Journal Published Online: 01 September 1987
Volume 10, Issue 3

Determining Preconsolidation Stress and Penetration Pore Pressures from DMT Contact Pressures

CODEN: GTJODJ

Abstract

Over recent years, several geotechnical explorations in clay deposits have shown the flat dilatometer test (DMT) to provide reasonable estimates of in-situ overconsolidation ratio with depth. Why should the horizontal stress index (KD = initial contact pressure minus hydrostatic pressure normalized to the effective overburden stress) show an empirical trend with over consolidation ratio (OCR)? It is postulated that, since the closing pressure and contact pressures are nearly equal, the initial contact pressure in clay is an approximate measure of the total pore pressure induced during penetration of the dilatometer blade. Published data from a clay site tested by a special DMT having a pore-pressure sensor, as well as piezocone/dilatometer data from seven other sites, support this hypothesis. Since the pore-pressure response of clay is influenced by the in-situ OCR, the initial effective DMT contact pressure can be used to profile the stress history.

Author Information

Mayne, PW
Law Engineering Testing Company, Washington, D.C.
Pages: 5
Price: $25.00
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Stock #: GTJ10947J
ISSN: 0149-6115
DOI: 10.1520/GTJ10947J