Performance-Based Vulnerability Assessment of Multi-Story Reinforced Concrete Structures Exposed to Pre- and Post-Earthquake Fire

Post-earthquake fire can potentially bring about much more damage than the earthquake itself. Performing a vulnerability assessment for a structure that has already sustained damage in an earthquake and is then exposed to fire is therefore of importance. This paper describes a performance-based investigation in which applied loads to a structure are appropriately quantified. To do so, a sequential structural analysis is performed on the Life Safety performance level of a three-story reinforced concrete frame selected from a building. For the analysis to be more realistic, the slab is also included in the frame analysis through the concept of effective length. The frame is first subjected to an earthquake load with the PGA of 0.30 g followed by a fire analysis, using the ISO834 fire curve and the iBMB fire curve. The time needed for the structure weakened by the earthquake to collapse under fire is then calculated. As a benchmark, fire-only analysis is also performed for the undamaged frame. Moreover, the effect of thermal spalling is considered in the slabs. The selected frame is evaluated under various failure criteria such as load capacity, displacement, and rate of displacement. The results show that no failure is observed when the frame is exposed to fire alone, either when using the ISO curve or the iBMB curve under various failure criteria. It is also shown that while the PEF resistance based on load capacity criteria under the ISO curve is around 120 minutes, it reduces to about 95 min under the iBMB curve. However, considering the rate of deflection failure criteria, the PEF resistance is around 103 min and 75 min under the ISO and the iBMB curves, respectively. It is then concluded that in the PEF analysis, the iBMB curve is more compatible with the concept of performance-based design than the ISO curve is.     

New species of organic-walled dinoflagellate cysts from the Maastrichtian–Danian boundary interval at Ouled Haddou,northern Morocco

Slimani, H., Louwye, S. & Toufiq, A., September 2012. New species of organic-walled dinoflagellate cysts from the Maastrichtian–Danian boundary interval at Ouled Haddou, northern Morocco. Alcheringa 36, 341–358. ISSN 0311-5518.

Seven new dinoflagellate cyst species and subspecies, previously figured under open nomenclature, from Maastrichtian and Danian deposits of Ouled Haddou (eastern external Rif Chain) in northern Morocco are formally described, and their stratigraphic ranges are clarified. Conosphaeridium lifum sp. nov. and Kenleyia chabaka sp. nov. have fibrous and reticulate wall surfaces, respectively. Oligosphaeridium saghirum sp. nov. is a small cyst with funnel-shaped distal process extremities. Spiniferella cornuta subsp. kacira subsp. nov. and Fibrocysta brevispinosa sp. nov. are distinguishable by their very short processes. Riculacysta chaouka sp. nov. is characterized by its perforate spinose ectophragm. Andalusiella bacita sp. nov. is a small and spindle-shaped cyst with only a single antapical horn.     

Effects of Near-Fault Pulses on Nonlinear Soil-Structure Systems

ABSTRACT

This paper is focused on effects of near-fault pulse characteristics on seismic performance of soil-structure systems considering foundation uplifting and soil yielding. To this end, an extensive parametric study is conducted. Mid-to-high-rise buildings of different aspect ratios (SR) resting on shallow mat foundations are investigated. Different vertical load-bearing safety factors (F_S) of foundation as well as different soil types (i.e. soft to very dense) are considered in this study. Finite element method is used for numerical modeling. The underlying soil is simply modeled with a set of nonlinear springs and dashpots beneath the foundation. Mathematical near-fault pulse models of fling step and forward directivity are used as input ground motions. The results show that reduction in structural drift demands due to nonlinear soil-structure interaction (SSI) is more considerable in the case of short-period pulses compared to long-period ones. In more precise words, significant reduction occurs when pulse-to-fixed-base period ratio falls within 0.7–1.5 in the case of directivity pulses and 0.5–1.4 in the case of fling pulses. It is also demonstrated that the beneficial effects of nonlinear SSI reduce when the number of stories increases.     

THE EFFECTS OF COLLATERALIZABLE INCOME AND DEBT OVERHANG ON ENTREPRENEURIAL INVESTMENT IN AN OPEN REGIONAL ECONOMY*

ABSTRACT We use a two‐period model to analyze the contractual relationship between entrepreneurs and venture capitalists in an open regional economy. First, we describe the first best investment contract, we study the second best investment contract in the presence of private information, and then we examine the impact of an exogenous second‐period income endowment (collateralizable income) on investment by entrepreneurs. Next, we analyze the interaction between entrepreneurs and venture capitalists when the regional government (RG) must pay off a per capita debt (debt overhang) which it finances by taxing successful second‐period entrepreneurs. We show that a rise in the per capita debt has an effect on investment that is analogous to a fall in the second‐period income endowment. In addition, the overhang of the RG's debt discourages entrepreneurial investment.     

The Dialogical Tradition of Iranian Modernity: Monazereh,Simultaneity, and the Making of Modern Iran

