73_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011

73_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011 -...

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

View Full Document Right Arrow Icon
X14 WiT( to aata acqUISlllon equLpment ISmro Pneumatic H lubing r'""" r+- Dilatometer Test (DMT) Soundings o Developed by Marchetti in Italy, some research at UF by Schmertmann and Davidson. ASTM standard just approved. o Wedge penetration with membrane on side. Stop at test depth. Apply and measure pressure from surface. Inflate membrane to measure lateral stress, Po, and stiffness, (P,- Po) over 1.1 mm movement at center. Each test requires 1-2 min. Typical depth increment 20 cm (8"). o Undrained test in clays, drained test in sands. o Wedge minimizes disturbance of soil properties. Flexible membrane of diameter D I "mm I E E ,. " ~ +-PO tp, <- <- +- l.l~-,m",m"+--II<- ~ lifiolf t Flexible membrane v MUD or PEAT O.5h---,I,,-,i,,M.,.-,J,.,\;-f,--! 0.1 0.2 0.3 0.6 0.8 1.2 1.8 13 8 Malerial index / D 100 o Measurements in horizontal direction related to vertical direction based on horizontal vs.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: vertical stress and empirical correlation. o Soil type estimate based on 1 and Eo (really a function of permeability). o Correlate 1-0 tangent modulus, M, to Eo. o Correlations available for OCR, ~', and co. o Can measure pressure P2 at end of test when membrane returns to initial position - provides estimate of insitu water pressure. Repeated P2 measurements can develop a pore pressure decay curve for rough estimate of c. ... o Material Index = I D = (p,-Po) (Po- u o ) p-u o Horizontal Stress Index = K o := 0, 0 0, o Dilatometer Modulus ~ lED = E 2 = 34.7( p, - Po) I (1-~ ) o Good profiling tool. Very repeatable. Lots of data. Primary measurements are stiffness and lateral stress....
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