119_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011

# 119_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011 -...

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DF9 ~ 00 = 12.75" ID = 11.75" tWall = 0.50" As = 19.2 in 2 w = 65.4 pit D =35' 4. Find pile toe resistance: Soil properties: ell = 0°, 'Ysat = 105 pcf unconfined compression strength, q u = 1400 psf Assume FS = 3, GWT at soil surface example 2 - Driven Pile in Cohesive Soil (Clay): Determine the allowable (design) load for the steel pipe pile (XS) shown at right. Also, if the design load is later increased by 20 k, how much pile length must be added? 1. Determine cohesion: C u = (qu 12) = 140012 = 700 psf (= 0.700 ksf) 2. Find pile/soil adhesion: a = 1.0 + (0.7- 0.5 kSf>( 0.5 -1.0 ) = 0.90 (interpolate) 1.5-0.5 ksf C a = 0.90 (0.7 ksf) = 0.630 ksf 3. Find pile shaft resistance: f s = etA. :: {"O kS4 (same over length of pile) ( flO/ "). ,,/(~'\ ('3 r ,) = 1-1, (,0 k as = (f s As) = C a (1t8D) = O. 1.10 k~.f (1T') J'l. '} '/' I ) AS)II""t PlUG, !;E.D a, = (q, At) = qd1ts 2 /4) = b. ,U v-~ f (1T) (''l. -:, 'j" /1'),"/(+) l.h :: 5. S'1 k (usually small for clay, check this against shaft resistance) 5. Find pile weight: assume plugged below ground surface, use buoyant weight W = S'(w ) + Ow'
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Unformatted text preview: = (5')(65.4 plf) + (35'){65.4 plf + (105 pcf)[1t(11. 75/12)2/4]- (62.4 pcf)[1t(12.75/12)2/4J} = 327 Ibs + (35'){65.4 + 79.1 - 55.3 pit) :: 327 + (3S'){89.2 pit) = 3449 Ib (= 3.45 k) t,;e:FindUltimatePileCapacity: pu=as+at-w: "13.,"0'-5.s~-)."1Sk. ':. ~s.+ ~ ~. Find Allowable Pile Capacity: Pa = Pu 1 FS = ":) 5'. '+ /1: :l ~. ':l. k ~;t2. The Additional Load of 20 k will be carried by shaft resistance since the unit end bearing and end area will not change. P a =25.2+20k=45.2k ¢ Pu=FSP a = ,.0 (.,s-."J. v..)=-'1S,{. k. P u = as + at - W = t s 1tBD + tt At - [S'(w) + Ow'] ,-. .. ~ = (0."'0 k~.f) (1Y) (I').::''i',/~·'/(~) ({))" s.s~ 1<-(5' ( lS. ., ('It) I D (8,.1 fIt)] (, k.;'oool~) o = = ~. 1031>-4 ),5crk -O.311c.-t>·(:«('jl)): ~.OI411)· ~.JLk; I)~'b k 6t1.~' p'lk, 1't.-"Jt~ '5"') :.need h, c... Jd ~s-1S.:: 30'...
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## This note was uploaded on 02/10/2012 for the course CEG 4012 taught by Professor Staff during the Fall '08 term at University of Florida.

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