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HomeMy WebLinkAboutKECHTER FARM FILING 2 - Filed SEPD-SURFACE EXPLORATION/PAVEMENT DESIGN REPORT - 2018-01-18TABLE OF CONTENTS SCOPE 1 SUMMARY OF CONCLUSIONS 1 SITE LOCATION AND PROJECT DESCRIPTION 2 FIELD AND LABORATORY INVESTIGATION 2 SUBSURFACE CONDITIONS 3 PAVEMENT DESIGN 3 Traffic Projections 4 Subgrade and Groundwater Conditions 4 Pavement Thickness Calculations 5 Pavement Recommendations 5 PAVEMENT SELECTION 6 SUBGRADE AND PAVEMENT MATERIALS AND CONSTRUCTION 6 WATER-SOLUBLE SULFATES 8 MAINTENANCE 9 SURFACE DRAINAGE 9 LIMITATIONS 10 FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS FIGURES 2 AND 3 – SUMMARY LOGS OF EXPLORATORY BORINGS FIGURE 4 – FLEXIBLE PAVEMENT DESIGN CALCULATIONS APPENDIX A – RESULTS OF LABORATORY TESTING APPENDIX B – SAMPLE SITE GRADING SPECIFICATIONS APPENDIX C – PAVEMENT CONSTRUCTION RECOMMENDATIONS APPENDIX D – MAINTENANCE PROGRAM TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 1 CTL  T PROJECT NO. FC06547.013-135 SCOPE This report presents the results of our Subgrade Investigation and Pave- ment Recommendations for the planned interior roadways for Phases 3 and 5 of Kechter Farm Subdivision, Filing 2 in Fort Collins, Colorado. The purpose of our subgrade investigation was to determine the subsurface conditions and to evalu- ate pavement support characteristics for our pavement recommendations. The report was conducted in general conformance with the Chapter 5 of the Larimer County Urban Areas Street Standards (LCUASS) dated January 2, 2001 (re- pealed and reenacted April 1, 2007) as adopted by the City of Fort Collins (City). This report was prepared from data developed during field exploration, la- boratory testing, engineering analysis, and experience with similar conditions. The report includes a description of the subsurface conditions found in explorato- ry borings, laboratory test results and pavement construction and material rec- ommendations for the construction of Tree Row Lane and portions of Spindle- brush Lane, Sapling Street, Fall Harvest Way, Medlar Place and Espalier Lane. If plans change significantly, we should be contacted to review our investigation and determine if our recommendations still apply. A brief summary of our con- clusions is presented below, with more detailed criteria contained in the report. SUMMARY OF CONCLUSIONS 1. Soils encountered in our borings consisted of 3½ to 6 feet of sandy clay fill over native sandy clay to the depths explored. Bedrock and groundwater were not encountered during this investigation. 2. The subgrade soils classified as A-7, which are considered to ex- hibit fair to poor subgrade support. 3. Mitigation for soft subgrade and expansive soils is recommended. We recommend treating the subgrade with fly ash. TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 2 CTL  T PROJECT NO. FC06547.013-135 4. Asphaltic concrete and Portland cement concrete are appropriate surface pavements. Minimum pavement recommendations will be provided in a supplemental report. SITE LOCATION AND PROJECT DESCRIPTION The project roadways are located within Kechter Farms in southeast Fort Collins, Colorado (Figure 1). The project includes the construction of Tree Row Lane and portions of Espalier Court, Medlar Street, Fall Harvest Way, Sapling Street and Spindlebrush Lane. At the time of our investigation, roadways were rough graded and buried utilities had been installed. FIELD AND LABORATORY INVESTIGATION Our field investigation consisted of drilling seven borings to a depth of ap- proximately 10 feet. The approximate locations of our borings are presented on Figure 1. The borings were drilled with 4-inch diameter solid-stem augers and a truck-mounted drill. Our field representative logged the soils encountered and collected samples. Drive samples were collected by driving a modified California sampler 12 inches with blows of a 140-pound hammer falling 30 inches. This method is similar to the standard penetration test and is typical for local practice. Summary logs of the borings, including field penetration test results, are present- ed on Figures 2 and 3. Samples were returned to our laboratory and examined by the geotech- nical engineer for this project. Laboratory testing was conducted in general ac- cordance with AASHTO and ASTM methods to determine classifications and subgrade support values. Laboratory testing included moisture content, dry den- sity, swell-consolidation, water-soluble sulfates, Atterberg limits and gradation analyses. Swell-consolidation tests were wetted at a confining pressure of 150 TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 3 CTL  T PROJECT NO. FC06547.013-135 pounds per square foot (psf) as required by LCUASS. Results of our laboratory tests are presented in Appendix A and summarized in Table A-I. Previous Investigations CTL|Thompson, Inc. completed previous subgrade investigations and pavement recommendations for Kechter Farm, Filing 1, Phases 1 through 4 (Pro- ject Nos. FC06547.003-135, FC06547.005-135 and FC06547.006-135) and Kechter Farm, Filing 2, Phases 1, 2 and 4 (Project Nos. FC06547.010-135, FC06547.011-135, FC06547.012-135). Results from our previous investigations were considered in preparation of this report. SUBSURFACE CONDITIONS Soils encountered in our borings generally consisted of 3½ to 6 feet of sandy clay fill over sandy clay to the depths explored. No bedrock or groundwa- ter was encountered in the borings. Swell-consolidation testing of nine samples indicated swell potentials of 0.1 to 2.7 percent. Particle size analyses indicated fines contents (percent passing the No. 200 sieve) of 66 to 82 percent. Further descriptions of the subsurface conditions can be found on our boring logs and in our laboratory test results. PAVEMENT DESIGN We understand the new roadways and improvements are regulated by the City of Fort Collins which requires the use of the AASHTO and CDOT pavement design methods for their roadways. These design methods require input param- eters for traffic projections for a specified design life, roadway classification, characteristics of the subgrade materials, type and strength characteristics of pavement materials, groundwater conditions, drainage conditions, number of construction stages, minimum pavement sections, and statistical data. TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 4 