scholarly journals Methods for the Assessment of Critical Properties in Existing Masonry Structures under Seismic Loads—The ARES Project

2020 ◽  
Vol 10 (5) ◽  
pp. 1576 ◽  
Author(s):  
Mislav Stepinac ◽  
Tomislav Kisicek ◽  
Tvrtko Renić ◽  
Ivan Hafner ◽  
Chiara Bedon
Keyword(s):  
Current Knowledge ◽  
Structural Response ◽  
General Tendency ◽  
Masonry Buildings ◽  
Masonry Structures ◽  
Building Stock ◽  
Existing Structures ◽  
Critical Issues ◽  
Reliable Design ◽  
Basic Features

Masonry structures are notoriously vulnerable to horizontal actions caused by earthquakes. Given the high seismicity of the European region, and that the European building stock comprises a lot of masonry buildings, knowledge about their structural response to seismic excitation is particularly important, but at the same time difficult to determine, due to the heterogenous nature of materials and/or constructional techniques in use. An additional issue is represented by the current methods for mechanical properties assessment, that do not provide a reliable framework for accurate structural estimations of existing buildings characterized by different typological properties. Every structure, in other words, should be separately inspected in regard to its mechanical behaviour, based on dedicated approaches able to capture potential critical issues. In this review paper, an insight on the Croatian ARES project is presented (Assessment and Rehabilitation of Existing Structures), including a state-of-the-art of the actual building stock and giving evidence of major difficulties concerning the assessment of existing structures. The most commonly used techniques and tools are compared, with a focus on their basic features and field of application. A brief overview of prevailing structural behaviours and Finite Element numerical modelling issues are also mentioned. As shown, the general tendency is to ensure “sustainable” and energy-efficient building systems. The latter, however, seem in disagreement with basic principles of structural maintenance and renovation. The aim of the ongoing ARES project, in this context, is to improve the current knowledge regarding the assessment and strengthening of structures, with a focus on a more reliable design and maintenance process for existing masonry buildings.

scholarly journals Performance of RC and Masonry Structures During 2019 Durrës Earthquake

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Marsed Leti
Keyword(s):  
Structural Damage ◽  
Structural Response ◽  
Poor Performance ◽  
Past Century ◽  
Masonry Structures ◽  
System Quality ◽  
Building Stock ◽  
Damage Level ◽  
Rc Building

Albania has suffered from major earthquakes in the past century that have caused varying levels of damage to buildings. As a result of the number of damaged buildings and loss of life, attention has focused mostly on the poor performance of reinforced concrete and masonry structures in low and mid-rise buildings. This paper presents the results of a reconnaissance visits to the disaster-stricken area in the Durrës region in Albania and covers many zones in the region where historical and modern buildings suffered serious structural damage or collapses during the November 26, 2019, Durrës Earthquake. Special emphasis was placed on masonry and RC buildings, since the damage level was high in these buildings. The consequences of the Durrës earthquake are important for similar masonry and RC building stock in other seismically vulnerable European cities. Regularity of the structural system, quality of the material utilized, the distribution of mass and stiffness through the building, the ratio of openings on masonry walls and diaphragm stiffness have a crucial influence on the structural response. Inappropriate interventions led to serious damage or collapses, resulting in casualties. Examples of numerous damage types, as witnessed during the site visits to the affected region are presented, along with technically explanation of causes for the damages.

scholarly journals Application of Shape Memory Alloys in Retrofitting of Masonry and Heritage Structures Based on Their Vulnerability Revealed in the Bam 2003 Earthquake

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4480
Author(s):  
Alireza Tabrizikahou ◽  
Marijana Hadzima-Nyarko ◽  
Mieczysław Kuczma ◽  
Silva Lozančić
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
High Strength ◽  
Masonry Structure ◽  
Masonry Buildings ◽  
Masonry Structures ◽  
Structural Failure ◽  
Reinforced Plastics ◽  
Existing Structures ◽  
The City

For decades, one of the most critical considerations of civil engineers has been the construction of structures that can sufficiently resist earthquakes. However, in many parts of the globe, ancient and contemporary buildings were constructed without regard for engineering; thus, there is a rising necessity to adapt existing structures to avoid accidents and preserve historical artefacts. There are various techniques for retrofitting a masonry structure, including foundation isolations, the use of Fibre-Reinforced Plastics (FRPs), shotcrete, etc. One innovative technique is the use of Shape Memory Alloys (SMAs), which improve structures by exhibiting high strength, good re-centring capabilities, self-repair, etc. One recent disastrous earthquake that happened in the city of Bam, Iran, (with a large proportion of masonry buildings) in 2003, with over 45,000 casualties, is analysed to discover the primary causes of the structural failure of buildings and its ancient citadel. It is followed by introducing the basic properties of SMAs and their applications in retrofitting masonry buildings. The outcomes of preceding implementations of SMAs in retrofitting of masonry buildings are then employed to present two comprehensive schemes as well as an implementation algorithm for strengthening masonry structures using SMA-based devices.

