Preventive Intervention for a Group of Buildings in the Historic Centre of Manresa (Barcelona)

The preservation of old downtowns has become a necessity of growing interest. New urban policies have been approved in different countries in order to revive the old city centers and make them economically sustainable. In this global trend, the municipality of Manresa (Barcelona) developed an important urban planning operation in the old district that included the demolition of a group of existing buildings and the construction of a new modern one in close proximity to a group of old residential buildings which are cultural heritage of the city. As a consequence, specific areas of risk were generated which lead to the adoption of precautionary measures to ensure safety. This article presents the preliminary analysis, diagnostics and monitoring carried out on this group of heterogeneous old buildings, as well as the results and precautionary measures taken to ensure their safety. The article also provides a translatable methodology that combines qualitative and quantitative aspects.     

A Simplified Drift-Based Assessment Procedure for Regular Confined Masonry Buildings in Seismic Regions

This article presents a simplified procedure for assessing the seismic performance of existing low-to-medium rise confined masonry (CM) buildings, which are a typical construction type in Latin-America. The procedure consists of the estimation of the peak roof and first-story inelastic drift demand of CM buildings. The expected peak inelastic displacement demand is related to drift-based fragility curves, which express the probability of being or exceeding two key damage states in the masonry panels, developed from a relatively large experimental database. The proposed procedure could be very useful for obtaining rapid estimates of expected performance during future earthquake events and for assessing the seismic vulnerability of regular confined masonry structures.     

九华山木结构古建筑病害防治探析

我国古建筑大多采用木材作为建筑结构的主要材料,木材为生物材料,很容易遭到各种损害,主要有自然糟朽和各种病虫害,其中最大的损害来自于病虫害.九华山是中国佛教四大名山之一,遗存了大量的古寺庙建筑,作为不可移动文物,古代建筑在各级文物保护单位中占有重要的地位.目前,除自然糟朽之外,对九华山古建筑结构造成生物损害的主要有白蚁、粉蠹虫、黄蜂等有害昆虫.因此,做好病虫害防治是保护古建筑的一项重要工作内容.     

Kobe and Northridge Two earthquakes compared

Abstract

The earthquakes striking Northridge, California in 1994 and Kobe, Japan just a year later highlighted the vulnerability of modern cities to natural hazards. The Northridge quake affected a suburban area, consisting of a mixture of residential and commercial districts but having no industrial plants of any great size. In Kobe, by contrast, the entire urban area, having a high concentration of population and buildings in the city centre, major industrial plants, and a large port area, was hit. This fact, and the higher price levels in Japan, explain why the extent of the losses in Kobe was significantly higher. The Kobe tremor demonstrated that much more attention must be paid in future to reinforcing important older buildings or buildings that are especially at risk. The fact that many modern high rise buildings survived intact showed that it is possible to design earthquake resistant structures, although the safety of steel frame structures, hitherto thought to be good, is now more questionable. Theories predicting that a similar event in a conurbation such as San Francisco or Tokyo–Yokohama could affect the entire world economy must now be viewed as having greater credibility.     

Modeling the Seismic Response of Modern URM Buildings Retrofitted by Adding RC Walls

Modern unreinforced masonry buildings with reinforced concrete slabs are often retrofitted by inserting reinforced concrete walls. The main advantages of this technique are the increase in strength and displacement capacity with respect to masonry structures. This article presents two modeling approaches for evaluating such structures: a shell-element model and a macro-element one. The objective is to formulate practical recommendations for setting up a macro-element model using as input the geometry of the structure and results from standard material tests. Structural configurations of masonry buildings, in which the insertion of reinforced concrete walls is an efficient retrofit technique, are also investigated.     

