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1.
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
2.
近海环境地球化学调查研究历史与现状 总被引:1,自引:0,他引:1
近海环境地球化学的研究是一支新兴的发展中的边缘性分支学科,由于环境问题的日益突出,该学科发展较为迅速。通过回顾我国近海环境地球化学调查的历史和综述当今国外该学科的研究现状,概括了该学科的主要进展,并指出存在的问题和今后的发展方向。 相似文献
3.
Spatio-temporal variability of small copepods (especially Oithona plumifera) in shallow nearshore waters off the south coast of South Africa 总被引:1,自引:0,他引:1
Francesca Porri Christopher D. McQuaid William P. Froneman 《Estuarine, Coastal and Shelf Science》2007,72(4):711-720
Although small copepods are one of the main dietary sources for many commercially important fish, their role in the pelagic trophic dynamics has traditionally been underestimated due to the methodology commonly used in plankton sampling. Temporal variation in abundance of adults and nauplii of small copepods (particularly Oithona plumifera) in nearshore waters on the south coast of South Africa was investigated fortnightly over 14 months at site (km) and location (100 m) scales. Sampling was within <500 m of the shore, where depth was ca. 10 m, using vertical hauls of an 80-μm mesh plankton net from 1 m above the seabed to the surface. Twenty-seven adult copepod taxa were recorded, but Oithona spp. was consistently the most abundant. Taxon richness was 7–19 on each sampling occasion. There was strong temporal variation (Oithona varied between 0 and 2300 m−3), but much of this was short-term variability (e.g. between consecutive sampling sessions), with no seasonality or other long-term discernable patterns. There were periods of consistently low numbers, but very high numbers often followed samples with low abundances. Nor was there spatial structure at the location scale, though numbers differed between sites. Despite considerable variability at the location scale within sites, Kenton consistently showed higher densities than High Rocks. Separate analyses, with Bonferroni adjustment, showed that this difference was significant on eight out of 21 occasions for Oithona, six for other pelagic copepods and three for nauplii. This suggests that hydrodynamics favour aggregation of plankton at Kenton. A high degree of short-term variability, with a tendency for aggregation of small zooplankton at certain sites has implications for both pelagic processes and food-web links between the benthic and pelagic environments. 相似文献
4.
贵州煤矿地质工程咨询与地质环境监测中心,由于市场定位准确,加强经营管理,树立品牌意识,尊重人才,加大人才培养力度,积极推进人事制度和分配制度改革,完善激励约束机制,使单位经济效益稳步上升,职工收入不断提高。 相似文献
5.
6.
This article presents a numeric comparative study of the inelastic structural response of base isolated buildings. The comparative study includes the following isolation systems: laminated rubber bearings, New Zealand one, pure friction and the frictional pendulum ones. The study is based on obtaining non‐linear response spectra for various design parameters using six earthquake records. Usually the base isolation of a new building seeks to maintain the structure in the linear elastic range. The response of old weak buildings or the response of new ones subjected to extreme earthquakes may not be, necessarily, in the aforementioned ideal elastic range. Consequently, it is important to characterize the response of isolated buildings responding inelastically. A conclusion from this research is that the isolators affect significantly the structural response of weak systems. Rubber isolators seem slightly less sensitive to plastification that may occur in the structure compared to friction isolators. Ductility demands in the structure are affected significantly by friction and neoprene protected systems, in particular sliding ones where larger demands are obtained. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
7.
对14根钢筋混凝土矩形梁进行抗剪加固试验,研究在受剪区粘贴高强复合纤维的加固效果和设计方法。主要分析了纤维粘贴量、包裹方法和剪跨比等因素对钢筋混凝土加固梁受剪性能的影响和作用。对试验梁进行了全过程分析,并基于试验结果,提出了抗剪加固设计中复合纤维设计应变的合理取值和计算公式,阐述了具体加固设计模型和设计方法。 相似文献
8.
探讨了45Mn2钻杆接头的各种热处理工艺降综合机械性能,应用断裂力学优选最佳热处理工艺,并已投入生产。 相似文献
9.
10.
一次强暴雨形成的动力机制 总被引:6,自引:0,他引:6
分析了1998年7月武汉强暴雨的天气演变特征,并从理论上探讨了强暴雨形成的动力机制。结果表明:低空急流先于暴雨生成,暴雨最强时低空急流也最强;高空急流入口区右侧及低空急流左侧非热成风梯度的存在,使得中尺度不稳定波的波振幅出现空间不稳定现象,高空急流右侧不稳定波的波振幅和低空急流左侧不稳定波的波振幅向暴雨区增加,暴雨区恰为这两支波叠加后振幅最大的区域,高低空急流耦合下的非热成风、中尺度对流-对称不稳定可能是这类强暴雨产生的动力原因之一。 相似文献