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HomeMy WebLinkAboutCT 04-26; ROBERTSON RANCH EAST VILLAGE PA 16, 17, & 18; PAVEMENT DESIGN REPORT MESA TRAIL; 2010-02-17: - - :• Geotechnical . Geologic . Coastal. Environmental p741 Palmer Way Carlsbad California 92010 (760) 438-3155 FAX (760) 931 0915 www geosoilsinc corn February 17, 2010 0 ' 0 W.O. 5981--E-p DR Horton 1021 Costa Pacifica Way, Suite 2107 Oceanside, California 92054 , " Attention: Mr. Tom Lombardi •" ' ' 0 Subject Pavement Design Report, Mesa Trail (Stations 10- to 12), Portion of 0 'Pláflnii'g Area 21 of Robertson Ranch, Carlsbad, 'San Diego County, 0 California * 0 ' Dear Mr. Lorhbardi: In accordance with your request, and the requirements of the City, GeoSoils, Inc (GSI) has prepared this pavement design report for asphalt concrete (AC) pavement at the subject site for pavement subgrade with resistance values less than 12 The recommendations presented herein include the use of subgrade enhancement geotextiles (SEG's) and subgrade lime treatment, as well as a modified (thickened), conventional asphaltic concrete over aggregate base section The scope of services provided in preparation of this report include a review of the referenced reports and documents (see the Appendix), an evaluation of the pavement section for the subject area, and preparation of this report Ile PAVEMENT DESIGN Pavement section evaluation was based on traffic index (TI) values provided by (O'Day Consult `-r personal communications) Pavement sections were evaluated in general accordance with the California Department of Transportation (Caltrans) Highway Design Manual of Instructions dnd the City of Carlsbad Standard Drawings (see the Appendix) Pavement sections presented are based on the aforkementloned criteria and resistance value (R-value) data (see the attached, ttached Figures 1 and'2), evaluated from soils exposed at, or near, final subgrade elevations within the subject area '13-value testing was performed In general accordance with the latest revisions to the Department of Transportation State of California, Material & Research Test Method No 301 The results of additional laboratory testing, including pH(ASTM C977) and sulfate (Caltest Method 417) evaluations, are included in the attached Figures 3 and 4 ASPHALT CONCRETE PAVEMENT Structural Section Traffic Indices (TI) were provided by the project civil engineer (O'Day Consultants, personal communication) as 5.0 for the subject traffic areas. An untreated R-value (see attached Figure 1) of 8 was evaluated for representative subgrade soils onsite. Where "un-treated" R-values are less than 12, alternative pavement design using subgrade treated with quicklime was requested by the City (Carlsbad, 1993). An R-value for lime treated subgrade (see attached Figure 2) of 74 was obtained for representative subgrade soils onsite and used in the pavement design presented herein. In addition to lime treated subgrade, and in consideration of cost, as well as environmental concerns regarding the long term durability and field implementation with the use of lime, additional methodologies to improve the performance of low R-value subgrades are therefore presented for consideration on this project without regard to order of preference, or performance. The methods included in our supplemental evaluation consist of the following: Increase the minimum untreated aggregate base section to exceed the minimum criteria for both Carlsbad (1993) and State of California (2008) for pavements on subgrades with R-values less than 12. See Table 1 below. Design pavement sections using SEG's per section 614.5 of the Highway Design Manual (State of California, 2008), the State of California (2009), and Mirafi (2005). See Table 2 below. Design pavement sections using a lime treated subgrade per Carlsbad (1993), Section 614.4 of the Highway Design Manual (State of California, 2008). See Table 3 below. In consideration of Mirafi (2005), increasing the overall base section thickness, or using SEG's are preferred as an alternative to lime treatment, have been evaluated and approved by Caltrans in similar applications. GSI has used a similar approach (i.e., with SEG), for a major roadway with low strength subgrades in the City of Oceanside, and with the City's review and approval. The recommended pavement sections, provided in general accordance with the City guidelines (City of Carlsbad, 1993), and the State of California (2008, 2009), are presented as follows: D.R. Horton W. 0. 