Relevant features of the valley seismic response: the case study of Tuscan Northern Apennine sector

The so called “valley effect” relates to the typical seismic response of basin shaped bedrock filled by quaternary sediments. It is an aspect of the renown “local seismic effect” that shall be taken into account when dealing with microzoning studies. Several experimental surveys and numerical simulations performed worldwide over the last 40 years, confirmed that valley responses under seismic excitations show common features in various geological contexts as far as the sedimentary valleys (e.g. alluvial and lacustrine plains), the intermountain valleys (e.g. alpine valleys) and graben shaped basins. Such features mainly depend on the basin geometry, referred to as the shape ratio SR, and the sediment and basin impedance contrast IC. Although researchers agree on the prominent role of local seismic effects for interpreting erratic damages caused by seismic shaking in urbanized areas, no fully shared strategies have been identified for taking into account valley effect within microzoning studies. In this paper, a numerical simulations on three models of trapezoidal shaped basins have been performed. These valley models relate to sediments and basins detected within the Tuscany Region territory during the VEL project. Results, in terms of the amplification index $\text{ F }_{\mathrm{A}}$ F A have been provided. Three “valley effect charts” for various SR and IC values have been propose for taking into account the local seismic effects due to the basin amplifications within microzoning maps.     

Shrinking ‘Smart’?: Urban Redevelopment and Shrinkage in Youngstown,Ohio

Abstract

This article analyzes the impact of the much-heralded Youngstown 2010 Plan and the enacting of a program of “controlled” or “managed” shrinkage. It is argued that while the program of redevelopment has had an impact on Youngstown and its national image, it represents an exclusionary project that has centered on redeveloping downtown areas and neglected many city neighborhoods which continue to experience high levels of unemployment, vacancy, and crime. The analysis is situated in relation to the contemporary literature on “shrinking cities.” Youngstown's experience raises critical questions regarding the nature of the challenges facing shrinking cities, the constraints on actions available to them due to state and federal funding, and the coherence of the concept of “smart shrinkage.”     

Characterizing European urban settlements from population data: a cartographic approach

ABSTRACT

The cartographic identification and characterization of urban settlements is problematic, particularly in varied areas or in large geographical extensions. This is due to the divergence between morphological area structures and data attribution, which is generally available at the level of administrative units. Most existing experiences focus on small regions or use indirect data, from which only indirect information can be derived. This paper proposes an identification of urban settlements in the European Union space, which combines urban population and shape through geographic information system (GIS) techniques. For that purpose, 1 km² cells with associated population data are used. A procedure is developed establishing three different types of urban settlements, according to population and population density values: high-density urban clusters, small and medium-sized towns, and very small towns. A validation of this procedure is performed using direct survey from local experts in 10 selected study areas. The final results show that 78,307 urban settlements can be identified: 88.17% of them are classified as “very small towns,” 10.75% as “small and medium-sized towns,” and 1.08% as high-density urban clusters. This exercise generates new information for the European Union and surrounding countries, and yields the basis for further research. All GIS operations are performed using vector layers, which is not usual in large-area regional studies.     

Metazoan/microbial biostalactites from present‐day submarine caves in the Mediterranean Sea

