Site characterization by seismic dilatometer (SDMT) in the city of L'Aquila

摘要

This paper presents a review of results obtained by a large number of seismic dilatometer tests (SDMT) carried out in the area of L'Aquila (Central Italy), after the April 6~th, 2009 earthquake. Due to the characteristics of the soils (mostly coarse-grained, non-penetrable materials), SDMT measurements were generally performed in backfilled boreholes, using the technique briefly described; in these conditions only the shear wave velocity V_s, without the other DMT parameters, was measured. The test results illustrated in the paper include: (a) SDMT typical results obtained by the normal penetration procedure (in a limited number of sites, mostly silts); (b) V_s-only profiles obtained by the backfilled borehole procedure; (c) comparisons of V_s profiles obtained by SDMT and by other techniques (Down-Hole, Cross-Hole, surface waves tests); (d) comparisons of V_s measured by SDMT and those estimated from mechanical DMT data. The V_s profiles provided by SDMT, combined with the information obtained from geological data and from other investigations, including boreholes down to a maximum depth of 300 m in the city centre, have been used for the soil characterization in numerical seismic response analyses. An example is illustrated in the paper.