Reconsidering Relocated Buildings: ICOMOS,Authenticity and Mass Relocation 1

ICOMOS charters guide global heritage conservation practices. Fundamental to most is the notion that a ‘monument is inseparable from the history to which it bears witness and from the setting in which it occurs.’ Yet buildings have been moved for centuries. Neither the fabric nor the size of a building, nor planning regulations, nor even heritage listing, have prevented their relocation. This article briefly examines the history of relocation, reviews attitudes to relocation in ICOMOS charters, and analyses two case studies involving the mass relocation of heritage buildings in the UK and in New Zealand to question the assumption that buildings lose their authenticity if moved.     

Rapid Diagnosis of Crack Patterns of Masonry Buildings Subjected to Landslide-Induced Settlements by Using the Load Path Method

One of the main difficulties, when dealing with landslide structural vulnerability, is the diagnosis of the causes of the crack pattern. This is also due to the excessive complexity of models based on classical structural mechanics that makes them inappropriate especially when there is the necessity to perform a rapid vulnerability assessment at the territorial scale. This is why in this article a new approach for the rapid diagnosis of crack patterns of masonry buildings subjected to landslide-induced settlements is proposed. This approach is based on the Load Path Method, recently applied to the interpretation of the behavior of masonry buildings subjected to landslide-induced settlements.     

Seismic Vulnerability of Historical Masonry Aggregate Buildings in Oriental Sicily

ABSTRACT

The seismic vulnerability assessment of historical UnReinforced Masonry (URM) buildings is a very complex task since it is strongly related to a great variety both of geometrical layouts and of masonry mechanical characteristics. In this article, some results of a Catania University research project, denomined “FIR 2014”, focused on the seismic vulnerability estimation of historical buildings, built in Catania after the 1963 earthquake, are presented. First, a detailed typological analysis of the considered urban fabric, characterized by typical residential masonry buildings, has been performed. Such analysis allowed recognizing an elementary structural modulus, which has been studied according to different geometrical layouts representative of isolated or aggregate buildings. The results of nonlinear static analyses, performed by applying an innovative macro-element approach, allowed for the assessment the seismic vulnerability of typical URM buildings coherently to the Italian seismic code. The adopted macro-element strategy for the seismic assessment of aggregate masonry buildings, although related to a specific historical center, may be applied to similar urban fabrics and can also be used for the calibration and validation of fast seismic assessment strategies, particularly useful for the evaluation of the seismic risk at urban scale.     

Simplified Mechanical Model to Estimate the Seismic Vulnerability of Heritage Unreinforced Masonry Buildings

Traditional or historic masonry structures occur in large populations throughout the world, particularly in preserved historical city clusters. Being non-engineered and aging these structures are in urgent need of assessment and seismic repair/rehabilitation. However, traditional masonry presents important challenges to computational modeling, owing to complexity of structural system, material inhomogeneity, and contact interactions that collectively can only be addressed through detailed 3D nonlinear representation. In this article, a simple performance assessment model is developed in order to address the need for preliminary assessment tools for this class of structures. The objective is to be able to rapidly identify buildings that are at higher risk in the event of a significant earthquake, potentially justifying a second round of more detailed evaluation. The proposed model defines the characteristics of a Single Degree of Freedom representation of the building, formulating consistent 3D shape functions to approximate its fundamental mode of vibration considering both in-plane and out-plane wall bending as a result of insufficient diaphragm action. Parametric expressions for the dynamic properties are derived in terms of the important geometric, material, and system characteristics, and are used to express local demand from global estimates. Acceptance criteria are established both in terms of deformation and strength indices to guide retrofit. An application example of the proposed assessment methodology is included to demonstrate the ability of the model to reproduce the essential features of traditional masonry buildings under seismic action.     

Build for the Living: Stone Buildings of the Yuan Dynasty

It is easy to find an association between stone architecture and the afterlife in pre-modern China, given that most architecture of brick and stone was used only for mortuary monuments. People in pre-modern China may have believed that timber architecture was for the living while stone architecture was for the deceased. The fact that stone architecture often was designed to imitate timber architecture further buttresses the dominance of timber, both structurally and aesthetically, in the architectural history of pre-modern China. This article focuses on several stone buildings that were built during the Yuan dynasty (1271–1368) for daily religious activities and were rare exceptions to the normative association of stone architecture with the afterlife. Through the study of the structure, decorative motifs and history of these stone buildings, I determine whether they were built to reflect the tradition of imitation timber architecture or were an exception to the dominance of timber architecture. I investigate how these stone buildings should be contextualized in the history of Yuan as well as the history of Chinese architecture.     