5981 -E-SC Mesa Trail, Planning Area 21 of Robertson Ranch February 17, 2010 FiIe:e:\wpl2\5900\5981 e.pdr2 Inc. Page 2 Pavement with Thickened Aggregate Base, Option A TABLE 1 - ASPHALTIC CONCRETE/AGGREGATE BASE APPROXIMATE TRAFFiC AREA Ti" SUBGRADE R-VALUE C. THICKNESS (lnches)3 :.AGGREGATE BASE THiCKNESS 4 (inches) 'Mesa Trail, Sta. 10-to 12 (Sample obtained from'Sta. 11 ) 50 (1) Per O'Day Consultants, (Improvement plans) . (2) Exceeds desin per, State of California (2008) (3) Per Carlsbad (1993) (4) Denotes Class 2 Aggregate Base R >78, SE >25) This alternativ includes increasing the minimum untreated agregate base section to exceed the minimum criteria for both Carlsbad (1993) and State of California (2008) The aggregate base thickness has been increased relative to sections shown in GSI (2009) and is at least 125 percent of the minimum design per Caltrans (2008). Pavement with Subgrade Enhancement Geotextule (SEG), Option B TABLE 2- ASPHALTIC CONCRETE/AGGREGATE BASE/SEG APPROXIMATE Ti'" SUBGRADE THICKNESS AGGREGATE BASE THICKNESS 4 SEGS (CalTrans, TRAFFIC AREA R-VALUE (2) (inches).. (inches 2009) 'Mesa Trail, Sta:.10- to 12 5.0 20 .4O- 131 5 (Sample -obtained from Sta.11 2) 5 Per O'Day Consultants, (Improvement plans) -. - Effective R-value when using SEG HP 570, or equivalent (State of California, 2008,2009) Exceeds City minimum, designper State of California (2008) Denotes Class 2 Aggregate Basó R >78; SE >25) (5) Class .131, Mirafi HP 570; or 'equivalent S This alternativeihcludesdesigipavement sections using SEG's per Section 614.5 of the Highway Design Manual (State of California 2008), the State of California (2009), and Mirafi (2005). Subgrádé.enhancernert geôtextile ( EG)used shall be Mirafi HP 570 (Class Bi), or equivalent. All SEG'sshallbe.placéd per the nanufacturers guidelines. Paverneñtwith Lime Treated Subgrade, Option C. . .. TABLE 3- ASPHALTIC CONCRETE/AGGREGATE BASE/ LIME TREATED SUBGRADE I Rfu"Tmt ;.6fl TREATED AC AGGREGATE APPROtMAUE TIE" TRAFFIC AREA SUBGRADE R -VALUE SUBGRADE R -VALUE THICKNESS BASE THICKNESS 3 (Inches) (inches) 'Mesa Trail, Sta. 10 to 12 5.0 74(2) 4.0 (Sample obtained from . . Sta. 11+50) . . .. . - Per O'Day Consultants, (Improvement plans) 4 percent Quicklime by weight. - - Denotes Class 2 Aggregate Base R >78, SE >25) •.. This alternative includes design pavement sections using âlime treated subgrade per. Carlsbad (1993), and section 614:4 of the Highway Design Manual (State of California, 2008). The percent (by weight) of quickliméLised in subgrade treatment shall be at least 4 percent The minimum treated subgrade thickness shall be 8 inches per Carlsbad (1993). Lime treatment shall be per the standard of pratice, and the National' Research Council (1987). . . . . . . . . General Installation onsiderations - All pavement installation, including preparation andcornpactidn of subgrade, compaction of base material and placement and rolling àf asphaltic coricrete, shall'be done in accordance with the City guidelines: áñd under the observation and testing of the project geotechnical engineer and/or the City., • . . . . The recommended, pavement- sections are meant as minimums.' If thinner or highly variable pavement sections are constructed, increased maintenance and repair may be needed. The: recommended pavement ections provided above are intended as a minimum guideline. If thinher, or highly vriable pavement sections are constructed, increased maintenance and repair could be expected If the ADT (average daily traffic) or ADTT (average