Monitoring field soil suction using a miniature tensiometer

An experimental device was developed to monitor the field soil suction using a miniature tensiometer. This device consists of a double tube system that ensures a good contact between the tensiometer and the soil surface at the bottom of the testing borehole. This system also ensures the periodical retrieving of the tensiometer without disturbing the surrounding soil. This device was used to monitor the soil suction at the site of Boissy-le- Châtel, France. The measurement was performed at two depths (25 and 45 cm) during two months (May and June 2004). The recorded suction data are analyzed by comparing with the volumetric water content data recorded using TDR (Time Domain Reflectometer) probes as well as the meteorological data. A good agreement between these results was observed, showing a satisfactory performance of the developed device.