ABSTRACT
Parametric design, algorithmic modeling, generative design, and associative design are only some of the keywords of a work paradigm that is becoming more and more popular, designed to respond to the complexities of contemporary architecture. Most commonly, such an approach is used for new buildings, but when algorithmic design meets heritage building information modeling (HBIM), the process can take on an even greater centrality—flexibility and control go hand-in-hand, ensuring precious tools for the planning of restoration interventions and management projects. This contribution, oriented to expand the use of these strategies to heritage, deals with the theme of parametric modeling of masonry vaults, a structural–architectural feature that in many forms and combinations characterizes most historic buildings. In particular, the connection of BIM software with algorithmic modeling software can allow the ‘translation' of complex geometric shapes into elements with full Level of Detail elements (LOD 500) while preserving, at the same time, the algorithmic editing functions. In this paper, it is illustrated as this approach permits the finetuning of the vaults' details, from time to time, based on different survey strategies (e.g., direct measurements, experimental tests, laser scanners, etc.). In other words, using this new connection in real time, architects can design restoration interventions tied to shapes, geometries, and masonry peculiarities that would otherwise be impossible to manage. An updatable virtualization of the actual state of a heritage building thus becomes affordable for the wider public (LOD G). There is also a valuable benefit for the heritage stakeholders in terms of protection of the architectural value and conscious planning in the restoration practice, especially in the museum field.
ABSTRACT
In this study, the just noticeable difference (JND) of loudness with respect to sound transmission through walls corresponding to a weighted noise reduction index R-w of 43 dB is investigated. Two types of walls typically used in Argentina are evaluated. One is masonry composed of solid autoclaved aerated concrete bricks with a thickness of 25 cm, and the other is a drywall composed of two 12.5 mm plasterboards with a 25 cm air chamber in between them, filled with glass wool. The JND is determined using the method of constant stimuli for both ascending and descending variations. The source signals used are two types of vacuum-cleaner sounds and two music signals. Online tests are conducted owing to restrictions imposed by the COVID-19, and the presentation level of the stimuli is adjusted based on the sensation level of each individual. Responses from 148 different listeners show no significant difference in the subjective responses among the source signals. Regarding the masonry, the JND values are 3.02 and 1.62 cm for the ascending and descending variations, respectively (corresponding R-w difference of 2 and 1 dB), whereas they are 4.55 and 1.26 cm for the drywall, respectively (1 dB for both).
ABSTRACT
Major efforts have been invested in the UK Residential sector to meet the increasing housing demands, deliver sustainability, and improve its resiliency against many uncertainties. While data/information within the UK residential sector relating to location, sizes and volumes are annually updated, there is limited emphasis on the methods of construction that support meeting housing demands. Over the years, it has been recognised that the UK residential sector has been dominated by two methods of construction: timber frame and masonry. This study aims to holistically compare timber frames with masonry as the two domineering construction methods for the UK residential sector. The comparison will be based on build costs, preference and drivers by construction professionals, longevity and consumer confidence, and sustainability. The research methodology was developed based on applying mixed methods of quantitative data analysis of build costs and qualitative data assessment of semi-structured interviews. The findings showed that, from a build cost perspective, masonry methods of construction are a more cost-effective choice with major variation in material cost. However, although the masonry method of construction was more favoured, in many respects, small-in-size developers show more tendency to timber frames, as this is being rationalised by meeting sustainability targets. Practical implications show that the future of the residential sector in meeting the housing demands would heavily depend on Modern Methods of Construction (MMC), as it offers a more optimised mechanism;however, the uptake of this is considerably low. Future studies will enquire into pillars to make MMC efficient in the UK residential sector.
ABSTRACT
An earthquake with a magnitude ranging from Mw = 6.9 (KOERI) to Mw = 7.0 (USGS) struck Samos Island in the Aegean Sea on October 30, 2020, with an epicentre 70 kms from the Izmir city centre in Turkey. The earthquake took place at 14:51 local time (11:51 UTC). The peak ground acceleration (PGA) of this earthquake was recorded to be 0.179 g at the epicentre of the earthquake. This earthquake occurred at a depth of 17.26 km (AFAD (2020) Izmir Earthquake Report, (In Turkish)) and lasted 16 s. The main shock from the earthquake triggered a tsunami that hit the building stocks built near the coast. During the gradual deregulation of COVID-19 pandemic regulations, various events caused considerable damage to the building stock, particularly in the Izmir Seferihisar and Bayrakli regions and resulted in a massive disruption of daily habits. The main shock caused 117 deaths in both Turkey and Greece, and 1632 people were also injured in Turkey. Moreover, several injuries occurred in Greece. A total of 103 buildings collapsed, 700 were severely damaged, 814 buildings were moderately damaged, and 7889 were slightly damaged. The basic aim of this paper is to briefly present the past and present seismotectonic characteristics of the region, present building stock, and former structural conditions before the earthquake, assess structural performance and classify distinguished earthquake-induced failures and damage due to the basin effect.
