Dilatometric Tests (DMT)
Used worldwide since 1975, DMT (Dilatometric Marchetti Test) is one of the most precise tools for in situ testing to determine settling and estimate the elasticity module (E) of prospected soil layers. Quick and simple to perform and applicable to almost any kind of soil, the test is regulated by ASTM and Eurocode 7.
The DMT test consists in a stainless steel blade with a thin circular expandable pushed into the ground. At every 0,2m pressure is applied to inflate the membrane. Electrical sensors provide the measures “A” and “B”.
The dilatometer blade can be advanced using a conventional CPT pusher and being an “in-situ” test, can obtain measures at several places in the same site and in different depths.
The field measures are processed in specific software, according to the methods of Marchetti and Schmertmann, providing parameters such as:
- At-rest earth pressure coefficient (Ko)
- Elasticity modulus (E)
- Shear resistance (Su)
- Internal friction angle (Φ)
- Soil classification
- Over consolidation ratio (OCR)