Preliminary Assessment on Seismic Vulnerability of Masonry Churches in Central Chile

ABSTRACT

The 2010 Maule Chile earthquake (Mw 8.8) caused extensive structural damage to the built heritage. In particular, the poor seismic performance of a set of unreinforced masonry (URM) churches highlighted the need to implement protective and safety strategies in order to preserve these buildings which exhibit unique constructive and typological features, as a result of a combination of Chilean and European construction cultures.

The peculiarity of this heritage and the high seismic hazard of Chilean territory have motivated the present study which aims to apply systematic procedures to assess the seismic vulnerability of these buildings. This article is of archival nature and presents a complete database generated from the geometrical, constructive, and structural characteristics of a representative stock of 106 churches located in central Chile, with the goal of proposing fragility curves to be used in seismic risk assessment. Considering variables related with geometrical, architectonic, and stylistic features, as well as damage levels for the 2010 Maule earthquake, this church sample is classified into three homogenous groups: colonial, neo-classic, and neo-gothic. Moreover, a preliminary qualitative assessment of the seismic capacity of these structures is provided using a survey and analysis of geometric indices for each of the three selected groups.     

Late Quaternary ostracods from Lake George,New South Wales

Fossil ostracods from the uppermost 3m of core LG4 from Lake George all have modern living representatives. This part of the core is thought to represent deposition during the last 60,000 years (see Singh et al., 1981b) and the lake hisotry is traced from a knowledge of the ostracod ecology.

The following distinct phases, and their respective timing, are postulated for Lake George (the timing of events should be considered with caution as few ¹⁴C dates are available): water fresh and lake full for the periods of 10,200 – 12,000 yBP and 19,100 – 20,700 yBP, water fresh, ephemeral at times, for the periods of 3,200–4,000 yBP, 7,000 yBP, 7,500 yBP, 8,500–10,200 yBP, 12,000–13,500 yBP, 20,700–23,500 yBP, 23,800–27,600 yBP and at some stage between 27,000 and 60,000 yBP; ephemeral saline water for a few short episodes between 3,200 and 4,000 yBP and for the periods of 15,600–17,400 yBP and 23,800–27,600 yBP; lake definitely dry between 17,400 and 19,100 yBP.

Data obtained from the ostracods correlate reasonably well with those of lake level fluctuations based on the study of ancient shorelines by Coventry (1976) and others based on facies analyses and the record of plant microfossils by Singh et al. (1981b).     

Aristocratic patronage,political networking and the shaping of a private sanctuary: Countess Clemence of Flanders and the early years of Bourbourg Abbey (c.1103–21)

This article discusses the geopolitical manoeuvres of the comital House of Flanders, especially of Countess Clemence of Burgundy, to consolidate comital influence and power in the border region of western Flanders, specifically in the area of Bourbourg. By analysing and mapping the shifting patterns of interaction between alliances of both secular and ecclesiastical stakeholders in the charters issued for the abbey of Bourbourg, a female house, during the first decades of the twelfth century, it argues that the foundation and patronage of Bourbourg were engineered to create a symbolic and geo-strategic key site where the interests of the counts of Flanders and their local representatives, the abbot of Saint-Bertin, and members of the local elite converged, and alliances balanced each other. Moreover, through an anthropological approach in which the charters are also considered within the supra-institutional context of the reform movement, this study offers new insights into the dynamic role of Countess Clemence as a promoter and benefactor of Bourbourg Abbey, and also as a manager of her personal network of allies.     

Firing technique characterization of black-slipped pottery in Praeneste by low field 2D NMR relaxometry

This study was aimed at individuating characteristics related to the pottery’s firing technique of Classical Roman producers, through the low field single-sided NMR relaxometry. The approach is based on a recent method of analysis, the correlation of the longitudinal and transverse NMR relaxation times of a liquid probe (in this case distilled water) filling the porous system of ceramics. The analyzed findings form two homogeneous classes with dating and place of production well established through the producer trademarks. Pottery findings belong to the black-slipped pottery productions of the Latin ancient city of Praeneste between third and second century B.C. and have been attributed to two different ”patriziae” production families: gens Samiaria and gens Trebonia. A further fragment with Greek kylix style, found in the same archaeological area, has also been analyzed, in order to understand if it had been imported from Greece, or made in Praeneste in imitation of the Greek style.