement alternate is adequate or acceptable. _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 7 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 PAVEMENT SELECTION PROCESS Based on the "AASHTO Guide for Design of Pavement Structures" (AASHTO, 1993), the pavement thicknesses presented in "Pavement Thickness Recommendations" are considered equivalent. However, careful judgment should be exercised when selecting a pavement alternate. The full-depth asphalt alternate consists of asphalt concrete overlying a prepared subgrade platform of at least 12 inches. The "Manual" allows for full-depth asphalt pavement if approved by the City Engineer, however, our experience indicates this type of pavement may exhibit edge line cracking which is common on plastic subgrade soils. Based on our laboratory test results, the soils encountered at the site classify as plastic soils, therefore, we suggest considering this risk if this alternate is selected. Generally, composite (multi-layered) pavements are considered less likely to exhibit edge line cracking. Several municipalities in the region believe an intermediate layer creates a transition zone within the pavement system that aids in the distribution of stress over the weaker subgrade materials. Based on the subgrade soil characteristics encountered at this site, it is our recommendation to utilize either of the composite pavement alternates. GENERAL DISCUSSION We understand several municipalities in the region allow "vertical" residential construction prior to the completion of the designed pavement structure (i.e., after placement of the bottom lift of asphalt). Our experience indicates construction traffic during the buildout phase often exceeds the anticipated daily traffic volume on residential streets. Pavement distress may occur on _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 8 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 incomplete pavement structures as a result of construction traffic. It is our recommendation to consider full placement of the designed pavement structure prior to vertical residential construction. In addition, bottom lift only paving allows accumulation of water since the drainage structures cannot be effectively utilized. This could result in wetting of the subgrade soils. DRAINAGE Long-term pavement performance is aided by proper drainage. Surface drainage is necessary for water to drain into the proper collection system instead of fully infiltrating into the subgrade soils below the pavement structure. If the pavement is not properly drained, the soils below the pavement structure may become saturated, and the subgrade will lose strength, ultimately affecting the performance of the pavement layers above (generally from imposed traffic loads). A pavement drain system should be considered near irrigated areas. Excessive irrigation could negatively impact the pavement structure. In addition, xeriscaping the landscaped areas is recommended. CONSTRUCTION RECOMMENDATIONS The following recommendations are intended as a guideline and not as replacement to the jurisdictional standards and specifications. Ultimately, it shall be the responsibility of the Contractor to abide by the standards and specifications stipulated in the "Manual". SUBGRADE Prior to paving operations, the subgrade must be prepared in a manner that allows for adequate pavement support. The entire subgrade should be proof-rolled with a loaded 988 front-end loader or similar heavy rubber tired vehicle (GVW of 50,000 pounds with 18-kip per axle at tire _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 9 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 pressures of 90 pounds per square inch (psi)) to detect any soft or loose areas. All areas exhibiting