Unreinforced masonry (URM) load-bearing walls were commonly used in historic buildings but are weak in shear and vulnerable to cracking and damage during seismic events. Structural engineers often need to study and design solutions to improve the structural response of shear walls. To strengthen them, mortar coatings reinforced with composite (carbon, glass, basalt, etc.) grids are used to enhance their lateral load-caring capacity, ductility, and stiffness. This grid is typically applied on both sides of the shear walls to form a sandwich structure, with the masonry material in the middle and the grid-reinforced coatings to act as thin-but-stiff skins. Anchors between the “skins” are crucial in establishing mechanical bonds and providing strength between the reinforcing material and the URM wall, frequently complemented by chemical bonding. This integrated system ensures the capability to withstand various loads until it attains its ultimate load capacity.
Incorrect placement of the anchor can hinder the desired composite behaviour of the URM wall, leading to premature failure. The location and size of each anchor hole are crucial, as multiple anchor holes are required to secure the reinforcing material throughout the wall effectively. Effective coordination and integration of these elements are essential for achieving the best results. Choosing the proper layout is vital, as an incorrect choice could lead to early wall failure.
This project aims to identify the factors that influence the behaviour of URM walls strengthened with anchors and to evaluate the effectiveness of different anchor layouts in improving the strength and ductility of URM walls. The results of this study will be used to develop design guidelines for placing anchors in URM walls.
Research Aims:
• To identify the factors that influence the behaviour of unreinforced masonry (URM) walls strengthened with composited grids and anchors using numerical simulations.
• To evaluate the effectiveness of different anchor layouts in improving the strength and ductility of strengthened URM walls using numerical simulations.
• To develop a comprehensive methodology for optimizing anchor placement in URM walls, combining systematic numerical simulations with empirical laboratory data, aiming to establish a robust, evidence-based approach for enhancing seismic reinforcement in Unreinforced Masonry structures.
Methodology:
The project will initiate with a targeted literature review to identify critical factors influencing the reinforcement of URM walls with anchors. This sets the foundation for the research’s analytical component. The study will primarily employ finite element modeling (FEM) and simulation, utilizing existing experimental data for model validation. A key focus will be on assessing different anchor layouts to enhance the strength and ductility of URM walls.
Complementing the simulations, experimental tests will be conducted to generate new data and validate simulation results. These tests aim to evaluate the effectiveness of various anchor layouts in real-world scenarios. Non-destructive evaluation techniques will be integrated into these tests to monitor damage progression and understand failure mechanisms.
The combination of simulation and experimental findings will lead to the development of practical design guidelines for effective anchor placement in URM wall reinforcement, contributing valuable insights for structural engineering in seismic areas.
Further Information:
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