CTL  T PROJECT NO. FC06547.013-135 Traffic Projections The traffic projections are based on vehicle loading, traffic volume, design period, and growth factor. Traffic projections are expressed as an 18-kip Equiva- lent Daily Load Application (EDLA) for a single day and as an 18-kip Equivalent Single Axle Load (ESAL) for the design period, which is typically 20 years. An ESAL for the roadways was provided by a representative of the City of Fort Col- lins using a 20-year design life. Table A presents the Design ESAL used with our calculations. TABLE A DESIGN 18-kip EQUIVALENT SINGLE AXLE LOADS (ESAL) Street Flexible ESAL, (20- Year Design Life) Rigid ESAL, (20- Year Design Life) Tree Row Lane, Espalier Court, Medlar Street, Fall Harvest Way, Sapling Street and Spindlebrush Lane 36,500 36,500 Subgrade and Groundwater Conditions The subgrade soils consist of sandy clay fill that classifies as A-7 in ac- cordance with AASHTO classification methods. A Hveem stabilometer test of a composite sample of the subgrade soil resulted in an R-value of less than 5. For this soil, we believe a design R-value of 5 is appropriate. Higher swelling soils were encountered during this investigation and have been encountered during previous investigations. LCUASS requires swell mitiga- tion where swell is 2 percent or greater. Based on the results of laboratory test- ing and LCUASS, we believe that mitigation for swell will be required. Soft, yield- ing soil is likely in some areas due to high moisture contents. Stabilization TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 5 CTL  T PROJECT NO. FC06547.013-135 should improve support over soft soils. Based on these considerations and to be consistent with adjoining roadways, we recommend the subgrade soil be stabi- lized. Fly-ash treated subgrade is commonly used in this area to improve stabil- ity of swelling and soft soil. Water-soluble sulfate tests indicate a single applica- tion of fly-ash is applicable to this site. Pavement Thickness Calculations We used 1993 AASHTO pavement design procedures to develop our pavement thickness calculations for both flexible and rigid pavements with input values provided by the City, LCUASS, and our laboratory tests and observations. For our design, we assumed the pavement would be constructed during a single stage. Input values including initial and terminal serviceability indices, reliability factor, layer strength coefficients, and minimum sections were provided by LCUASS. Hveem testing of a composite sample of the subgrade soil in the la- boratory resulted in a design R-value of 5, which we converted to a resilient modulus of 3,020 psi based on CDOT criteria. For rigid pavement design, we estimated a modulus of subgrade reaction (k-value) of 100 psi/in based on de- gree of saturation and soil classification. Pavement Recommendations We have provided pavement design alternatives for new construction in- cluding hot mix asphalt (HMA) on aggregate base course (ABC) and Portland cement concrete (PCC) pavement. Pavement calculations are included in Figure 4. Pavement thickness alternatives are presented on Table B. Additional dis- cussion regarding advantages and disadvantages of the pavement alternatives and their expected performance is included under the PAVEMENT SELECTION section of this report. TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 6 CTL  T PROJECT NO. FC06547.013-135 TABLE B MINIMUM PAVEMENT THICKNESS RECOMMENDATIONS Roadway Hot Mix Asphalt (HMA) + Aggregate Base Course (ABC)+ Chemically Stabilized Subgrade (CSS) Portland Cement Con- crete (PCC) + Chemically Stabilized Subgrade (CSS) Tree Row Lane, Espalier Court, Medlar Street, Fall Harvest Way, Sapling Street and Spindlebrush Lane ESAL = 36,500 4” HMA + 6” ABC+ 12” CSS 6” PCC+ 12” CSS PAVEMENT SELECTION Both HMA/ABC composite (flexible) and PCC (rigid) pavements are ex- pected to perform well for the roadways. However, PCC pavement has better performance in freeze-thaw conditions and should require less long-term mainte- nance than HMA pavement. PCC pavement is also recommended for sections that may experience frequent stopping and turning, heavy point loads, or chemi- cal spills. SUBGRADE AND PAVEMENT MATERIALS AND CONSTRUCTION The construction materials are assumed to possess sufficient quality as reflected by the strength factors used in our design calculations. Materials and construction requirements of LCUASS and CDOT Standard Specifications for Road and Bridge Construction should be followed. Subgrade preparation will only apply to areas planned for new construction. TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 7 CTL  T PROJECT NO. FC06547.013-135 Based on the results of laboratory testing, LCUASS, and experience with similar soils of the area, we recommend mitigation for swell and soft soils. We understand for swell mitigation the City typically uses a prescribed amount of about 12 percent fly ash stabilizing agent for 12 inches of the subgrade when a mix design is not prepared. Lime may also be considered as an effective stabiliz- ing agent for this project. The pavement design includes a ½-credit for chemical treatment. If a mix design with the selected chemical stabilizing agent is per- formed and a strength gain specified in LCUASS is achieved, credit is allowed towards a reduction in the recommended thicknesses of pavement materials. Minimum 7-day compressive strengths of 150 psi for fly ash treated subgrade and 160 psi for lime treated subgrade, verified with field tests from samples ob- tained during the field mixing operations, are required for full credit. In the event swell is not reduced to 2 percent or less, we should be consulted to amend our recommendations. The method of applying the stabilizing agent to the soil will depend partly on the level of water-soluble sulfates in the subgrade soil. A reaction of water- soluble sulfates in the soil and available calcium in the stabilizing agent can oc- cur creating the mineral ettringite, which can swell causing detrimental effects to the pavement surface. If unacceptable concentrations of water-soluble sulfates are present in the soil, the double-application method can reduce the risk of pavement heave due to ettringite formation to an acceptable level. Concentra- tions of water-soluble sulfates were measured in six samples at or below 0.02 percent. Our threshold limit of water-soluble