This paper presents a mechanical characterization of Miocene overconsolidated clays of the Lisbon subsoil, carried out by pressuremeter tests. These tests were run in the scope of the enlargement of the Lisbon underground net. The tests were performed with a Ménard pressuremeter and a Cambridge selfboring pressuremeter, both with a pressure capacity of 10 MPa.

The main results are presented in this paper. Among the results achieved, the coefficient of earth pressure at rest was computed, as well as the increasing law with depth of deformability and resistance parameters. In the end, a correlation between the Ménard limit pressure and the undrained shear strength was established. It was found that the more common correlations between these two parameters published in the literature underestimate the undrained shear strengths. However, some of those correlations were established from tests where the limit pressures were at least 2 to 3 times smaller than those obtained in present study.