Iranian modernity has chiefly been examined in the context of a dialectical antagonism between “traditionalists” and “modernists”—main categories comprised of related sub-headings such as “Islamist” versus “secular,” “reactionary” versus “revolutionary,” and “regressive” versus “progressive.” Following this approach, Iranian adaptations of modernity have often been (de)historicized as a theater of national “awakening” resulting from the toils of secular intellectuals in overcoming the obstinate resistance of traditional reactionaries, a confrontation between two purportedly well-defined and mutually exclusive camps. Such reductionist dialectics has generally overwritten the dialogic narrative of Iranian modernity, a conflicted dialogue misrepresented as a conflicting dialectic. It has also silenced an important feature of Iranian modernity: the universally acknowledged premise of the simultaneity and commensurability of tradition with modernity. The monazereh (disputation or debate) is the account of the interaction between rival discourses that engaged in opposing, informing, and appropriating each other in the process of adapting modernity. Narrativizing the history of Iranian modernity as the conflict between mutually exclusive binaries overlooks its hyphenated, liminal¹1 The notion of liminality has been theorized in different capacities. The anthropologist Victor Turner first used the idea of liminality in his study of tribal and religious rituals during which an initiate experiences a liminal stage when he belongs neither to the old order nor yet accepted into his new designation. Victor Turner, The Ritual Process: Structure and Anti-structure (Chicago, IL: Aldine, 1969). Turner’s insight has been expanded to investigate the general question of status in society. See, for example, Caroline Walker Bynam, Fragmentation and Redemption (New York: Zone Books, 1992), 27–51. Bynam applies Turner’s notion of liminality to the lives of Medieval female saints, arguing that Turner’s liminal passage applies more readily to the male initiate but does not in most cases reflect the experience of female initiates in Medieval times. Jungian psychology has shifted the focus from liminality as a stage in social movement to a step in an individual’s progress in the process of individuation. Jeffrey Miller, The Transcendent Function (New York: State University of New York Press, 2004), 104. See also: Peter Homans, Jung in Context: Modernity and the Making of a Psychology (Chicago, IL: University of Chicago Press, 1979). Others have used liminality to describe cultural and political change, have prescribed its application to historical analysis, or have made reference to “permanent liminality” to describe the condition in which a society is frozen in the final stage of a ritual passage. Respectively, Agnes Horvath, Bjorn Thomassen, and Harald Wydra, “Introduction: Liminality and Cultures of Change.” International Political Anthropology (2009); Agnes Horvath, Modernism and Charisma (Basingstoke: Palgrave, Macmillan, 2013); and Szakolczai, Reflexive Historical Sociology (New York: Routledge, 2000), 23. Finally, the notion of liminality has been applied to the analysis of mimetic behaviour and to the emergence of tricksters as charismatic leaders, given the association of the figure of the trickster with imitation. Respectively, Agnes Horvarth, Modernism and Charisma (Basingstoke: Palgrave, Macmillan, 2013), 55; and Arpad Szakolczai, Reflexive Historical Sociology (New York: Routledge, 2000), 155. This latter sense seems to apply to the history of Iranian modernity, for the anxiety of imitation was indeed one of its central concerns, and influential figures such as Mirza Malkum Khan (1833–1908) were sometimes perceived (though this was not universally the case) as saviours or tricksters alternatively by different people. On this issue, Fereydun Adamiyat notes how different people had different views of Malkum. The “despotic prince Zill al-Sultan” considered him to be of equal status to Plato and Aristotle. Aqa Ibrahim Badayi’ Nigar thought he was devoid of “the fineries of knowledge and literature (latīfah-i dānish va adab). Minister of Sciences and chief minister Mukhbirul Saltanah Hidayat thought “whatever Malkum wrote has been said in other ways in [Sa’di’s] Gulistan and Bustan.” Fekr-e Azadi (Tehran: Sukhan, 1340/1961), 99. Mehdi Quli Khan Hedayat’s view of Malkum Khan was summed up in these words: “This Malkum knew some things in magic and trickstery and finally did some dishonorable things and gave the dar al-fonun a bad reputation,” Khaterat va Khatarat (Tehran: Zavvar, 1389/2010), 58. Having said that, my use of the notion of liminality, though informed by the theoretical perspectives cited above, diverges from them in one important aspect: liminality as perceived by contemporary theory seems to be based on a pre-/post- understanding of non-liminal statuses accompanied by a desire on the part of the subject to emerge from the liminal state. This approach does not explain liminality as a site for the synthesis of coexisting identities. The munāzirah is precisely the account of such a process. In the context of Iranian modernity, the discourse of tradition was not perceived as prior to the discourse of modernity, as we shall amply see. In fact, European civilizational progress was deemed to have resulted from the successful implementation of Islamic principles. Therefore, while the history of Iranian modernity can still be analyzed as a liminal stage where a weakened old order meets the promise of a new order, it must be understood in terms of the encounter of simultaneous and parallel discourses. It is in this sense that liminality is employed in this study.View all notes identity—a narrative of adaptation rather than wholesale adoption, of heterogeneity rather than homogeneity, of dialogues rather than dialectics. The monazereh is the account of modern Iranian histories.     

“Neither Ākhūnd nor Fukulī”: Munāzirah and the Discourse of Iranian Modernity

Iranian modernity has chiefly been examined in the context of a dialectical antagonism between “traditionalists” and “modernists”—the main categories comprised of related sub-headings such as “Islamist” versus “secular,” “reactionary” versus “revolutionary,” and “regressive” versus “progressive.” Following this binaristic approach, Iranian adaptations of modernity have often been (de)historicized as a theatre of national “awakening” resulting from the toils of secular intellectuals in overcoming the obstinate resistance of traditional reactionaries, a confrontation between two purportedly well-defined and mutually exclusive camps. Such reductionist dialectics has generally overwritten the dialogic narrative of Iranian modernity, a conflicted dialogue misrepresented as a conflicting dialectic. It has also silenced an important feature of Iranian modernity: the universally acknowledged premise of the simultaneity and commensurability of tradition with modernity. The monāzereh (disputation or debate) is the account of the interaction between rival discourses that engaged in opposing, informing, and appropriating each other in the process of adapting modernity. Narrativizing the history of Iranian modernity as the conflict between mutually exclusive binaries overlooks its hyphenated, liminal identity—a narrative of adaptation rather than wholesale adoption, of heterogeneity rather than homogeneity, of dialogics rather than dialectics. The monāzereh is the account of modern Iranian histories.