Caracterização geotécnica do subsolo do campo experimental de geotecnia e de fundações da Universidade Federal do Ceará

Abstract

Employing geotechnical assays both in the laboratory and in field, this work aimed to characterize the subsoil of the Experimental Field of Geotechnics and Foundations at Federal University of Ceará (CEGEF - UFC), in order to subsidize future geotechnical works. The methodology included carrying out geotechnical tests and collecting results of other works done previously to this research. Tests of physical characterization, performed aiming at data collection, were: granulometry by sieving and sedimentation, real density, liquidity limit (wL), plastic limit (wP), natural moisture, compaction in the standard Proctor energy and in filter paper. The special geotechnical tests, whose results were collected from other works, were: oedometer, direct shear and triaxial of densified and drained types (CD). The field tests, the results of which were also collected, were: Standard penetration test (SPT), GPR, plate loading on natural and flooded soil and horizontal load test. From the analysis of the parameters obtained from the geotechnical tests, it was verified that the subsoil presented open granulometry, i.e., it is poorly graded and has non-plastic characteristics. In addition, according to the Unified Soil Classification System (U.S.C.S), it can be classified as a granular silt-sand soil of the SM group. The oedometer tests allowed the observation of an increase in soil rigidity with depth, whose maximum value was 2 m. The determination of the effective stress friction angle (ϕ’) of the soil, from the triaxial and direct shear tests, were convergent and showed maximum variations of about 2º across the methods. The cohesive intercept, in turn, varied up to about 2 kPa. With the accomplishment of this scientific work, it is also intended to form a database referring to the geotechnical properties of the subsoil of the experimental field analyzed.