Practical Simulation Tools for the Seismic Analysis of Timber-Framed Masonry Structures

Konstantinidis

et al. 2021

Infrastructures

The seismic response of five cultural heritage towers erected between the 9th and 10th century AD are investigated herein. Firstly, their architectural and modal characteristics were studied in the light of seismic events that hit the monuments. There exist several historical reports of strong earthquakes, as well as damaged structures and collapses. The limit analysis is adopted to examine the post-elastic behavior of the towers up to collapse due to out-of-plane failure. Recurrent damage modes were collected from recent earthquakes and a classification of four possible collapse mechanisms in towers and slender masonry structures is here proposed: overturning, separation of perpendicular walls, diagonal cracking, and dislocation of the belfry. A thorough examination of the towers under investigation verified the proposed damage classification. The capacity curves were derived combining the capacity curves of each of the collapse mechanisms. Damage thresholds were defined on these curves in correspondence with damage states. The studied group of structures is representative of a wider typology. A statistical approach was adopted to describe damage with seismic intensity, and vulnerability curves were generated. The results of this study will improve the understanding of the performance and the collapse mechanisms of slender masonry structures under seismic loading and provide a characterization of seismic vulnerability for the studied cultural heritage types of towers.

Section: Introductionmentioning

confidence: 99%

Assessment and Fragility of Byzantine Unreinforced Masonry Towers

Konstantinidis

et al. 2021

Infrastructures

“…The empirical formulas (Kouris 2013) are applied to define the constitutive law of each panel in terms of horizontal shear vs. displacement. 4.…”

Section: Analysis and Pushover Curves Of The Typical Buildingmentioning

confidence: 99%

Fragility Curves and Loss Estimation for Traditional Timber-Framed Masonry Buildings in Lefkas, Greece

Computational Methods in Applied Sciences

Kappos

2015

Self Cite

This is the accepted version of the paper.This version of the publication may differ from the final published version. Abstract The 2003 earthquake in the Greek island of Lefkas, has revived the interest for the local anti-seismic technique based on the use of timber-framed masonry, whose adequate performance during the earthquake revealed the merits of this rather sophisticated, albeit traditional, construction. A key feature of the Lefkas structures is their dual structural system. The secondary system is activated once the ground storey stone masonry piers of the primary system (which includes timber-framed masonry in all storeys) fail. In this regard, two different structural models are presented herein to simulate the response of each system. A macro-model based on nonlinear (NL) strut elements and point plastic hinges is intended to model the timber-framed masonry. NL analyses are carried out for one, two and three storey buildings , which represent the most common cases in Lefkas. Furthermore, an investigation is carried out regarding the foundation of the buildings resting on soft alluvial deposits. Pushover curves are derived from the NL analyses of the buildings and are then converted to capacity curves using the characteristics of the predominant mode. On these curves four damage states (slight damage, moderate damage, heavy damage, and collapse) are defined on the basis of criteria related to the actual response of the building. Then, fragility curves in terms of spectral displacement are generated, adopting a log-normal statistical distribution. These curves are converted into PGA values using a selected response spectrum. Utilising these fragility curves a seismic loss scenario for the 2003 Lefkas earthquake is developed for the timber-framed masonry stock of Lefkas city. Permanent repository link

Numerical Investigation and Empirical Seismic Vulnerability Assessment of Timber-Framed Masonry Buildings

Handbook of Research on Seismic Assessment and Rehabilitation of Historic Structures

Kappos

2015

This chapter describes the development of traditional timber-framed masonry techniques as an anti-seismic measure in the course of time and their corresponding seismic effectiveness. Firstly, the evolution of timber framed structures from the Bronze Age to date is presented and the effects on their seismic resistance of the structural changes to which these structures have been subjected since the most ancient construction. It is noted that the appearance of timber in the body of masonry walls in prehistoric Greece after strong seismic events is the first time in the history of mankind that an effort is made to provide a rational method for seismic resistance to buildings. The seismic performance of traditional structures during recent earthquakes is also discussed. A variety of advanced analytical modelling strategies for these buildings is presented, from a detailed micro-model to macro-model procedures. The potential seismic vulnerability of these buildings is investigated using statistical data from recent earthquakes. Empirical fragility curves in terms of PGA, PGV and macroseismic intensity from the 2003 Lefkas earthquake damage data are presented.