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HomeMy WebLinkAboutSUB200900161 Study Road Plan and Comps. 2012-05-09 • !.w A < , GEO-TERRAIN ORGANIZATION , INC. "Your Goals Founded On Our Information Fredericksburg, VA Office: 540-834-7134 • Fax: 540-720-9006 • Richmond, VA Office: 804-662-0170 May 9, 2012 Beights Corporation Attn: Justin Beights 5380 Golf Drive Suite 103 Crozet. Virginia 22932 RE: California Bearing Ratio Test Results Old Trail Block 3b Albemarle County, Virginia GTO Project No.: 12G-111-008 Dear Mr. Beights: As requested. Geo-Terrain Organization, Inc. (GTO) has obtained representative samples of pavement subgrade soils at locations staked by the civil engineering consultant and contractor at the above referenced project. Samples were where feasible based upon previous investigation and California Bearing Ratio (CBR) tests were performed to verify the required pavement design thicknesses for the proposed development. The full distances of roadway included within the Old Trail Block 3b project limits are part of this analysis. Pavement thicknesses for the roadway were established based upon the traffic count provided by the civil engineering consultant and laboratory testing performed on samples of proposed subgrade soils. The following results were obtained by performing CBR testing in general accordance with Virginia Test Method (VTM) 8. The soils on site generally classify as sandy silts.As tested,these materials have an average soil support values, confirmed by an average CBR value of 6.1. In paved areas,the soil up to six(6) inches below planned subgrade elevations for controlled fills should be compacted to ninety five percent(95%)of its maximum dry density as determined by VTM-1 (AASHTO T-99) Specifications. The final six (6) inches up to subgrade should be compacted to at least one hundred percent (100%) of its maximum dry density. Moisture contents of the subgrade should conform to the moisture specifications set in the VDOT Road and Bridge Specification manual. Any sidewalk,curb and gutter, and driveway areas should also be treated as above. • 205 Tyler Von Way-Suite 107, Fredericksburg, VA 22405 • 10404 Patterson Ave - Suite 201, Richmond, VA 23238 Beights Corporation Re: California Bearing Ratio Test Results Old Trail Block 3b May 9, 2012 Page 2 r The following recommended pavement section is based on the VDOT Vaswani design method for Secondary Road Pavement. using the above mentioned average CBR value of 6.1. This value should be representative of the soils that may be encountered at pavement subgrades. The resiliency factor for the soil,given by the site location in Albemarle County and soil classifications, is 1.0,and the thickness equivalency factor used is 1.67. The maximum design traffic volume is estimated to be 316 vehicles per day,one direction,for Mornington Lane, Mornington Court,and Mornington Place. This traffic volume was assumed to contain five(5)percent heavy truck traffic. Pavement Sections for Old Trail Block 3b, Mornington Lane, Place, Court: Asphaltic Concrete Surface Course, VDOT SM-9.5 2.0 inches Aggregate Subbase Course, VDOT 21A 7.0 inches i Subgrades that have been exposed to weather changes or disturbances should be scarified approximately six (6) inches and recompacted to 100% of Maximum Dry Density immediately prior to the placement of the aggregate base course. The roadway subgrade is also subject to proofroll utilizing a fully loaded tandem axle dump truck or similar pneumatic tire equipment to verify stability prior to the placement of the aggregate base course. Thank you for the opportunity to assist you in this capacity. If you have any questions regarding this letter, please do not hesitate to contact our office. Sincerely, ��K0 7:Z'oi Geo Sincerely, .