Current Issue : October - December Volume : 2019 Issue Number : 4 Articles : 5 Articles
.e phenomenon of hospital functional interruption has been widely observed in the historical moderate-strong earthquakes,\nindicating that hospital functionality cannot be well considered in the current seismic design methods. .e concept of seismic\nresilience pays enough attention to postearthquake functionality of buildings, and it is particularly significant for the urban\nhospitals which play critical role in the urban postearthquake rescue and recovery. .is study proposes a framework to assess the\nseismic resilience of urban hospitals, by incorporating the fault tree analysis (FTA) to consider the interdependency between the\ndamage of nonstructural components and the functionality of medical equipment, as well as the effect of external supplies on the\nfunctionality of hospital. .e proposed framework is then applied to a case-study hospital, and the results indicate that this\nhospital needs 1.1 days to resume emergency functionality under REDi repair strategy after design basis earthquake (DBE), while it\nneeds 28.8 days to resume emergency functionality under REDi repair strategy after maximum considered earthquake (MCE). It is\nfound that the seismic resilience of this hospital after MCE cannot meet the community requirements on the recovery time, and\nnecessary measures are needed to improve the seismic resilience. .e proposed framework provides the quantitative results of\nseismic resilience assessment in the preearthquake environment and can further support emergency response planning and\nseismic retrofits strategies....
Stress interference of multiplied fractures has significant influences on the propagation\nbehavior of hydraulic fractures in roads, bridges, clay formations, and other forms of engineering. This\npaper establishes a crossing criterion and initiation angle model with comprehensive consideration of\nremote stress, stress intensity near the tip of fracture, and stress interference of multiplied fractures.\nCompared with the existing crossing criterion and initiation angle model, the ability to cross natural\nfractures decreases. Furthermore, the secondary initiation angle decreases with consideration of\nmultiplied fracture propagation. The length of hydraulic fractures and natural fractures has little\ninfluence on the secondary initiation angle. With the increase in fracture space, the stress interference\nbetween fractures decreases, and as a result, the initiation angle begins to increase and then decrease.\nDiffering from the propagation behavior of single fracture, the initiation angle basically does not vary\nwith the increasing of net pressure under the high intersection angle between hydraulic fractures and\nnatural fractures. Under a low intersection angle condition, the bigger the net pressure is, the smaller\nthe initiation angle is. These results have great significance when analyzing the propagation behavior\nof multiplied fractures in real-world applications....
A new method for analysis of counter beams is presented in the paper. The\nanalysis has taken into account their stiffness EI, Winklerâ??s space with modulus\nof subgrade reaction k and equality deformities of the foundation beam\nwith the ground. The solution is found by using the numerical analysis of the\nWinklerâ??s model, with variation of different moduli of the subgrade reaction\nk2 outside the force zone r , while under the force P exists the modulus of the\nsubgrade reaction k, up to the definition of minimum bending moments. The\nexponential function k 2(r ), as the geometric position of the minimum moments\nis approximately assumed. From the potential energy conditions of the\nreciprocity of displacement and reaction, the width of the zone r and the\nmodulus of the subgrade reaction k 2 are explicitly determined, introducing in\nthe calculation initial and calculation soil displacement wsi successively. At\nthe end of the paper, it presented numerical example in which the influence\nof k and k1 values on bending moments of the counter beam is analyzed. The\nessential idea of this paper is to decrease the quantity of the reinforcement in\nthe foundations, beams, i.e . to obtain a cost-efficient foundation construction....
The design and construction of tall and slender steel structures is always\nchallenging. This paper discusses several design aspects (structural information,\nanalysis methods, applied loads, cost optimisation) and a case study regarding\nthe design and construction of 10-m-tall windbreak panels for a\nGreek electricity producer. The purpose of the panels is to reduce wind turbulence\nand improve the performance of the electricity producerâ??s air-cooled\ncondenser. In this case, the main wind load acts in the longitudinal direction,\nwith friction inducing only a small amount of wind load in the transverse direction.\nThe steel columns are constructed from 10-m-tall hot-rolled IPE 270\n(S235) cross-sections, and are supported by cables in the longitudinal direction\nand bracing systems in the transverse direction. Concrete anchorages\nand concrete footings are used for the cables and steel columns, respectively.\nSystem optimisation is investigated in terms of the steel weight, cable length,\nand overall cost, and practical issues are explained regarding technical decisions.\nFurthermore, the construction details, construction methods, and cost\nestimation are discussed....
In order to make informed decisions on routine maintenance of bridges of expressways, the hierarchical regression analysis\nmethod was used to quantify factors influencing routine maintenance cost. Two calculation models for routine maintenance cost\nbased on linear regression and time-series analysis were proposed. The results indicate that the logarithm of the historical routine\nmaintenance cost is the dependent variable and the bridge age is the independent variable. The linear regression analysis was used\nto obtain a cost prediction model for routine maintenance of a beam bridge, which was combined with the quantity and price, and\nverified by a physical engineering example. In order to cope with the cost changes and future demands brought about by the\nemergence of new maintenance technologies, the time-series analysis method was used to obtain a model to predict the engineering\nquantities for the routine maintenance of a bridge based on standardized minor repair engineering quantities. Taking\ninto account the actual cost of the minor repair project as well as the time-series analysisâ?? sample size demands, the annual\nengineering quantity was randomly decomposed into four quarterly data quantities, and the time-series analysis result was verified\nby physical engineering. These results can improve the calculation accuracy of the routine maintenance costs of reinforced\nconcrete beam bridges. Furthermore, it can have a certain application value for improving the cost measurement module of bridge\nmaintenance management systems....
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