Masonry Italian Code-Conforming Buildings. Part 1: Case Studies and Design Methods

ABSTRACT

Several architectural configurations of unreinforced masonry residential buildings are designed according to the different methods proposed in the Italian code: rules for the so-called simple masonry buildings, linear and nonlinear static analyses. Always complying with code requirements, for each building-site combination, the design was made, as much as possible, without an excessive margin of safety. The different design methods provided buildings with very different levels of safety, being linear static analysis largely overconservative with respect to the nonlinear static approach. These buildings were then analyzed in the companion paper.     

The Variance of Collapse Capacity of Symmetric and Asymmetric Low-Rise RC-SMF Buildings

This study primarily investigates if the building asymmetry changes the variance of collapse capacity. The example models are five-story reinforced concrete buildings. The variance of collapse capacity is evaluated by first-order-second-moment method. There is a difference between the results of symmetric and asymmetric building models, independent of torsional behavior. The influence of record-to-record variability is more important than the effects of modeling uncertainty on the variance of collapse capacity. Plastic rotation capacity is the most important contributor to the variance of collapse capacity of high ductile buildings independent of the asymmetry.     

Revisiting Historic Buildings through the Senses Visualising Aural and Obscured Aspects of San Vitale,Ravenna

Applying new information technologies to Cultural Heritage enables us to discover the unexplored characteristics of visual and aural attributes of historic buildings. In this article a new technology to measure acoustic 3D Impulse Responses in historic interiors is described and applied to the sixth-century church of San Vitale at Ravenna, Italy. The virtual reconstruction of this important UNESCO World Heritage Site revealed otherwise obscured yet intentional details of its architectural design. The results of measuring the internal spatial parameters are used to recreate San Vitale’s historical components and to re-sound original music of the little known Ravennate rite.     

Comparison of Nonlinear Static Methods for the Seismic Assessment of Plan Irregular Frame Buildings with Non Seismic Details

The use of Nonlinear Static Procedures (NSPs) for the seismic assessment of plan irregular buildings is challenging. The most common pushover-based approaches have led to adequate results in regular buildings, and hence, there is a need to verify the validity of such methods on the assessment of irregular structures. In this article, four commonly used nonlinear static procedures (CSM, N2, MPA, ACSM) are applied on the assessment of two existing five- and eight-story plan-asymmetric buildings in Turkey. The accuracy of the different NSPs is evaluated through comparisons with the results derived from nonlinear dynamic analyses. The results are presented in terms of interstory drifts, normalized top displacements, lateral displacement profiles, chord rotations, base shear, and top displacement ratios. The performance of such procedures in evaluating the damage limitation according to the Eurocode8 is also verified. Special attention is given to the ACSM (Adaptive Capacity Spectrum Method) whose performance in 3D plan irregular buildings has recently been tested. Conclusions about the performance of each NSP are outlined at the end of the article.     

Preserving ‘the Enemy’s’ architecture: preservation and gentrification in a formerly Palestinian Jerusalem neighbourhood

This article relates to the preservation of Palestinian buildings in Jerusalem and raises the question why state-sanctioned institutions act to preserve Palestinian architecture built pre-1948, bearing in mind the context of a difficult past and an on-going conflict? The article addresses the manner in which Jerusalem’s authorised heritage discourse focuses only on preserving Palestinian buildings’ tangible aspects (architectural styles), and not on intangible aspects such as the narrative of their builders. The main argument is that while preservation is presented as a civilised practice, it is driven by the commodification of the buildings and sites and their valued ‘authenticity’. The common practice is to ‘preserve’ these buildings by developing them to create more housing units. This practice inevitably leads to gentrification. Moreover, even when intangible aspects of heritage are pushed aside, preserving these buildings comes with the ‘risk’ of them being used as memory sites for subaltern groups. The article focuses on one formerly Palestinian West Jerusalem neighbourhood, Baka, where gentrification was triggered by historic Palestinian homes and where the neighbourhood’s development continues to be linked with historic preservation.     

