Typology and seismic stability analysis of vaults in the historical city of Masouleh

Arches are one of the most efficient innovations that architects have used to cover ceilings, wide openings, or as decorative elements in various structures. The purpose of the research includes the typology and the functioning of arches in the historical city of Masouleh during an earthquake. The research questions are as follows: Are several types of arches used in the architecture of the historical city of Masouleh? Which of the Masouleh arches shows a better structural performance during an earthquake? The research method is in the form of field studies, and Abaqus 2022 finite element software was used to analyze the earthquake resistance of Masouleh arches, which occurred in cities such as Bam (2003), Rudbar Manjil (1991) and Tabas (1978). The research results indicate that the historical city of Masouleh has 19 arches, and high-rise and low-rise Panjohaft arches are the most common types. The Roman arch construction method is the most common method used in Masouleh arches. The results show that 78% of Masouleh arches have adequate structural capacity against earthquakes, and Keshesar neighborhoods with 37% and Khanebar neighborhood with 21% have the most arches and Reyhanebar neighborhood with 10% have the lowest amount of arches in Masouleh. Also, the results of the seismic analysis of the 19 arches of Masouleh show that the low-rise Haftopanj arch, which is made using the Roman brick masonry method located in the Asad neighborhood, had the weakest structural performance against earthquakes, and the forty-five-degree arch with the Roman construction method, located in Masjedbar neighborhood, had the most appropriate structural performance in seismic simulation.