-•�' '�n, Inc. C�L�'� O 9 • it • '-ter Fanara, P.0 -w GeotechnicalIte Engin ' ,p ,a, ' 'scmii Nvti, 'i C:/GTO Documents/GTO Geotechnical 2012/12G-111-008/BI3b CBR Letter 5-9 12.doc f Virginia Department of Transportation—Pavement Design Guide © 1996 (rev2000) Appendix IV Flexible Pavement Design Worksheet for New Subdivision Streets This sheet is intended for use and submission in conjunction with VDOT's Subdivision Street Requirements County N4a. '( Date: I /'— Subdivision Do U A p , .." Street Name ,group)Ain goo,4,1 Gtw. AfVN oty ii,s, /2ce. Developer /5r}HY Cop Phone: ADT Projected traffic for the street segment considered,as defined in the Subdivision Street Requirements. CBR0 Design CBR=Average of CBRT x 2/3 and modified only as discussed in the Pavement Design Guide. CBRT CBR value of the subgrade sample,taken and tested as specified in the Pavement Design Guide DME VDOT District Materials Engineer EPT Equivalent projected traffic HCV Number of Heavy Commercial Vehicles(e.g. trucks,buses,etc.,with 2 or more axles and 6 or more tires). %HCV Percentage of the total traffic volume composed of Heavy Commercial Vehicles. RF Resiliency Factor=Relative value of the subgrade soil's ability to withstand repeated loading. SSV Soil support value of subgrade(SSV=CBR0 x RF) DP Thickness index of proposed pavement design computed by the Conventional Pavement Design Method DR Thickness index required,based on Design ADT and SSV,determined by Appendix II. - i; `: :: �; -- <Ste `Z 'Determine:p0fig ""t.: - 'atep, etermme eslgct, T,;;. .:�„t...� . . R rt ���:.: .,. ru.,_ -. �;;•.�:, �:• .. •��; :�, �� '?��'�CBR, RF arid'SSV 'st'4"'�}�:? ADT 3 (6 Sample DBRT Resiliency Factor (RF) 1 # 1 Y• 7 Source Value %HCV= 100 x HCV x ADT) .57. #2 r• y- Table 1 /d or Z,O 20 x HCV Note:For #3 Appendix I %HCV>5%, # DME approved RF I 1a Note:For%HCV C 5%,use ADT EPT>ADT PP # For preliminary designs,use the lowest RF # value in the equation Design ADT T :' =•: ( Use greater of ADT or EPT 3r O CBRD x RF _ . ",;S5V M ( 444i ) x ( /° ) = 0 Step 3:-Pavement Design (Check appropriate box and show proposed pavement design below.) i (A) Limited to Design ADT S 400 -Show pavement material notations and thickness from Appendix IV Tables A and B. D (B) Show pavement section as developed in the Pavement Design Guide. DR = /0 v (See Appendix Ill for material notations and thickness equivalency values(a)). from Appendix 0 Description of Proposed Pavement Section Materialal/Notation ,/'n [ Thickness, h a l (a x h) /� � Surface 47 (01e. 5ry 7 r 2.0 l 61 3 W Base t► i " UA f 7`0 icc 2.v Subbase I Dp must equal or exceed the value of DR. D?= E(a x h)_ /d.3 26 BEARING RATIO TEST REPORT VTM-008 (2005) 200 2 160 - f-- 16 r :N Q 120 1.2 c :a i N d / = IY / I O a r H / / I 80 J 0.8 a f/j c a) o_ 40 — 0.4 I i I 0 0 0 0.1 0.2 0.3 0.4 0.5 0 24 48 72 96 Penetration Depth (in.) Elapsed Time(hrs) Molded __ _ Soaked CBR(%) _ Linearity Max. Density Percent of Moisture Density Percent of Moisture Correction I Surcharge Swell (pcf) 1 Max.Dens. (%) (pcf) Max.Dens. (%) 0.10 in. 0.20 in. (in.) (lbs.) (%) 1 0 105.9 99.8 19.0 104.7 I 98.6 24.2 6.7 6.5 0.000 10 1.2 -- _ 2 A — — .._ — — 3O Material Description Max. Optimum — — --- USCS Dens. Moisture LL PI (pcf) (%) Brown and Reddish Brown sandy Silt,trace mica and gravel ML 106.1 19.2 0 1 0 Project No: 12G-1 I I-008 Test Description/Remarks: Project: Old Trail Asphalt Coring 3a,b,Carriage Park, West End Square Std. Proctor Compaction Source of Sample: MorniDEpitli:ando*ation 10+25(Approx.) Sample Number: I Date: 5-9-12 BEARING RATIO TEST REPORT Geo-Terrain Organization Figure Moisture-Density Relationship Test Curve No.: 1 Project No.: 12G-111-008 Date: 5-9-12 Project: Old Trail Asphalt Coring 3a,b,Carriage Park,West End Square Source: Mornington Lane Station 10+25 Sample No.: I Elev./Depth: subgrade (Approx.) Remarks: MATERIAL DESCRIPTION Description: Brown and Reddish Brown sandy Silt,trace mica and gravel Classifications - USCS: ML AASHTO: A-4(0) Nat. Moist. = 18.5% Sp.G. = 2.65 Liquid Limit= 0 Plasticity Index= 0 % > No.4= 1.8% % < No.200= 75.9% ROCK CORRECTED TEST RESULTS UNCORRECTED Maximum dry density= 106.1 pcf 105.4 pcf Optimum moisture= 19.2% 19.5% 140 Test specification: I I ASTM D 698-91 Procedure A Standard Oversize correction applied to each point 130 J — - �— 120 I 100% SATURATION CURVES 1_ FOR SPEC. GRAY EQUAL TO. I I 2.8 2.7 a 110 1 l l —_ 2.6 1100 , I 1 1 90 1 I I 1 1 80 - J- - 1 1 I _ 1 I I 70 0 5 10 15 20 25 30 35 40 Water content, % Figure Geo-Terrain Organization Particle Size Distribution Report 000 S � o �op o . o f0 en N .