Sharif University of Technology Scientia Iranica 1026-3098 Articles in Press 2025 01 27 Numerical modeling and laboratory study of layered Gypsum-Concrete specimens with joints 23805 10.24200/sci.2025.65020.9254 EN Alireza Bagher Shemirani Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran Journal Article 2024 07 27 The presence of joints and defects around openings contributes to the instability of these flaws. In nature, rocks and concrete materials are often layered, anisotropic, and contain numerous joints. This article discusses laboratory preparation and testing of layered gypsum-concrete specimens with varying geometries. Specifically, single joints above the openings were created at different angles and subsequently tested. The study focused on the instability and failure of the specimens in relation to the angularity of joints, anisotropy, and the geometry of the openings. Additionally, numerical modeling of the tested specimens was conducted using ABAQUS software to analyze the behavior of the openings when interacting with joints or faults. To ensure accuracy, ABAQUS was calibrated using data from uniaxial compression tests. The modeled specimens were then examined under uniaxial compression conditions, incorporating various opening configurations with joints. The findings indicated that tensile cracks were the most prevalent mode of failure in these modeled specimens. Notably, as the distance from the tunnel roof to the joint increased, its impact on tunnel instability diminished due to an increase in failure stress. https://scientiairanica.sharif.edu/article_23805_e940f0ae37f00037c53205906f508ccf.pdf