46_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011

46_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011 - a Z...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
p30 I av _ a(vv + V s ) _ a(eV s + V s ) _ av s v ae av s aso-- - -8-+ s-+- at at at at at at and since avs = 0 at and V s = V o = (dXdYdZ) where eo = initial void ratio and Va = the initial volume 1+e o 1+e o av ae (dXdYdZ) ae . .. . k a'u ( 1 ) ae then -0 = V s -0 = - and substituting Into (2) glves--,- = -- - (3) ot ot 1+e o at ywa Z 1+e o at the change in void ratio in (3) is caused by an increase in effective stress (with a corresponding decrease in pore water pressure) and for small strains may be assumed linearly related to the void ratio as: ae = -a,aa'z = a,au (4) substituting (4) into (3) we get ~ a;u = (~) ~u = m, au Yw a Z 1+ eo ot at where and av= coeHicient of compressibility m v = ( a v ) = coefficient of volume compressibility 1 + eo k _k(1+e o ) 2 finally we define: coefficient of consolidation = C v = - =--:"':=1 units (L fT) Ywmv Ywav so that: C v a;u = au which is Terzaghi's 1-D consolidation theory
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: a Z at a The above partial differential equation has been solved using simple boundary conditions and dimensionless parameters as follows: """,'.'."'."".".".','.,,," ,':,;i';););';'.;'.'.'.;'.;';';":,; ~~\~~~~::~~~;~~':~~~~n:.~~;~'~ \~\~ .~,., ...,;.,: . .,::~;.,: . .,:.~: . .,;.,~., .., T = cvt (H/NJ' where: U H N T t = a given average percent consolidation for the clay layer = thickness of the clay layer = number of drainage paths (= 1 or 2) (note that H/N = the maximum length of the drainage path) = a dimensionless time factor corresponding to the given U = time required to reach U...
View Full Document

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.

Ask a homework question - tutors are online