Characterization of stiff residual soils with dynamically push-in DMT

摘要

DMT (Marcheti Flat Dilatometer Test) has been increasingly used with success in the evaluation of geomechanical properties of soft to medium soils, with moderate compacity or consistency (N_(SPT) < 30). The insertion of the Flat Blade has been traditionally made by static pushing, which is an operational limitation in hard to stiff soils, in particular in heterogeneous saprolitic residual soils. This has been limiting the practitioners, when, as in Portugal, pressuremeter test is not common practice, leading to rely exclusively in dynamic penetration test (such as SPT or DPSH - super-heavy dynamic probing), which are very limited in, among other levels, deriving stiffness properties. In this context, the dynamic penetration of the DMT blade has been explored as an alternative to static push-in, assuming that the characteristics of the test - by inducing a solicitation that is eminently horizontal, may, in some way, preserve the intrinsic characteristics of the natural soil. This is being explored as a possible potential of this device for these natural ambient. The present paper will be presenting a comparative analysis of the results obtained in both static and dynamically push-in DMT tests in weathered profiles of granitic masses and reference earthfills.