daily truck traffic) increased beyondthat intended, as reflected by the TI iied for design, increased m n ainteance and repair could be required for the pavement section. Consideration should be iven to the increased potential for distress from overuse of paved street areas by heavy equipment and/or construction related heavy traffic (e.g., concrete trucks, loaded supply trucks, etc.), particularly.when the final section is not in place (i.e., topcoat). Best management construction pactices shOuld be followed at all times, especially during inclement \weather' . . . . PAVEMENT GRADING RECOMMENDATIONS General All section changes shall be properly transitioned. If adverse conditions are encountered during the preparation of subgrade materials, special construction methods may need to be employed. AGSI representative shall be present for the preparation of subgrade, base rock, and asphalt concrete. Subgrade Within street and parking areas, all surficial deposits of loose soil material shall be removed and recompacted as recommended. After the loose soils are removed, the bottom is to be scarified to a depth of at least 12 inches, moisture conditioned as necessary, and compacted to 95 percent of the maximum laboratory density, as determined byASTM test designation D 1557. Deleterious material, excessively wet or dry pockets, concentrated zones of oversized rock fragments, and any other unsuitable materials encountered during grading shall be removed. The compacted fill material shall then be brought to the elevation of the proposed subgrade for the pavement. The subgrade shall be proof-rolled in order to ensure a uniform firm and unyielding surface. All grading and fill placement shall be observed by the project soil engineer and/or his representative. Base Rock Compaction tests are required for the recommended base section. Minimum relative compaction required will.be 95 percent of the laboratory maximum density as determined by ASTM test designation D 1557. Base aggregate shall be in accordance with Section 26 of Caltrans Standard specifications (California Department of Transportation, 2006), for Caltrans Class 2 aggregate base. Paving Prime coat may be omitted if all of the following conditions are met: The asphalt pavement layer is placed within two weeks of completion of base and/or subbase course. Traffic is not routed over completed base before paving. Construction is completed during the dry season of May through October. The base is kept free of debris prior to placement of asphaltic concrete D.R. Horton : W.O. 5981 -E-SC Portion of PlanningArea21, Robertson Ranch February 17, 2010 File: e:\wp9\5900\5981e.pdr2 Page 5 GeoSoils, Inc. If construction is performed during the wet season of November through April, prime coat may be omitted if no rain occurs between completion of base course and paving and the time between completion of base and paving is reduced to three days, provided the base is free of loose soil or debris. Where prime coat has been omitted and rain occurs, traffic is routed over base course, or paving is delayed, measures shall be taken to restore base course and subgrade to conditions that will meet specifications as directed by the geotechnical consultant. Drainage Positive drainage shall be provided for all surface water to drain toward the curb and gutter, or to an approved drainage channel. Positive site drainage shall be maintained at all times. Water shall not be allowed to pond or seep into the ground. Over-watering of landscape areas should be avoided. Due to the low R-values, wet subgrade conditions could significantly reduce the life of the pavement. Therefore, it is imperative that subgrade materials are not allowed to become wet or saturated or allow water to flow into trenches or behind curbs. OTHER DESIGN PROFESSIONALS/CONSULTANTS The design civil engineer shall review the recommendations provided herein, incorporate those recommendations into their plans, and by explicit reference, make this report part of their project