Abstract
On October 31, 2002, a ML=5.5 earthquake struck the Molise region in Southern Italy. The strongly non-uniform damage distribution observed in the town of San Giuliano di Puglia suggested that site amplification significantly affected the seismic response of the Toppo Capuana marly clay formation.
The geotechnical laboratories of both the University of Napoli and the Technical University of Bari were entrusted by the Department of Civil Protection of the Italian Government with the experimental investigation of the geotechnical properties of the marly clay, in order to develop seismic microzonation studies. Laboratory tests were carried out on undisturbed borehole samples taken at depth along two orthogonal sections crossing the town center. The testing programme consisted of standard classification tests, one-dimensional and isotropic compression tests at medium-high pressures, cyclic and monotonic triaxial tests and both cyclic and dynamic torsional shear tests carried out at variable frequencies. The geotechnical investigation identified the presence of three main geotechnical units within the Toppo Capuana formation: grey marly clays at depth, overlayed by a few metre thick stratum of intensely fissured tawny clay, and a thin cover of softer soils disturbed by repeated sliding; the laboratory tests were developed on samples from each of these units.
The paper discusses the main experimental results and the consequent interpretation of the stress-strain behaviour of the tested soils, characterizing in particular the dependency of the soil pre-failure behaviour and strength on its stress state and history, strain level and strain rate.
The influence of the different meso-strucures was not recognisable on the physical properties, but clearly affected the mechanical behaviour of tawny and grey clays, which exhibited more pronounced scale effects. The experimental data permitted to evaluate the effects of the degree of fissuring on compressibility, strength and small strain behaviour; in particular, the different meso-structures of the tawny and grey clays were reflected by the comparison between yielding stresses in one-dimensional compression, the peak strength values, as well as by the small strain stiffness and damping ratio.
All such effects are conceptually consistent, and significantly reflect on the subsoil modelling for seismic response analyses of the subsoil to the seismic sequence.
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References
ASTM (1976). Annual Book of ASTM standard, Part 19. Philadelphia.
Baranello S., Bernabini M., Dolce M., Pappone G., Rosskopf C., Sanò T., Cara P.L., De Nardis R., Di Pasquale G., Goretti A., Gorini A., Lembo P., Marcucci S., Marsan P., Martini M.G., Naso G. (2003). Rapporto finale sulla Microzonazione Sismica del centro abitato di San Giuliano di Puglia. Department of Civil Protection, Rome, Italy.
BS 8004 (1986). Code of practice for foundations. British Standard Institutions, London.
Cafaro F. & Cotecchia F. (2001). Structure degradation and changes in the mechanical behaviour of a stiff clay due to weathering. Géotechnique 51:441–453.
Chandler R.J. & Apted J.P. (1988). The effect of weathering on the strength of London clay. Quarterly Journal of Engineering Geology, 21:59–68.
d’Onofrio A., Silvestri F., & Vinale F. (1999). A new torsional shear device. ASTM Geotechnical Testing Journal 22(2):107–117
d’Onofrio A. & Silvestri F. (2001). Influence of micro-structure on small-strain stiffness and damping of fine grained soils and effects on local site response. Proc. IV international Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, San Diego. CD-ROM, University of Missouri, Rolla.
Fookes P.G. & Denness B. (1969). Observational studies on fissure patterns in cretaceous sediments of South-East England. Géotechnique, 19(4): 453–477.
Giaccio B., Ciancia S., Messina P., Pizzi A., Saroli M., Sposato A., Cittadini A., Di Donato V., Esposito P. & Galadini F. (2004). Caratteristiche geologico-geomorfologiche ed effetti di sito a San Giuliano di Puglia (CB) e in altri abitati colpiti dalla sequenza sismica dell’ottobre-novembre 2002. II Quaternario (Italian Journal of Quaternary Sciences), 17(1):83–99.
Guerricchio A. (2005). Private communication. University of Calabria.
Hardin B.O. & Drnevich V.P. (1972). Shear modulus and damping in soils: design equations and curves. Journal of the Soil Mechanics and Foundations Division, ASCE, 98(SM7):667–692.
ISRM (1993). Metodologie per la descrizione quantitativa delle discontinuità nelle masse rocciose. Rivista Italiana di Geotecnica, 2:151–197.
Melidoro G. (2004). Private communication. Technical University of Bari.
Morgenstern N.R. & Eigenbrod K.D. (1974). Classification of argillaceous soils and rocks. Journal of the Geotechnical Enginering Division, ASCE, 100(GT10):1137–1156.
Penna A. (2001). Effetti delle tecniche di preparazione sul comportamento meccanico di un limo argilloso costipato. Master thesis (in italian), University of Napoli Federico II.
Petillo C. (2004). Risposta sismica del centro abitato di San Giuliano di Puglia. Master thesis (in italian), University of Napoli Federico II.
Puglia R. (2005). Analisi della risposta sismica locale di San Giuliano di Puglia. Research report (in italian), University of Calabria.
Rampello S., Silvestri F. & Viggiani G. (1994). The dependence of small strain stiffness on stress state and history of fine grained soils: the example of Vallericca clay. Proc. I Intern. Symp. on ‘Pre-failure Deformation Characteristics of Geomaterials’, Sapporo, 1:273–279. Balkema, Rotterdam.
Rampello S., Silvestri F. & Viggiani G. (1995). The dependence of G0 on stress state and history in cohesive soils. Panel discussion. Proc. I Intern. Symp. on ‘Pre-Failure Deformation Characteristics of Geomaterials’, Sapporo, 2:1155–1160. Balkema, Rotterdam.
Schofield A.N. & Wroth C.P. (1968). Critical state soil mechanics. McGraw-Hill, London.
Vitone C. (2005). Comportamento meccanico di argille da intensamente a mediamente fessurate. Ph.D. Thesis (in italian), Technical University of Bari.
Vitone C., Cotecchia F., Santaloia F. & Cafaro F. (2005). Preliminary results of a comparative study of the compression behaviour of clays of different fissuring. Proc. Intern. Conference on Problematic Soils, Cyprus, 1173–1181.
Walker B.F., Blong R.J. & McGregor J. P. (1987). Landslide classification, geomorphology and site investigation. Soil Slope Instability and Stabilisation, 1–52. Balkema, Rotterdam.
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Silvestri, F., Vitone, C., d’Onofrio, A., Cotecchia, F., Puglia, R., de Magistris, F. (2007). The Influence of Meso-Structure on the Mechanical Behaviour of a Marly Clay from Low to High Strains. In: Ling, H.I., Callisto, L., Leshchinsky, D., Koseki, J. (eds) Soil Stress-Strain Behavior: Measurement, Modeling and Analysis. Solid Mechanics and Its Applications, vol 146. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-6146-2_17
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DOI: https://doi.org/10.1007/978-1-4020-6146-2_17
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