Seismic Retrofitting Techniques for Historic Adobe Buildings

This article presents a comprehensive overview of the techniques available for the seismic retrofitting of adobe buildings. It analyzes these techniques’ viability from a structural engineering standpoint and evaluates their suitability in the context of historic preservation. Analysis was based on an exhaustive review of studies addressing retrofitting techniques of earthen structures, as well as consultation with field experts. The guiding principles of conservation relating to the structural reinforcement of monuments were taken into account. Traditional techniques that enhance the stability of the building, such as wooden ring beams, wooden ties interconnecting parallel walls, corner keys, and the addition of buttresses were found to be effective solutions since they employ compatible and low-cost materials such as earth and wood. When these techniques prove insufficient, minimally invasive measures such as introducing a plywood diaphragm, horizontal steel rods, a geomesh covered with mud rendering or a strapping system can be appropriate.     

Investigation Techniques for the Seismic Response Assessment of Buildings Located in Historical Centers

ABSTRACT

It is an acknowledged fact that historical centers, given its significance from the cultural and architectural viewpoint, bring further challenges in terms of maintenance planning, survey, and safety assessment. The preparation of an adequate investigation plan and the extent of data to be collected is highly reliant on many aspects, such as the category of the architectonic asset, the importance of the heritage site, or the resources available, for example. In what regards the seismic response assessment of urban cultural heritage assets located in historical centers, the amount and detail of data also depend on this article, scale of assessment, and current state of conservation and occupation. Within this framework, this article provides an overview of the state of the art of investigation techniques currently used in survey operations, which are currently available for improving the knowledge level of urban cultural heritage assets within historical centers, as a supporting tool for the seismic response assessment of such singular assets. Finally, acknowledging the lack of accuracy when evaluating the seismic response of an asset enclosed in aggregate as an isolated structure, this article also focuses on the identification of the main particularities inherent to buildings enclosed in aggregate.     

The gentrification of progressive red-light districts and new moral geographies: the case of Amsterdam and Zurich

Even though there is a long tradition of red-light districts (RLD) being concentrated within the city centre, gentrification policies in many European cities now aim at spatially dispersing the sex market (and its workers) to the fringes of the city. Moving RLDs out of the city centre (or transforming them into more-upscale entertainment provision) calls into question the physical place allotted to sex work in our cities, as well as the moral geography behind these decisions. This article examines urban regeneration processes in two particular European cities – Amsterdam and Zurich – both cities with a long history of progressive drug and sex-work policies where sex work has been part of the visible urban fabric. In the article we look at urban policies and the legal framework, as well as at moral reasoning and discourses around the legitimacy of moving sex-workers away from city centres. We argue that in both cities moral arguments play an important role in the legitimization of the transformation of the RLD which contributes to a new race and gender order that stigmatises sex-workers as a group as if they were all victims of trafficking.     

Full-Scale Experimental Verification of Soft-Story-Only Retrofits of Wood-Frame Buildings using Hybrid Testing

The FEMA P-807 Guidelines were developed for retrofitting soft-story wood-frame buildings based on existing data, and the method had not been verified through full-scale experimental testing. This article presents two different retrofit designs based directly on the FEMA P-807 Guidelines that were examined at several different seismic intensity levels. The effects of the retrofits on damage to the upper stories were investigated. The results from the hybrid testing verify that designs following the FEMA P-807 Guidelines meet specified performance levels and appear to successfully prevent collapse at significantly higher seismic intensity levels well beyond for which they were designed. Based on the test results presented in this article, it is recommended that the soft-story-only retrofit procedure can be followed when financial or other constraints limit the retrofit from bringing the soft-story building up to current code or applying performance-based procedures.