plans. LIMITATIONS The materials encountered on the project site and utilized for our analysis are believed representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. Inasmuch as our study is based upon our review and engineering analyses and laboratory data, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty is express or implied. Standards of practice are subject to change with time. GSl assumes no responsibility or liability for work or testing performed by others, or their inaction, or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. D.R. Horton W.O. 5981 -E-SC Portion of Planning Area 21, Robertson Ranch February 17, 2010 Fi1e:e:\wp9\5900\5981e.pdr2 GeoSoils, Inc. Page 6 The opportunity to be of service is greatly appreciated. If you have any questions, please do not hesitate to call our office. Respectfully submitte/OFE 104, 'TG'N GeoSoils, Inc. (L No. 1934 i oGE2) A' /Lh/ 4Eit* Robert G. Crisman Andrew T. Guatelli OF CA Engineering Geologist, CEG 1934 Geotechnical Engineer, GE 23 RGC/ATG/JPF/jh Attachments: Figure 1 - Untreated R-value Test Result Figure 2 - Treated R-value Test Result Figure.3 - pH Evaluation Figure 4 - Soil Sulfate Evaluation Appendix - References Distribution: (4) Addressee D.R.Horton • Portion of Planning Area 21, Robertson Ranch File:e:\wp9\5900\5981 e.pdr2. • W.O. 5981 -E-SC February 17, 2010 Page 7 GeoSoils, Inc. •. TT DPClMFtJ A B C 0 Compactor air pressure PSI 200 110 80 Water added 3.2 5.2 6.7 Moisture at compaction % 14.0 16.0 17.5 Height of sample IN 2.47 2.62 2.58 Dry density PCF 117.6 111.6 108.8 R-Value by exudation 12 8 6 R-Value by exudation, corrected 12 8 6 Exudation pressure PSI 634 316 224 Stability thickness FT 1.13 1.18 1.20 Expansion pressure thickness FT 0.871 0.301 0.00 flFSIcN CAICULATION DATA SAMPLE INFORMATION Traffic index, assumed 5.0 Gravel equivalent factor, assumed 1.25 Expansion, stability equilibrium 0 R-Value by expansion NA R-Value by exudation 8 R-Value at equilibrium 8 Expansion, Stability Equilibrium 3.00 2.50 rg 2.0D U) .0 U') U') 1.50 Sample Location: Mesa Trail 11+50 Sample Description: Gray Sandy Clay Notes: PA 21 0% Retained on 3/4 inch sieve Test Method: Cal-Trans Test 301 R-Value By Exudation 80 - :: 60 I 50 €1) 40 a) U i-1.00 CD > 0 0 050 0.00I"'''I'''l''''!' II' 0.00 0.50 1.00 1.50 2.00 2.50 3.00 Cover Thickness by Expansion Pressure (ft) 'Ti 800 700 600 500 400 300 200 100 0 Exudation Pressure (psi) GeoSoils, Inc. 72°F ric? 5741 Palmer Way Carlsbad, CA 92008 \... V) Telephone: (760) 438-3155 Fax: (760) 931-0915 R - VALUE TEST RESULTS Project: DR HORTON Number: 5981-E-SC Date: Jan-10 Figure: 1 Expansion, Stability Equilibrium U, , 1.00 0.50 TEST SPECIMEN A B C D compactor air pressure PSI 350 350 350 Water äddéd % 4.0 5.0 6.0 Moistureat compaction % 150 16.0 17.0 Height of sample IN 2.47 . 2.5 2.52 Pry density . PCF 115.4 113.7 112.0 RValuebyéxudaton 85 76 63 R-Value by exudation, corrected 85 76 63 Exudation pressure PSI 4.18 320 237 Stability thickness . FT 0.19 0.31 0.47 Expansion pressure thickness FT 1 0. 171 0.101 0.00 DESIGN CALCULATION DATA SAMPLE INFORMATION Traffic index, assumed .5.0 Gravel equivalent factor, assumed• 1.5 Expansion, stability equilibrium 0 R-Value by expansiOn NA RValué by exudation 74 R-Value at equilibrium 74 Sample Location: Mesa.Trail 11+50 Sample Description: Gray Brown Sandy clay (WI Lime) Notes: 3% Lime COntent (Calcium Oxide) Robertson Ranch PA21 Test Method:. Cal-Trans Test301 R-Value By Exudation 100 90 80 = 70 ------ - - ---- - 60 a' :3 50 40 30 20 0.00 I I I I I I I 0.00 0.50. 1.00 1.50 2.00 Cover Thickness by Expansion Pressure (ft) 10 800 700 600 500 400 300 200 100 0 Exudat!on Pressure (psi) GeoSoils lnc R - VALUE TEST RESULTS 5741 Plmér Way Project: DR HORTON Carlsbad, CA 92008 . Telephone: (60)438-3155 Number: .5981-E-SC Fax:. (760) 931-0915 Date: .Feb-1.0 Figure: 2 Eades &trimesASTM. C'977 %Lime 0% 78 25/o . . 12.2.. 2.4 4% 1245 1Z0J -1•L6t- .