Biostalactites formed by metazoan–microbialite associations from three submerged marine caves in the Plemmirio Peninsula (south of Syracuse, Ionian Sea) are randomly distributed and show different sizes and morphologies, as well as variations in surface roughness/smoothness. The biostalactites consist of crusts a few centimeters thick of small serpulids and other metazoans, associated with fine‐grained carbonate; the larger ones often include a nucleus of serpulid tubes (Protula). The metazoans include mainly serpuloideans, sponges, bryozoans and foraminifers but microbial carbonates are also significant components. The composition of both the living communities and thanatocoenoses on the outer surfaces, as well as the composition and fabric of the internal framework, were analysed and used to reconstruct the history of the caves. All of the identified sessile faunas mainly consist of cryptic and sciaphilic dwellers that reflect cave conditions and their variations through time. The distribution pattern, composition and abundance of the present‐day dwellers largely depend on the degree of roughness of the biostalactite surfaces and their positions within the caves. It has been suggested that the Protula specimens in the nuclei represent pioneer populations that formed aggregates during the early cave colonization phase, in response to relatively high food supply from seawater inflow and intruding continental waters. By contrast, the outer metazoan–microbialite carbonates reflect more confined conditions in the caves caused by Holocene sea‐level rises. Hypotheses are proposed for biostalactite growth, taking into account information about the growth rates of some constituents, and evidence of dissolution effects. Similarities and differences between these biostalactites and other Holocene deposits previously described from submarine caves in the Mediterranean Sea and in tropical reefs are discussed.     

Archaeo-Geophysics Surveys in Pompeii

Within the extraordinary archaeological site of Pompeii, the Porta Nocera necropolis represents one of the most important sites with funerary monuments, burials and associated graves. The inherent informative potential of the archaeological/monumental heritage present in the Porta Nocera necropolis poses notable problems for the conservation and restoration of the structures and surfaces of the funerary monuments. Brought to light at different times during the second half of last century, they show signs of degradation caused by atmospheric agents and the rising level of the water table, which threatens the foundations. Other important monuments could be still buried. In order to verify both the state of preservation of the foundations of funerary buildings, the presence of still active causes of deterioration and the probable presence of other buried archaeological structures, integrated geophysical surveys, with ground penetrating radar (GPR), passive (Self Potential—SP) and active electrical resistivity tomography (ERT), were undertaken. Furthermore a three-dimensional model of the entire necropolis was created. This involved the creation of a specific survey methodology, combining laser scanning with ortho-photogrammetry using shots taken on the ground and from the air by the use of a drone. The integration of the acquired data allows us to plan future interventions of restoration.     

HD 134 518: A Main-Sequence Detached or a Semi-detached Eclipsing Binary?

We have analyzed PRZYBYLSKY 's (1981) photometric observations of HD 134518, an eclipsing binary with a period of 1.15 days and a β Lyrae type light curve. Performing a grid of solutions with different assumed values of the mass ratio by means of the WILSON -DEVINNEY method we have determined the photometric elements of this variable, which shows an extremely low mass ratio (q = mc/mh = 0.06) and appears as semi-detached system. The discrepancies between the WILSON -DEVINNEY solution and the WOOD solution (GIURICIN et al. 1982) are pointed out. Die photometrischen Beobachtungen PRZYBYLSKYS (1981) von HD 134 518, einem Bedeckungsveränderlichen mit P = 1^d.15 und einer β-Lyrae-artigen Lichtkurve, wurden analysiert. Mittels der WILSON -DEVINNEY -Methode wurden für verschiedene Masseverhältnisse die photometrischen Elemente des Veränderlichen bestimmt, der ein extrem niedriges Massenverhältnis (q = mc/mh = 0.06) besitzt und halbgetrennt zu sein scheint.     

Numerical analysis of piled rafts

An approximate numerical method for the analysis of piled raft foundations is presented. The raft is modelled as a thin plate and the piles as interacting non-linear springs. Both the raft and the piles are interacting with the soil which is modelled as an elastic layer. Two sources of non-linearity are accounted for: (i) the unilateral contact at the raft–soil interface and (ii) the non-linear load–settlement relationship of the piles. Both theoretical solutions and experimental results are used to verify that, despite the approximations involved, the proposed method of analysis can provide satisfactory solutions in both linear and non-linear range. © 1998 John Wiley & Sons, Ltd.     

Chemo-mechanical behaviour of lightweight cemented soils

Acta Geotechnica - In this paper, a multi-scale analysis of the effect of foam on chemo-mineralogical and microstructural features of the soil–cement–water system is presented....