Confined masonry as practical seismic construction alternative–the experience from the 2014 Cephalonia Earthquake

Karantoni, Fillitsa V.; Pantazopoulou, Stavroula J.; Ganas, A.

doi:10.1007/s11709-017-0390-1

Cited by 11 publications

(4 citation statements)

References 19 publications

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“…45,46 Nevertheless, several countries experienced that confined masonry (CM), which is characterized by bearing masonry panels framed by small reinforced concrete horizontal and vertical elements (tie-beams and tie-columns), has improved seismic performance with higher lateral resistance and overall ductility. [47][48][49][50][51][52][53] CM structures have shown a very satisfactory behavior during moderate and strong earthquakes, 54,55 representing a sound alternative to bare and masonry-infilled reinforced concrete (RC) frame buildings. 56 Recently, the last of these authors started a research program aimed to assess and improve the dynamic performance of masonry structures by using the CM technique.…”

Section: Introductionmentioning

confidence: 99%

Damage detection via modal analysis of masonry structures using shaking table tests

Pepi

Cavalagli

Gusella

et al. 2021

Earthq Engng Struct Dyn

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In the last two decades, the use of modal parameters to detect and localize structural damage has gained increasing interest in the scientific community. The work reported in the literature mainly deals with the change of natural frequencies due to changes in structural properties given by damage. This approach relies on the accurate modal parameters estimation, which is still a very difficult task especially when complex structural systems are of interest. Furthermore, damage detection and localization can be highly inaccurate if natural frequencies are used only, regardless of the associated mode shapes. This paper investigates the effectiveness of vibration-based methods for dynamic identification and damage detection on masonry structures using experimental tests and operational modal analysis. In particular, ambient vibration tests are first used to obtain modal parameters of two different building models made up of unreinforced and confined masonry, respectively. A shaking table is then used to give a sequence of increasing seismic loads to each of the two masonry models. Damage-induced variations of the modal parameters, i.e., natural frequencies and associated mode shapes, are estimated after each seismic level using the structural vibrations caused by a low-level white noise base excitation. The obtained results give useful information on the effectiveness of vibration-based methods to detect and localize different damage patterns on masonry structures using changes in the modal parameters. Furthermore, it was possible to assess the different seismic performance of the confined masonry structural system compared to the unreinforced masonry.

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Section: Introductionmentioning

confidence: 99%

Damage detection via modal analysis of masonry structures using shaking table tests

Pepi

Cavalagli

Gusella

et al. 2021

Earthq Engng Struct Dyn

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

“…Marques and Lourenco 7 experimentally studied the behavior of unconfined and confined masonry structures and compared it against the pushover response of the corresponding computational model. Karantoni et al 23 analyzed the applicability of confined masonry in the restructuring of Ionian Island following the devastating earthquake of 1953. The selected structures particularly the Arogi building in Cephalonia demonstrated seismically resilient performance during the severe 2014 earthquake in the near-fault condition that caused excessively high acceleration.…”

Section: Introductionmentioning

confidence: 99%

Bi‐directional collapse fragility assessment by DFEM of unreinforced masonry buildings with openings and different confinement configurations

Deb

Yuen

Lee

et al. 2021

Earthq Engng Struct Dyn

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Unreinforced masonry (URM) buildings that are characterized by brittle, heterogeneous, and anisotropic responses have complex nonlinear dynamic behavior and high vulnerability under seismic loading. While masonry confined by tie‐columns and lintel beams can achieve better ductility and stability, the wall openings induce stress concentration around the corners and diminish the strength. Furthermore, the interacting in‐plane and out‐of‐plane responses of masonry walls could significantly affect the post‐cracking behavior and increase the collapse risk. To attain reliable seismic design of confined masonry buildings with openings, the collapse fragility under bi‐directional seismic loading shall be addressed and thoroughly investigated in this study. Advanced discrete finite element models (DFEM) with coupled damage‐plasticity traction‐separation law, which can simulate complex nonlinear dynamic behavior such as disintegration and progressive collapse, were developed for the masonry structures and validated against experimental results. Four one‐storey residential masonry buildings: (1) unconfined (UCM), (2) confined by tie‐columns at four building corners (CM‐I), (3) confined by toothed tie‐columns (CM‐II), and (4) confined by toothed tie‐columns and lintel beams (CM‐III) were considered. A series of incremental dynamic analyses (IDA) with 15 bi‐directional ground motions and fragility analyses were performed to investigate the dynamic characteristics, base shear, hysteresis behavior, failure mechanism, collapse probability, and exceedance probability for different drift limits were studied in‐depth. CM‐II with toothed tie‐columns had the lowest collapse probability and fragility at different drift limit states. The introduction of lintel beams to CM‐III lead to an increase of the storey‐drift‐based fragility compared to CM‐II, as a result of the increased maximum base shear of CM‐III with higher post‐damage stiffness. The lintel beams also inflicted short‐column effects on the tie‐columns. Nevertheless, the lintel beams could delay the out‐of‐plane collapse of the masonry walls by shortening the effective wall arching length. In some cases, the CM‐III could achieve better performances than CM‐II even in terms of storey drifts. The response variations of CM‐III to the changing of the non‐intensity related ground motion parameters are also lower than CM‐II.

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“…Their results concluded that the connecting bars at the vertical wall-to-column connections and the horizontal-wall reinforcement were quite effective for improving seismic performance. Karantoni et al [5] examined the seismic behavior of the confined masonry by FEM linear analysis and compared it to that of URM structures. They found this low-cost alternative method of construction is a very effective means of producing earthquake-resilient structures.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Performance of Confined Autoclaved Fly-Ash-Brick Masonry Walls under Cyclic Loading

et al. 2021

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In order to solve the limitations of masonry structures, such as poor seismic performance, complicated construction techniques, and energy wastage of wall materials, a new type of confined autoclaved fly-ash-brick wall was proposed and its mechanical performance was analyzed. An axial compression test of autoclaved fly-ash-brick short columns was carried out to analyze the failure mode and obtain the constitutive parameters of the brick. Meanwhile, a low-cyclic loading test of an assembly using an autoclaved fly-ash-brick wall was carried out to prove the correctness of the numerical model. Under multiple influencing parameters, the seismic performance of the assembly of autoclaved fly-ash-brick walls was analyzed by a numerical-simulation method. The results show that (1) the seismic performance of the assembled autoclaved fly-ash-brick walls is better than that of cast-in-place masonry walls; (2) low-strength mortar leads to premature cracking, which is unfavorable to earthquake resistance of the walls; and (3) the bearing capacity of the wall is increased and then decreased with the increase of the vertical compressive stress, so the number of layers of brick masonry structural should be limited. In addition, some construction measures were proposed to improve the mechanical performance of assembled autoclaved fly-ash-brick walls.

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Confined masonry as practical seismic construction alternative–the experience from the 2014 Cephalonia Earthquake

Cited by 11 publications

References 19 publications

Damage detection via modal analysis of masonry structures using shaking table tests

Damage detection via modal analysis of masonry structures using shaking table tests

Bi‐directional collapse fragility assessment by DFEM of unreinforced masonry buildings with openings and different confinement configurations

Mechanical Performance of Confined Autoclaved Fly-Ash-Brick Masonry Walls under Cyclic Loading

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