Numerical simulation of the in-plane response of masonry walls retrofitted with “splints and bandages” systems

Dhir, Prateek Kumar; Rapicavoli, Davide; Panto, Bartolomeo; Szyniszewski, Stefan

Abstract

Unreinforced masonry (URM) buildings represent the majority of existing structures in many low-income seismic regions around the world. Most of these buildings were not designed to resist seismic loading and are characterised by poor materials and poor structural details. As a result, they are highly vulnerable to earthquakes, as evidenced by significant damage and failures observed after past events. For this reason, various seismic retrofit techniques have been introduced in recent decades. Among these there is a retrofitting technique called "splints and bandages" – consisting of applying on the two faces of the wall external vertical and horizontal cement-mortar steel-reinforced strips – largely adopted in Nepal after the 2015 Gorkha earthquake. Despite this, reliable numerical tools to assess the seismic response of masonry walls after the interventions have not been adequately exploited in the literature. This paper presents the results of numerical simulations conducted on a brick-masonry wall reinforced by the “splints and bandages” technique, tested in the laboratory by applying in-plane lateral loading, to investigate the accuracy and efficiency of models based on macroscale masonry descriptions, which are largely adopted in research and engineering practice: the continuous Finite Element (FE) model with an isotropic damage-plasticity constitutive law, and the Discrete Macro-Element Method (DMEM) -- implemented in the advanced structural software Abaqus and HiStrA, respectively -- are developed and used to simulate the response of the wall prototype up to failure. The predictions of the macroscale models are compared to the experimental findings and the numerical results of a more refined mesoscale FE model in terms of load-displacement curves and failure mechanisms. First, the mesoscale FE model is used to evaluate the material parameters not directly evaluated in the experimental campaign by fitting the load-displacement capacity curve registered in the laboratory. Then, the FE and DMEM macroscale models are calibrated according to the obtained mesoscale material parameters to evaluate the accuracy of these simplified approaches. Subsequently, extensive parametric analyses are conducted to assess the role of the main macroscopic masonry parameters on the global response of the wall. The comparisons evidenced that macroscale models can effectively simulate splints-and-bandages-retrofitted masonry (RM) walls subjected to in-plane loading, with good consistency observed between the two adopted modelling strategies. Moreover, the analyses shed light on the effectiveness of this retrofitting methodology and the role of the main material parameters, like tensile and fracture energy, on the non-linear and ultimate system responses.

Citation

Dhir, P. K., Rapicavoli, D., Panto, . B., & Szyniszewski, S. (2025). Numerical simulation of the in-plane response of masonry walls retrofitted with “splints and bandages” systems. Engineering Structures, 342, Article 120678

• Journal Article Type: Article
• Acceptance Date: May 26, 2025
• Online Publication Date: Jul 1, 2025
• Publication Date: Nov 1, 2025
• Deposit Date: Jul 1, 2025
• Publicly Available Date: Jul 1, 2025
• Journal: Engineering Structures
• Print ISSN: 0141-0296
• Electronic ISSN: 1873-7323
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 342
• Article Number: 120678
• Public URL: https://durham-repository.worktribe.com/output/4150439