Historic masonry churches exposed to slow-moving landslides: A critical damage assessment

This paper deals with the damage assessment of historic masonry churches exposed to slow-moving landslides. A damage survey campaign was carried out on 33 listed churches located in the Liguria region (Italy) in areas affected by slow-moving landslides. For each church, information about zoning, state of activity and direction of landslide phenomena was collected and analyzed. Knowledge of each building’s main geometric and structural features, history and past interventions was gained by means on-site surveys and archival research. A detailed field-survey of crack patterns and deformations was also performed. Based on the critical assessment of the damage observed, preliminary conclusions on the structural response of historic masonry churches to slow-moving landslides were made. Recurrent types of damage and damage mechanisms were also identified

Characterization of multilayer stack parameters from X-ray reflectivity data using the PPM program: measurements and comparison with TEM results

Future hard (10 -100 keV) X-ray telescopes (SIMBOL-X, Con-X, HEXIT-SAT, XEUS) will implement focusing optics with multilayer coatings: in view of the production of these optics we are exploring several deposition techniques for the reflective coatings. In order to evaluate the achievable optical performance X-Ray Reflectivity (XRR) measurements are performed, which are powerful tools for the in-depth characterization of multilayer properties (roughness, thickness and density distribution). An exact extraction of the stack parameters is however difficult because the XRR scans depend on them in a complex way. The PPM code, developed at ERSF in the past years, is able to derive the layer-by-layer properties of multilayer structures from semi-automatic XRR scan fittings by means of a global minimization procedure in the parameters space. In this work we will present the PPM modeling of some multilayer stacks (Pt/C and Ni/C) deposited by simple e-beam evaporation. Moreover, in order to verify the predictions of PPM, the obtained results are compared with TEM profiles taken on the same set of samples. As we will show, PPM results are in good agreement with the TEM findings. In addition, we show that the accurate fitting returns a physically correct evaluation of the variation of layers thickness through the stack, whereas the thickness trend derived from TEM profiles can be altered by the superposition of roughness profiles in the sample image

Effect of Slow-Moving Landslides on Churches in the Liguria Region: a Geotechnical Approach

Protecting cultural heritage from water-soil interaction related threats is a current issue and the prediction of the effects induced on buildings by landslides is very challenging. The main difficulties lie in the lack of detailed information about landside movements as well as in the modeling of soil-structure interaction. This paper study the effects of a particular category of slow-moving landslides, namely active rotational and translational slides with movement rates of the order of some mm/year, on buildings of historical and cultural interestsuch as churches. Three case studies located in the Liguria region (Italy) were analyzed by performing FEM and LEM numerical analyses on sections representative of the slope

The spatially resolved star formation history of CALIFA galaxies: Cosmic time scales

This paper presents the mass assembly time scales of nearby galaxies observed by CALIFA at the 3.5m telescope in Calar Alto. We apply the fossil record method of the stellar populations to the complete sample of the 3rd CALIFA data release, with a total of 661 galaxies, covering stellar masses from 10$^{8.4}$ to 10$^{12}$ M$_{\odot}$ and a wide range of Hubble types. We apply spectral synthesis techniques to the datacubes and process the results to produce the mass growth time scales and mass weighted ages, from which we obtain temporal and spatially resolved information in seven bins of galaxy morphology and six bins of stellar mass (M$_{\star}$) and stellar mass surface density ($\Sigma_{\star}$). We use three different tracers of the spatially resolved star formation history (mass assembly curves, ratio of half mass to half light radii, and mass-weighted age gradients) to test if galaxies grow inside-out, and its dependence with galaxy stellar mass, $\Sigma_{\star}$, and morphology. Our main results are as follows: (a) The innermost regions of galaxies assemble their mass at an earlier time than regions located in the outer parts; this happens at any given M$_{\star}$, $\Sigma_{\star}$, or Hubble type, including the lowest mass systems. (b) Galaxies present a significant diversity in their characteristic formation epochs for lower-mass systems. This diversity shows a strong dependence of the mass assembly time scales on $\Sigma_{\star}$ and Hubble type in the lower-mass range (10$^{8.4}$ to 10$^{10.4}$), but a very mild dependence in higher-mass bins. (c) All galaxies show negative $\langle$log age$\rangle_{M}$ gradients in the inner 1 HLR. The profile flattens with increasing values of $\Sigma_{\star}$. There is no significant dependence on M$_{\star}$ within a particular $\Sigma_{\star}$ bin, except for the lowest bin, where the gradients becomes steeper.Comment: 15 pages, 13 figures, 3 tables, accepted for publication in Astronomy & Astrophysics. *Abridged abstract

Effect of slow-moving landslides on a vaulted masonry building: The case of San Carlo Borromeo church in Cassingheno (Genova)

This paper presents the structural analysis of San Carlo Borromeo church, a masonry building located in Cassingheno (Genoa, Italy) in an area affected by a slow-moving landslide. A deep knowledge of the building in terms of geometry, structural configuration, history and construction phases was acquired by means of on-site surveys and archival research. The crack patterns were surveyed in detail and the deformations were studied through a point cloud obtained from a LIDAR survey. The comparison between the landslide direction and the damage observed showed discrepancies and suggested the presence of foundation settlements due to other phenomena. To identify the actual causes of damage, a finite element model (FEM) of the building in its hypothetical undeformed configuration was created. The geometry of such configuration was reconstructed starting from the point cloud obtained from the LIDAR survey and removing geometrical defects such as leaning of walls, deformation of vaults and inclination of tie-rods. To simulate the effects produced by the landslide and the foundation settlements on the building over time, nonlinear analyses were performed by imposing different displacement fields at the foundation plane in multiple steps. The damage predicted numerically was then compared with the one experienced by the building, showing good agreement