The design and field evaluation of a new dual pressure and temperature tapered probe

The T2P is a new penetration device that measures temperature at its tip and pore pressure at a point just above the tip and at a second location near the base of the probe shaft. The main purpose of the T2P, recently designed and fabricated at MIT, is to reduce the time required to accurately estimate in-situ pore pressures (u₀) of marine sediments. This goal will be accomplished by using the two-point matching method (Whittle et al., 1997; 2001) to compare measured partial T2P dissipation records with theoretical dissipation curves, derived using the Strain Path Method (Baligh, 1985) and total or effective stress soil models. A four-day field program was conducted at a test site in Newbury, Massachusetts to evaluate the design and performance of the T2P. The field program was designed with the intention of performing a number of dissipation tests at a series of elevations within a deep deposit of Boston Blue Clay. Twenty-four hour operation of the data acquisition system allowed overnight dissipation data to be collected. Two boreholes were used to collect a total of eight pore pressure dissipation records, whose length ranged from 0.74 to 19.74 hours. It is not clear if any of the eight monitoring periods were of sufficient duration for full dissipation to occur; it is suspected that measurement periods longer than 20 hours are required to allow complete dissipation around the probe, which is in agreement with previous research (Varney, 1998). The field test data was used to estimate u at various locations within the clay, using the inverse time extrapolation method and the two-point matching method.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Civil and Environmental Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Chartier, Matthew G. (Matthew Garth)

Advisor dc:contributor.advisor

• John T. Germaine.

• Civil and Environmental Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/31153

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/31153