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Feasibility of pre-earthquake strengthening of buildings based on cost-benefit and life-cycle cost analysis, with the aid of fragility curves 总被引：1，自引：1，他引：0
There are two fundamental questions this article aims to deal with. First, whether a pre-earthquake strengthening of a large
and heterogeneous building stock (the emphasis here is on building types common in S. Europe), is economically feasible or
not, and second what is the optimal retrofit level for mitigating the seismic risk. To this purpose contemporary decision
making tools, namely cost-benefit and life-cycle cost analyses, are tailored to the needs of the present study, and implemented
with the aid of an ad-hoc developed new software application (COBE06). A method for estimating the reduction in structural
vulnerability due to retrofit is proposed, as well as a methodology to determine the optimum retrofit level using the fragility
curve approach. Finally, the proposed methodology is used in a pilot application that concerns the city of Thessaloniki, and
results are drawn for the feasibility of strengthening the reinforced concrete building stock in this city. 相似文献
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The Athabasca oil sands deposit, Alberta, Canada, is one of the largest known hydrocarbon accumulations. The efficient exploitation of this deposit, as well as other oil sand accumulations throughout the world, is based onin situ recovery and surface mining methods. Quantitative modeling of deposit heterogeneity provides a valuable engineering tool. In the present study, conditional simulation was used to model oil-saturated zones in part of the Athabasca deposit. This technique generates equiprobable models of thein situ variability of essential deposit attributes that honor the available data and their spatial statistics. The application of the technique is based on the delineation of geologically homogeneous zones within the host McMurray Formation, their statistical validity, and the integration of geological interpretations. The geological framework is developed, and subsequently, high resolution conditionally simulated models of three identified hydrocarbon-bearing zones are generated, in terms of the zone boundaries and the percent weight of oil saturation. These models serve as “what-if” tools for risk assessment and future planning. 相似文献
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Mathematical Geosciences - Modern approaches for the spatial simulation of categorical variables are largely based on multi-point statistical methods, where a training image is used to derive... 相似文献
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de Carvalho Joao Pedro Dimitrakopoulos Roussos Minniakhmetov Ilnur 《Mathematical Geosciences》2019,51(6):793-810
Mathematical Geosciences - High-order sequential simulation methods have been developed as an alternative to existing frameworks to facilitate the modeling of the spatial complexity of non-Gaussian... 相似文献
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Nonsmooth dynamics prediction of measured bridge response involving deck‐abutment pounding 
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下载免费PDF全文 Earthquake‐induced deck‐abutment contact alters the boundary conditions at the deck level and might activate a different mechanical system than the one assumed during the design of the bridge. Occasionally this discrepancy between the assumed and the actual seismic behavior has detrimental consequences, for example, pier damage, deck unseating, or even collapse. Recently, an insightful shake‐table testing of a scaled deck‐abutment bridge model 1 , showed unexpected in‐plane rotations even though the deck was straight. These contact‐induced rotations produced significant residual displacements and damage to the piers and the bents. The present paper utilizes that experimental data to examine the validity and the limitations of a proposed nonsmooth dynamic analysis framework. The results show that the proposed approach satisfactorily captures the planar rigid‐body dynamics of the deck which is characterized by deck‐abutment contact. The analysis brings forward the role of friction on the physical mechanism behind the rotation of the deck, and underlines the importance of considering the frictional contact forces during deck‐abutment interaction even for straight bridges, which typically are neglected. Finally, the paper investigates the sensitivity of the rotation with respect to macroscopic contact parameters (i.e., the coefficient of friction and the coefficient of restitution). Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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Predicting the rocking response of structures to ground motion is important for assessment of existing structures, which may be vulnerable to uplift and overturning, as well as for designs which employ rocking as a means of seismic isolation. However, the majority of studies utilize a single rocking block to characterize rocking motion. In this paper, a methodology is proposed to derive equivalence between the single rocking block and various rocking mechanisms, yielding a set of fundamental rocking parameters. Specific structures that have exact dynamic equivalence with a single rocking block, are first reviewed. Subsequently, approximate equivalence between single and multiple block mechanisms is achieved through local linearization of the relevant equations of motion. The approximation error associated with linearization is quantified for three essential mechanisms, providing a measure of the confidence with which the proposed methodology can be applied. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Elias G. Dimitrakopoulos Nicos Makris Andreas J. Kappos 《Bulletin of Earthquake Engineering》2011,9(2):561-579
In this paper the seismic response of inelastic structures with unilateral contact is revisited with dimensional analysis.
All physically realizable contact types are captured via a non-smooth complementarity approach. The implementation of formal
dimensional analysis leads to a condensed presentation of the response and unveils remarkable order even though two different
types of non-linearity coexist in the response: the boundary non-linearity of unilateral contact and the inelastic behaviour
of the structure itself. It is shown that regardless the intensity and frequency content of the excitation, all response spectra
become self-similar when expressed in the appropriate dimensionless terms. The proposed approach hinges upon the notion of
the energetic length scale of an excitation which measures the persistence of ground shaking to impose deformation demands.
Using the concept of persistency which is defined for excitations with or without distinct pulses, the response is scaled
via meaningful novel intensity measures: the dimensionless gap and the dimensionless yield displacement. The study confirms
that contact may have a different effect on the response displacements of inelastic structures depending on the spectral region.
In adjacent inelastic structures, such as colliding buildings or interacting bridge segments, contact is likely to alter drastically
the excitation frequencies’ at which the system is most vulnerable. Finally, it is shown that the proposed approach yields
maximum response displacements which correlate very well with the persistency of real earthquakes for a bridge system with
considerably complex behaviour. 相似文献
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