sulfates in soils for single application of fly ash or lime for stabilization is 0.5 percent. Based on our test results, we believe single application is appropriate for the site. Recommendations for chem- ically stabilized subgrades are presented in Appendix C. Preparation of the sub- grade should extend from back-of walk to back-of-walk where feasible. TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 8 CTL  T PROJECT NO. FC06547.013-135 These criteria were developed from analysis of the field and laboratory data, our experience and LCUASS requirements. If the materials cannot meet these requirements, our pavement recommendations should be re-evaluated based upon available materials. Materials planned for construction should be submitted and the applicable laboratory tests performed to verify compliance with the specifications. WATER-SOLUBLE SULFATES In addition to the interaction of water-soluble sulfates with chemical treat- ment agents, concrete that is exposed to sulfate-rich soils can be subject to sul- fate attack. If concrete pavements or structures will not be in contact with sulfate- rich soils, by means of an aggregate base course layer or other materials, the risk of sulfate attack should be low. We measured water-soluble sulfate concen- trations in six samples from this site. Concentrations measured were 0.02 per- cent or below. Water-soluble sulfate concentrations less than 0.1 percent indicate Class 0 exposure to sulfate attack for concrete that is exposed to the soils, according to the American Concrete Institute (ACI). For this level of sulfate concentration, ACI indicates any type of cement can be used for concrete that is exposed to the soils. In our experience, superficial damage may occur to the exposed surfaces of highly permeable concrete, even though sulfate levels are relatively low. To control this risk and to resist freeze-thaw deterioration, the water-to-cementitious material ratio should not exceed 0.50 for concrete in contact with soils that are likely to stay moist due to surface drainage or high-water tables. Concrete should be air entrained. TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 9 CTL  T PROJECT NO. FC06547.013-135 Sulfate attack problems are comparatively rare in this area when quality concrete is used. The risk is also lowered to some extent by damp-proofing the surfaces of concrete walls in contact with the soil. ACI indicates sulfate re- sistance for Class 1 exposure can be achieved by using Type II cement, a maxi- mum water-to-cementitious material ratio of 0.50, and a minimum compressive strength of 4,000 psi. We believe this approach should be used as a minimum at this project. The more stringent measures outlined in the previous paragraph will better control risk of sulfate attack and are more in alignment with written industry standards. MAINTENANCE Routine maintenance, such as sealing and repair of cracks, is necessary to achieve the long-term life of a pavement system. We recommend a preven- tive maintenance program be developed and followed for all pavement systems to assure the design life can be realized. Choosing to defer maintenance usually results in accelerated deterioration leading to higher future maintenance costs, and/or repair. A recommended maintenance program is outlined in Appendix D. Excavation of completed pavement for utility construction or repair can destroy the integrity of the pavement and result in a severe decrease in service- ability. To restore the pavement top original serviceability, careful backfill com- paction before repaving is necessary. SURFACE DRAINAGE A primary cause of premature pavement deterioration is infiltration of wa- ter into the pavement system. This increase in moisture content usually results in the softening of aggregate base course and subgrade soil and eventual failure of the pavement. In addition, parts of Colorado experience many freeze-thaw cy- TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 10 CTL  T PROJECT NO. FC06547.013-135 cles each season that can result in deterioration of the pavement. We recom- mend that subgrade, pavement, and surrounding ground surface be sloped to cause surface water to run off rapidly and away from pavements. Backs of curbs and gutters should be backfilled with compacted fill and sloped to prevent pond- ing adjacent to backs of curbs and to paving. The final grading of the subgrade should be carefully controlled so the pavement design cross-section can be maintained. Low spots in the subgrade that can trap water should be eliminated. Seals should be provided within the curb and pavement and in all joints to reduce the possibility of water infiltration. LIMITATIONS This report has been prepared for the exclusive use of Toll Brothers Inc. for the purpose of providing geotechnical design and construction criteria for the proposed project. This report was prepared from data developed during our field exploration, laboratory testing, engineering analysis, and experience with similar conditions. The borings were spaced to obtain a reasonably accurate under- standing of the existing pavements and subsurface conditions. The borings are representative of conditions encountered only at the exact boring locations. Var- iations in subsurface conditions not indicated by our borings are always possible. The recommendations contained in this report were based upon our understand- ing of the planned construction. If plans change or differ from the assumptions presented herein, we should be contacted to review our recommendations. Due to the changing nature of site characterization, standards, and prac- tices, the information and recommendations provided in this report are only valid for one year following the date of issue. Following that time, our office should be contacted to provide, if necessary, any updated recommendations as appropriate for the engineering methodologies used at that time. LEGEND: INDICATES APPROXIMATE LOCATION OF EXPLORATORY BORING INDICATES ROADWAYS INCLUDED IN THIS INVESTIGATION INDICATES LOT NUMBER 2 INDICATES BLOCK NUMBER TH-1 1 HARMONY ROAD KECHTER ROAD INTERSTATE 25 ZIEGLER RD. S. TIMBERLINE RD. SITE TRILBY RD. 1 2 3 4 5 6 7 8 9 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 9/12 18/12 5/12 WC=17.6 DD=112 SW=1.5 SS=<0.01 WC=16.7 DD=114 LL=44 PI=25 -200=75 WC=17.6 DD=112 SW=1.5 SS=<0.01 WC=16.7 DD=114 LL=44 PI=25 -200=75 