unstable subgrade conditions such as loose soils, pumping, or excessive movement, should be overexcavated to a firm soil layer or to a maximum depth of 2 feet, whichever is shallowest, and replaced with suitable compacted fill. If unstable subgrade conditions persist, AGW should be contacted for our opinion. The subgrade should only be prepared when ambient conditions are such that they will not impede from the Contractor achieving the required density and moisture content. Frozen soil should never be used as subgrade fill. If no unstable areas are observed during the proof-roll or after removal and replacement of unsuitable soils, the entire subgrade may be prepared by windrowing, tilling or by removing at least 12 inches of subgrade from proposed pavement subgrade elevation. If necessary, add or reduce moisture to the required moisture content. The subgrade fill should be placed in maximum 8-inch loose lifts and compacted to 95% of Standard Proctor (ASTM D698) maximum dry density at optimum to +3.0% of optimum moisture content for compaction of A-6 to A-7-6 soils. The fill should be compacted to 95% of Modified Proctor (ASTM D1557) maximum dry density at −2.0% to +2.0% of optimum moisture content for compaction of other soils. If additional fill is required to reach the pavement subgrade elevation, the fill should have a soil classification similar to or better than the poorest soils encountered during this study. The subgrade should be free of organics, vegetation, large rocks, or any other deleterious materials. The pavement subgrade should be crowned to the appropriate grade lines. Additional compactive effort should be applied along edged concrete structures such as curbs and crosspans. _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 10 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 AGGREGATE BASE COURSE The aggregate base course (ABC) should consist of aggregate which meets particular specifications for gradation, plasticity, abrasion wear, and strength. We recommend the use of a material meeting CDOT "Class 6" specifications and having an R-value equal to or exceeding 78. The ABC should be tested to determine compliance with these specifications prior to use. If the material used does not meet the particular specifications, then the thickness calculations and recommendations should be revised. The ABC should be placed in loose lifts not exceeding 8 inches and should be compacted to a minimum of 95% of Modified Proctor maximum dry density (ASTM D1557). Aggregate thicknesses exceeding 8 inches should be placed and compacted in two separate lifts. The ABC should not be placed when weather conditions impede achievement of the required compaction. ASPHALT CONCRETE SURFACE Asphalt material should conform to an agency approved mix design that states the SHRP Gyratory design properties (i.e., maximum density, optimum asphalt content, job mix formula, recommended mixing and placing temperatures, etc.). We recommend that the aggregate used in the asphalt meet Colorado Department of Transportation "Grading S", "Grading SX", "Grading SG", or equivalent regulatory aggregate specifications. If the material does not meet or exceed these specifications, the asphalt thickness should be revised. The asphalt material should be placed in lifts a minimum of three times the aggregate size and should be compacted to 92 to 96% of Theoretical Maximum Specific Gravity for Super Pave Mixes. Materials standards and specifications in the "Manual" are required. Asphalt binder selection should be appropriate for each roadway classification. The paving contractor is responsible for mix submittal to the _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 11 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 agency. Field