Laserfiche WebLink
drainage blanket and toe drain be consvuc[ed. The plans call fora 6-inch diame[er pipe be <br />placed is the toe drain. We recommend that the pipe consis[ of perfora[ed PVC pipe meeting <br />the requirements for Schedule 5034 in accordance with ASTM. The free draining gravels to <br />be used in the toe drain should mee[ the specifications outlined on page 13-5-I1 of the <br />spe~carions for the toe drain materials. We would also recommend tha[ the same free <br />draining materials be aced for the drainage blanket. [t is our understanding [har Connell <br />Resourc.~ s. in Milner, Colorado, is presently produang a washed aggregate ma[erial which <br />would meet this specifica[ion. The plans ~ll for the drainage blanke[ to be a minirnum of 1 <br />fop[ thick: however, we would recommend tha[ the drainage blanke[ be a.minimum of 2 feet in <br />thickness. In addition, we recommend that [he toe drain and drainage blanket be wrapped. <br />top and bottom, with Mira[i 140N or as equivalent product. The base of the embankmen[. <br />below the drainage sys[em should be underlain with Mvan 140N and no[ [he S(HIX. <br />a) ~ s[abiii[y analysis of the embankment structure has not been completed for this project. <br />Therefore, based on our conversa[ion with you. otu firm will complete a s[ability analysis for <br />this structure using SB-Slope and the slope configurations shown on the project plans. It is <br />our understanding that the fill materials to be placed in [he embankment will come From the <br />cu[ slopes being constructed For Haul Roads Y-B and Y-~. We will use [he [riaxial shear <br />strength information obtained earlier on these materials for [he embankment fill materials. <br />The results of the s[abili[v analvsis will be forwarded to your office as soon as [hev are <br />completed. <br />If you have any ouestions regarding IF[is~letter, our observa[ions or reeommendadons or iF we may be of <br />Further service, please con[act this office. <br />Sincerely, \aa~iuuwuum;tn~~ <br />NORTI-IWFSI;CQLO[~QBf~(t'J'~(~S, INC., <br />~, i <br />r^i~`-i <br />Brian D. Len. P.1.~-a; 2'~~"'°Q- r. <br />ice. ~ .: VC <br />,,~ ,... <br />• <br />lob No. 75•Z784 Nonnwes~ Coloraaa Cunsunants. lac. Page ' <br />