TH-1 18/12 11/12 15/12 WC=15.7 DD=113 LL=42 PI=24 -200=71 WC=17.7 DD=111 SW=1.4 WC=17.0 DD=115 SW=0.1 SS=0.020 WC=15.7 DD=113 LL=42 PI=24 -200=71 WC=17.7 DD=111 SW=1.4 WC=17.0 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 11/12 8/12 10/12 WC=22.2 DD=105 SW=0.7 WC=22.2 DD=105 SW=0.7 TH-4 12/12 6/12 4/12 WC=22.2 DD=104 SW=0.4 SS=<0.01 WC=28.2 DD=90 SW=0.2 WC=22.2 DD=104 SW=0.4 SS=<0.01 WC=28.2 DD=90 SW=0.2 TH-5 17/12 8/12 12/12 WC=17.9 DD=111 SW=2.7 SS=<0.01 WC=20.5 LL=38 PI=18 -200=82 WC=17.9 DD=111 SW=2.7 SS=<0.01 Roadway(s): Reliability 75 % Standard Deviation 0.44 Initial Serviceability 4.5 Terminal Serviceability 2 Resilient Modulus 3,020 psi Design ESALs 36,500 Layers Structural Coefficient Drainage Thickness SN HMA 0.44 1 4 1.76 ABC 0.11 1.05 6 0.69 CSS* 0.1 1 6 0.60 SUM 3.05 *Full credit for chemical treatment toward structural design requires a mix design be prepared and tested FIGURE 4 Design Structural Number 2.48 Local - Residential (All Roadways, 12" Chemical Stabilization) Flexible Structural Design TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM PAVEMENTS CTL|T PROJECT NO. FC06547.013-135 TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 APPENDIX A RESULTS OF LABORATORY TESTING Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT= 112 PCF From TH - 1 AT 2 FEET MOISTURE CONTENT= 17.6 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 111 PCF From TH - 2 AT 4 FEET MOISTURE CONTENT= 17.7 % TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013 APPLIED PRESSURE - KSF APPLIED PRESSURE - KSF COMPRESSION % EXPANSION Swell Consolidation FIGURE A-1 COMPRESSION % EXPANSION -4 -3 -2 -1 0 1 2 3 EXPUND ANS ION ER C ON S TA N T PREDUE SSU RE TO W ETT IN G -4 -3 -2 -1 0 1 2 3 E X P A N SIONC UND ER ON ST A N T P R E SSU RE DUE TO W ET T IN G 0.1 1.0 10 100 0.1 1.0 10 100 Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 115 PCF From TH - 2 AT 9 FEET MOISTURE CONTENT= 17.0 % Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT= 106 PCF From TH - 3 AT 4 FEET MOISTURE CONTENT= 21.3 % TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013 APPLIED PRESSURE - KSF APPLIED PRESSURE - KSF COMPRESSION % EXPANSION Swell Consolidation FIGURE A-2 COMPRESSION % EXPANSION -4 -3 -2 -1 0 1 2 3 EXPUND ANS ION ER C ON S TA N T PREDUE SSU RE TO W ETT IN G -4 -3 -2 -1 0 1 2 3 E X P A N SIONC UND ER ON ST A N T P R E SSU RE DUE TO W ET T IN G 0.1 1.0 10 100 0.1 1.0 10 100 Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT= 105 PCF From TH - 4 AT 2 FEET MOISTURE CONTENT= 22.2 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 104 PCF From TH - 5 AT 4 FEET MOISTURE CONTENT= 22.2 % TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013 APPLIED PRESSURE - KSF APPLIED PRESSURE - KSF COMPRESSION % EXPANSION Swell Consolidation FIGURE A-3 COMPRESSION % EXPANSION -4 -3 -2 -1 0 1 2 3 EXPUND ANS ION ER C ON S TA N T PREDUE SSU RE TO W ETT IN G -4 -3 -2 -1 0 1 2 3 E X P A N SIONC UND ER ON ST A N T P R E SSU RE DUE TO W ET T IN G 0.1 1.0 10 100 0.1 1.0 10 100 Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 90 PCF From TH - 5 AT 9 FEET MOISTURE CONTENT= 28.2 % TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013 APPLIED PRESSURE - KSF COMPRESSION % EXPANSION Swell Consolidation Test Results FIGURE A-4 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 E XP AN SI OC N U NDER O NST ANT P RE SS U RE D UE TO W ETTIN G 0.1 1.0 10 100 Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT= 111 PCF From TH - 6 AT 2 FEET MOISTURE CONTENT= 17.9 % Sample of FILL, CLAY, SANDY (CL) DRY UNIT WEIGHT= 107 PCF From TH - 7 AT 2 FEET MOISTURE CONTENT= 19.6 % TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013 APPLIED PRESSURE - KSF APPLIED PRESSURE - KSF COMPRESSION % EXPANSION Swell Consolidation FIGURE A-5 COMPRESSION % EXPANSION -3 -2 -1 0 1 2 3 4 EXPUND ANS ION ER C ON S TA N T PREDUE SSU RE TO W ETT IN G -4 -3 -2 -1 0 1 2 3 E X P A N SIONC UND ER ON ST A N T P R E SSU RE DUE TO W ET T IN G 0.1 1.0 10 100 0.1 1.0 10 100 Sample of FILL, CLAY, SANDY (CL) GRAVEL 0 % SAND 25 % From TH - 1 AT 4 FEET SILT & CLAY 75 % LIQUID LIMIT 44 % PLASTICITY INDEX 25 % Sample of FILL, CLAY, SANDY (CL) GRAVEL 0 % SAND 29 % From TH - 2 AT 2 FEET SILT & CLAY 71 % LIQUID LIMIT 42 % PLASTICITY INDEX 24 % TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013 Gradation Test Results FIGURE A-6 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. Sample of FILL, CLAY, SANDY (CL) GRAVEL 1 % SAND 32 % From TH - 3 AT 2 FEET SILT & CLAY 67 % LIQUID LIMIT 44 % PLASTICITY INDEX 25 % Sample of CLAY, SANDY (CL) GRAVEL 1 % SAND 17 % From TH - 6 AT 4 FEET SILT & CLAY 82 % LIQUID LIMIT 38 % PLASTICITY INDEX 18 % TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013 Gradation Test Results FIGURE A-7 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. Sample of CLAY, SANDY (CL) GRAVEL 0 % SAND 34 % From TH - 7 AT 4 FEET SILT & CLAY 66 % LIQUID LIMIT 47 % PLASTICITY INDEX 24 % Sample of GRAVEL % SAND % From SILT & CLAY % LIQUID LIMIT % PLASTICITY INDEX % TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013 Gradation Test Results FIGURE A-8 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 PASSING WATER- MOISTURE DRY LIQUID PLASTICITY APPLIED NO. 200 SOLUBLE DEPTH CONTENT DENSITY LIMIT INDEX SWELL* PRESSURE SIEVE SULFATES BORING (FEET) (%) (PCF) (%) (PSF) (%) (%) DESCRIPTION TH-1 2 17.6 112 1.5 150 <0.01 FILL, CLAY, SANDY (CL) TH-1 4 16.7 114 44 25 75 FILL, CLAY, SANDY (CL) TH-2 2 15.7 113 42 24 71 FILL, CLAY, SANDY (CL) TH-2 4 17.7 111 1.4 150 CLAY, SANDY (CL) TH-2 9 17.0 115 0.1 1,100 0.02 CLAY, SANDY (CL) TH-3 2 18.3 110 44 25 67 FILL, CLAY, SANDY (CL) TH-3 4 21.3 106 1.0 150 0.02 FILL, CLAY, SANDY (CL) TH-4 2 22.2 105 0.7 150 FILL, CLAY, SANDY (CL) TH-5 4 22.2 104 0.4 150 <0.01 CLAY, SANDY (CL) TH-5 9 28.2 90 0.2 1,100 CLAY, SANDY (CL) TH-6 2 17.9 111 2.7 150 <0.01 FILL, CLAY, SANDY (CL) TH-6 4 20.5 38 18 82 CLAY, SANDY (CL) TH-7 2 19.6 107 1.0 150 0.01 FILL, CLAY, SANDY (CL) TH-7 4 28.5 47 24 66 CLAY, SANDY (CL) SWELL TEST RESULTS* TABLE A-I SUMMARY OF LABORATORY TESTING ATTERBERG LIMITS Page 1 of 1 * NEGATIVE VALUE INDICATES COMPRESSION. TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL|T PROJECT NO. FC06547.013 TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 APPENDIX B SAMPLE SITE GRADING SPECIFICATIONS TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 B-1 SAMPLE SITE GRADING SPECIFICATIONS 1. DESCRIPTION This item shall consist of the excavation, transportation, placement, and compac- tion of materials from locations indicated on the plans, or staked by the Engineer, as necessary to achieve site elevations. 