故宫太和殿木构件现状分析及加固方法研究

为加强对古建筑的维修保护,故宫博物院对太和殿进行了勘查,发现如下木构件问题:西山挑檐檩跨中挠度过大;三次间正身顺梁及山面扶柁木榫头位置下沉10cm;明间藻井下垂13cm,井口爬梁已经开裂.通过运用结构力学相关方法,对这些构件的结构现状进行理论分析,研究了问题产生的原因,讨论了相应的加固方案,解决了这些问题.结果表明:西山挑檐檩虽然挠度较大,但强度满足要求,不需要加固;山面扶柁木榫头下沉的原因是局部受弯强度不足,但已通过支顶解决该问题;正身顺梁榫头下沉的可能原因是材料老化,局部受拉、弯、剪强度不足,通过采用钢木组合结构进行了加固;藻井下沉的原因是木材老化,井口爬梁抗弯及抗压承载力不足,通过采用扁钢箍加固的方法进行了加固.研究结果可为古建筑保护及修缮提供参考.     

明清古建筑木结构典型抗震构造问题研究

为保护古建筑,采用分类统计方法,研究了我国明清古建筑木结构的典型抗震构造问题。基于大量工程现场勘查结果,对古建筑木结构的典型抗震构造问题进行了归纳汇总,分析了原因,提出了加固建议;基于典型算例,对古建筑木结构加固方法进行了深入论证。结果表明:我国古建筑木结构的柱子、斗棋、榫卯节点、梁架、屋顶等各部位都容易产生开裂、糟朽、变形、拔榫等抗震构造问题并影响结构的抗震性能,而这些问题的产生原因主要与木结构的构造特征、木材材料性质及施工保养等因素有关;对这些抗震构造问题及时采取合理有效的加固措施,可减轻或避免结构产生的震害。     

青海吾屯下寺民居木构件设计研究

中国传统的木构架建筑,将木材这一主要的结构材料充分运用并将其性能发挥的淋漓尽致,在许多方面可以与现代建筑中的钢筋混凝土材料相媲美。所谓＂木构架＂,就是建筑的结构与骨架,一般由柱、梁、檩、枋、椽以及斗拱等构件组成,这些构件按照一定的模数合理排列布置,构成所要营造的建筑的整体支撑框架,从而起到稳固建筑整体与承托屋顶等部分重量的作用。本文以青海省黄南藏族自治州同仁县吾屯下寺当地木构架民居构建过程中用到的木构件为例,与中国传统木构架中的木构件进行对比研究。     

江右赣系风土建筑谱系基质构成概观

面对城乡改造进程的快速发展,如何保存和传承地域风土建筑精华是目前亟待开展的重要研究方向。赣语方言区内有三个风土区系,即以抚州为风土重镇,以抚广片方言片区为核心范围的临川风土区系;以南昌为风土重镇,以昌靖片方言片区为核心范围的豫章风土区系;以吉安为风土重镇,以吉茶片方言片区为核心范围的庐陵风土区系。从人文地理的视角,以赣语方言区为参照,可梳理出江右赣系匠作的中心,在聚落形态、宅院形制、结构类型、装饰特征和匠作风习五个方面提炼出其谱系基质;在此基础上,进一步阐释江右赣系建筑谱系与东南地区其他谱系之间的关联和影响。江右赣语方言区聚落形态的基质包括：两重山水、“以水绕田,凿池而居”、双层防御、“前礼后居,长列布局”和“礼居分离,向心布局”;宅院形制的基质包括：“明堂”格局与比例,过白、四水归堂和明堂坑池;结构类型的基质包括：“金字”扇架、插接抬梁式结构与“一檩三件”、穿枋挑檐和插接或搭接檐檩出檐、清水青砖空斗墙;装饰的基质包括：扁平的雕饰、构造化装饰、乐平戏台雕饰;匠作风习的基质包括：定点、定向和定时、游梁和金斗屋、“压白”尺法、梁纱帽、莲花撑和扶栋檩。本研究对该地域风土建筑遗产价值的研判和保...     

