High Capacity Tensiometers: performance and behaviours

Joao Mendes*, Armin Jamali, Abdallah Najdi, Agostino W. Bruno, Pere C. Prat, Olivier Buzzi, Domenico Gallipoli, Alberto Ledesma, David Toll

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

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Abstract

High capacity tensiometers (HCT) allow the direct measurement of soil matric suction, and their major limitation is the occurrence of cavitation. In this paper HCT designs using different ceramic filters with varied air entry values (AEV), varied reservoir sizes, and different pressure transducers are assessed as to determine the impact that each component may have in the HCT performance. Moreover, the effectiveness of first saturation and resaturation processes is discussed in relation to the time required to prepare/recover HCTs. The results obtained with the different designs show that the measuring range is directly linked to the AEV of the ceramic filter and that the choice of materials used for the various components may affect the reliability of measurements in field installations if the thermal performance is not accounted for in the calibration procedure. The use of a 1hr high vacuum pre-stage followed by overnight water pressurisation at pressures equal or above the AEV of the ceramic filter was found to be the quickest process to fully saturate an HCT for the first time. While resaturation time for an HCT can be reduced to as little as a few minutes if the HCT is resaturated immediately after cavitation has occurred.
Original languageEnglish
Article number22001
Number of pages6
JournalE3S Web of Conferences
Volume382
DOIs
Publication statusPublished - 24 Apr 2023
EventUNSAT 2023: 8th International Conference on Unsaturated Soils “Towards Unsaturated Soils Engineering” - Milos Conference Centre - George Iliopoulos, Milos, Greece
Duration: 2 May 20235 May 2023
https://www.unsat2023.org/

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