2. GENERAL The Soils Engineer shall be the Owner's representative. The Soils Engineer shall approve fill materials, method of placement, moisture contents, and percent compaction, and shall give written approval of the completed fill. 3. CLEARING JOB SITE The Contractor shall remove all trees, brush, and rubbish before excavation or fill placement is begun. The Contractor shall dispose of the cleared material to pro- vide the Owner with a clean, neat appearing job site. Cleared material shall not be placed in areas to receive fill or where the material will support structures of any kind. 4. SCARIFYING AREA TO BE FILLED All topsoil and vegetable matter shall be removed from the ground surface upon which fill is to be placed. The surface shall then be plowed or scarified to a depth of 8 inches until the surface is free from ruts, hummocks or other uneven fea- tures, which would prevent uniform compaction by the equipment to be used. 5. COMPACTING AREA TO BE FILLED After the foundation for the fill has been cleared and scarified, it shall be disked or bladed until it is free from large clods, brought to the proper moisture content and compacted to not less than 95 percent of maximum density as determined in accordance with ASTM D 698. 6. FILL MATERIALS Materials classifying as CL, SC, SM, SW, SP, GP, GC, and GM are acceptable. Fill soils shall be free from organic matter, debris, or other deleterious substanc- es, and shall not contain rocks or lumps having a diameter greater than three (3) inches. TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 B-2 7. MOISTURE CONTENT Fill materials shall be moisture treated. Clay soils should be moisture-treated to between optimum and 3 percent above optimum moisture content as determined from Standard Proctor compaction tests. Sand soils should be moistened to within 2 percent optimum moisture content. Sufficient laboratory compaction tests shall be made to determine the optimum moisture content for the various soils encountered in borrow areas. The Contractor may be required to add moisture to the excavation materials in the borrow area if, in the opinion of the Soils Engineer, it is not possible to obtain uniform moisture content by adding water on the fill surface. The Contractor may be required to rake or disk the fill soils to provide uniform moisture content through the soils. The application of water to embankment materials shall be made with any type of watering equipment approved by the Soils Engineer, which will give the desired results. Water jets from the spreader shall not be directed at the embankment with such force that fill materials are washed out. Should too much water be added to any part of the fill, such that the material is too wet to permit the desired compaction from being obtained, rolling, and all work on that section of the fill shall be delayed until the material has been al- lowed to uniformly dry to the required moisture content. The Contractor will be permitted to rework wet material in an approved manner to hasten its drying. 8. COMPACTION OF FILL AREAS Selected fill material shall be placed and mixed in evenly spread layers. After each fill layer has been placed, it shall be uniformly compacted to not less than the specified percentage of maximum density. Fill materials shall be placed such that the thickness of loose material does not exceed 8 inches and the compacted lift thickness does not exceed 6 inches. Compaction, as specified above, shall be obtained by the use of sheepsfoot roll- ers, multiple-wheel pneumatic-tired rollers, or other equipment approved by the Engineer. Compaction shall be accomplished while the fill material is at the specified moisture content. Compaction of each layer shall be continuous over the entire area. Compaction equipment shall make sufficient trips to insure that the required density is obtained. TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 B-3 9. COMPACTION OF SLOPES Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction operations shall be continued until slopes are stable, but not too dense for planting, and there is no appreciable amount of loose soil on the slopes. Compaction of slopes may be done progressively in increments of three to five feet (3' to 5') in height or after the fill is brought to its total height. Permanent fill slopes shall not exceed 3:1 (horizontal to vertical). 10. DENSITY TESTS Field density tests shall be made by the Soils Engineer at locations and depths of his choosing. Where sheepsfoot rollers are used, the soil may be disturbed to a depth of several inches. Density tests shall be taken in compacted material be- low the disturbed surface. When density tests indicate that the density or mois- ture content of any layer of fill or portion thereof is below that required, the partic- ular layer or portion shall be reworked until the required density or moisture con- tent has been achieved. 11. COMPLETED PRELIMINARY GRADES All areas, both cut and fill, shall be finished to a level surface and shall meet the following limits of construction: A. Overlot cut or fill areas shall be within plus or minus 2/10 of one foot. B. Street grading shall be within plus or minus 1/10 of one foot. The civil engineer, or duly authorized representative, shall check all cut and fill areas to observe that the work is in accordance with the above limits. 12. SUPERVISION AND CONSTRUCTION STAKING Observation by the Soils Engineer shall be continuous during the placement of fill and compaction operations so that he can declare that the fill was placed in gen- eral conformance with specifications. All site visits necessary to test the place- ment of fill and observe compaction operations will be at the expense of the Owner. All construction staking will be provided by the Civil Engineer or his duly authorized representative. Initial and final grading staking shall be at the ex- pense of the owner. The replacement of grade stakes through construction shall be at the expense of the contractor. TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 B-4 13. SEASONAL LIMITS No fill material shall be placed, spread or rolled while it is frozen, thawing, or dur- ing unfavorable weather conditions. When work is interrupted by heavy precipi- tation, fill operations shall not be resumed until the Soils Engineer indicates that the moisture content and density of previously placed materials are as specified. 