Seismic Analysis of Masonry Gravity Dams Using the Discrete Element Method: Implementation and Application

Much research in recent years has focused on the seismic analysis of concrete and earthfill dams, and few works have addressed the case of masonry dams. The structural behavior of masonry dams is controlled essentially by its discontinuous nature, which may induce significant nonlinear response during an intense earthquake. In this article, a numerical tool based on the Discrete Element Method is presented, aimed at the static, dynamic, and hydromechanical analysis of masonry gravity dams. The use of discontinuous models is mandatory for the study of failure mechanisms involving the masonry discontinuities, the dam-rock interface or the rock mass joints. The Discrete Element Method is able to assemble continuous and discontinuous meshes simultaneously in the same model, providing a versatile tool to consider various assumptions and levels of analysis, ranging from simplified to detailed structural representations. A comprehensive study of the seismic behavior of Lagoa Comprida Dam, located in Portugal, is presented. Both continuous and discontinuous models were developed to assess the main failure mechanisms, including overstress, partial and global sliding, and overturning.     

The SAFE Experimental Research on the Frequency Dependence of Shear Wall Seismic Design Margins

The SAFE experimental programme consists of a series of 10 specimens of shear walls, with different reinforcement ratios, tested until their ultimate capacity under seismic input motion by the pseudo dynamic method. A unique input signal is used, calibrated for controlling the seismic demand. Its input central frequency is selected so that for some specimens it is lower than their eignenfrequency, while for other ones it is the opposite. In conclusion there is clear experimental evidence that design margins are much larger in the second case (input central frequency larger than structure eignenfrequency) than in the first one.     

Eros and Dionysus

Abstract

Liberty was once praiseworthy because it enabled a free choice for the good. Technology recasts the classical link between liberty and virtue by making human well-being depend on technological advance. Till recently, technology signified human mastery over nature. But now virtual reality offers itself as a substitute for nature. Unlike machines which hold us at a distance, it draws us in with images. It no longer shapes the soul indirectly through the effects of using machines, but involves the soul directly. The modern attempt to bracket the soul has brought it back virtually. The argument between fight and flight is at a standstill. Instead, the irony which many lament as a feature of postmodernity can provide a distance from the technologies which have made themselves necessary.     

The Origins of the Concept of ‘Palaeolithic Art’: Theoretical Roots of an Idea

This paper explores the origin and theoretical roots of the concept of ‘Palaeolithic art’ in the late nineteenth and early twentieth centuries (1895–1906). It identifies three main sources for this concept: the Western category of ‘art’, the idea of evolution and the notion of primitive. This article shows how the traditional conception of ‘Palaeolithic art’ is a particular case of the wider idea of ‘primitive art’, a category that was born as an attempt to harmonise the notion of ‘primitive society’ and the nineteenth-century bourgeois concept of ‘art’. Additionally, I discuss this traditional conception as the source of a number of ideas that have persisted in our way of interpreting Palaeolithic images until recently, including the understanding of prehistoric images through the lens of the modern notion of ‘art’, their interpretation in symbolic-religious terms and their formal definition based on the idea of naturalism.     

A Simplified Model to Evaluate the Dynamic Rocking Behavior of Irregular Free-Standing Rigid Bodies Calibrated with Experimental Shaking-Table Tests

A simplified model to evaluate the dynamic rocking behavior of free-standing irregular rigid bodies under earthquake-induced forces is proposed. The model analyzes the response of a three-dimensional irregular rigid body using a numerical approach that considers a critical section and two equivalent rectangular rigid blocks. Experimental shaking-table tests were carried out on modular prototypes, which allow the replication of representative mass distributions, sizes, and/or slenderness ratios for typical objects. The tests were used to calibrate the numerical model. It was found that the dynamic behavior under irregular conditions (asymmetrical shape and/or non-uniform mass distribution) can be estimated with the appropriate geometric and density considerations.     

