• Computers and Concrete
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• v.33 no.5
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• pp.573-594
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• 2024

This article presents a research study, with both laboratory and field tests, of a deep foundation in a markedly anisotropic medium. Particularly it has focused on the evaluation of the behavior of a pile, one meter in diameter, embedded in a rocky environment with difficult conditions, in the Flysch of the Spanish city of San Sebastián. To carry out the research, the site of a bridge over the Urumea River was chosen, which was supported by pre-excavated reinforced concrete piles. 4 borings were carried out, by the rotation and washing method, with continuous sampling and combined with flexible dilatometer tests. In the field, an Osterberg load test (O-cell) was performed, while in the laboratory, determinations of natural moisture, natural unit weight, uniaxial compressive strength (UCS), point load strength (PLS), compressive wave propagation velocity (V_c) and also triaxial and direct shear tests were carried out. The research results indicate the following: a) the empirical functions that correlate the UCS with the PLS are not always linear; b) for the studied Flysch it is possible to obtain empirical functions that correlate the UCS with the PLS and with the V_c; c) the bearing capacity of the studied Flysch is much greater than if it is evaluated by different load capacity theories; d) it is possible to propose an empirical function that allows evaluating the mobilized shear strength (τ_m), as a function of the UCS and the displacement relative of the pile (δ_r).

• Economic and Environmental Geology
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• v.5 no.4
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• pp.231-239
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• 1972

The central region of South Korea is composed of Precambrian formations and Jurassic Daebo granites and is divided tectonically into three provinces, that is, the Ok chon geosynclinal zone in the middle, the Kyonggi massif on the north and northwest side, and the Ryongnam massif on the south and southeast side. The general trend of the Okchon geosynclinal zone and the distribution of Daebo granites is northeast, the Sinian direction. The Kyonggi massif is composed of Precambrian Y onchon system, Sangwon system, gneisses, and Daebo granites, and the Ryongnam massif also Precambrian Ryongnam and Yulri systems, gneisses, and Daebo granites. Precambrian formations in both areas are of flysch type sediments and may be roughly correlated with each other. These formations except Sangwon and Yulri systems are thought to be early to middle Precambrian age and have acted as basement for the Okchon geosyncline where late Precambrian Okchon system was deposited. The Okchon geosynclinal zone is divided into paleogeosynclinal zone to southwestern parts where the Okchon system is distributed, and neogeosynclinal zone to northeastern parts where nonmetamorphosed Paleozoic sediments are dominantly cropped out. Both zones are separated by upthrust created by Daebo orogeny of Jurassic period, which continues southwesterly to bind the Okchon geosynclinal zone and the Ryongnam massif at southwestern parts bisecting Korea peninsula diagonally. Three periods of structural development are recognized in the area. Folds and faults of preTriassic age prevail in the Kyonggi massif. Many isoclinal folds and thrusts originated by Jurassic Daebo orogeny are aligned in the Okchon paleogeosynclinal zone paralleling to the geosynclinal axis so that same formation appears repeatedly in narrow strips, whereas fold axis in neogeosynclinal zone trerid west-northwesterly which might be of Triassic in age and modified by later Daebo orogeny. Discontinuity of geology and structure of Okchon geosynclinal zone is attributed to shifting of the geosyncline through geologic time.