Evaluation of the Self-Boring Pressuremeter in Sands.
Abstract
Eleven SBPT's in Ticino sand (TS) whose results together with those of the first test run on Hokksund sand (HS) are summarized on Table 1. All these tests have been performed using the ideal installation procedure. It has been discovered during the 1-D stressing that the three Caskometer strain arms are subjected to a pronounced mechanical compliance which is responsible, according to the writers opinion, for the following highly undesirable phenomena: (1) The observed lift-off pressure (p sub o) does not correspond to the applied horizontal boundary stress, sigma sub o. The difference (p sub o - delta ho) increases with an increase of relative density (DR) and with the magnitude of the stress applied to the specimen; (2) The lift-off of the three strain arms does not occur simultaneously. In view of these compliance problems, a number of simple checks on the Camkometer strain arms have been performed. These results are summarized. It was decided to expand the present research programme with a number of flat dilatometer tests Marchetti 1980 performed in the CC. The aim was to investigate the reliability of this device to deliver information about the existing in situ lateral stress, sigma sub h sub o. The results of these tests are summarized. The tests have been performed simulating field conditions; the dilatometer has been inserted into the CC specimen after 1-D stressing and then the DM expansion has taken place. A series of shear tests on both TS and HS have been performed using the Bishop type ring shear apparatus with the aim of assessing the constant volume angle of shearing resistance, phi prime sub cv of the test sands.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1985
- Accession Number
- ADA157842
Entities
People
- M. Jamiolkowski
- R. Bellotti