Advancing seismic monitoring of masonry structures with smart bricks: recent developments and future prospects

Abstract

Masonry structures constitute a significant portion of the world's cultural heritage, and ensuring their structural and seismic safety presents formidable challenges. These challenges include highly nonlinear mechanical behavior, complex failure mechanisms, heterogeneous material properties, and intricate modeling requirements. Structural health monitoring (SHM) has emerged as a pivotal approach to comprehending how these structures respond to seismic events, thus enhancing safety assessments and enabling informed decision-making. However, SHM for masonry structures remains exceptionally challenging due to the aforementioned complexities. Traditional SHM methods, reliant on global response data, often struggle to pinpoint damage effectively. Concurrently, externally attached off-the-shelf sensors prove inadequate for monitoring masonry structures with extensive and intricate geometries. Such sensors typically provide localized information that does not adequately represent the broader structural response evolving within structural macro-elements. To surmount these challenges, novel sensing strategies are imperative to establish a more direct connection between damage assessment and decision-making. In this context, author's research group at the University of Perugia, Italy, is pioneering innovative strain-based SHM techniques for existing masonry structures. The key approach involves the deployment of "smart bricks," which are strain-sensing micro-composite clay bricks capable of generating electrical outputs when subjected to external loads. These smart bricks replace conventional bricks at specific locations, supplying valuable data for damage identification through average masonry strain comparisons under permanent loads before and after seismic events. This work highlights group's recent achievements in sensor development, encompassing sensor fabrication, characterization, and damage identification. Additionally, the talk will delve into the journey towards achieving a truly intelligent masonry by integrating smart bricks with smart mortar layers, providing insights into the detection of cracks and larger-scale structural damage within these heritage structures.