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HomeMy WebLinkAboutSUB200500186 Calculations Road Plan and Comps. 2005-11-11 . 4 Nam, 'Vv Virginia Department of Transportation-Pavement Design Guide C 1996 APPENDIX V - Sample Pavement Design A two lane road is proposed for construction in Prince William County, east of I-95, and will sustain a traffic count of 2500 with a growth rate of 3%, based on a September 1995 traffic count. Heavy commercial vehicles account for 6% of the traffic volume. Construction is expected to be finished in 2003. Soils tests yielded a classification of A-5 with 45% sand with no mica and a Design CBR of 6.3. The following designs might be considered. Compute Design ADT=Present ADT x [1 +(GR.)]" Since %HCV>5%, compute EPT and substitute result for the "Present ADT" • EPT=2500+20 [2500(0.06- 0.05)] =2500+20 [25 ] =3000 .'i USE Design ADT= 3000 [ 1 +(0.03)](10+2003.1995) = 3000 [1.03)18= 3000 [ 1.70] = 5100 ADT Compute SSV from Equation 1 SSV=6.3 x 2.5 (ref. Table 1)= 15.75 Required Design Thickness Index(DR)from nomograph,Appendix II, is 18. - 25.0 - 24.0 30,000 - 23.0 20,000 10,000 - 20.0 - 19.0 30- �-...-. i" ' *- 18.0 - _. -- -- 4,000 — 17.0 _ 3,000 - 16.0 12-- 2,000 -- 15.0 11- 10-- 1,000 - 14.0 9 800 — 13.0 8— 600 7— -- 12.0 6-1 400 11.0 5- - 10.0 4- -_. 300 3— 9.0 2- 200 — SSV 100 i0..,-- 8.0 Scale 50 — 7.0 Design ADT -- 6.4 Scale -- s.o DR Thickness Index Scale (Sample pavement designs appear on the next page.) R . Nov 23 COMMlJl111 . ...r.. ...W e. . .. r Virginia D. ent of Transportation-Pavement Design 41 •e ® 1996 . Appendix IV Flexible Pavement Design Worksheet for New Subdivision Streets This sheet is intended for use in conjunction with VDOT's Subdivision Street Requirements County .lase_ -R_i -lir.. Date: t i / i i /0 Subdivision1--i - 0t L A G, 6T �.s'T 1.1 D-r C;e_o vl�.. Street Name t N L._A rti ___. Developer °moo 1`V-t..TE—t--°l - 1Z- Phone: or/ t _ 15°t t ADT Projected traffic for the street segment considered,as defined in'the Subdivision Street Requirements. CBRD 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=CBRD 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. Step 1: Determine Design ADT< Step 2: Determine Design Values ADT Co© CBR, RF and SSV Sample CBRT Resiliency Factor (RF) %HCV= 100 x HCV_ADT # 1Source Value EPT=0.20(%HCV x ADT) # 2 Table 1 or # 3 Appendix I 20 x HCV Note:For # DME approved RF Note:For%HCV S 5%,use ADT %HCV>S%, # i EPT>ADT For preliminary designs,use the # 0 lowest RF value in the equation Design ADT=greater of ( �� CBRD x RF = SSV ADT or EPT ( ) x ( 1 ) = -S Step 3 Pavement Design (Check appropriate boxand show proposed pavement design below) ❑ . (A) Limited to Design ADT s 400-Show pavement material notations and thickness from Appendix IV Tables A and B. ❑ (B) Show pavement section as developed in the Pavement Design Guide. : DR Si (See Appendix III for material notations and thickness equivalency values(a)). i from Appendix II • Description of Proposed Pavement Sectio \----- Material Notation Thickness,h__. a (a x h) 1 Surface j M-- Z.Pc el i.. .C... OA- i— 2 iki ,2.26. 