Evidence-based creep induced damage progression in masonry structures

历史砖石建筑的准确预期寿命对于实现可持续保护计划和防止意外的危及生命的故障起着至关重要的作用。在这方面，加拿大的砖石存量是大量的，这些结构的文化价值是显著的。根据加拿大历史遗迹名录，超过20%的加拿大历史建筑已经被拆除。因此，需要一种基于先进计算模型的策略，通过了解历史建筑的老化和机械退化过程来更好地保护历史建筑。然而，由于结构的固有复杂性和材料特性的不确定性，开发一种系统的方法来捕捉砖石建筑的长期行为是具有挑战性的。本研究项目旨在提供一种新的基于证据的非连续分析框架（基于离散元法，DEM），预测遗产砌体建筑长期力学行为的不利影响，从而通过考虑其现有条件来解决随时间变化的强度退化和累积损伤现象。将开发一种有效的三维非连续体建模策略，包括材料特性的不确定性，并在DEM中实施随时间变化的接触模型，以探索砌体的蠕变行为。现有砖石结构的现状（例如，国会图书馆和渥太华圣母院大教堂）将通过数据驱动的非破坏性技术进行诊断。结构的现状，包括结构损伤、裂缝、规则和不规则几何特性，将使用图像处理和激光扫描技术进行记录，并将其集成到拟议的建模策略中。此外，建议的建模方法将在实际案例研究中进行，并进行全面的参数分析，这将作为保护我们的建筑文化遗产的建议的基础。所获得的知识将有助于预防和警告任何危及生命的情况，除了消除文化遗产的损失和避免昂贵的维修费用。研究结果将推动砌体结构计算模型的发展，更好地理解砌体结构的长期损伤积累和相应的倒塌机制。新的见解将指导地方当局和政策制定者通过准确诊断和预测加拿大建筑文化遗产的时间相关损害进展和预期寿命，优先考虑最脆弱的历史砖石结构。这项研究计划将为HQP提供宝贵的培训机会，包括编码、数值建模、基于视觉的数据处理和砌体结构的损伤评估，为他们提供追求高度追求的学术或工业职业所需的技能。

The accurate life expectancy of historic masonry buildings plays a vital role in achieving sustainable conservation plans and preventing unexpected life-threatening failures. In this regard, the masonry stock in Canada is substantial, and the cultural value of those structures is significant. According to the Canadian Register of Historic Places, over 20% of Canada's historic buildings have already been demolished. Thus, a strategy based on advanced computational models is needed to better preserve historic buildings by understanding their aging and mechanical deterioration processes. However, developing a systematic approach to capturing the long-term behaviour of masonry buildings is challenging due to the inherent complexity of the structures and uncertainties in the material properties. This research program aims to offer a novel evidence-based discontinuum analysis framework (based on discrete element method, DEM) predicting the adverse effects of long-term mechanical behaviour of heritage masonry buildings, thus addressing time-dependent strength degradation and accumulated damage phenomena by considering their existing conditions. An effective 3D discontinuum modeling strategy, including the uncertainties of the material properties, will be developed, and time-dependent contact models will be implemented in DEM to explore the creep behaviour of masonry. The current state of existing masonry structures (e.g., Library of Parliament and Notre-Dame Cathedral Basilica, Ottawa, ON) will be diagnosed by data-driven non-destructive techniques. The as-is condition of structures, comprising structural damages, cracks, and regular and irregular geometrical properties, will be documented using image processing and laser scanning technologies to be integrated into the proposed modeling strategy. Moreover, the proposed modeling approach will be performed on real-case studies, together with a comprehensive parametric analysis, which will act as the basis for recommendations to protect our built cultural heritage. The knowledge gained will yield to prevent and warn for any life-threatening condition of the historical masonry buildings in addition to eliminating the loss of cultural heritage and avoiding expensive repairing costs. The outcomes will elicit advances in the computational modeling of masonry structures as well as a better understanding of their long-term damage accumulation and corresponding collapse mechanisms. New insights will guide the local authorities and policy-makers to prioritize the most vulnerable historic masonry structures through accurate diagnosis and prediction of the time-dependent damage progression and life expectancy of Canada's built cultural heritage. This research program will offer invaluable training opportunities for HQP in coding, numerical modeling, vision-based data processing, and damage assessments of masonry structures, providing them the necessary skills to pursue highly sought academic or industrial careers.