Assessment of the seismic capacity increase of masonry buildings strengthened through the application of GFRM coatings on the walls

2017 ◽  
Vol 2 (4) ◽  
pp. 300 ◽  
Author(s):  
Natalino Gattesco ◽  
Ingrid Boem
2010 ◽  
Vol 133-134 ◽  
pp. 623-628
Author(s):  
Marco Munari ◽  
Gianluca Busolo ◽  
Maria Rosa Valluzzi

A mechanical based method for the evaluation of the seismic capacity of masonry buildings’ classes in terms of damage limit states is presented: the purpose of the study is to achieve, in the framework of vulnerability analyses at territorial scale, reliable values for the damage level of vulnerability classes of masonry buildings, depending on the seismic input level. This approach is, in fact, designed as a “1st level” tool based on easily traceable information provided by expeditious surveys. Once identified a limited number of typological, physical and mechanical parameters that are necessary to define each vulnerability class, a significant number of simplified models of masonry buildings belonging to each class has been created. Non-linear static analysis of these models allowed the creation of bilinear elastic perfectly plastic capacity curves: the displacement capacity described by these curves is related with the actual displacement values required by seismic intensities associated to different return periods. It is so possible to identify, for different vulnerability classes and different seismic inputs, the loss of capacity in terms of damage level of each building. An application of the method to models representative of masonry buildings in the historical centre of Sulmona, in L’Aquila province, and a comparison of the results with others obtained with other methodologies of assessment are presented.


Author(s):  
Amaryllis Mouyiannou ◽  
Andrea Penna ◽  
Maria Rota ◽  
Francesco Graziotti ◽  
Guido Magenes

The seismic capacity of a structure is a function of the characteristics of the system as well as of its state, which is mainly affected by previous damage and deterioration. The cumulative damage from repeated shocks (for example during a seismic sequence or due to multiple events affecting an unrepaired building stock) affects the vulnerability of masonry buildings for subsequent events. This paper proposes an analytical methodology for the derivation of state-dependent fragility curves, taking into account cumulated seismic damage, whilst neglecting possible ageing effects. The methodology is based on nonlinear dynamic analyses of an equivalent single degree of freedom system, properly calibrated to reproduce the static and dynamic behaviour of the structure. An application of the proposed methodology to an unreinforced masonry case study building is also presented. The effect of cumulated damage on the seismic response of this prototype masonry building is further studied by means of nonlinear dynamic analyses with the accelerograms recorded during a real earthquake sequence that occurred in Canterbury (New Zealand) between 2010 and 2012.


Author(s):  
John Christianson

The Local Government Act allows local bodies to take powers requiring building owners to upgrade masonry buildings to a reasonable level of seismic capacity. The State Opera House is one such building. The theatre was built in 1913 and allows for seating for 1300 patrons
 on three levels. The building is of
 brick construction with walls up to 685mm thick and 23,000mm high without intermediate support. Although the Wellington City Council generally requires buildings to achieve two thirds of the standard
laid down by NZS 1900 Chap. 8:1965 the
 City Engineer requested that the Opera House be upgraded to full compliance with that standard. As a preliminary to
detail design, tests were made on brick beam samples to determine what quality
of brickwork existed within the building and what levels of stress could be
reliably used in panel configurations.
 From these tests we determined a bond strength of 0.1MPa in mortar joints
and F’c (Brick) 10MPa. This investigation was coupled with an extensive structural survey to supplement the meagre amound
 of information from drawings and original specification.


Buildings ◽  
2012 ◽  
Vol 2 (3) ◽  
pp. 218-230 ◽  
Author(s):  
Fulvio Parisi ◽  
Nicola Augenti

2014 ◽  
Vol 19 (3) ◽  
pp. 357-382 ◽  
Author(s):  
Zeeshan Ahmad ◽  
Khan Shahzada ◽  
Bora Gencturk ◽  
Akhtar Naeem Khan ◽  
Rashid Rehan ◽  
...  

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 604
Author(s):  
Michele Mirra ◽  
Geert Ravenshorst

The inadequate seismic performance of existing masonry buildings is often linked to the excessively low in-plane stiffness of timber diaphragms and the poor quality of their connections to the walls. However, relevant past studies and seismic events have also shown that rigid diaphragms could be detrimental for existing buildings and do not necessarily lead to an increase in their seismic performance. Therefore, this work explores the opportunity of optimizing the retrofitting of existing timber floors by means of a dissipative strengthening option, consisting of a plywood panel overlay. On the basis of past experimental tests and previously formulated analytical and numerical models for simulating the in-plane response of these retrofitted diaphragms, in this work nonlinear incremental dynamic analyses were performed on three case–study buildings. For each structure three configurations were analyzed: an as-built one, one having floors retrofitted with concrete slabs and one having dissipative diaphragms strengthened with plywood panels. The results showed that the additional beneficial hysteretic energy dissipation of the optimized diaphragms is relevant and can largely increase the seismic performance of the analyzed buildings, while rigid floors only localize the dissipation in the walls. These outcomes can contribute to an efficient seismic retrofitting of existing masonry buildings, demonstrating once more the great potential of wood-based techniques in comparison to the use of reinforced concrete for creating rigid diaphragms.


2010 ◽  
Vol 452-453 ◽  
pp. 513-516 ◽  
Author(s):  
Qiang Zhou ◽  
Bai Tao Sun ◽  
Pei Lei Yan

In this paper, the typical seismic damage of earthquake fortification and non-earthquake fortification masonry buildings are analyzed and the causes are illustrated, which are based on a large number of earthquake disaster survey data of Ms8.0 Wenchuan earthquake, Ms6.4 Baotou earthquake and Ms7.8 Tangshan earthquake and so on. According to the damage statistics data of several past earthquakes of China in recent years, the difference of damaging phenomenon and rate of earthquake damage of earthquake fortification and non-earthquake fortification masonry buildings in highly and lowly seismic regions are discussed and analyzed. Finally, based on the analysis conclusions, how to improve the seismic capacity of masonry buildings are discussed combining current seismic design code of China and some reasonable suggestions on the post-disaster reconstruction of masonry buildings have been given.


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