高陡濒倾土遗址边坡加固后的变形行为

土遗址边坡加固不同于一般边坡加固是在于其文物属性。对于高陡濒临倾倒的边坡一般采取“去头补脚”的方式进行处理,而对于土遗址边坡须遵从原状保护的原则。土遗址边坡加固后演化过程具有独有的特征。为此,边坡的变形监测资料对分析边坡变形演化规律及边坡稳定性至关重要。采用南瑞大坝全自动变形监测仪对交河故城513亚区濒倾边坡加固后的变形进行实时监测,精度达0.01mm。通过对变形数据分析,阐明其变形行为特征,进而挖掘加固后边坡演化过程。研究表明,加固后边坡表现出明显的非线性特征,具体表现为常态稳变和局部突变特性;变形可划分为明显的趋势性变形、周期震荡式变形和随机性变形。研究结论对于类似土遗址边坡加固效果评价具有重要意义     

故宫古建筑结构可靠性问题研究

为保护故宫古建筑,采用归类汇总与理论分析相结合的方法,研究了故宫古建筑木结构的典型残损问题。基于大量现场勘查及理论分析结果,对故宫古建筑存在的典型可靠性问题进行了分类汇总,分析了产生这些问题的原因,提出了可行性加固建议。通过典型算例,对古建筑木结构加固方法进行了深入论证。结果表明:故宫古建筑木结构的柱子、斗栱、榫卯节点、梁架、屋顶、墙体等各部位都容易产生开裂、糟朽、变形、拔榫等可靠性问题并影响结构整体的稳定性能,而这些问题的产生原因主要与木结构的构造特征、木材材料性质及施工保养等因素有关;针对不同的可靠性问题,采取合理有效的加固方法,可提高古建筑结构整体的稳定性能。     

古建糟朽角梁抗弯性能数值模拟研究

为保护木构古建筑,以故宫抚辰殿东北角梁为例,采用数值模拟方法,研究了角梁糟朽后剩余部分的抗弯性能。根据该角梁的仔角梁糟朽现状,建立了基于剩余部分的有限元模型,进行了内力和变形分析。基于数值模拟结果,获得了角梁剩余部分拉、压、弯、切应力及变形情况。结果表明:仔角梁糟朽情况下,角梁剩余截面仍能满足内力和变形要求,其主要原因在于老角梁已提供充足的承载截面。     

探讨道路桥梁维修与加固施工技术

社会经济的发展与道路的通畅密不可分。中国正在积极采取科学有效的道路养护和管理措施,以提高公路桥梁工程的质量。科学的维修加固技术可以有效地延长公路桥梁的使用寿命,确保公路运输的可持续发展。加强对路桥养护管理重点问题的深入分析,采取预防性养护措施,确保路桥工程的全面改善。探索维修技术,采用先进技术,提高路桥工程质量,确保人民生命财产安全。     

故宫太和殿二层斗拱竖向加载试验

为了更好地保护古建筑,采取静力试验方法,以故宫太和殿二层平身科、柱头科、角科斗拱为对象,研究了竖向荷载作用下斗拱的受力性能。基于上述3种斗拱构造特征,制作了1∶2比例模型,进行了竖向加载试验,讨论了不同斗拱在荷载作用下的破坏形式、内力及变形特征,归纳了斗拱的竖向刚度计算模型。结果表明:竖向荷载作用下,太和殿二层斗拱的坐斗及与之相交的头翘、正心瓜拱容易产生破坏,且模型倒置时下层构件受力要小于上层构件。对于不同斗拱而言,斗拱极限承载力:平身科角科柱头科;斗拱变形及残余变形量:柱头科角科平身科;斗拱延性:角科柱头科平身科。竖向荷载作用下,太和殿二层斗拱的竖向刚度计算模型可简化为三折线段形式。     

古代丝织品的丝素蛋白加固保护

目前采用一般的物理加固和化学加固方法对脆弱丝织品进行保护存在着一定的缺陷和限制,为此,本工作利用与丝织品具有同源性和亲和性的丝素蛋白对清代丝织品进行加固保护。清代丝织品在丝素蛋白浓度为1.0%、戊二醛浓度为0.005%、浸渍时间(T1)为40min、浸渍时间(T2)为60min的较优工艺条件下,断裂强力从5.22N提高到10.68N,断裂伸长率从3.24%提高到4.12%,硬挺度略有改变,提高了0.08×10-2mN.m。同时,利用FT-IR、TG和SEM等对加固前后清代丝织品的结构进行了表征。实验结果显示,利用丝素蛋白加固丝织品文物是一种有效的方法,在提高古代丝织品强度的同时,不对丝织品的外观与手感造成影响。     

Numerical Simulation and Seismic Fragility Analysis of a Self-Centering Steel MRF with Web Friction Devices