14. NOTICE REGARDING START OF GRADING The contractor shall submit notification to the Soils Engineer and Owner advising them of the start of grading operations at least three (3) days in advance of the starting date. Notification shall also be submitted at least 3 days in advance of any resumption dates when grading operations have been stopped for any rea- son other than adverse weather conditions. 15. REPORTING OF FIELD DENSITY TESTS Density tests made by the Soils Engineer, as specified under "Density Tests" above, shall be submitted progressively to the Owner. Dry density, moisture con- tent, of each test taken, and percentage compaction shall be reported for each test taken. 16. DECLARATION REGARDING COMPLETED FILL The Soils Engineer shall provide a written declaration stating that the site was filled with acceptable materials, or was placed in general accordance with the specifications. APPENDIX C PAVEMENT CONSTRUCTION RECOMMENDATIONS TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 C-1 SUBGRADE PREPARATION Chemically Stabilized Subgrade (CSS) 1. Utility trenches and all subsequently placed fill should be properly compacted and tested prior to subgrade preparation. As a mini- mum, fill should be compacted to 95 percent of standard Proctor maximum dry density. 2. The subgrade should be stripped of organic matter and should be shaped to final line and grade. 3. The contractor or owner’s representative should have a mix design performed in general accordance with ASTM D 558 using the actu- al site soils and the approved stabilizing agent (lime, fly ash or a combination of lime and fly ash). Scheduling should allow at least two weeks for the mix design to be completed prior to construction. 4. High calcium quicklime should conform to the requirements of ASTM C 977 and ASTM C 110. Dolomitic quicklime, magnesia quicklime with magnesium oxide contents in excess of 4 percent, or carbonated quicklime should not be used. 5. Fly ash should consist of Class C in accordance with ASTM C 593 and C 618. 6. All stabilizing agents should come from the same source as used in the mix design. If the source is changed, a new mix design should be performed. 7. Stabilizing agents should be spread with a mechanical spreader from back of curb to back of curb for detached sidewalks or back of walk to back of walk for attached sidewalks, where applicable. 8. The subgrade should be mixed to the specified depth and at the specified concentration until a uniform blend of soil, stabilizing agent and water is obtained and the moisture content is at least 2 percent (for fly ash) and 3 percent (for lime) above the optimum moisture content of the design mixture (ASTM D 558). 9. If lime is used, a mellowing period of up to seven days may be re- quired following initial mixing. Once the pH of the mixture is 12.3 or higher and the plasticity index is less than 10, the soils shall again be mixed and moisture conditioned to at least 3 percent over opti- TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 C-2 mum moisture content and compacted to at least 95 percent of the mixture’s maximum dry density (ASTM D 558). Up to sev- en additional days may be required for curing prior to paving. The treated surface shall be kept moist or sealed with emulsified as- phalt. Traffic should not be allowed on the surface during the mel- lowing and curing periods. 10. If fly ash is used, the mixture should be moisture conditioned to at least 2 percent over optimum moisture content and compacted to at least 95 percent of the mixture’s maximum dry density (ASTM D 558) within 2 hours from the time of initial fly ash mixing. 11. If a lime/fly ash combination is used, the lime should be mixed first and allowed to mellow as indicated for lime treatment in item 9. Following the mellowing period, the fly ash should be added, mois- ture conditioned and compacted as indicated above within 2 hours of initial fly ash mixing. 12. Samples of loose, blended stabilizing agent/soil mixture should be sampled by a representative of CTL Thompson, Inc. for compres- sive strength testing (ASTM D 1663) to determine compliance (op- tional) when full credit for the FASS layer is used in the pavement thickness design. 13. Batch tickets should be supplied to the owner or owner’s repre- sentative with the application area for that batch to determine com- pliance with the recommended proportions of fly ash to soil. 14. The subgrade should be re-shaped to final line and grade. 15. The subgrade should be sealed with a pneumatic-tire roller that is sufficiently light in weight so as to not cause hairline cracking of the subgrade. 16. Where sulfate concentrations are over 0.5 percent, a double treat- ment method should be performed. When a double treatment is re- quired, the first half of the stabilizing agent should be placed, mois- ture treated and allowed to mellow or cure for at least two weeks. The remaining half of the stabilizing agent plus an additional 0.5 (for lime) to 2 (for fly ash) percent shall then be applied. 17. Mixing of the fly ash, lime, or lime/fly ash treated subgrade should not occur if the temperature of the soil mixture is below 40o F. TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 C-3 18. We recommend a minimum of 2 days curing prior to paving. The surface of the stabilized area should be kept moist during the cure period by periodic, light sprinkling if needed. Strength gains will be slower during cooler weather. Traffic should not be permitted on the treated subgrade during the curing period. The subgrade should be protected from freezing or drying at all times until paving. 19. The treated areas will gain greater strength if they are allowed to cure for 1 to 3 days prior to paving. Construction traffic on the treated subgrade prior to pavement section construction should be limited and the subgrade should be protected from freezing or dry- ing at all times until paving. 