Question

A 5-ft fill is proposed to level a site. This fill is to be 7.5- acres in area. - -- -ts'. FicL GW 8-117 pep CH - FA Cury ca soops cas 0.01 -0.03 Tom C 0. 0 Belloopst BEDRock a) How long would you expect the consolidation settlement to take at this site? (10 pts) b) To get this consolidation down to 1 year, how far apart would you design to put your wick drains? (10 pts)

Answer 1

Data: Curen +5 Area = 4.50 cu. = 0.01 y day ca soost CR = 0.01 hey' = ||3pcf Sci = 1100bsf Bed Rock C = 0.03 ft/ day the Increase in stres (AO) = 11785 ar'= 585 psf ! The Initial effective strus Cool before placing - fill = rxh = 113 x 3.5 I a center of day Tool= 395.5 pst To = 395-8 psf the primary / Final Consolidation settlement is given by (Sf oe) st Alt Gr Sf - HCc logo out T ite Lood Final effective stress of' = tot sol = 395.5 + 585 O = 980.568 Note: As the final effective stress is bus than the bre-consolidation prus Cow = 1100 pet I it is a Over-consolidated soil henie use Recompression indix "ca & st = 7x0.01 lego 198015 90 395.5 J 1 + 1,5185 SH = 0.01096m | Pamary settlement to get loi Initial rod sato ung the relation Ird = arw I take le=2.75 L ite I 8=62.4 . = 113 = 2.758 62.4 -1.8185 Hlo

Time at which expect settlement occus I U = 100% (2) Degree of consolidation =100%, For u > 60% Time facto. = 1.781 - 0:937 log. [wo - %] For ggt. Albrocimal y ty = 1181 con olidation u=99%. I. thing the relation to Cut I where Co Coefficient of Consolidation d = t for double drainage P = It for single drainage = 1781 = 0.03 Atbay xt For it gat. consolidations t = 2908.97 days to ocau. So for achieving 100% consolidation take infinitely long time. 2 To acheive this in Year: during the selation I some dr degree for of consolidation & 2 290897 - 72 365 Joc = 2.479 E ~ 25 A

Honu Tarsft F drain day Vuoi 2.5 ft Place the the the top same drain airft above and belour of Clay Layer to achieve degree of Consolidation of gg.%.