This article presents the seismic fragility analysis of a self-centering steel moment-resisting frame (SC-MRF) with web friction devices. A detailed numerical model of the SC frame was developed using the Open System for Earthquake Engineering Simulation (OpenSees) and the elastoplastic responses of the SC-MRF were studied, including the strength degradation under cyclic loading, tendon rupture, beam buckling, bolt bearing and friction loss, etc. The proposed simulation approach is validated by comparing the simulated results with those in existing hybrid-simulation tests, quasi-static pushover test and low cyclic tests, where good agreement is observed. In addition to the well-established performance limit states (i.e., immediate occupancy, collapse prevention and global dynamic instability), two unique performance limit states (i.e., the recentering and repairable limit states) are defined for the SC-MRF. Finally, incremental dynamic analyses are conducted to evaluate the seismic fragilities regarding the five performance limit states.     

Against Nostalgia: Place and Memory in Myles Lalor's ‘Oral History’

Western thought tends to see aboriginal identity as dependent upon a particularistic ubiety. Myles Lalor, a New South Wales Aborigine, proposes another kind of identity which recognises that for his generation the tie between place and people is liable to be ruptured, but asserts that wherever there are Aboriginal people there are other places to be Aboriginal. Lalor presents his refusal of nostalgia in the form of an autobiography which articulates memories through a sense of his own agency.     

Economic policy and development in Austrian Lombardy, 1815-1859

The question of economic integration is not new in Europe. Historically, the birth and construction of nation-states was important in stimulating interest in the systematic relationships between political and economic integration. In the case of the multinational structure of the Habsburg monarchy in the nineteenth century, the result was an economic policy that, for political reasons, aimed to unite the material interests of a state that was completely heterogeneous in other respects. Lombardy was a case in point. Traditionally the region had been in the economic vanguard in central Europe. When it again became part of Austria in 1815 it also became subject to the imperial policy of political integration. As a result its economic priorities were partially reformulated. On the one hand, Austria had a protectionist system aimed at autarky which made incentives to industrial production a priority. Lombardy's purely mercantilist outlook, on the other hand, was based around the production of a few highly specialized goods, most notably silk, for export. Conflict between economic interests in Lombardy was the inevitable result. Nevertheless, the imperial government had to take account of the fact that it was impossible to restrict Lombardy's international trade relations exclusively to the Austrian market. And the problems that beset any effort to tie the Lombard economy into a denser network of relationships with the Austrian market were not due to the political formation of the Italian nation because Northern Italy, and Lombardy in particular, continued to occupy an anomalous position within the context of the Italian economy.     

Flexural Behavior of Typical Chinese Traditional Timber Stitching Beams

In Chinese traditional timber buildings, stitching is very common. When the bearing capacity or the rigidity is inadequate, a timber beam is often strengthened with another beam using the stitching method. The timber stitching beams are mainly of two types—the small-top/big-bottom type and the big-top/small-bottom type. To study the bending behavior of these two types of timber stitching beams, including the failure mode, the flexural capacity, the strain distribution at mid-span section, and the maximum deflection, bending tests are carried out on 14 timber stitching beams with Chinese traditional conformation for seven pine beams and seven fir beams. The results show that the failure modes of the small-top/big-bottom type of stitching beams all show brittle fractures at the bottoms of the bottom beams. The failure modes of the big-top/small-bottom type of stitching beams all show brittle fractures at the bottoms of the top beams. The distribution of section strain along the height of each part of the beam basically obeys plane hypothesis. Based on the theoretical and experimental analysis, the calculation formulas of flexural capacity and maximum deflection of these two types of timber stitching beams made of pine and fir are presented.     

四件唐代铁镞的修复

为了将4件出土的唐代铁镞修复展出,通过对其保存状况仔细观察和分析后,借鉴德国修复方法和材料,制定科学的修复方案。修复效果明显,铁镞基本恢复原貌。     

时间地理学的企划概念及其研究案例

企划是为完成任何意愿和目标而进行的一系列必要的简单或复杂的任务,即为达到某个个人或组织的长期或短期目标而实施的活动。企划研究旨在建立意图和实现之间的桥梁,从个体或组织主体意图的视角构建活动之间的关系,它不仅关注时空间行为的客观发生,还关注时空间行为的计划和时空间行为结果的影响反馈等主观方面。企划视角下的时间被看作将"未来"不断转换为"过去"的连续过程,一个完整的企划包括孕育计划、活动实现、影响反馈三个主要阶段,基于企划可以分析个体行为的闭环决策过程。个体企划与组织企划交织的情景分析有助于解释个体时空间行为以及个体企划与组织企划的关系。沃尔沃乌德瓦拉工厂"结构性变革"的案例为如何从组织企划与个体企划交织的视角探索组织管理变革及其综合效益评价提供了很好的启示。企划视角下的日常活动研究将极有可能推动时间地理学从主客观结合、能动被动结合的微观视角透视日常活动决策的黑箱,进而对时空间行为进行解释和预测,最终实现物质世界时空制约与人的时空意图的统一。     

