Dating Historical Buildings: An Update on the Possibilities of Absolute Dating Methods

The reconstruction of the history of a building represents a difficult task, as written information is not usually available or incomplete. Some building materials (e.g., bricks, wood) have been classically used for absolute dating while on others has been considered unreliable (e.g., stone). However, developments and tests performed in the last 20 years have shown important advances on the use of such methods, increasing the possibilities of successful reconstruction of building chronologies, although most of these advances are still scarcely known by the community involved in the site management (e.g., archaeologists, architects). Both, radiocarbon and luminescence dating have been the most successful techniques but others, such as archaeomagnetism, can also be used. Even, some important events such as fires could be dated. The purpose of this work is to provide an overview of the last achievements of absolute dating techniques available in building materials.     

Experimental Dynamic Testing and Numerical Modeling of Historical Belfry

The experimental characterization of historical bell towers and wall belfries can provide important information for the calibration of numerical models as well as to implement proper restoration strategies. Within this framework, the presented study is concerned with the experimental dynamic assessment of an ancient belfry dating back to 1537. The structure is part of the “Santa Maria in Aracoeli Church” (Rome, Italy), an important heritage construction placed on the summit of the Capitoline Hill, close to the building that hosts the Major’s office. Several field tests have been conducted using accelerometers, and records obtained under different dynamic loading scenarios have been examined. Moreover, experimental accelerations have been elaborated to estimate the most important modal features of the structure and to validate a finite element model. Field tests have confirmed that severe vibrations are induced when the bells swing, and thus a slight reduction of the swing angle has been suggested in order to provide an immediate and inexpensive benefit to the structure. A new set of field tests demonstrates that the new swing angle is sufficient to reduce the induced vibrations while preserving the original sound.     

Analysis of the Effect of Provisional Ties on the Construction and Current Deformation of Mallorca Cathedral

This article presents the analysis of the structure of Mallorca Cathedral taking into account the influence on the structural behavior of auxiliary iron ties used during the construction process. Recent studies (Roca et al. 2012, 2013) presented some hypotheses about the construction process of the cathedral. This article complements the previous results by considering the use of auxiliary ties as temporary stabilizing device during the construction. Evidence of the use of ties during the construction has been recognized after a comprehensive survey. The study of the role of such ties and the effect of their later removal are studied by a FE analysis carried out on a representative bay of the structure. The study includes a time-dependent FE analysis after the removal of the ties to assess the long-term structural behavior. The results of the numerical analysis are compared with the deformation trends identified by means of a recent monitoring campaign.     

Regeneration and Structural Strengthening of the Fortress of Arnara,Latium, Italy

The fortress of Arnara is a small castle in a high seismic hazard zone in Latium, Italy, which represents a landmark for the local population. It was chosen as a case study, being a perfect example of Middle Age fortress, well preserved during the centuries despite some strong earthquakes damaged it in the past. The project presented here is a significant example of how the interest of a community to regenerate an ancient structure for its re-use can pave the way to a complete structural strengthening, which includes anti-seismic concepts aiming at retrofitting the ancient fortress walls. The overall project joins architectural and structural solutions. The architectural solution aims at a functional reconfiguration of the spaces, so to attract the locals to reuse it, while at the same time highlighting some valuable architectural features of the fortress. The structural solution aims at improving the seismic resistance of the masonry walls with a structural intervention that is respectful and integrates with the existing forms. This was achieved by means of a tenso-structure that has the two-fold role of reconnecting the different portions of the structures and of endowing it with a distinctive architectural sign. This project demonstrates that rediscovery of architectural heritage can also be pursued by proposing a new use for these structures, following an appropriate regeneration strategy that must take into account the cultural features of the territory, being at the same time respectful of the past history of the buildings.     

Seismic Assessment of the Lima Cathedral Bell Towers via Kinematic and Nonlinear Static Pushover Analyses

ABSTRACT

The protection of cultural heritage against earthquake induced actions is one of the main challenges the earthquake engineering science and practice are facing. This article presents a seismic assessment study on one of the most ancient colonial buildings present in Peru, the Cathedral of Lima, focusing on its towers. A historical review highlighted how these structures, together with the whole Cathedral, suffered intense damage and partial collapse during previous earthquakes. In order to identify the structure main deficiencies, both linear kinematic analyses and nonlinear static analyses have been performed. Different nonlinear finite element models have been created to evaluate the influence of the adjacent walls. Different load distributions have been compared to evaluate how simplified patterns could provide results close to load distributions taken from a modal analysis of the complex. A simple retrofit strategy, consisting on the introduction of steel ties, has also been studied as a reference. Results show good correlation between kinematic and pushover analyses. The construction, when compared to the requirements of the national code for new buildings, results significantly vulnerable, pointing out the need to accept some structural damage even after seismic retrofit.     

无锡曹家祠堂古建筑保护

无锡曹家祠堂的木构件槽朽和白蚁蛀蚀情况十分严重,彩绘也大部脱落。本文介绍了在维修保护曹家祠堂的过程中使用的现代科技方法,对于保护古建筑有其重要的参考价值。     

徽州古村落群旅游差异性开发的竞合分析

独特的地域文化蕴育了徽州众多的古村落。徽州古村落群的高度集聚效应,诱发了区内古村落旅游资源的集聚屏蔽竞争,同时古村落市场感知的替代效应导致古村落旅游资源开发的抑制竞争。论文认为,徽州古村落群的旅游开发应坚持差异性开发战略,在现状发展的基础上,以古村落的不同特色价值、空间构成、标志性景观等差异性特征为基础,加快建设区内交通设施、构建良好的空间竞合格局,提高徽州古村落间的网络化水平,促进旅游流的畅通与基地旅游模式的形成。     

南通近代建筑的历史地位和形成特点

南通是中国近代早期的工业基地之一,曾以模范县的美誉闻名于世。南通近代建筑是随着工商业兴起的,它是南通人依靠自己的力量,学习和吸收西方建筑艺术所形成的,在中国近代建筑史上占有一定的地位。南通近代建筑的形成有鲜明的特点,保护好这些建筑,有十分重要的意义。     

化学材料在南通天宁寺古建筑维修中的应用

天宁寺是江苏省重点文物保护单位,该建筑历经千年风霜雨雪,虫蛀霉烂,残损情况十分严重。本文简要分析了古建筑的落架大修与化学加固两种方案的利弊得失,重点介绍了化学材料在木构古建筑维修、加固中的应用。     

水平地震作用下大式带斗栱木结构古建筑的抗倒塌性能分析

基于根据宋代《营造法式》制作的某单层单开间殿堂式木结构振动台模型,建立了考虑柱础滑移隔震、榫卯半刚性连接及斗栱减震性能的空间杆系有限元模型。通过模型的数值计算值与振动台实测数据之间的对比分析,验证了建模方法的正确性。提出了柱脚滑移倒塌的相对位移判定准则及柱架层间倒塌的最大层间位移角判定准则,并采用增量动力分析(IDA)方法对这两种倒塌机制进行研究。结果表明:木结构古建筑在普通地震波作用下不易出现柱脚滑移倒塌;层间倒塌为长周期地震波作用下最易出现的倒塌机制;相对于普通地震波而言,木结构古建筑受长周期地震波作用的影响更大。