scholarly journals FIELD OBSERVATIONS OF THE 2015 (NOVEMBER 17, MW 6.4) LEFKAS (IONIAN SEA, WESTERN GREECE) EARTHQUAKE IMPACT ON NATURAL ENVIRONMENT AND BUILDING STOCK OF LEFKAS ISLAND

2017 ◽  
Vol 50 (1) ◽  
pp. 499 ◽  
Author(s):  
E. Lekkas ◽  
S. Mavroulis ◽  
V. Alexoudi
Keyword(s):  
Strong Earthquake ◽  
Stone Masonry ◽  
Masonry Buildings ◽  
Field Observations ◽  
Ionian Sea ◽  
Structural System ◽  
Secondary Effects ◽  
Building Stock ◽  
Western Greece ◽  
Earthquake Environmental Effects

On Tuesday, November 17, 2015 at 07:10:07 (UTC) a strong earthquake struck Lefkas Island (Ionian Sea, Western Greece) with magnitude Mw 6.4, depth of about 7 km and epicenter located 20 km southwest of Lefkas town. The seismic activity in the region was essentially expected after the 2003 Lefkas earthquake and the 2014 Cephalonia earthquakes. Between these earthquake affected areas, the tectonic stresses were not released after the 1948 Lefkas earthquakes. Instead, they were intensifying and accumulating until the generation of the 2015 event. It was felt in Lefkas and the surrounding region and caused the death of 2 people, the injury of 8 others, earthquake environmental effects (EEE) and damage to buildings and infrastructure. Secondary EEE were observed in western Lefkas and included ground cracks, slope movements and liquefaction. Primary effects were not detected in the field. Buildings damage were mainly observed in villages of Dragano-Athani graben in southwestern Lefkas. Among structures constructed with no seismic provisions, the stone masonry buildings and monumental structures suffered most damage, while the traditional buildings with dual structural system performed relatively well. Reinforced-concrete buildings were affected not so much by the earthquake itself but by the generation of secondary effects.

Seismic assessment and improvement of unreinforced stone masonry buildings

2016 ◽  
Vol 49 (2) ◽  
pp. 148-174 ◽  
Author(s):  
Marta Giaretton ◽  
Dmytro Dizhur ◽  
Francesca Da Porto ◽  
Jason M. Ingham
Keyword(s):  
New Zealand ◽  
Seismic Vulnerability ◽  
Unreinforced Masonry ◽  
Seismic Assessment ◽  
Stone Masonry ◽  
Minor Amount ◽  
Assessment Procedure ◽  
Masonry Buildings ◽  
Building Stock ◽  
A Minor

Following the 2010/2011 Canterbury earthquakes considerable effort was applied to the task of developing industry guidance for the seismic assessment, repair and strengthening of unreinforced masonry buildings. The recently updated “Section 10” of NZSEE 2006 is one of the primary outputs from these efforts, in which a minor amount of information is introduced regarding vintage stone unreinforced masonry (URM) buildings. Further information is presented herein to extend the resources readily available to New Zealand practitioners regarding load-bearing stone URM buildings via a literature review of the traditional European approach to this topic and its applicability to the New Zealand stone URM building stock. An informative background to typical stone URM construction is presented, including population, geometric, structural and material characteristics. The European seismic vulnerability assessment procedure is then reported, explaining each step in sequence of assessment by means of preliminary inspection (photographic, geometric, structural and crack pattern surveys) and investigation techniques, concluding with details of seismic improvement interventions. The challenge in selecting the appropriate intervention for each existing URM structure is associated with reconciling the differences between heritage conservation and engineering perspectives to reinstating the original structural strength. Traditional and modern techniques are discussed herein with the goal of preserving heritage values and ensuring occupant safety. A collection of Annexes are provided that summarise the presented information in terms of on-site testing, failure mechanisms and seismic improvement.

scholarly journals Seismic Vulnerability Assessment of Historical Masonry Buildings in Croatian Coastal Area

2021 ◽  
Vol 11 (13) ◽  
pp. 5997
Author(s):  
Željana Nikolić ◽  
Luka Runjić ◽  
Nives Ostojić Škomrlj ◽  
Elena Benvenuti
Keyword(s):  
Seismic Vulnerability ◽  
Pushover Analysis ◽  
Damage Index ◽  
Stone Masonry ◽  
Masonry Buildings ◽  
Building Stock ◽  
Ground Acceleration ◽  
Index Method ◽  
Vulnerability Index Method ◽  
Non Linear