•' •:. The oppoitunity to be f service -•' is questions, kindly call Very' truly yours ' ••:' .. . you have any 'P. S01LS,.ASPHALT- :,DE.SIGN TECHNOLOGY 1s La IeI Ic • Ma I I I ,..---PROFESSI ONAL PAVEMENT ENGINEERING A CAUFORNIA CORPORATION February .1, 2010 GeosOi1, qie, 5741 Palmer Way Suite D. Carlbad, CaJiforiii'a 92008 Dear Mr. Crisman: Proj ect No. 36.725 Testing of the. bulk soil sample delivered to our labrato.iy has been, completed. Results are as follow•s Reference: 598 i-E-SC; Dr. PA2I Mesa Trail 11+50 RCE 30659 SR1i1:nui, W.O. 5981-E-SC Figure 3 2700 S. GRAND AVENUE SANTA ANA, CA: 92705-5404 .(7.14) 5463468 • FAX (714) 546-5841 INFO@LABELLEMARVIN COM Prime Testing, Inc. 41695 Elm Street Ste 201 Murneta CA 92562 ph(95i)894-2682 • fx(951)894;2683 Work Order No.: 10A4200 Client: 'GeoSoHs, Inc. Project No.: 5981-'E-Sc Project Name:, DR Horton, Robertson Ranch PA21 Report Date: February 10, 2010 Laboratory Test(s) Results.Summary Thubjt soil sample was processed in'accordancè With Californ.Test Method. CIM 643 and tested fbi Sulfate Content (CTM 417). The test results follow: Sulfate Sulfate Sample Identification Content Content. (mg/kg) (% by wgt). Mesa Trail 11+50 390 0.039 ND=No Detection We appreciate the opportunity to serve you Please do not hesitate to contact us with any questions or clarifications regarding these results or procedures. L i) /L : (' ..... Ahmet K. Kaya. Laboratory Manager wwwpiirnetesting.cpni W.O. 5981-E-SC Figure 4 APPENDIX REFERENCES California Department of Transportation, 2006, Caltrans, Standard specifications, May printing. Carlsbad, City of, 1993, Standards for design. and construction of public works improvements in the City of Carlsbad. GeoSoils, Inc., 2009, Pavement design report, Wind Trail Way (Stations 16 to 18 +76 ), Alander Court (Stations 12to 19), and Cascade Street (Stations 12to 15), portion of Planning Area 16 of Robertson Ranch, Carlsbad, San Diego County, California, W.O. 5949-E-SC, dated December 2. 2008, Memo, Clarification of pavement design report, Glen Avenue, Station 26 +30 to the Cul Du Sac, Robertson Ranch East Village, City of Carlsbad, San Diego County, California, W.O. 5353-B-SC, dated October 31. 2007a, Pavement design report, Improvement of "loop" roads, Wind Trail Way, Glen Avenue, and Hilltop Street, Robertson Ranch East Village, City of Carlsbad, San Diego County, California, W.O. 5384-E-SC, dated October 31. 2007b, Pavement design report, Improvement (widening) of College Boulevard (Stations 103 to 11820), and Cannon Road (Stations .127 to 159), City of Carlsbad, San Diego County, California, W.O. 5354-E-SC, dated September 18. 2007c, Review of R-value data, Improvement (widening) of College Boulevard (Stations 103 to 118 0), and Cannon Road (Stations 127 to 159+00 City of Carlsbad, San Diego County, California, W.O. 5354-E-SC, dated September 4. 2004a, Revised pavement design report, College Boulevard Stations 78 to 101, Reach C, Calavera Hills II, Carlsbad, San Diego County, California, W.O. 4028-E-SC, dated April 19. 2004b, Revised pavement design report, College Boulevard Stations 101 to 118-,. Reach B, Calavera Hills II, Carlsbad, San Diego County, California, W.O. 4029-E-SC, dated April 23. 2004c, Third revision of pavement design report, Calavera Hills II, Cannon Road Stations 125 to 164, City of Carlsbad, San Diego County, California, W.O. 4030-E-SC, dated May 14. Mirafi, 2005, Benefits of subgrade stabilization using geosynthetics versus lime treated soil, Technical Note TN7LIME-01 05, dated May 1. GeoSoils, Inc. National Research Council (U.S.). Transportation Research Board, 1987, Lime Stabilization, State of the art Report 5, Committee on Lime and Lime-Fly Ash Stabilization, last modified September 25, 2009. NEWCON90, 1991 Computer program for the determination of asphalt pavement sections, dated April 30. State of California, Department of Transportation, 2009, Guide for designing subgrade enhancement geotextiles, dated April 28. State of California, Department of Transportation, 2008, Highway design manual of instructions, dated July 1. 11 W.O. 5981 -E-SC Page