20. Placement, mixing and compaction of stabilized subgrade should be observed and tested by a representative of our firm. TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 C-4 PAVEMENT MATERIALS AND CONSTRUCTION Aggregate Base Course (ABC) 1. A Class 5 or 6 Colorado Department of Transportation (CDOT) specified ABC should be used. 2. Bases should have a minimum Hveem stabilometer value of 72, or greater. ABC must be moisture stable. The change in R-value from 300-psi to 100-psi exudation pressure should be 12 points or less. 3. ABC bases should be placed in thin lifts not to exceed 6 inches and moisture treated to near optimum moisture content. Bases should be moisture treated to near optimum moisture content, and com- pacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). 4. Placement and compaction of ABC should be observed and tested by a representative of our firm. Placement should not commence until the underlying subgrade is properly prepared and tested. Hot Mix Asphalt (HMA) 1. HMA should be composed of a mixture of aggregate, filler, hydrated lime and asphalt cement. Some mixes may require polymer modi- fied asphalt cement, or make use of up to 20 percent reclaimed as- phalt pavement (RAP). A job mix design is recommended and pe- riodic checks on the job site should be made to verify compliance with specifications. 2. HMA should be relatively impermeable to moisture and should be designed with crushed aggregates that have a minimum of 80 per- cent of the aggregate retained on the No. 4 sieve with two mechan- ically fractured faces. 3. Gradations that approach the maximum density line (within 5 per- cent between the No. 4 and 50 sieves) should be avoided. A gra- dation with a nominal maximum size of 1 or 2 inches developed on the fine side of the maximum density line should be used. TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 C-5 4. Total void content, voids in the mineral aggregate (VMA) and voids filled should be considered in the selection of the optimum asphalt cement content. The optimum asphalt content should be selected at a total air void content of approximately 4 percent. The mixture should have a minimum VMA of 14 percent and between 65 per- cent and 80 percent of voids filled. 5. Asphalt cement should meet the requirements of the Superpave Performance Graded (PG) Binders. The minimum performing as- phalt cement should conform to the requirements of the governing agency. 6. Hydrated lime should be added at the rate of 1 percent by dry weight of the aggregate and should be included in the amount pass- ing the No. 200 sieve. Hydrated lime for aggregate pretreatment should conform to the requirements of ASTM C 207, Type N. 7. Paving should be performed on properly prepared, unfrozen sur- faces that are free of water, snow and ice. Paving should only be performed when both air and surface temperatures equal, or ex- ceed, the temperatures specified in Table 401-3 of the 2006 Colo- rado Department of Transportation Standard Specifications for Road and Bridge Construction. 8. HMA should not be placed at a temperature lower than 245o F for mixes containing PG 64-22 asphalt, and 290o F for mixes containing polymer-modified asphalt. The breakdown compaction should be completed before the HMA temperature drops 20o F. 9. Wearing surface course shall be Grading S or SX for residential roadway classifications and Grading S for collector, arterial, indus- trial, and commercial roadway classifications. 10. The minimum/maximum lift thicknesses for Grade SX shall be 1½ inches/2½ inches. The minimum/maximum lift thicknesses for Grade S shall be 2 inches/3½ inches. The minimum/maximum lift thicknesses for Grade SG shall be 3 inches/5 inches. 11. Joints should be staggered. No joints should be placed within wheel paths. 12. HMA should be compacted to between 92 and 96 percent of Maxi- mum Theoretical Density. The surface shall be sealed with a finish roller prior to the mix cooling to 185o F. TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 C-6 13. Placement and compaction of HMA should be observed and tested by a representative of our firm. Placement should not commence until approval of the proof rolling as discussed in the Subgrade Preparation section of this report. Sub base, base course or initial pavement course shall be placed within 48 hours of approval of the proof rolling. If the Contractor fails to place the sub base, base course or initial pavement course within 48 hours or the condition of the subgrade changes due to weather or other conditions, proof roll- ing and correction shall be performed again. Portland Cement Concrete (PCC) 1. Portland cement concrete should consist of Class P of the 2005 CDOT - Standard Specifications for Road and Bridge Construction specifications for normal placement or Class E for fast-track pro- jects. PCC should have a minimum compressive strength of 4,200 psi at 28 days and a minimum modulus of rupture (flexural strength) of 600 psi. Job mix designs are recommended and periodic checks on the job site should be made to verify compliance with specifica- tions. 2. Portland cement should be Type II “low alkali” and should conform to ASTM C 150. 3. Portland cement concrete should not be placed when the subgrade or air temperature is below 40°F. 4. Concrete should not be placed during warm weather if the mixed concrete has a temperature of 90°F, or higher. 5. Mixed concrete temperature placed during cold weather should have a temperature between 50°F and 90°F. 6. Free water should not be finished into the concrete surface. Atom- izing nozzle pressure sprayers for applying finishing compounds are recommended whenever the concrete surface becomes difficult to finish. 7. Curing of the portland cement concrete should be accomplished by the use of a curing compound. The curing compound should be applied in accordance with manufacturer recommendations. TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 C-7 8. Curing procedures should be implemented, as necessary, to pro- tect the pavement against moisture loss, rapid temperature change, freezing, and mechanical injury. 9. Construction joints, including longitudinal joints and transverse joints, should be formed during construction or sawed after the concrete has begun to set, but prior to uncontrolled cracking. 10. All joints should be properly sealed using a rod back-up and ap- proved epoxy sealant. 11. Traffic should not be allowed on the pavement until it has properly cured and achieved at least 80 percent of the design strength, with saw joints already cut. 12. Placement of portland cement concrete should be observed and tested by a representative of our firm. Placement should not com- mence until the subgrade is properly prepared and tested. 