4, S Base /(177 . -r-fi'i_ -1 G ►lA ©46 . . Subbase A-,--1-1}} Ca = (0 DP must equal or exceed the value of DR. DP=E(a x h)= 0 il i pis ---c '21 MA-sc44 -rvIC k-.Sc-fio,.D , Virginia D . • ent of Transportation-Pavement Design %= r e ® 1996 Appendix IV Flexible Pavement Design Worksheet for Yew Subdivision Streets This sheet is intended for use in conjunction with VDOT's Subdivision Street Requirements County Date: i / t 1 /n5 Subdivision -4- �y ►-1�.4 C� AT 4-E*-31-r�O.T Street Name t t4 A 1_ c.N Developer �o r� 1-�t`-,1 Phone: 07 - 1set ADT Projected traffic for the street segment considered,as defined in'the Subdivision Street Requirements. CBRD 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=CBRD 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. Step 1: Determine Design ADT` Step 2: Determine Design Values ADT Co© CBR, RF and SSV %HCV CBRT ^ Resiliency Factor (RF) %HCV= 100 x HCV_ADT # 1 Source Value EPT=0.20(%HCV x ADT) # 2 Table 1 or # 3 Appendix I 20 x HCV Note:ForDMEPP approved RF # Note:For%HCV S 5%,use ADT %HCV>5%, # EPT>ADT For preliminary designs,use the # lowest RF value in the equation Design ADT=greater of CBRD x RF = SSV ADT or EPT ( ) x ( I ) _ Step 3 Pavement Design(Check appropriate box and show proposed pavement design below.) ❑ . (A) Limited to Design ADT 5 400-Show pavement material notations and thickness from Appendix IV Tables A and B. ❑ (B) Show pavement section as developed in the Pavement Design Guide. DR 6 (See Appendix III for material notations and thickness equivalency values(a)). i from Appendix II Description of Proposed Pavement Section Material Notation Thickness,h a (a x h) Surface S M 2 �, '�Oie l.-._ RI 2125 4. s Base �C Ptd Z1 CQ tt`I © �, 3 . Subbase ,�l;-f-} . Com . l C? ° e 4l ° 'y ° D must equal or exceed the value of D . DP= ( )_ Nuv1 -j 2005 21 COMMU NIr_y DEVELOPMENT Virginia Department of Transportation—Pavement Design Guide C 1996 APPENDIX V- Sample Pavement Design A two lane road is proposed for construction in Prince William County, east of I-95, and will sustain a traffic count of 2500 with a growth rate of 3%, based on a September 1995 traffic count. Heavy commercial vehicles account for 6% of the traffic volume. Construction is expected to be finished in 2003. Soils tests yielded a classification of A-5 with 45% sand with no mica and a Design CBR of 6.3. The following designs might be considered. Compute Design ADT=Present ADT x[1 +(GR.)]" Since %HCV>5%, compuleEPZ and,jtbjtitute result for the "Present ADT" • EPT=2500+20 [2500(0.06- 0.05)] =2500+20 [25 ] =3000 .'. USE Design ADT= 3000 [ 1 +(0.03)](10+2003-1995) = 3000 [1.03]18= 3000 [ 1.70] = 5100 ADT Compute SSV from Equation 1 SSV=6.3 x 2.5 (ref. Table 1)= 15.75 Required Design Thickness Index(DR)from nomograph,Appendix II, is 18. • — 25.0 — 24.0 30,000 — 23.0 20,000 10,000 — 20.0 30-- — 19.0 112 — 6 ,11 )' 18.0 1 —•-- --- �^^ 4, -- 17.0 13— 3,0000 -- 16.0 12-- 2,000 -- 15.0 11-- 10— 1,000 -- 14.0 8-- 800 --- 13.0 8— _ 600 -- 12.0 6-- 400 -- 11.0 4—~ 900 -- 10.0 3-- 2— '— 200 -- 8.0 --__ 1-- SSV 100 – 6.0 Scale 50 -- 7.0 Design ADT -- 6.4 Scale -- s,o DR Thickness Index Scale (Sample pavement designs appear on the next page.) 23