单檐歇山式木构古建抵抗极端烈度地震试验调查研究

为更好地保护我国古建筑,基于《单檐歇山式古建筑抗震性能振动台试验》的相关成果,研究了强震作用下我国明清官式木构古建的抗震性能,制作了与该论文相同的试验模型,进行了振动台试验。通过对模型输入烈度逐渐增强的1940年El-centro波,并考虑地震波为水平双向作用,分析了强震作用下不同构造的试验现象,开展了详细的震后调查,获得了不同构造在强震作用下的抗震性能和震害机制。结果表明:强震作用下,我国明清官式木构古建的振动形式表现为柱架、斗拱、梁架及屋顶的近似同步往复摇摆;主要震害包括柱底偏移、榫卯节点开裂、拔榫、斗拱偏移及错位、额枋-垫板分离、墙体倒塌等,但承重木构架受损不严重,结构未产生倒塌。其良好抗震性能的原因与古建筑的构造特征密切相关。     

Liminality in nature-based tourism experiences as mediated through social media

Abstract

The intersection between social media, liminality and nature-based tourism experiences hasn’t been the focus of previous tourism research. Such intersection, on the other hand, is illustrative of how social media relate to the constitution and performance of tourism spatialities, tourist identities, storytelling and place-making, and can lead to relevant theoretical contributes. We aim to investigate how liminality is expressed in relation to nature-based experiences by tourists on social media, and what role social media plays in mediating liminality during nature-based tourism experiences. The analysis is based on a participatory netnography of images and text posts, as well as online interviews with users of the popular social media Instagram. Findings show that the expression of tourism experiences in nature is closely related to specific notions of liminal otherness as opposed to the urban life and the everyday, where nature and wilderness are expressed as related to the genuine, the authentic and a true inner self. Creative combinations of pictures, captions and hashtags make it easier for tourists to express the contrast between the natural landscape and the everyday landscape once they returned home. These combinations also relate closely to performances of resistant and alternative selves and communities. At the same time, such performances are mediated and contested between freedom of self-expression, surveillance and social norms, an aspect that makes their liminal nature ambiguous.     

Kinned to be Norwegian: transnational adoptees' positioning in relation to whiteness and the negotiation of nationhood

Embedded in ongoing discussions on everyday nationhood in the context of migration‐related diversity, this article explores how Norwegian transnational adoptees, as border subjects, negotiate their national belonging and identities by positioning themselves in relation to whiteness. By doing so, it further explores the relationship between race and nation. The analysis demonstrates that transnational adoptees position themselves as white when encountering the norm of whiteness, which the author argues in favour of understanding as continued process of doing race. While phenotypic differences trigger a process of racialisation through which transnational adoptees can easily be placed in a minoritised position, adoption provides them with unique access to whiteness, mostly along the negotiable and intertwined dimensions of kinship and the notion of ‘origin’, referred to as the place where they grew up. The article argues that individuals' positioning along majoritisation/minoritisation processes is another important dimension to understand one's multiple and fluid national identity and belonging in migration‐related diversity. The analysis also furthers the discussions on hierarchy of belonging by highlighting the relevance of kinship in intersection with race.     

The German-Jewish soldier: from participant to victim

The story of German-Jewish soldiers and veterans of World War I illustrates how, under circumstances of inclusion (even if incomplete) rather than vicious persecution, Jewish suffering in wartime, and with it the forms of collective memory and strategies for commemoration of the dead, could closely parallel, even intersect with, the suffering of Germans as a whole. To be sure, the points of intersection were accompanied by points of deflection. Even when Jews served, fought, suffered and died as German soldiers, their interpretations of the war experience, and their communities’ postwar memory and commemorative practices, differed from those of other Germans. In many ways, however, German-Jewish veterans suffered the aftermath of the war as did other Germans; they shared the prevailing fury over war guilt and reparations, and they retained a strong pride in their military service, a pride through which they interpreted the events of 1933–1945.