76_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011

76_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011 - o )...

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X17 :'t 2/\ .. .. f "- . I . -- - - -- - - ::::::- - - - - - . -- --- 0 - .. . .. on xA F .. ~ ~h; On (1bfin.J) SOO 2 , 6 8 10 Loose, unifonn rrne sand above waItT table c '" 2.79 kPa 6 '0 (. '" 32.1 Q r" 0.9992 ~ 30 - . 4 .S " ~ , .. ~ 20 ; , , 10 0 0 0 10 20 30 '0 SO 60 70 0. (kPa) Iowa Borehole Shear Test (BST) o Handy, 1982) o Insert SST device into borehole, expand against borehole sides with constant pressure, and then pull to measure shear strength. o Run tests at different expansion pressures to estimate Mohr-Coulomb failure envelope. o Plate size can be changed for ,..... lower/higher shear strength. o Test is basically drained if run slow enoughUudge by results). Pore pressure escapes quickly. Iowa Stepped (K
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Unformatted text preview: o ) Blade o Developed by Dr. R.L. Handy at Iowa State University (figure from Bowles, 1996) o Use to estimate lateral stress and coefficient Ko. o Measure pressure against blade at same depth with 4 different blade thicknesses and extrapolate to zero thickness. Membrane size -1.5" diameter. o Very susceptible to damage. Works well in soft clay. '" lOOmm p:r Pre5surc scnMlr (0 Io.!. . ~ 10 v 8-,-I-,.1 CO) 3 400f------<-2--,f---!'. ..,''''.5~--:'f--~7;';.S+8 r,rom ~ ~ 100 ~ % ~--- H _-.----70 _---.---60 _----___ p, .. S6 kPa 50 150 1\, = y;: P.-II K. _ /'v-u (a) Typical log. log data plot. (b) Dimensions, mm....
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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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