(1) Background: The protection of built heritage in historic cities located in seismically active areas is of great importance for the safety of inhabitants. Systematic care and planning are necessary to detect the seismic vulnerability of buildings, in order to determine priorities in rehabilitation projects and to continuously provide funds for the reconstruction of the buildings. (2) Methods: In this study, the seismic vulnerability of the buildings in the historic center of Kaštel Kambelovac, a Croatian settlement located along the Adriatic coast, has been assessed through an approach based on the calculation of vulnerability indexes. The center consists of stone masonry buildings built between the 15th and 19th centuries. The seismic vulnerability method was derived from the Italian GNDT approach, with some modifications resulting from the specificity of the buildings in the investigated area. A new damage–vulnerability–peak ground acceleration relation was developed using the vulnerability indexes and the yield and collapse accelerations of buildings obtained through non-linear static analysis. (3) Results: A seismic vulnerability map, critical peak ground accelerations for early damage and collapse states, and damage index maps for two return periods have been predicted using the developed damage curves. (4) Conclusions: The combination of the vulnerability index method with non-linear pushover analysis is an effective tool for assessing the damage of a building stock on a territorial scale.

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.

Experimental Seismic Performance Evaluation of Unreinforced Brick Masonry Shear Walls

2015 ◽  
Vol 31 (1) ◽  
pp. 215-246 ◽  
Author(s):  
Mohammed Javed ◽  
Guido Magenes ◽  
Bashir Alam ◽  
Akhtar Naeem Khan ◽  
Qaisar Ali ◽  
...  
Keyword(s):  
Seismic Performance ◽  
Primary Source ◽  
Shear Walls ◽  
Brick Masonry ◽  
Stone Masonry ◽  
Masonry Buildings ◽  
Kashmir Earthquake ◽  
Equivalent Viscous Damping ◽  
Seismic Performance Evaluation ◽  
Story Drift

Unreinforced masonry buildings, constructed with stones or bricks, are common in the northern areas of Pakistan. In the October 2005 Kashmir earthquake, the seismic performance of stone masonry buildings was found to be poor, which was the primary source of fatalities. Unreinforced brick masonry (URBM) buildings, however, performed well even in severely jolted areas. The performance of URBM could have been much better if the affected buildings were constructed by using proper guidelines. Taking lessons from the disaster, an experimental investigation, based on typical geometry and precompression levels of the URBM shear walls in the affected region, was conducted to evaluate their seismic performance. Twelve walls were tested in the in-plane direction using quasi-static cyclic loading. First-story drift ratios for various performance levels in URBM buildings are proposed. The influences of relative precompression level and aspect ratio on the damage pattern, ultimate drift ratio, and equivalent viscous damping of the walls are examined.

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.

An inventory of unreinforced load-bearing stone masonry buildings in New Zealand

2014 ◽  
Vol 47 (2) ◽  
pp. 57-74 ◽  
Author(s):  
Marta Giaretton ◽  
Dmytro Dizhur ◽  
Francesca Da Porto ◽  
Jason M. Ingham
Keyword(s):  
New Zealand ◽  
Cross Section ◽  
Construction Materials ◽  
Masonry Wall ◽  
Stone Masonry ◽  
Building Stock ◽  
Building Inventory ◽  
Building Information ◽  
Canterbury Earthquake Sequence ◽  
Almost All

Almost all unreinforced stone masonry (URSM) buildings in New Zealand were constructed between 1860 and 1910, typically in regions where natural stone was sourced from local quarries, fields and rivers. These buildings form an important part of the country’s architectural heritage, but the performance of URSM buildings during earthquake induced shaking can differ widely due to many aspects related to the constituent construction materials and type of masonry wall cross-section morphology. Consequently, as a step towards gaining greater knowledge of the New Zealand URSM building stock and its features, an exercise was undertaken to identify and document the country-wide URSM building inventory. The compiled building inventory database includes: (i) general building information, such as address, building owner/tenant and building use; (ii) architectural configuration, such as approximate floor area, number of storeys, connection with other buildings, plan and elevation regularity; and (iii) masonry type, such as stone and mortar types, wall texture and wall cross-section morphology. From this exercise it is estimated that there is in excess of 668 URSM buildings currently in existence throughout New Zealand. A large number of these vintage URSM buildings require detailed seismic assessment and the implementation of seismic strengthening interventions in order to conserve and enhance this component of New Zealand’s cultural and national identity. The entire stock of identified buildings is reported in the appended annex (688 total), including 20 URSM buildings that were demolished following the Canterbury earthquake sequence.

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