Methods and Approaches for Blind Test Predictions of Out-of-Plane Behavior of Masonry Walls: A Numerical Comparative Study

ABSTRACT

Earthquakes cause severe damage to masonry structures due to inertial forces acting in the normal direction to the plane of the walls. The out-of-plane behavior of masonry walls is complex and depends on several parameters, such as material and geometric properties of walls, connections between structural elements, the characteristics of the input motions, among others. Different analytical methods and advanced numerical modeling are usually used for evaluating the out-of-plane behavior of masonry structures. Furthermore, different types of structural analysis can be adopted for this complex behavior, such as limit analysis, pushover, or nonlinear dynamic analysis.

Aiming to evaluate the capabilities of different approaches to similar problems, blind predictions were made using different approaches. For this purpose, two idealized structures were tested on a shaking table and several experts on masonry structures were invited to present blind predictions on the response of the structures, aiming at evaluating the available tools for the out-of-plane assessment of masonry structures. This article presents the results of the blind test predictions and the comparison with the experimental results, namely in terms of formed collapsed mechanisms and control outputs (PGA or maximum displacements), taking into account the selected tools to perform the analysis.     

Long-term land-use changes in small/medium-sized cities. Enhancing the general trends and local characteristics

Small and medium-sized cities represent the backbone of the European territory, promoting cohesion and an economic base for development. The study compares the spatial and temporal trajectories of land use in three small/medium-sized cities located in central Portugal, between 1958 and 2011. The cities of Viseu, Leiria and Castelo Branco were chosen because they are located in different urban sub-systems and because of the different factors that frame their alterations in land use, occupation and consequent urban development. The research evaluates the transformations, supported by indicators to explain the spatial dynamics of losses and gains and a principal component analysis compares the land-use trajectories for the three cities. The general results reveal an increase from the central part of the study areas to the periphery, contrasting with a continuous decrease of the agricultural parts, illustrating peri-urbanization and rururbanization processes. The study allows identification of the dynamics in the three analysed areas, highlighting the different rhythms of change and relating them to the particularities that exist in each city. The methodology represents an advantage for the analysis and evaluation of territorial dynamics related to land-use change, and made possible the identification of the different forces.     

Assessment of the Permeability of Historical Defensive Systems: the Case of the Lines of Torres Vedras

As the largest part of military usage of the territory depends on a thorough analysis of its morphology, spatial analysis with Geographic Information Systems (GIS) software reveals a great potential as a way for studying battlefields and/or other military buildings and scenarios from the past, while supporting interpretations of territorial occupation and related organization of military forces through event simulation. This paper presents a GIS-based method to model and assess the permeability of historical defensive systems from the period that preceded the mechanization of warfare of the late nineteenth century, i.e., based on artillery installed in fortifications. The method was applied to analyze the permeability of the Lines of Torres Vedras (LTV) defensive system, a multi-line fortification complex which was operational during the Peninsular War in the beginning of the nineteenth century and located north of Lisbon, Portugal. The structures of the LTV and local terrain were modelled in GIS using a set of proposed parameters that support territorial analysis, combined with the capability of contemporary weaponry. A methodical quantification and combination of these parameters enabled a better understanding of the systemic design of the defensive lines in terms of its permeability, contributing to a discussion of the LTV particular military setting based on the interpretation of these indicators. Global and sectorial analyses of the permeability of the LTV defensive system were conducted.     

The Development Authority and the formative years of the Israeli land regime

The history of Israel’s land allocation regime is traced from its inception in the formative years (1948–60), focusing on distribution of urban land to private and business entities. Rich archival materials provide documentation regarding the Development Authority (DA), established in 1950, and its practices. The prohibition on selling “national lands,” zealously observed in Israel’s rural regions, was never closely adhered to in urban areas. The DA’s double role, as a major actor in land allocation as well as the institution representing the “rules of the game,” serves as a platform for a preliminary examination into institutional path dependency theories.     

The representation of Mongolia in contemporary travel writing: imaginative geographies of a travellers' frontier

This article analyses the representation of Mongolia in five works of travel writing published since the fall of the country's communist regime in 1990. It argues that this travel writing is characterized by a discourse that generates and circulates an ‘imaginative geography’ of Mongolia as a ‘travellers' frontier’. Support for this argument is derived from highlighting sets of collective, cohesive representations, performances and speaking positions that crosscut the works studied. It is maintained that these have the effect of naturalizing a very particular conceptualization of Mongolia as a frontier destination in the age of globalization and mass tourism. This research adds to an established body of geographical scholarship on travel writing, but departs from it by considering contemporary works rather than ones from the colonial period. In doing so it attempts to illustrate the relevance of contemporary travel writing as an object of study for geographers seeking to explore the anatomy of today's imaginative geographies, which have clear links to, but are not entirely mediated by, the discourses that characterize colonial travel writing.