testing conducted by AGW will not relieve the paving contractor from proper mix and binder selection. Asphalt concrete should not be placed when weather conditions are such that the materials cannot be properly placed or compacted. The asphalt concrete should be placed on a prepared surface, graded to the appropriate elevation. In no case should the asphalt concrete be placed on frozen subgrade or base. When applicable, a tack coat should be applied at joints, adjacent to curbs, gutters or crosspans. The Contractor is responsible for establishing rolling patterns to determine the amount of effort required to meet the compaction requirements. Field testing conducted by AGW will not relieve the Contractor from proper compaction and construction of the pavement. LIMITATIONS This pavement study was based upon laboratory testing of samples obtained at widely spaced locations. Variations in subsoil conditions could occur between sample locations. We should evaluate and test the subgrade and pavement materials during construction to determine that our recommendations have been properly interpreted. However, A. G. Wassenaar, Inc. shall not be responsible for constant or exhaustive inspection of the work, the means and methods of construction or the safety procedures employed by Client's contractor. Client shall hold its contractor solely responsible for the quality and completion of the project, including construction in accordance with the construction documents. Any duty hereunder is for the sole benefit of the Client and not for any third party, including the contractor or any subcontractor. The Owner should be aware that this report was prepared utilizing the "Manual" standards. Highly plastic and expansive soils pose a significant risk to pavement structures. This risk includes heave and _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 12 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 cracking upon wetting. In addition, utility backfill settlement is a risk of development that can affect pavement performance. The Client is aware that isolated to more wide-spaced damage may occur. Longitudinal cracking parallel to the curb line may be indicative of an expansive subgrade becoming wetted. The only positive solution is removal of the subgrade materials to the depth of wetting and replacement or treatment. The "Manual" specifications do not require that the Client take these measures, but the Client should be aware that these measures are the only solution to dealing with highly plastic and expansive soils. As this is generally economically unfeasible, this design may be used as an attempt to provide a reasonable cost-effective pavement structure. The Owner assumes all liability for the performance of this pavement structure. We are available to discuss the risks associated with this design. 0 150 300 Scale in Feet N VICINITY MAP NOT TO SCALE TEST BORINGS ARE OVERLAID ON THE "REGISTRY RIDGE", PREPARED BY UNITED CIVIL DESIGN GROUP, DATED JUNE 9, 2016. ALL LOCATIONS ARE APPROXIMATE. NOTES: REGISTRY RIDGE, SEVENTH FILING FORT COLLINS, COLORADO TB-5 1. 2. SITE PLAN AND VICINITY MAP PROJECT NO. 162847 PS FIGURE 1 TB-6 TB-1 TB-2 TB-7 TB-3 TB-4 HORNET DRIVE BON HOMME RICHARD DRIVE CABOT COURT CABOT COURT ENTERPRISE DRIVE NIMITZ DRIVE SITE ENTERPRISE DRIVE NIMITZ DRIVE REGISTRY RIDGE, SEVENTH FILING N FORT COLLINS, COLORADO 0 150 300 Scale in Feet DRIVE LOCAL RESIDENTIAL AND PRIVATE DRIVES (ESAL = 73,000; M = 3,829 psi) ALT ACS (IN) ABC (IN) TOTAL (IN) A 6.5 - 6.5 B 4.5 6.0 10.5 C 5.0 12.0 17.0 ACS - ASPHALT CONCRETE SURFACE ABC - AGGREGATE BASE COURSE NOTE: ALTERNATES A AND B REQUIRE MOISTURE TREATMENT TO A DEPTH OF AT LEAST TWO FEET BELOW THE PROPOSED PAVEMENT SUBGRADE ELEVATION (SEE "EXPANSIVE SUBGRADE CONDITIONS" IN TEXT OF REPORT). ALTERNATE C REQUIRES APPROVAL FROM THE MUNICIPALITY. THE CONSTRUCTION PLANS INDICATE THIS PORTION OF STREET CONSISTS OF CONCRETE PAVERS. SEE DETAIL 2/C902 OF THE APPROVED CONSTRUCTION PLANS. NOTES: 1. TEST BORINGS ARE OVERLAID ON THE "REGISTRY RIDGE", PREPARED BY UNITED CIVIL DESIGN GROUP, DATED JUNE 9, 2016. 