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Low•vaf,;,,ne poac resign 11.79
<br /> Step 4: Enter the seasonal 18-kip ESAL traffic in DBS = DBS +(0.5 x GL)
<br /> Column 4 of Table 4.4. Assuming that truck traffic is
<br /> distributed evenly throughout the year,the lengths of whcr_
<br /> the seasons should be used to proportion the total
<br /> rro;erted 18-kip ESAL traffic to each season. If the GL =total estimated aggregate(gravel)loss(in
<br /> road is load-zoned (restricted) during certain critical inches) overt.e perfirmance period.
<br /> periods, the total traffic may be distributed oniv
<br /> among those seasons when truck traffic is allowed. If, for z-amplc, the total estimated gravei doss was 2
<br /> (Total traffic of 21,00 18-1:1-ip ESAL applications and inches and the averag:base thickness req,.L ed was 10
<br /> a seasonal pattern corresponding to U.S. Climatic inches.the;resign thickn•ss of the aggregate base layer
<br /> Reion III was used in the example in Table 4.5.) would be
<br /> Step 5: Within each of the four tables,estimate t.5e DBS = 10+ (0.5 x 2) = I l inches -
<br /> allowable 18-kip ESAL traffir for each of the four
<br /> seasons using the serviceabI:ire-based nomograph in Stepp: The final step of the design chi n procedure
<br /> Figure 4.2, and enter in Column 5. If the resilient for aggregate-surfaced roads is to convert a portion of
<br /> modulus of the roadbed soil(during the frozen season) the aggregate base layer thickness to an equivalent
<br /> is such that the allowable traffic exceeds the upper thicYn-ss of subbase material. This is =Om' plished
<br /> limit of-i a nomograph. ass�fine a practical value of With tue aid of Fig- re 4.5. Select the final base
<br /> `uU.nvG 18-kin ESAL. t.-ic�.ess dc-ired.DBS,(6 incites is usr:d in the exunple).
<br /> Dra;v a Lnc to he inu' "mr itUt s o:the$= ase
<br /> „tL*-P is % IIL:i s'ach c-The four'.:.�b*,=.CSZ:.^..3'.::me, �:.a'�s.:.i� �.4.�{}�}t?S? IS ���a.^^ Y1".:�.>C I. 4:0
<br /> 1L` ac Y:w-for �sCb Lei *-ue �; ZC'055 .�^.iyEWCU£.n L"C ZC,R_ C=M i. ,11i..M2 to :y.0
<br /> �sonz-L:sW...w':;r�aim 2-�c.S:.:.Itr3 :.^J^_'yi.'J21217.'2 c� SCtl'.2L'.�CII S^_. :}3s.'. '�+^.2C=:.L"..4"�.- ,.�5; Da�►4.�e{,�- ;rd= 6
<br /> ?�C £Ili^. In _:pit" n T. Igis Il, it dig �L'C `.:.-.1 t.b..i:. sue 3: in the Z, �9 w.":L�7'a�yf'YI-he
<br /> » r:52i enI d, n -t.w.r ,3
<br /> ,:o'ulus of tn:roadbed toil is such tIL3L Lie aallowab:z dnC mc'-= s r~i C .a,_,.;i.e:;3 .Ers _0 {�psi
<br /> :tz upper Emit of .;e nomOL-Taah in the e.,arnp:e), drt:=iine the a quip d sub�e
<br /> thickness, DSB(8 incases).
<br /> assume z pn.,:.trial valise of 600,000 18-lip ESAL.
<br /> Step 7: Compute the seasonal damage values in 4.2 DESIGN CATALOG
<br /> each of the four tables for the semiceabihay criteria by
<br /> dividing the projected seasonal traffic(Column 4) by :e purpose of this Sectic • is to provide the user
<br /> the allowable traffic in that season(Column 5). Enter %ith a means for identifying reasonable pavement
<br /> these seasonal damage values in Column 6 e f Table 4.4 structural designs suitable for low-volume roads.The
<br /> corresponding to serviceability criteria. Next, follow catalog of designs presented here covers aggregate-
<br /> these same instructions for rutting criteria,i.e.,divide surfaced roads as well as both flexible and rigid
<br /> Column 4 by Column 7 and enter in Column 8. pavements. It is important to note, however, that
<br /> although the structural designs presented represent
<br /> Step 8: Compute the total damage for both the precise solutions using the design procedure described
<br /> seniceability and rutting criteria by adding the seasonal in the previous section,they are based on a unique set
<br /> damages.When this is accomplished for all four tables of assumptions relative to design requirements and
<br /> (corresponding to the four trial base thicknesses), a envirorimcntal conditions.The followi gspecifIcassump-
<br /> graph of total damage versus base layer thickness tiors apply to all three types of structural designs
<br /> should be prepared.The average base layer thickness, considered:
<br /> DBS, required is determined by interpolating in this
<br /> trash for a total damage equal to 1.0. Figure 4.4 (1) All designs are based on the structural
<br /> pro,6lde�, an example in which the design is controlled rceuircmcnt for one perf"orrnance period,
<br /> by the sen•;ccabdav criteria: DBS is equal to i U tncl;es. rerard!.ss of the tie• ;inten-al.T`;e range of -
<br /> �It^ ti' l is base la'. (:.. (rat•� !;\ !S for Ills h.X lb!e any r1C' ra\e-
<br /> .'1. :CS IJ 1',tl%P—I_,0,Uu'Q ^.Y 1,C0;)
<br /> b_ us:d for C :S1�n l: t:1C �".
<br /> ~- � C: mil( d)i lam- '^, ���.•\1_ .1,^^�.�1(it�,^.S. �.:: CtaU\51�.�
<br /> t;o e% traU1C !Or a CrC ..Ic-
<br /> l. ( the desi n t^ d!el
<br /> ." ;c}.nes5 a ;r- S.,;•.:ce;i ro.:d des;fir. 1; be:`,\ecr. IU,GU'J and
<br /> uslr." the follo\\Ing equation: IUU,COJ i6-yip CS:\L appllcauons.
<br />
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