- n \ ik it i ; ; 100 1I II II II R i! A g it I 1 I 90 1 1 CC L j z 50 w C a 40 30 20 i 10 „ .-i 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE - mm. %+3„ %Gravel %Sand %Fines 1 Coarse Fins Coarse Medium ' Floe Sift I Clay 0.0 I 0.0 1.8 2.4 5.5 14.4 75.9 SIEVE PERCENT SPEC.' PASS? Material Description SIZE FINER PERCENT (X=NO) Brown and Reddish Brown sandy Silt,trace mica and .375 100.0 gravel #4 98.2 #10 95.8 #40 90.3 Atterberg Limits #60 86.1 PL= 0 LL= 0 P1= 0 #200 75.9 Coefficients D90=0.4068 D85=0.2196 D60= D50= D30= D15= D10= Cu= Cc= Classification USCS= ML AASHTO= A-4(0) Remarks (no specification provided) Source of Sample: Momington Lane Station 10+25(Approx.) Depth: subgrade Sample Number: I Date: 5-9-l2 P PClient: Beights Corporation Project: Old Trail Asphalt Coring3a,b,CarriagePark.WestEndSquare G@O-Terrain Organization Project No: 12G-111-008 Figure BEARING RATIO TEST REPORT VTM-008 (2005) 200 2 1 I 160 — 1.6 - j N O_ i u 120 — I .- - ..---- 1.2 c N . zfr2 ce 0) c coO .J 80 -- 0 8 c m 1 40 — 0 4 - — 0 0 0 0.1 0.2 0.3 0.4 0.5 0 24 48 72 96 Penetration Depth (in.) Elapsed Time(hrs) Molded Soaked CBR(%) Linearity Max. Density Percent of Moisture Density Percent of Moisture Correction Surcharge Swett (pcf) Max. Dens. (%) (pcf) j Max.Dens. (%) 0.10 in. 0.20 in. (in.) (Ibs.) (%) 1 O 103.8 99.7 19.8 102.2 98.1 1 25.4 5.4 5.6 0.000 10 1.6 20 3 ❑ Material Description Max. Optimum — ---- — — USCS Dens. Moisture LL PI (pcfl (%) Brown and Reddish Brown sandy Silt,trace mica,clay,gravel ML 104.1 19.4 34 7 Project No: 12G-1 l 1-008 Test Description/Remarks: Project: Old Trail Asphalt Coring 3a,b,Carriage Park,West End Square Std. Proctor Compaction Source of Sample: MorniDBpithPlaob&taalion 10+00(Approx.) Sample Number: Date: 5-9-1 BEARING RATIO TEST REPORT Geo-Terrain Organization I Figure _ Moisture-Density Relationship Test Curve No.: 2 Project No.: 12G-111-008 Date: 5-9-12 Project: Old Trail Asphalt Coring 3a,b,Carriage Park,West End Square Source: Mornington Place Station 10+00 Sample No.: 2 Elev./Depth: subgrade (Approx.) Remarks: MATERIAL DESCRIPTION Description: Brown and Reddish Brown sandy Silt,trace mica,clay,gravel Classifications - USCS: ML AASHTO: A-4t5) Nat. Moist. = 21.1 % Sp.G. = 2.65 Liquid Limit= 34 Plasticity Index = 7 % > No.4= I.1 % %< No.200= 71.9% ROCK CORRECTED TEST RESULTS UNCORRECTED Maximum dry density= 104.1 pcf 103.6 pcf Optimum moisture 19.4% 19.6% 140 MI I ' Test specification: ASTM D 698-91 Procedure A Standard Oversize correction applied to each point 130 120 100% SATURATION CURVES — — FOR SPEC. GRAV. EQUAL TO: — 2.8 2.7 ;i 110 —,-_ 2.6 -0 1111\1141114111k1444. 40- 100 -- I 90 80 l ! 1 70 0 5 10 15 20 25 30 35 40 Water content, % Figure Geo-Terrain Organization Particle Size Distribution Report _ o00 � - < < s . ooa o� o < o co : 'u w `.�` It iR x # 7!I ' I ) I I I I I 90 1 80 70 w 60 Z LT_ z 50 - w U a 40 • 30 20 13 3 100 10 1 0.1 0.01 0,001 GRAIN SIZE -mm. +3„ %Gravel f %Sand %Fines - Coarse Fine 1Coarse' Medium Fine Silt 1 Clay 0.0 0.0 I.I 3.3 4.4 19.3 7 I.9 SIEVE PERCENT SPEC.* PASS? Material Description SIZE FINER PERCENT (X=NO) Brown and Reddish Brown sandy Silt.trace mica,clay, 375 100.0 gravel #4 98.9 #10 95.6 #40 91.2 AtterbergLimits #60 87.3 PL= 27 LL= 34 P1= 7 #200 71.9 Coefficients D90=0.3488 D85=0.2001 060= D50= D30= D15= D10= Cu= Cc= Classification USCS= ML AASHTO= A-4(5) Remarks (no specification provided) Source of Sample: Mornington Place Station 10+00(Approx.) Depth: subgrade Sample Number: 2 Date: 5-9-12 Client: Beights Corporation Project: Old Trail Asphalt Coring3a,b,CarriagePark,WestEndSquare Geo-Terrain Organization _ Project No: 126-111-008 Figure