Paleosols are recurrent features in alluvial successions and provide information about past sedimentary dynamics and climate change. Through sedimentological analysis on six sediment cores, the mud-dominated succession beneath the medieval 'Two Towers' of Bologna was investigated down to 100 m depth. A succession of weakly developed paleosols (Inceptisols) was identified. Four paleosols (P1, P2, P3 and PH) were radiocarbon-dated to 40-10 cal ka BP. Organic matter and CaCO 3 determinations indicate low groundwater levels during soil development, which spanned periods < 5 ka. The development and burial of soils, which occurred synchronously in the Bologna region and in other sectors of the Po Plain, are interpreted to reflect climatic and eustatic variations. Climatic oscillations, at the scale of the Bond cycles, controlled soil development and burial during Marine Isotope Stage (MIS) 3 (P1 and P2). Rapid sea-level oscillations probably induced soil development at the MIS 3/2 transition (P3) and favored burial of PH after 10 ka BP. Weakly developed paleosols in alluvial successions can provide clues to millennial-scale climatic and environmental variations. In particular, the paleosol-bearing succession of the Po Plain represents an unprecedent record of environmental changes across the Late Pleistocene (MIS 3 and 2) in the Mediterranean region.

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Stability and strength analysis of leaning towers A thesis submitted for the degree of Doctor of Philosophy Michela MarchiDottorato di ricerca in Ingegneria Geotecnica, XX ciclo Università degli studi di Parma January, 2008Many ancient towers are afflicted by stability problems. The evaluation of the overall safety of historical towers is one of the most important items in the preservation of the national and worldwide artistic heritage. This thesis is concerned with models appropriate for the stability assessment of tower foundations, which is related to: bearing capacity failure, due to lack of soil strength, and instability of equilibrium, due to lack of soil stiffness. Both of these hazards are tackled using a work-hardening plasticity model for surface footings.New developments have been introduced into the foundation modelling in relation to prediction of displacements and creep behaviour. These improvements have been used develop a methodology that can deal in a unified way with the two major failure mechanisms of such foundations.Finally, a new interpretation of the influence of creep on tower stability is explained. Such an analysis provides not only a complete framework within which both possible collapse mechanisms can be assessed but also a prediction of which of them is most likely to occur.The analysis, which has been developed in the form of a Mathematica notebook, and applied to the Pisa Tower and the Santo Stefano bell tower, can be also used to study the influence of foundation strengthening procedures.

There is mounting evidence in favour of replacing the e against [Formula: see text] diagram, conventionally used to represent soil compressibility in an oedometer, with a log(v) against [Formula: see text] diagram, which significantly improves the linearity of virgin loading and unloading paths. This paper presents a simple, new formulation of the ‘intrinsic’ compression and ‘sedimentation’ compression lines for a range of insensitive, sedimentary marine clays presented in Burland’s 1990 Rankine Lecture by using a log(v) against [Formula: see text] interpretation of the data.

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