scholarly journals Fragility curves for Italian URM buildings based on a hybrid method

2021 ◽  
Author(s):  
A. Sandoli ◽  
G. P. Lignola ◽  
B. Calderoni ◽  
A. Prota
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Limit State ◽  
Ultimate Limit State ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Seismic Behaviour ◽  
Building Stock ◽  
Ground Acceleration ◽  
Damage Scenario

AbstractA hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions. Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minimum value of PGAs defined for each building class. To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber macroseismic intensity scale has been used and the corresponding fragility curves developed. Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.

Mechanical Properties of Fired-Clay Brick Masonry Models in Moist and Dry Conditions

2014 ◽  
Vol 624 ◽  
pp. 307-312 ◽  
Author(s):  
Cristina Gentilini ◽  
Elisa Franzoni ◽  
Gabriela Graziani ◽  
Simone Bandini
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Point Of View ◽  
Shear Behaviour ◽  
Masonry Buildings ◽  
Masonry Structures ◽  
Clay Brick ◽  
Clay Bricks ◽  
Dry Conditions ◽  
Rising Damp

Rising damp is one of the main issues affecting masonry buildings. However, its consequences on the mechanical performance of masonry structures are not so largely explored. In this paper, the compressive and shear behaviour of masonry triplets, manufactured with solid fired-clay bricks and cement-based mortar, is investigated in dry and moist conditions. The results are interpreted on the basis of the features of the single materials, from both a mechanical and microstructural point of view.

scholarly journals The use of approximate methods of seismic assessment of structures

2018 ◽  
Vol 188 ◽  
pp. 03010
Author(s):  
Maria Basdeki ◽  
Argyro Drakakaki ◽  
Charis Apostolopoulos
Keyword(s):  
Seismic Performance ◽  
Mechanical Performance ◽  
Corrosion Damage ◽  
Masonry Structures ◽  
Seismic Evaluation ◽  
Approximate Methods ◽  
Rc Structures ◽  
Existing Structures ◽  
Corrosion Factor ◽  
Masonry Tower

Greece is an earthquake prone area, which is also exposed to coastal environment. Most existing buildings present common characteristics, concerning quality of the materials and environmental conditions [1].The vulnerability of these structures is exteriorized under powerful seismic loads. This is because they were designed, according to older regulations, primarily to bear vertical loads and secondarily to bear horizontal loads, an indicative sign of the absence of anti-seismic design. Designing and evaluation of the seismic performance of existing structures is a really complex issue, because structural degradation phenomenon is related to both corrosion damage of steel reinforcement on RC structures and high vulnerability of masonry. Precisely, the inadequate seismic performance of masonry structures, which is recorded under intense earthquakes, is attributed to the characteristics of masonry and to the ageing phenomena of the materials. For the seismic inspection of masonry structures, both EC2 and OASP can be used [3], although there is often a great misunderstanding concerning the range of the maximum permissible interventions, the financial inability and modern perceptions of redesigning [2]. On the other hand, in the case of RC structures, there is no prediction –concerning the corrosion factor- included in the international regulations and standards. In the current study is presented an experimental procedure, concerning a RC column before and after corrosion. An estimation concerning the drop of its mechanical performance has taken place, indicating the importance of the corrosion factor. Additionally, an existing monumental masonry tower building, was subjected to seismic evaluation [4]. Both OASP and EC2 inspection methods were used. The results pointed out that, for medium–intensity earthquakes, both analytical and approximate methods are respectable and reliable.

Testing of Masonry Structures for Seismic Assessment

1996 ◽  
Vol 12 (1) ◽  
pp. 145-162 ◽  
Author(s):  
G. Michele Calvi ◽  
Gregory R. Kingsley ◽  
Guido Magenes
Keyword(s):  
Energy Dissipation ◽  
Experimental Evaluation ◽  
Unreinforced Masonry ◽  
Seismic Assessment ◽  
Experimental Techniques ◽  
Masonry Buildings ◽  
Masonry Structures ◽  
Seismic Loadings ◽  
Energy Dissipation Capacity ◽  
Reduced Scale

The experimental evaluation of strength, deformability, and energy dissipation capacity of unreinforced masonry buildings subjected to seismic loadings presents unique and complex problems, both for laboratory and field evaluations. The paper addresses these problems, focusing on the relative merits and roles of several experimental techniques, including quasistatic, dynamic, and pseudodynamic loadings at full and reduced scale.

