Nonlinear finite element modeling and seismic analysis of Thai historical masonry wall structures

Abstract Ayutthaya is a significant heritage tourism destination in Thailand, with numerous historical sites featuring ancient brick walls. Assessing their stability and structural integrity requires accurate material data and appropriate modeling techniques. This paper describes nonlinear finite element modeling of Thai historical masonry wall structures. The presented models are used to perform nonlinear seismic analysis. A section of the historical wall in Wat Phra Si Sanphet, Ayutthaya, is selected as a research case. Three-dimensional laser scanning data show that the wall is arranged in an S-shape along the east–west direction. The wall materials are red bricks and lime mortar produced locally in the 15th century CE. Affected by natural weathering and geological movement, the surface mortar of the historical wall has visible peeling and damage, and the brick units are partially broken or displaced. Three finite element modeling methods using the concrete damage plasticity theory, namely, a detailed micro-model, a simplified micro-model, and a macro-model, are proposed and compared with previously published laboratory tests of masonry prisms. The results reveal that the simplified micro-model is the most suitable. Consequently, a seismic analysis of the historical wall in Wat Phra Si Sanphet, Ayutthaya, is performed using the simplified micro-model. Examples of possible wall damage profiles are provided, and guidance for structural reinforcement is provided.