Collapses of school or dormitory buildings experienced in recent earthquakes raise the issue of safety as a major challenge for decision makers. A school building is ‘just another structure’ technically speaking, however, the consequences of a collapse in an earthquake could lead to social reactions in the complex aftermath of a seismic tremor more than any other type of structure may possibly cause. In this paper a school building that collapsed during 2011 Tabanli, Van Earthquake in eastern Turkey, is analysed in order to identify the possible reasons that led to collapse. Apart from the inherent deficiencies of RC buildings built in Turkey in the 80's and 90's, its structural design exhibits a strikingly high asymmetry. In the analyses conducted, much attention has been given to the direction of the earthquake load and its coincidence with the bi-axial structural response parameters. The failure of the structure to comply with the 1975 Code, in vigor at the time of construction, has also been evaluated with respect to the structure’s collapse. Among the parameters that controlled the collapse, the high plan asymmetry and the coincidence of the vulnerable directions with the dominant shaking direction were critical, as well as the underestimation of the seismic hazard and the lateral design force level, specified by the then Turkish Earthquake Code.
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The majority of houses in the Groningen gas field region, the largest in Europe, consist of unreinforced masonry material. Because of their particular characteristics (cavity walls of different material, large openings, limited bearing walls in one direction, etc.) these houses are exceptionally vulnerable to shallow induced earthquakes, frequently occurring in the region during the last decade. Raised by the damage incurred in the Groningen buildings due to induced earthquakes, the question whether the small and sometimes invisible plastic deformations prior to a major earthquake affect the overall final response becomes of high importance as its answer is associated with legal liability and consequences due to the damage-claim procedures employed in the region. This paper presents, for the first time, evidence of cumulative damage from available experimental and numerical data reported in the literature. Furthermore, the available modelling tools are scrutinized in terms of their pros and cons in modelling cumulative damage in masonry. Results of full-scale shake-table tests, cyclic wall tests, complex 3D nonlinear time-history analyses, single degree of freedom (SDOF) analyses and finally wall element analyses under periodic dynamic loading have been used for better explaining the phenomenon. It was concluded that a user intervention is needed for most of the SDOF modelling tools if cumulative damage is to be modelled. Furthermore, the results of the cumulative damage in SDOF models are sensitive to the degradation parameters, which require calibration against experimental data. The overall results of numerical models, such as SDOF residual displacement or floor lateral displacements, may be misleading in understanding the damage accumulation. On the other hand, detailed discrete-element modelling is found to be computationally expensive but more consistent in terms of providing insights in real damage accumulation.
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A decade ago many gushed at the possibilities of 3D printers and other DIY tech. Today makers are increasingly shaking off their initial blind enthusiasm to numerically control everything, rediscovering an interest in sociocultural histories and futures and waking up to the environmental and economic implications of digital machines that transform materials. An accumulation of critique has collectively registered that no tool, service, or software is good, bad, or neutral—or even free for that matter. We’ve arrived at a crossroads, where a reflective pause coincides with new critical initiatives emerging across disciplines.What was making? What is making? What could making become? And what about unmaking? The Critical Makers Reader features an array of practitioners and scholars who address these questions. Together, they tackle issues of technological making and its intersections with (un)learning, art and design, institutionalization, social critique, community organizing, collaboration, activism, urban regeneration, social inequality, and the environmental crisis.
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