Bulletin of Earthquake Science and Engineering

Bulletin of Earthquake Science and Engineering

Numerical Investigation of the Effect of Brickwork Configuration on the Strengthening of Unreinforced Masonry Walls Using CFRP Sheets

Document Type : Research Article

Authors
Sina Kamali 1
Mahdi Adibi 2
1 M.Sc. Graduate of Structural Engineering, University of Bojnord, Bojnord, Iran,
2 Associate Professor, Faculty of Engineering, University of Bojnord, Bojnord, Iran
10.48303/bese.2025.2044648.1210
Abstract
Masonry structures have long been widely used throughout the world due to their simple construction process and economic advantages. However, severe earthquake-induced damage in recent decades has demonstrated the high vulnerability of unreinforced masonry (URM) structures against seismic loading. Therefore, investigating the seismic behavior of masonry walls and improving their structural performance are of significant importance in earthquake-prone regions. The present study aims to numerically evaluate the seismic behavior of 200 mm thick URM walls with two different brickwork configurations, namely running-bond and stack-bond arrangements, in both unstrengthened and CFRP-strengthened conditions under cyclic lateral loading. In the strengthened specimens, both wall types were retrofitted using diagonal CFRP strip configurations. In addition, the running-bond wall was also strengthened using a combined configuration consisting of diagonal and horizontal CFRP strips.
A simplified micro-modeling approach based on the finite element method was adopted to simulate the masonry walls. The numerical models were validated against available experimental results reported in the literature. The seismic performance of the investigated walls was assessed through the analysis of hysteretic behavior and seismic response parameters, including ductility ratio, load-carrying capacity, effective stiffness, energy dissipation, and strength degradation.
The results obtained from the unstrengthened walls indicate that the running-bond masonry wall exhibits higher ductility, greater load-carrying capacity, larger hysteretic energy dissipation, and lower strength degradation compared with the stack-bond masonry wall. In the CFRP-strengthened condition using the diagonal strengthening scheme, the stack-bond wall demonstrated higher ductility, effective stiffness, load-bearing capacity, energy dissipation, and strength degradation than the strengthened running-bond wall. Overall, the strengthening effect of CFRP sheets on the seismic response parameters was found to be more significant in the running-bond wall compared with the stack-bond wall.
Furthermore, the results reveal that the combined strengthening configuration consisting of diagonal and horizontal CFRP strips does not provide a substantial improvement over the diagonal strengthening scheme in terms of ductility enhancement and prevention of strength degradation in the masonry wall. The findings of this study highlight the important influence of brickwork configuration on the effectiveness of CFRP strengthening techniques and provide useful insights for the seismic retrofit design of unreinforced masonry structures.
Keywords
Masonry Wall
Brickwork Configuration
Seismic Load
Finite Element Modeling
Subjects
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  • Receive Date 17 November 2024
  • Revise Date 14 June 2025
  • Accept Date 12 July 2025