Academy / Marchetti flat dilatometer
The Marchetti Flat Dilatometer (DMT) consists of a flat blade which is driven into the soil. The blade has a fine circular metal membrane which can be expanded horizontally in the soil using pressurized gas.
The pressure P0 which is needed to start membrane movement is measured, as is the pressure P1 which is required to produce a displacement of 1.1 mm in the centre of the membrane. These two measurements are taken at regular intervals, usually of 20 cm.
The penetration can be carried out statically, by means of a CPT truck, allowing both test methods to be used as part of a single survey campaign, without additional costs.
As well as being a quick and repeatable test which causes minimal disturbance to the soil, the DMT has the following specific advantages: