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91.
This article presents a methodology for the seismic vulnerability assessment of current buildings, suitable for the study of historical centers at the regional scale. The applicability is demonstrated with reference to four case studies: the historical center of the city of Foggia (Italy) and three other small towns of this province, for a total of 4519 housing units. Field data were collected by several teams of technicians by means of a survey form, provided in electronic format. The subsequent data processing and drawing of vulnerability maps was performed using geographical information system (GIS) technology. The collected data were used also for the validation of the algorithm, by comparing the results with those of the methodology used by the Gruppo Nazionale per la Difesa dai Terremoti (GNDT [Italian National Group for Defense Against Earthquakes]), which is widely adopted in Italy. The results of the research study and the application showed some critical points, related to the poor nature of the information collected and to the reliability of the final results. These issues are analyzed and discussed, proposing a strategy for improving the methodology.  相似文献   
92.
孙兵 《安徽史学》2016,(5):55-62
从湖广等地的情况来看,有明一代,偏安之地城池迟迟未建、安定时期任其圮坏等"不修城"的情形颇为常见。官民财力匮乏、不利的地形环境、官员因循苟且、舆论习于将修城视为劳民伤财等不利条件限制之下,各地官民修城消极懈怠的状况相当普遍,近乎世风。这种始终无法消除的消极因素对明代的筑城政策及其实施产生了多方面的影响:明前期修筑、维护城池主要限于驻军各地,对于其他众多普通州县并未从严要求,以示体恤民情,以免招致民怨;明廷对各地修城频频申令、施压,但收效欠佳;各地往往迫于"寇盗"威胁及上司督责的压力才兴工修城,而前者的作用尤为突出。学者所谓明代"一贯积极、严厉的"筑城政策促成了各地广修城池的看法似乎并不完全切合史实,一些流行已久的相关认识亦有修正、澄清的必要。  相似文献   
93.
故宫灵沼轩是一座砌体结构与钢结构组合而成的文物建筑。为有效对其保护,采用数值模拟方法,研究了风振作用下结构的动力响应。基于灵沼轩结构现状,建立了有限元模型。通过模态分析,获得了灵沼轩的基频和主振型;通过对结构施加y向脉动风荷载,研究了重现期为50年时结构的风振特性,评价了结构在风荷载作用下的安全现状。结果表明:灵沼轩结构基频为f=5.75Hz,在x及y向的主振型以局部振动为主;脉动风压作用下,结构保持稳定振动状态,但顶部位置加速度峰值偏大。另风压作用下,砌体结构部分位置的抗拉强度不足,应在日常维护中予以重视;钢结构部分由于材料强度大,因而不会出现强度破坏。  相似文献   
94.
Thin-folded Shell for the Renewal of Existing Wooden Roofs   总被引:1,自引:0,他引:1  
In this article, a technique for the renewal of historic building wooden roofs is presented. The solution can be used for the strengthening of existing wooden roofs against excessive lateral thrusts on the peripheral wall or for the recovery of the attics, as it allows removing the existing structural elements, such as possible wooden truss-works of no artistic value. With minor adaptations, the solution can be addressed to enhance the building seismic performance. The technique is minimally impairing on existing buildings and can be applied also in new constructions.

The technique is based on the construction of a thin folded shell, overlaying the existing pitches. Emphasis is given to lightweight folded shells, obtained by overlaying thin plywood panels on the existing roof rafters and planks, without modifying the overall architectural layout.

The technique conceptual design is discussed and a simplified analytical method is proposed, which allows for the clarification of the role of each structural component and can be adopted for the folded shell proportioning and design. The analytical results are validated against numerical results obtained with reference to some case studies. Ultimately, emphasis is given to the detailing, whose correct execution is mandatory for the success of the proposed structural intervention.  相似文献   

95.
ABSTRACT

Guanhua (official language), Guoyu (national language), and Putonghua (common language) are generally regarded as different names for the same thing in different eras, but from the perspective of cultural history, there are many subtle semantic differences between these three concepts, symbolizing how different social classes and political groups defined their particular experiences, expectations, and efforts to take action. Guoyu, which replaced Guanhua in the late Qing Dynasty, is closely bound up with the construction of modern nationalism. In the 1930s, leftist intellectuals imbued Putonghua with strong proletariat attributes and overtones of indigenous and ethnic equality, wielding it as a tool for critiques against Guoyu. Although Putonghua returned to certain key positions of Guoyu after the mid-1950s, it putatively emphasized the legacy of the leftist language movement, and represented a new political identity. Through these “proper names” for the standard language, it was possible not only to launch a political and social “revolution,” but also to smooth over the historical rifts that this engendered, by repeatedly revising the concepts of “written” and “standard” to form a linear national narrative.  相似文献   
96.
ABSTRACT

Historical centers are always composed of masonry building aggregates often designed without respecting seismic design criteria. The current seismic Italian code does not foresee a clear calculation method to predict their static nonlinear behavior. For this reason, in this article the seismic response of structural units into masonry aggregates has been predicted through a simplified modeling approach. The implemented procedure has been calibrated on the results of a numerical model performed by using the Equivalent Frame Method (EFM), implemented within a Finite Element Method (FEM) calculation program, used to investigate a basic building compound representative of the constructive techniques developed in the past decades in the Southern Italy.

First, the whole aggregate has been modeled and analyzed in the nonlinear static field in order to evaluate the seismic behavior of both intermediate and head structural units.

Later on, the seismic response of these structural units, considered as isolated structures, has been assessed by considering in simplified way their position in the aggregate, as well as the influence of other constructions.

Finally, the achieved results on the above single analysis cases have been compared with those deriving from the investigation of the whole building compound, allowing to confirm the effectiveness of the proposed novel analysis procedure.  相似文献   
97.
古建筑具有重要的文化价值和经济价值,是重要的不可再生文化遗产。中国的古建筑以木为主要结构,而木结构的耐火等级低,这就造成了中国古建筑面临了一个极大的隐患——火灾,因此对古建筑木构件的防火处理与性能的研究迫在眉睫。为此,试验选取3种不同的木材和5种不同的阻燃剂作为研究对象,首先对涂覆不同阻燃剂的木材进行表观特征测量,然后分别采用热重分析法和扫描电子显微镜测试技术进行表征测试,最后分析阻燃木材的各种力学性能测试。研究结果表明:喷涂阻燃剂的木材其性能效果均优于未喷涂的木材。特别针对未涂油漆的原木构件,可以采用有机磷杂环阻燃剂或磷—氮类阻燃剂;普通油漆的木构件则适用于磷—氮类阻燃剂,而处理桐油木构件应用磷—氮类阻燃剂或阻燃油。  相似文献   
98.
20世纪初年,民族主义成为中国最主要的社会思潮,与此同时,中国史学的话语权也发生了变动,以"史界革命"相号召的"新史学"渐成主流。具有近现代意义的西藏历史研究也于此时启动,体现了现实救亡图存的政治诉求,在历史思想方面实践传统的藩属话语体系向近现代民族国家话语转变,在西藏历史研究文本中近现代民族国家观念得以初步确立。  相似文献   
99.
Trace element compositions of raw clay, fired clay and Roman ceramic building material (CBM) from Carpow Roman fortress, Newburgh, Scotland and the city of York, England have been determined through the use of inductively coupled plasma-mass spectrometry (ICPMS). It is confirmed that the firing of clay does not disturb any of the sample’s trace element composition and that trace element protolith identification is an applicable tool for fingerprinting the source of material used in CBM construction. It is also demonstrated through the particular proportions of LREE/HREE; Th/Co; La/Sc; La/Lu; Eu/Sm values on CBM from Carpow that these material were likely manufactured from clay used in the York Roman tile manufacturing industry, therefore suggesting importation. The transport of CBM from York to Carpow provides a useful addition to known examples of the long-distance shipping of CBM. It is postulated that similar analysis to that conducted here could be used to identify important trade networks within the Roman Empire.  相似文献   
100.
The cardinal role of tragedy in Morgenthau's theory of international politics has hardly gone unnoticed. Indeed there is now a considerable corpus of literature that established the importance of tragedy as a central concept around which Morgenthau's theory revolved. This paper builds upon this already developed framework and employs tragedy not as an analytical category but as a metaphor employed by Morgenthau to approach the nation-state. It is claimed that the idea of tragedy underpinned his notion of the nation-state inasmuch as it did his view of individual human beings. As such the notion of tragedy informed consistently Morgenthau's analyses of national tragedies that were like the self-defeating nationalism of Germany. It also informed his efforts to avert potential national tragedies from materialising as his attempts to influence US foreign policy demonstrated. It is finally claimed, that far from a descent into despair, Morgenthau's realism signified a conscious effort to go beyond the tragedy of the nation-state.  相似文献   
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