2. ALL LOCATIONS ARE APPROXIMATE. BON HOMME RICHARD R CABOT COURT CABOT COURT HORNET DRIVE PAVEMENT THICKNESS RECOMMENDATIONS PROJECT NO. 162847 PS FIGURE 1A U:\PROJECT FILES\162847 REGISTRY RIDGE FILING 7\PAVEMENT\GINT\162847S_GT2018-04-12 REGISTRY RIDGE PS.GPJ CLIENT Lokal Homes PROJECT NUMBER 162847 PS TEST BORING 1 TEST BORING 2 PROJECT NAME Registry Ridge PROJECT LOCATION Fort Collins, Colorado TEST BORING 3 TEST BORING 4 D E P T H I N F E E T 0 2 4 6 8 10 12 14 27 / 12 MC = 9 B -#200 = 76 LL = 35 PI = 17 12 / 12 DD = 103 MC = 12 SW150 = 1.1 B -#200 = 73 LL = 37 PI = 18 10 / 12 DD = 109 MC = 17 12 / 12 MC = 11 B -#200 = 64 LL = 31 PI = 11 13 / 12 U:\PROJECT FILES\162847 REGISTRY RIDGE FILING 7\PAVEMENT\GINT\162847S_GT2018-04-12 REGISTRY RIDGE PS.GPJ CLIENT Lokal Homes PROJECT NUMBER 162847 PS TEST BORING 5 PROJECT NAME Registry Ridge PROJECT LOCATION Fort Collins, Colorado TEST BORING 6 TEST BORING 7 D E P T H I N F E E T 0 2 4 6 8 10 12 14 21 / 12 DD = 104 MC = 14 SW150 = 3.1 B -#200 = 77 LL = 38 PI = 18 13 / 12 DD = 108 MC = 16 B -#200 = 75 LL = 37 PI = 17 6 / 12 DD = 105 MC = 15 SW150 = 0.8 10 / 12 DD = 104 MC = 17 SW150 = 2.0 B -#200 = 74 LL = 40 PI = 22 U:\PROJECT FILES\162847 REGISTRY RIDGE FILING 7\PAVEMENT\GINT\162847S_GT2018-04-12 REGISTRY RIDGE PS.GPJ CLIENT Lokal Homes PROJECT NAME Registry Ridge PROJECT NUMBER 162847 PS PROJECT LOCATION Fort Collins, Colorado SOIL DESCRIPTIONS Fill, clay, stiff to very stiff, silty, sandy Clay, stiff to very stiff ABBREVIATIONS DD Dry density of sample in pounds per cubic foot (pcf) MC Moisture content as a percentage of dry weight of soil (%) SW150 Percent swell under a surcharge of 150 pounds per COM150 Percent compression under a surcharge of 150 pounds per -#200 Percent passing the Number 200 sieve (%) LL Liquid Limit PI Plasticity Index NP Non-Plastic NV No Value pH Acidity or alkalinity of sample in pH units R Resistivity in ohms.cm WS Water soluble sufates in parts per million (ppm) CL Chlorides in percent (%) x/y X blows of a 140-pound hammer falling 30 inches were required x/y SS X blows of a 140-pound hammer falling 30 inches were required C-x Depth of cut to grade (rounded to the nearest foot) F-x Depth of fill to grade (rounded to the nearest foot) FG Finished grade (rounded to the nearest foot) NR No sample recovered Bounce Sampler bounced during driving B Bulk sample AS Auger sample Moderately to well cemented layer Depth at which practical drilling refusal was encountered Water level at time of drilling Water level Caved depth Notes: 1. Test borings were drilled April 5, 2018 . 2. Location of the test borings were measured by pacing from features shown on the site plan. 3. The horizontal lines shown on the logs are to differentiate materials and represent the approximate boundaries between materials. The transitions between materials may be gradual. 4. Elevations were not provided. 