In situ tests by Medusa DMT

The Medusa DMT is a self-contained cableless probe able to autonomously perform dilatometer tests using a blade with standard dimensions. The pressurization is applied using a hydraulic motorized syringe, which enables volumetric control during membrane expansion. An electric cable may optionally be used for obtaining real-time test data and for monitoring automation parameters during the execution of the measurements. For deeper investigations, the cable may be omitted and the instrument may work independently, performing measurements at preset time intervals and storing the results in the embedded memory. Initially conceived only for offshore testing, the Medusa DMT provides higher quality dilatometer data also onshore, with the possibility of additional measurements not feasible with the traditional pneumatic equipment. This paper illustrates a validation of Medusa DMT data compared with adjacent measurements carried out using the traditional pneumatic equipment. Other preliminary measurements obtained with this new instrumentation in the field, in particular short dissipation tests prior to membrane expansion, are presented.