ABSTRACT
The paper addresses the problem of indirect and direct measurement of negative pore water pressure. Indirect measurement is performed by means of two techniques: vapour equilibrium technique and axis translation technique. The assumptions made for indirect measurement are illustrated and discussed. Then, direct measurement of pore water tension is addressed. The problems related to construction and use of tensiometer are illustrated. As the main drawback of tensiometer measurement is cavitation, this phenomenon is considered. To focus on the problem, the case of bubble dynamics is first analysed. Then, cavitation triggered by gas nuclei entrapped in crevices or pores is examined. Conclusions are finally drawn on possible cavitation mechanisms inside the tensiometer.