5. Boring logs shown in this report are subject to the limitations, explanations, and conclusions of this report. LEGEND AND NOTES FIGURE 4 square foot (psf) upon wetting (%) square foot (psf) upon wetting (%) to drive a 2.5-inch outside diameter sampler Y inches to drive a 2.0-inch outside diameter sampler Y inches 0 10 20 30 40 50 60 70 80 90 100 100 10 1 0.1 0.01 0.001 0 10 20 30 40 50 60 70 80 90 100 Cobbles Liquid Limit 35 Plasticity Index 17 Clay/Silt (%) 76 Sand (%) 19 Gravel (%) 5 Sample Description Clay, sandy Classification A-6(11), LEAN CLAY with SAND(CL) fine Silt (Non-Plastic) to Clay (Plastic) Sand coarsemedium Gravel coarsefine PERCENT PASSING (%) PARTICLE SIZE (MM) Sample Location Test Boring No. 1 at a depth of 0 feet to 5 feet GRADATION AND ATTERBERG TEST RESULTS FIGURE 5 PROJECT NO. 162847 PS 0 10 20 30 40 50 60 70 80 90 100 100 10 1 0.1 0.01 0.001 0 10 20 30 40 50 60 0 10 20 30 40 50 60 70 80 90 100 100 10 1 0.1 0.01 0.001 0 10 20 30 40 50 60 70 80 90 100 Cobbles Liquid Limit 31 Plasticity Index 11 Clay/Silt (%) 64 Sand (%) 29 Gravel (%) 7 Sample Description Clay, very sandy Classification A-6(5), SANDY LEAN CLAY(CL) fine Silt (Non-Plastic) to Clay (Plastic) Sand coarsemedium Gravel coarsefine PERCENT PASSING (%) PARTICLE SIZE (MM) Sample Location Test Boring No. 3 at a depth of 0 feet to 5 feet GRADATION AND ATTERBERG TEST RESULTS FIGURE 6 PROJECT NO. 162847 PS 0 10 20 30 40 50 60 70 80 90 100 100 10 1 0.1 0.01 0.001 0 10 20 30 40 50 60 0 10 20 30 40 50 60 70 80 90 100 100 10 1 0.1 0.01 0.001 0 10 20 30 40 50 60 70 80 90 100 Cobbles Liquid Limit 38 Plasticity Index 18 Clay/Silt (%) 77 Sand (%) 23 Gravel (%) 1 Sample Description Fill, clay, sandy Classification A-6(13), LEAN CLAY with SAND(CL) fine Silt (Non-Plastic) to Clay (Plastic) Sand coarsemedium Gravel coarsefine PERCENT PASSING (%) PARTICLE SIZE (MM) Sample Location Test Boring No. 5 at a depth of 0 feet to 5 feet GRADATION AND ATTERBERG TEST RESULTS FIGURE 7 PROJECT NO. 162847 PS 0 10 20 30 40 50 60 70 80 90 100 100 10 1 0.1 0.01 0.001 0 10 20 30 40 50 60 0 10 20 30 40 50 60 70 80 90 100 100 10 1 0.1 0.01 0.001 0 10 20 30 40 50 60 70 80 90 100 Cobbles Liquid Limit 40 Plasticity Index 22 Clay/Silt (%) 74 Sand (%) 24 Gravel (%) 2 Sample Description Fill, clay, sandy Classification A-6(15), LEAN CLAY with SAND(CL) fine Silt (Non-Plastic) to Clay (Plastic) Sand coarsemedium Gravel coarsefine PERCENT PASSING (%) PARTICLE SIZE (MM) Sample Location Test Boring No. 7 at a depth of 0 feet to 5 feet GRADATION AND ATTERBERG TEST RESULTS FIGURE 8 PROJECT NO. 162847 PS -5 -4 -3 -2 -1 0 1 2 3 4 5 100 1,000 10,000 105 Dry Unit Weight (pcf) 103 CONSOLIDATION - % - SWELL Sample Description Fill, clay, sandy Moisture Content (%) 12 Sample Location Test Boring No. 2 at a depth of 1 feet APPLIED PRESSURE - PSF PROJECT NO. 162847 PS SWELL - CONSOLIDATION TEST RESULTS FIGURE 9 -5 -4 -3 -2 -1 0 1 2 3 4 5 100 1,000 10,000 105 Dry Unit Weight (pcf) 101 CONSOLIDATION - % - SWELL Sample Description Fill, clay, sandy Moisture Content (%) 15 Sample Location Test Boring No. 4 at a depth of 1 feet APPLIED PRESSURE - PSF Water Added Swell under constant pressure because of wetting Water Added Consolidation under constant pressure because of wetting -5 -4 -3 -2 -1 0 1 2 3 4 5 100 1,000 10,000 105 Dry Unit Weight (pcf) 104 CONSOLIDATION - % - SWELL Sample Description Fill, clay, sandy Moisture Content (%) 14 Sample Location Test Boring No. 5 at a depth of 1 feet APPLIED PRESSURE - PSF PROJECT NO. 162847 PS SWELL - CONSOLIDATION TEST RESULTS FIGURE 10 -5 -4 -3 -2 -1 0 1 2 3 4 5 100 1,000 10,000 105 Dry Unit Weight (pcf) 105 CONSOLIDATION - % - SWELL Sample Description Fill, clay, sandy Moisture Content (%) 15 Sample Location Test Boring No. 6 at a depth of 9 feet APPLIED PRESSURE - PSF Water Added Swell under constant pressure because of wetting Water Added Swell under constant pressure because of wetting -5 -4 -3 -2 -1 0 1 2 3 4 5 100 1,000 10,000 105 Dry Unit Weight (pcf) 104 CONSOLIDATION - % - SWELL Sample Description Fill, clay, sandy Moisture Content (%) 17 Sample Location Test Boring No. 7 at a depth of 1 feet APPLIED PRESSURE - PSF PROJECT NO. 162847 PS SWELL - CONSOLIDATION TEST RESULTS FIGURE 11 Water Added Swell under constant pressure because of wetting DESIGN "R" VALUE GRAPH FIGURE 12 RESISTANCE VALUE ("R" - VALUE) DRY DENSITY (PCF) MOISTURE (%) EXUDATION PRESSURE R-VALUE 0 100 200 300 400 500 600 700 0 5 10 15 20 25 30 35 POINT 1 2 3 4 "R" - VALUE AT 300 PSI EXUDATION _______________ DATE: APRIL 24, 2018 PROJECT NO.: 162847 PS PROJECT: REGISTRY RIDGE LOCATION: TEST BORING 7 (0-5') 18 112.6 16.8 277 13 114.2 16.4 283 17 115.4 16.1 395 20 1993 AASHTO Pavement Design DARWin Pavement Design and Analysis System A Proprietary AASHTOWare Computer Software Product A. G. Wassenaar, Inc. Flexible Structural Design Module Local Residential and Private Drives Registry Ridge Seventh Filing Fort Collins, Colorado Project Number 162847-PS Flexible Structural Design 18-kip ESALs Over Initial Performance Period 73,000 Initial Serviceability 4.5 Terminal Serviceability 2 Reliability Level 80 % Overall Standard Deviation 0.44 Roadbed Soil Resilient Modulus 3,829 psi Stage Construction 1 Calculated Design Structural Number 2.60 in Effective Roadbed Soil Resilient Modulus Roadbed Resilient Period Description Modulus (psi) 1 Winter 20,000 2 Spring 2,500 3 Summer 4,627 4 Fall 4,627 Calculated Effective Modulus 3,829 psi Specified Layer Design Struct Coef. Layer Material Description (Ai) Drain Coef. (Mi) Thickness (Di)(in) Width (ft) Calculated SN (in) 1 Hot Bituminous Pavement 0.44 1 4.5 - 1.98 2 Aggregate Base Course 0.11 1 6 - 0.66 Total - - - 10.50 - 2.64 FIGURE 13 Layered Thickness Design Thickness precision Actual Struct Coef. Layer Material Description (Ai) Drain Coef. (Mi) Spec Thickness (Di)(in) Min Thickness (Di)(in) Elastic Modulus (psi) Width (ft) Calculated Thickness (in) Calculated SN (in) 1 Hot Bituminous Pavem... 0.44 1 - - - - 5.91 2.60 Total - - - - - - - 5.91 2.60 FIGURE 14 1993 AASHTO Pavement Design DARWin Pavement Design and Analysis System A Proprietary AASHTOWare Computer Software Product A. G. Wassenaar, Inc. Flexible Structural Design Module Local Residential and Private Drives Registry Ridge Seventh Filing Fort Collins, Colorado Project Number 162847-PS Flexible Structural Design 18-kip ESALs Over Initial Performance Period 73,000 Initial Serviceability 4.5 Terminal Serviceability 2 Reliability Level 80 % Overall Standard Deviation 0.44 Roadbed Soil Resilient Modulus 3,829 psi Stage Construction 1 Calculated Design Structural Number 2.60 in Specified Layer Design Struct Coef. Layer Material Description (Ai) Drain Coef. (Mi) Thickness (Di)(in) Width (ft) Calculated SN (in) 1 Hot Bituminous Pavement 0.44 1 5 - 2.20 2 Aggregate Base Course 0.11 1 12 - 1.32 Total - - - 17.00 - 3.52 FIGURE 15 TABLE I SUMMARY OF LABORATORY TEST RESULTS April 26, 2018 Project Number 162847 Registry Ridge, Seventh Filing Fort Collins, Colorado 1 of 1 Liquid Limit Plastic Limit Plasticity Index 1 0-5 Clay, sandy A-6(11) 76 35 18 17 1 1 Clay, sandy 9 2 0-5 Fill, clay, sandy A-6(12) 73 37 19 18 2 1 Fill, clay, sandy 103 12 1.1 2 9 Clay, sandy 109 17 3 0-5 Clay, very sandy A-6(5) 64 31 20 11 3 1 Clay, very sandy 11 4 0-5 Fill, clay, sandy A-6(9) 73 35 21 14 <100 4 1 Fill, clay, sandy 101 15 -0.3 4 9 Clay, sandy 110 17 5 0-5 Fill, clay, sandy A-6(13) 77 38 20 18 5 1 Fill, clay, sandy 104 14 3.1 6 0-5 Fill, clay, sandy A-6(12) 75 37 20 17 6 1 Fill, clay, sandy 108 16 6 9 Fill, clay, sandy 105 15 0.8 7 0-5 Fill, clay, sandy A-6(15) 74 40 18 22 <100 7 1 Fill, clay, sandy 104 17 2.0 Test Boring Number Depth (feet) Soil Type AASHTO Soil Classification Natural Dry Density (pcf) % Passing #200 Sieve Atterberg Limits Water Soluble Sulfates (ppm) Swell / Consolidation (-) (%) 1 Natural Moisture (%) Notes: 1 Indicates Percent Swell or Consolidation (−) when wetted under a 150 psf load, unless otherwise noted. NV - indicates No Value NP - indicates Non-Plastic _____________________________________________________________________________ Pavement