From smart growth to European spatial planning: a new paradigm for EU cohesion policy post-2020

Formally initiated in 1989, European Union (EU) cohesion policy (ECP) has since passed through a series of metamorphoses, along its five programming periods, while becoming the most financed EU policy. As its name indicates, its initial goals were earmarked for promoting economic and social cohesion, following the intentions expressed in the Single European Act. Since then, from a policy strategy intervention point of view, ECP has shifted into a financial tool to promote investment for growth and jobs. In the meantime, European spatial planning (ESP), which had its debating pinnacle with the release of the European Spatial Development Perspective, by 1999, has declined in interest and narrowed into a novel notion of Territorial Cohesion. In this challenging context, this article analyses the implementation and main impacts of ECP and proposes a new strategic paradigm, built around a novel ‘ESP’ vision, backed by the main pillars and dimensions of territorial development and cohesion. More particularly, we suggest that the current rationale for a smart, sustainable and inclusive growth could instead fuel an alternative strategic design based on a cohesive and sustainable development vision: green economy, balanced territory, good governance and social cohesion.     

Avian resources at a Mexican site at the time of the Spanish Conquest

The time of the Spanish Conquest in America saw a major biological interchange caused by human action. In the native people it was expressed by major changes in the use of animals, due to the introduction of domestic European fauna. This theme is discussed here based on a review of ethnohistorical sources and a small body of recent archaeological evidence. An analysis is presented of the use of birds at a Mexican settlement inhabited in the sixteenth century at the time of Spanish contact. The bird remains, 456 fragments, are from the site of El Japon, southeast of Mexico City. The main avian resources were domestic fowl, Gallus gallus, turkey, Meleagris gallopavo, and four species of ducks. The exploitation of scrub jay, Apheolocoura coerulescens is recorded for the first time in Mexican archaeo-ornithology. The study confirms ethnohistorical information about the introduction of the domestic fowl, but also shows that native resources were more widely used than is known from the chronicles of the sixteenth century. © 1997 John Wiley & Sons, Ltd.     

Neanderthal Survival in the North of the Iberian Peninsula? Reflections from a Catalan and Cantabrian Perspective

In the debate over Western Europe??s Middle to Upper Palaeolithic transition we need to consider the importance of both the chronology and the ecological context of the different techno-complexes, as well as the organization of production and consumption activities. In this article we study the adaptative strategies of Middle Palaeolithic human communities based on the information obtained from archaeological sites north of the river Ebro. This transition in the northern part of the peninsula presents a chronological and geographic dichotomy, with the appearance of the Upper Palaeolithic and survival of the Middle Palaeolithic. The geographic distribution appears to indicate intergroup competition and the existence of contact, albeit of an unverified nature. This competition would explain the time that elapsed before one of the cultural, and perhaps biological, groups triumphed over the other in a process culminating in the expansion of Upper Palaeolithic technology.     

Thinking Politically about Sustainable Development in the Tropical Forests of Latin America

This article examines a number of factors which facilitate the adoption and success of policies and projects to promote grassroots sustainable development – that is, the sustainable, multiple use of forests at the community level, including aspects of local self-reliance and control of economic resources. I will argue that the extractive reserve legislation in Brazil and community forestry projects in Mexico and Peru depended on the formation of pro-grassroots development coalitions. The exact make-up of those coalitions depended on three factors: (1) the initial disposition of key governmental and dominant class actors to such policies; (2) the intensity of local conflicts and the extent of community organization; and (3) the involvement of international actors. The cases suggest that in the absence of serious government or upper class opposition, the adoption and durability of such policies and projects can be promoted by the formation of a coalition of organized communities, domestic non-governmental organizations (NGOs), some allied government agencies, and support from international actors. However, when key government agencies and socio-economic élites are fundamentally opposed to sustainable development initiatives at the grassroots level, much higher levels of community organization, conflict, and domestic and international support appear to be necessary.     

Familiar Kinship? Palaeogenetic and Isotopic Evidence from a Triple Burial of the Cogotas I Archaeological Culture (Bronze Age,Iberian Peninsula)

This paper examines the identification of kinship relations in archaeological multiple burials and advocates the application of different methods and lines of research to clarify such issues in relation to funerary practices. Recognizing family relationships – an important task in research on prehistoric societies – is especially complicated and interpretations have often been made without an adequate empirical basis. Bioarchaeological, isotopic and DNA analyses applied to the triple burial of Los Tolmos (Cogotas I archaeological culture, Iberian Bronze Age) have provided direct information on this issue. In this respect, the new results also imply the need to consider gender constructs in greater depth and to be more open‐minded towards other forms of relationship in the past beyond the traditional heteronormative nuclear family.