scholarly journals Seismic vulnerability of traditional masonry building a case study of Byasi, Bhaktapur

2017 ◽  
Vol 4 ◽  
pp. 24-30
Author(s):  
Shyam Sundar Basukala ◽  
Prem Nath Maskey
Keyword(s):  
Seismic Vulnerability ◽  
Linear Time ◽  
Fragility Curves ◽  
Time History ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Masonry Structures ◽  
Rapid Visual Screening ◽  
Visual Screening

Historic buildings of Nepal are mainly constructed from masonry structure. Since masonry structures are weak in tension which leads to the failure of structure. So, to avoid possible damage in environment lives and property it is urgent to conduct vulnerability assessments. Seismic vulnerability of historic masonry buildings constructed in Bhaktapur at Byasi area is carried out for the case study. Five load bearing masonry buildings were selected out of 147 buildings considering opening percentage, storey and type of floor for modeling in SAP 2000 V10 Various methods of rapid visual screening (FEMA 154, EMS 98) are used to determine the vulnerability of the selected building. The Selected Building response is carried out by linear time history analysis. The seismic vulnerability of masonry structures is determined in terms of fragility curves which represent the probability of failure or damage due to various levels of strong ground motions for different damage state slight, moderate, extensive and collapse. From the result of Rapid Visual Screening (RVS) and Fragility curves of the buildings it is found that whole, buildings are found vulnerable from future earthquake.

Fibreglass Reinforced Polymer Structure Response under Different Impact Scenarios

2019 ◽  
Vol 827 ◽  
pp. 13-18
Author(s):  
Giuseppe Lamanna ◽  
Alessandro Greco ◽  
M. Manzo ◽  
Enrico Armentani ◽  
Constantin Gheorghe Opran
Keyword(s):  
Volume Fraction ◽  
Critical Role ◽  
Structural Response ◽  
Loading Conditions ◽  
Specific Strength ◽  
Reinforced Polymer ◽  
Drop Mass ◽  
Critical Issues ◽  
Polyester Matrix ◽  
Dynamic Loading Conditions

Composite materials are increasingly used in those fields where it is necessary to achieve the requirements of lightweight and high mechanical properties. Even though their high specific strength which get these materials very attractive, especially for the transport field, there are several critical issues that still limit their application in primary structures. Among these, dynamic loading conditions play a critical role because they can significantly lower their residual strength. This paper aims to investigate experimentally the structural response of a 25 mm thick Omega composite structure under different impact loading conditions. The investigated test article consists of E-glass fibres (40% volume fraction) reinforced polyester matrix. The structure is covered by a HELIOPOL 1401 M AGC W 11 gelcoat layer and it has been impacted through a drop mass of 3.94 kg, dropped from heights of 50 mm, 75 mm, 100 mm, 150 mm, 200 mm, 250 mm, 350 mm and 500 mm.

scholarly journals Seismic vulnerability of vernacular Newari buildings in Nepal: observations and analysis of damage due to 1934, 1988, 2011, and 2015 earthquakes

2018 ◽  
Author(s):  
Dipendra Gautam ◽  
Hugo Rodrigues
Keyword(s):  
Seismic Vulnerability ◽  
Masonry Buildings ◽  
Fragility Functions ◽  
Masonry Structures ◽  
Collapse Prevention ◽  
Damage Probability Matrices ◽  
Damage Probability ◽  
Probability Matrices

Abstract. This paper reports the seismic vulnerability of vernacular Newari buildings based on the damage observations during four major earthquakes (1934, 1988, 2011 and 2015) that struck Bhaktapur city. Some specific features that contributed to collapse prevention in traditional masonry buildings are also highlighted in this paper. In this paper, we have outlined the insights of each earthquake using forensic interpretations and the recommendations by various researchers after 1934 and 1988 earthquakes are compared in terms of their implementation. With the help of damage database recorded during 1934, 1988 and 2015 earthquakes, we have created damage probability matrices and empirical fragility functions for traditional masonry structures. The fragility functions and damage probability matrices derived in this study highlight that most of the vernacular Newari buildings are likely to be collapsed in the case of strong to major earthquakes.

Implications of cumulated seismic damage on the seismic performance of unreinforced masonry buildings

2014 ◽  
Vol 47 (2) ◽  
pp. 157-170 ◽  
Author(s):  
Amaryllis Mouyiannou ◽  
Andrea Penna ◽  
Maria Rota ◽  
Francesco Graziotti ◽  
Guido Magenes
Keyword(s):  
Nonlinear Dynamic ◽  
Fragility Curves ◽  
Seismic Damage ◽  
Unreinforced Masonry ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Seismic Capacity ◽  
Building Stock ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses

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.

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