1 APPENDIX D MAINTENANCE PROGRAM TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 D-1 MAINTENANCE RECOMMENDATIONS FOR FLEXIBLE PAVEMENTS A primary cause for deterioration of pavements is oxidative aging resulting in brittle pavements. Tire loads from traffic are necessary to "work" or knead the asphalt concrete to keep it flexible and rejuvenated. Preventive maintenance treatments will typically preserve the original or existing pavement by providing a protective seal or rejuvenating the asphalt binder to extend pavement life. 1. Annual Preventive Maintenance a. Visual pavement evaluations should be performed each spring or fall. b. Reports documenting the progress of distress should be kept current to provide information on effective times to apply pre- ventive maintenance treatments. c. Crack sealing should be performed annually as new cracks ap- pear. 2. 3 to 5 Year Preventive Maintenance a. The owner should budget for a preventive treatment at approxi- mate intervals of 3 to 5 years to reduce oxidative embrittlement problems. b. Typical preventive maintenance treatments include chip seals, fog seals, slurry seals and crack sealing. 3. 5 to 10 Year Corrective Maintenance a. Corrective maintenance may be necessary, as dictated by the pavement condition, to correct rutting, cracking and structurally failed areas. b. Corrective maintenance may include full depth patching, milling and overlays. c. In order for the pavement to provide a 20-year service life, at least one major corrective overlay should be expected. TOLL BROTHERS INC. PHASES 3 AND 5 – KECHTER FARM FILING 2 CTL  T PROJECT NO. FC06547.013-135 D-2 MAINTENANCE RECOMMENDATIONS FOR RIGID PAVEMENTS High traffic volumes create pavement rutting and smooth, polished surfac- es. Preventive maintenance treatments will typically preserve the original or ex- isting pavement by providing a protective seal and improving skid resistance through a new wearing course. 1. Annual Preventive Maintenance a. Visual pavement evaluations should be performed each spring or fall. b. Reports documenting the progress of distress should be kept current to provide information of effective times to apply preven- tive maintenance. c. Crack sealing should be performed annually as new cracks ap- pear. 2. 4 to 8 Year Preventive Maintenance a. The owner should budget for a preventive treatment at approxi- mate intervals of 4 to 8 years to reduce joint deterioration. b. Typical preventive maintenance for rigid pavements includes patching, crack sealing and joint cleaning and sealing. c. Where joint sealants are missing or distressed, resealing is mandatory. 3. 15 to 20 Year Corrective Maintenance a. Corrective maintenance for rigid pavements includes patching and slab replacement to correct subgrade failures, edge dam- age and material failure. b. Asphalt concrete overlays may be required at 15 to 20 year in- tervals to improve the structural capacity of the pavement. 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC) SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR. 7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PERCENT PASSING 0 10 20 30 50 60 70 80 90 100 PERCENT RETAINED 40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC) SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR. 7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PERCENT PASSING PERCENT RETAINED 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC) SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR. 7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PERCENT PASSING 0 10 20 30 50 60 70 80 90 100 PERCENT RETAINED 40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC) SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR. 7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PERCENT PASSING PERCENT RETAINED 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC) SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR. 7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PERCENT PASSING 0 10 20 30 50 60 70 80 90 100 PERCENT RETAINED 40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC) SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR. 7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PERCENT PASSING PERCENT RETAINED 0 10 20 30 40 50 60 70 80 90 100 WC=20.5 LL=38 PI=18 -200=82 TH-6 10/12 7/12 7/12 WC=19.6 DD=107 SW=1.0 SS=0.010 WC=28.5 LL=47 PI=24 -200=66 WC=19.6 DD=107 SW=1.0 SS=0.010 WC=28.5 LL=47 PI=24 -200=66 TH-7 DEPTH - FEET DRIVE SAMPLE. THE SYMBOL 11/12 INDICATES 11 BLOWS OF A 140-POUND HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES. FILL, CLAY, SANDY, MOIST, STIFF TO VERY STIFF, BROWN TO DARK BROWN 1. NOTES: THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS IN THIS REPORT. CLAY, SANDY, MOIST, MEDIUM-STIFF TO STIFF, BROWN, TAN 4. LEGEND: DEPTH - FEET THE BORINGS WERE DRILLED ON OCTOBER 25, 2017, USING 4-INCH DIAMETER CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG. Summary Logs of Exploratory Borings FIGURE 3 WC DD SW -200 LL PI UC SS - - - - - - - - INDICATES MOISTURE CONTENT (%). INDICATES DRY DENSITY (PCF). INDICATES SWELL WHEN WETTED UNDER OVERBURDEN PRESSURE (%). INDICATES PASSING NO. 200 SIEVE (%). INDICATES LIQUID LIMIT. INDICATES PLASTICITY INDEX. INDICATES UNCONFINED COMPRESSIVE STRENGTH (PSF). INDICATES SOLUBLE SULFATE CONTENT (%). 2. TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013-135 3. GROUNDWATER WAS NOT ENCOUNTERED IN THIS INVESTIGATION. DD=115 SW=0.1 SS=0.020 TH-2 15/12 12/12 7/12 WC=18.3 DD=110 LL=44 PI=25 -200=67 WC=21.3 DD=106 SW=1.0 SS=0.020 WC=18.3 DD=110 LL=44 PI=25 -200=67 WC=21.3 DD=106 SW=1.0 SS=0.020 TH-3 Summary Logs of Exploratory Borings FIGURE 2 DEPTH - FEET DEPTH - FEET TOLL BROTHERS INC. PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL | T PROJECT NO. FC06547.013-135 4 5 6 7 8 1 2 3 4 5 6 7 8 9 16 15 14 13 12 11 10 9 16 15 14 13 12 11 10 9 16 15 14 13 12 11 10 9 1 2 3 4 5 Tree Row Lane 6 Spindlebrush Lane Sapling Street Fall Harvest Way Medlar Place Espalier Lane TH-1 TH-2 TH-3 TH-4 TH-5 TH-6 TH-7 FIGURE 1 Locations of TOLL BROTHERS INC. Exploratory Borings PHASES 3 AND 5 - KECHTER FARM FILING 2 CTL I T PROJECT NO. FC06547.013-135 0 50' 100' APPROXIMATE SCALE: 1" = 100' VICINITY MAP (FORT COLLINS, COLORADO) NOT TO SCALE