The Algeciras Unit is formed, in part, of the following geological formations: calcareous flysch (Eocene), red pellitic succession (lower Oligocene), and micaceous sandstones and marls flysch (oligoceneaquitanian). In these anisotropic formations, 14 boreholes between 15 and 20 m of depth were drilled and undisturbed and also paraffinic core samples were recovered and brought to laboratory for obtaining specimens and test the materials to characterize them from the geotechnical point of view. From the undisturbed samples 87 specimens were cored in different directions: vertical (parallel to the borehole), horizontal (with axis parallel to the direction of the bedding plane), and horizontal (with axis perpendicular to the direction of the bedding plane) and were tested: In this paper some interesting results are presented.
This paper presents some results obtained in a study done for the geotechnical characterization of three anisotropic formations present in the Strait of Gibraltar area (Cadiz, Spain), forming part of what is known as Algeciras Unit. They are the following ones:
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Micaceous Sandstones and Marls Flysch (Upper Oligocene) it was named as Zone 1. Hereafter it will be designed as FMAM.
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Red Pellitic Succession (Middle-Lower Oligocene). It was named as Zone 2, hereafter PR.
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Calcareous Flysch (Eocene). It was named Zone 3, hereafter FC.
In these formations 14 boreholes were performed, between 15 and 20 m of depth each one. Undisturbed samples, drilled with triple tube, and also paraffinic core samples were recovered and brought to laboratory for obtaining specimens and test the materials to characterize them from the geotechnical point of view.
From the undisturbed samples 87 specimens were cored and tested in laboratory, 41 specimens from zone 1 (FMAM), 29 from zone 2 (PR) and 17 from zone 3 (FC). This zone 3was very fractured being this the reason why there was a lower number of specimens, as it was difficult to find pieces long enough to cut specimens. Due to this reason, the results obtained in FC formation may not be as representative as the obtained in the other two formations.