Study Lokal Homes, LLC Project Number 162847 1 Registry Ridge, Seventh Filing A. G. Wassenaar, Inc. April 26, 2018 APPENDIX PAVEMENT MAINTENANCE Flexible pavement structures are typically designed for service periods of 20 years. However, timely and proper maintenance during the life of the pavement is essential to reach the designed service period and to possibly extend the serviceability of the pavement. We recommend the implementation of a maintenance program aimed at preserving the structural integrity of the pavement. The implementation of available maintenance operations varies depending upon pavement type and on-site conditions. Flexible Pavements Flexible pavements in this region will exhibit some type of pavement distress during their service life. Periodic maintenance and rehabilitation should be anticipated in order to reach the anticipated design life. Typically, minor cracks may develop within the first three years. Crack sealant should be utilized immediately upon recognition of these cracks to reduce further deterioration and/or potential moisture induced damage. The use of crack sealants may extend the life of the pavement by two to five years before any other treatment is applied. A variety of seal coats are available and can delay the need for a major surface structural treatment. However, careful engineering judgment should be utilized to determine the type of seal application that is most appropriate. Seal coats should not be applied on pavements with severe cracks, raveling or potholes. Fog seals typically have an estimated service life of approximately one to two years but should only be utilized on structurally sound pavements. Slurry seals generally have a service life of four to seven years and are commonly utilized on pavements exhibiting no to low pavement distress. Chip seals aid in slowing surface oxidation, minor raveling, and sealing small cracks. Chip seals are considered to have a service life of approximately four to seven years. Structural mill and overlay is a rehabilitation technique that generally occurs within eight to 12 years after initial construction. This technique should only be utilized on stable pavements with minor surface distress and a strong base. Conventional structural mill and overlay operations are typically known to have a service life of eight to 14 years. 70 80 90 100 Cobbles Liquid Limit 37 Plasticity Index 17 Clay/Silt (%) 75 Sand (%) 24 Gravel (%) 1 Sample Description Fill, clay, sandy Classification A-6(12), LEAN CLAY with SAND(CL) fine Silt (Non-Plastic) to Clay (Plastic) Sand coarsemedium Gravel coarsefine PERCENT PASSING (%) PARTICLE SIZE (MM) Sample Location Test Boring No. 6 at a depth of 0 feet to 5 feet 70 80 90 100 Cobbles Liquid Limit 35 Plasticity Index 14 Clay/Silt (%) 73 Sand (%) 25 Gravel (%) 3 Sample Description Fill, clay, sandy Classification A-6(9), LEAN CLAY with SAND(CL) fine Silt (Non-Plastic) to Clay (Plastic) Sand coarsemedium Gravel coarsefine PERCENT PASSING (%) PARTICLE SIZE (MM) Sample Location Test Boring No. 4 at a depth of 0 feet to 5 feet 70 80 90 100 Cobbles Liquid Limit 37 Plasticity Index 18 Clay/Silt (%) 73 Sand (%) 25 Gravel (%) 2 Sample Description Fill, clay, sandy Classification A-6(12), LEAN CLAY with SAND(CL) fine Silt (Non-Plastic) to Clay (Plastic) Sand coarsemedium Gravel coarsefine PERCENT PASSING (%) PARTICLE SIZE (MM) Sample Location Test Boring No. 2 at a depth of 0 feet to 5 feet WS <100 0 2 4 6 8 10 12 14 D E P T H I N F E E T SEE FIGURE 4 FOR LEGEND AND NOTES TO TEST BORINGS TEST BORING LOGS FIGURE 3 DD = 101 MC = 15 COM150 = 0.3 B -#200 = 73 LL = 35 PI = 14 WS <100 14 / 12 DD = 110 MC = 17 0 2 4 6 8 10 12 14 D E P T H I N F E E T SEE FIGURE 4 FOR LEGEND AND NOTES TO TEST BORINGS TEST BORING LOGS FIGURE 2