Impact of retrofitting work on vulnerability reduction of local buildings in Kabul, Afghanistan

Rapid urbanisation of Afghan cities without proper construction regulation has exposed their population to a high risk of damage from disasters such as earthquakes. With the growing construction of local non-engineered buildings and an existing level of hazard of 0.8 g, a high risk of casualties and building damage threatens Kabul in the event of a disaster. This study reports and evaluates a recent retrofitting project in Kabul City by ‘Project for City Resilience’, carried out under the supervision of the United Nation Human Settlements Program (UN-Habitat) for 48 retrofitted sun-dried clay brick masonry buildings in Kabul. The project was executed by local masons and welders who were trained as a part of the project, and the main tasks included installation of an additional steel frame, additional reinforced concrete foundation ring, ceiling replacement and wall strengthening (via mesh and plaster). After a visual assessment of retrofitted buildings considering the original retrofitting design and actual work done, a vulnerability index for retrofitted buildings was developed based on a behaviour modifier factor, which was assigned to each retrofitting activity using a combination of values and a proportion of scores for each retrofitting activity. The results indicate that training of local masons and welders to undertake retrofitting activities could decrease the damage ratio by 15% – 20% for peak ground acceleration values of 0.3 g and higher. The methods mentioned in this study can be used to make existing sun-dried clay brick masonry buildings sufficiently resistant to earthquakes of moderate-to-severe intensity.

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Post-earthquake Damage Simulation of Two Colonial Unreinforced Clay Brick Masonry Buildings Using the Equivalent Frame Approach

Structures ◽

10.1016/j.istruc.2019.01.010 ◽

2019 ◽

Vol 19 ◽

pp. 212-226 ◽

Cited By ~ 7

Author(s):

Salvatore Marino ◽

Serena Cattari ◽

Sergio Lagomarsino ◽

Dmytro Dizhur ◽

Jason M. Ingham

Keyword(s):

Brick Masonry ◽

Earthquake Damage ◽

Masonry Buildings ◽

Clay Brick ◽

Equivalent Frame ◽

Damage Simulation

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Seismic fragility assessment of nonstructural components in unreinforced clay brick masonry buildings

Earthquake Engineering & Structural Dynamics ◽

10.1002/eqe.3238 ◽

2020 ◽

Vol 49 (3) ◽

pp. 285-300 ◽

Cited By ~ 2

Author(s):

Hossein Derakhshan ◽

Kevin Q. Walsh ◽

Jason M. Ingham ◽

Michael C. Griffith ◽

David P. Thambiratnam

Keyword(s):

Brick Masonry ◽

Seismic Fragility ◽

Masonry Buildings ◽

Clay Brick ◽

Nonstructural Components

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Performance of early masonry, cob and concrete buildings in the 14 November 2016 Kaikoura earthquake

Bulletin of the New Zealand Society for Earthquake Engineering ◽

10.5459/bnzsee.50.2.194-205 ◽

2017 ◽

Vol 50 (2) ◽

pp. 194-205 ◽

Cited By ~ 5

Author(s):

Dmytro Dizhur ◽

Marta Giaretton ◽

Jason Ingham

Keyword(s):

Concrete Structures ◽

Structural Response ◽

Brick Masonry ◽

Masonry Buildings ◽

Clay Brick ◽

Out Of Plane ◽

Recording Station ◽

Building Components ◽

Vertical Ground ◽

Kaikoura Earthquake

The performance of historic buildings during the 14 November 2016 Mw7.8 Kaikoura, New Zealand earthquake is reported, focusing on early stone and clay brick masonry buildings, vintage concrete structures, cob cottages, and the non-structural masonry chimneys and veneers of buildings located in the upper part of the South Island (Marlborough and North Canterbury regions). To better document structural response, the intensity of horizontal and vertical ground motion from the nearest recording station is graphically placed alongside the assessed level of damage. In response to numerous strong earthquakes that have previously occurred in the area a large number of highly vulnerable buildings or non-structural building components were previously either seismically retrofitted or demolished, thereby reducing the level of damage and loss of life during the 2016 Kaikoura earthquake. Seismically retrofitted stone and clay brick masonry buildings and cob cottages exhibited good performance, while some vintage concrete structures and partially strengthened cob cottages suffered moderate to extensive levels of damage. A large stock of URM chimneys in Picton, Seddon and Rotherham were previously removed while in other locations chimneys presented a variety of responses. Rural masonry veneer dwellings located in Seddon and Waiau experienced high damage levels, typically resulting in out-of-plane collapse of the masonry veneer.

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Fragility curves for Italian URM buildings based on a hybrid method

Bulletin of Earthquake Engineering ◽

10.1007/s10518-021-01155-4 ◽

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.

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