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ff-7•r <br />Table 4.3. Effective roadbed soil resilient moduiut values. M (pal). that may be used In <br />• the design of flexible pavements for low - volume roads. Sug values <br />depend on the U.S. climatic region and the reletivequality of the roadbed soil. <br />• <br />Retative Quality of Roadbed Soil. <br />U.S. <br />lrif r:tsoo <br />- • <br />Region Very Poor Poor <br />Fair Good Very Good <br />3 2.800• 3.700 <br />5.000 ' 6,800 9100 . <br />d 2.700 3.400 <br />a SOO 5.500 7w1W <br />in 2.700 3.000 <br />4.000 4.400 5.700 <br />IV 3.200 4,100 <br />5.600 7.900 11.70+0 <br />V 3.100 3.700 <br />6.0Q0 S,Oti�3 B,200 <br />vI 2=0 Z -, :00 <br />_. 00. 4.504 <br />♦w's.'�w .t��. ZJ::t� -s., !!loo'.ittts �: �t <br />.-. ' - ..n• - <br />` of roadbedsoii d.—:rioped for <br />dCst;n= Louldzar D. used in lieu of <br />(SeL 1 2 31. ' <br />1- pro »= t►tscri' d _ <br />;: : '•' <br />'�LCSW d 1gn. requirc sr_ used w c cr acd <br />i17t1 tI'.e computaziQttsl c jjri in Sable 4.4 sae the <br />Tar primary design rcgtir = =ts for a <br />dt L' art c STaphs for ,.,:zip:biiity ( 2 d1 <br />• surfac. roads (n) include: <br />ruzdag {Fg 4.3). An exatapie of t;fe application of <br />certain steps of this procedure is presented in Table <br />45 <br />• <br />(3) seasonal resilient moduli of the roadbed soil <br />(Section 2-3.1 or general criteria in Section <br />4. 1.1 maybe used if bctt.. information is not <br />available), <br />the predicted future traffic, w (Section <br />21.2), for the period, <br />(?) the I=gttss of the seasons (Section 2.3.1: or <br />criteria in Section 4. 1.1 may be used if better <br />iaformatica'is not availabk), <br />(4) elastic modulus. E (psi), of ats,reg to base <br />layer. (Sec :ion 2.3.3), <br />,:) elsstic'moduWs, E � (psi), of <br />iunb:tse yer kSecnon :._.3). <br />,;:si-n servie bi!'ity lass. -PSI (Sec"on <br />2.2A) <br />) <br />(7) allowable rcttinr,, RD (inches). in scrfa_e <br />la)er (Section 2.3.2), and <br />t1 'A 4� 71 'ON <br />Step l: Select four levels of eggrcgate case thickness, <br />D w hich should bound the nrobabIt solution. For <br />this, four separate tables, identical to Table 4.4. should <br />be prepared. finer each of the four uzial base thickness, <br />D in the uppe. left -hand corntr of cub of the four <br />tables (D = 8 inches is used in the example). <br />Step 2: Enter the design scrviceability loss as well as <br />the allowable rutting in the appropriate boxes of each <br />of the four tables. <br />Step 3: Enter the appropriate seasonal resaitnt <br />(- 'astir) mod uliof the rosdbcd( S0andtruet:rgrtgate <br />base E (psi) in Columm 2 and 3, r:s:ee- <br />ti. -e:)', of Table 4.4. The has rnedcttu Va:::es Mal be <br />prJeort10n.:! to t'1c resii:enI u of t` = r01C <br />sn, d.::AC a c. t mac:'. so n. A COR :,� =1 %5r:°. vt <br />Ps. •.:: s ,:_c.i to t`.., exaMT .'_:oac::.. _ a <br />ot ti�'�:CL'2tC:Sn.. :a:;:s21r1:! <br />con. .2:cnt t!n: : ne-_$ of s;S bt ai: t%.:t ;! =i t.t'h. Null <br />provid;: some sh-cid.*. Cainsttircn tro. ^. ^c::a!rrozf urc <br />cf (Crts). <br />'UoiiPt)ossw Siam U1aiS4n <br />Revised March 2010 (PR06) Attachment 2.05.3(3) -8 -12 <br />_IAIJ/ I ' I 0 nn7 •n7 'lvui <br />