ABSTRACT
Two strong earthquakes hit Thessaly region on March 3rd, 2021 (Mw = 6.3) and on March 4th, 2021 (Mw = 6.1). The epicentres of the earthquakes were located at approximately 23 and 29 km respectively NW of Larissa, one of the most populous cities in Greece. Several aftershocks followed thereafter. Although no injuries were recorded, several structures suffered significant damage close to the epicentre, while some others collapsed. Approximately 300 residents of the village of Damasi were transferred to temporary settlements and tents. The event occurred during the COVID19 lockdown and created significant stress and disruption to residents. This paper focuses on the earthquake swarm itself as well as the damages observed in residential buildings, schools, and churches in the earthquake-stricken region. The earthquakes mainly impacted low-rise domestic masonry buildings, while the more modern reinforced concrete structures built following the recent seismic regulations were almost unaffected. The typology of buildings in the region, together with photographs demonstrating the extent of damage are presented herein. Despite the rather satisfactory performance of modern buildings in recent earthquakes in Greece, the preliminary investigations from the Thessaly Earthquakes showed that there is still a significant level of vulnerability in existing masonry building stock constructed using traditional methods and materials. This issue could re-emerge in future earthquakes striking other rural areas of Greece, something that needs to be addressed systematically in the future. [ FROM AUTHOR] Copyright of Bulletin of Earthquake Engineering is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)
ABSTRACT
”Braila Emergency County Hospital (ECH)” historical monument represents one of the main objectives of structural rehabilitation in both Braila county and Braila city. Thus, a structural strength verification for Pavilion B, Section 2, using ETABS software was performed, in order to find optimal retrofitting (rehabilitation) solutions. This analytical procedure proved to be beneficial and absolutely necessary, due to observations regarding the spatial contribution of masonry shear walls and finally the proper establishment of capable/design efforts. Following the structural calculation, it was concluded that the best solution would be to use composite materials for retrofitting a certain number of masonry shear walls, as classical retrofitting methods proved to be more expensive and structurally inefficient. Furthermore, in the context of the COVID-19 pandemic, the solution to use composite materials is beneficial, as it would entail no personnel or patients to be evacuated during the rehabilitation works, i.e. the hospital being able to continue to operate.
ABSTRACT
The surprisingly heavy social impacts were amplified by a combination of circumstances such as damage concentrated in the dense urban city center, the number of people requiring alternative accommodation and the relatively cold weather. Interdisciplinary research and training in particular in the fields of Earthquake Engineering and Seismic Risk assessment and management is crucial for improving the design of new structures, retrofitting the existing ones and efficiently respond and recover from disastrous earthquakes. The analysis is conducted on a tramway network scale to identify critical locations by performing continuous monitoring on the tramway network and risk analysis based on the distance of buildings from the track, vibration amplitude at source, and building damage. The paper presents a failure analysis of the bell tower of the church of St. Francis of Assisi on Kaptol in Zagreb subjected to seismic activity using the finite-discrete element method—FDEM.
ABSTRACT
Many bridges and other structures worldwide present a lack of maintenance or a need for rehabilitation. The first step in the rehabilitation process is to perform a bridge inspection to know the bridge′s current state. Routine bridge inspections are usually based only on visual recognition. In this paper, a methodology for bridge inspections in communication routes using images acquired by unmanned aerial vehicle (UAV) flights is proposed. This provides access to the upper parts of the structure safely and without traffic disruptions. Then, a standardized and systematized novel image acquisition protocol is applied for data acquisition. Afterwards, the images are studied by civil engineers for damage identification and description. Then, specific structural inspection forms are completed using the acquired information. Recommendations about the need of new and more detailed inspections should be included at this stage when needed. The suggested methodology was tested on two railway bridges in France. Image acquisition of these structures was performed using an UAV for its ability to provide an expert assessment of the damage level. The main advantage of this method is that it makes it possible to safely accurately identify diverse damages in structures without the need for a specialised engineer to go to the site. Moreover, the videos can be watched by as many engineers as needed with no personal movement. The main objective of this work is to describe the systematized methodology for the development of bridge inspection tasks using a UAV system. According to this proposal, the in situ inspection by a specialised engineer is replaced by images and videos obtained from an UAV flight by a trained flight operator. To this aim, a systematized image/videos acquisition method is defined for the study of the morphology and typology of the structural elements of the inspected bridges. Additionally, specific inspection forms are proposed for every type of structural element. The recorded information will allow structural engineers to perform a postanalysis of the damage affecting the bridges and to evaluate the subsequent recommendations.
ABSTRACT
This paper highlights the principal features of the Mw5.4 Zagreb earthquake. Located within the city limits at a depth of 10 km, the earthquake generated a peak ground acceleration of more than 0.2 g and a maximum spectral acceleration of about 0.6 g at 0.1 s in the historic downtown area. The situation was particularly challenging since the event occurred amid a partial Covid-19 lockdown at temperatures close to 0 °C, emphasizing the extensive and complex vulnerability of the local communities and individuals. 27 people were reported severely injured, one of which later died. The surprisingly high economic costs, needed to achieve a full reconstruction of damaged buildings and infrastructure in the affected area, are currently evaluated at more than 10B euros. Description of the organization of the emergency response in the first days and the observed damage to buildings is given with typical examples. The focus is on the performance of older masonry residential and cultural heritage buildings in the historic downtown, their inspection and evaluation of damage to structural and non-structural components. This information provides the basis for understanding of the negative impacts and clarifies the overall context identifying the enablers and barriers to the still ongoing recovery process. It also helps to increase the awareness of the seismic vulnerability of European cities with similar construction practices.
ABSTRACT
In this contribution are reported the first results of an experimental campaign conceived to evaluate the performance of FRCM (Fiber Reinforced Cementitious Matrix) composite materials for the recovery and restoration field of heritage buildings. With reference to the risks of seismic collapse concerning ancient masonry buildings, the peculiar structural behaviour of “in falso” walls, a typology of load-bearing masonries built without a direct load path to the foundations, has been examined. The tests have been conducted, through an experimental setup specially designed, on two rectangular walls characterized by the same basic traits: the first one in unreinforced masonry, the second presenting a non-canonical “truss-like” application of bands of composites. Alongside the progression of the experimental campaign - delayed due to the COVID outbreak - that in the near future will engage other two masonry panels enhanced by different applications of the FRCM, the creation of a FEM will be achieved gathering data from the new tests in order to replicate the complex mechanical behaviour of the FRCM composites with reference to the skills and time required for different installation modalities. © 2021 COMPDYN Proceedings.