LIMIT ANALYSIS MODEL FOR A FAST EVALUATION OF CHINESE MASONRY PAGODAS VULNERABILITY

A masonry pagoda is usually a single independent structure. It has a large volume and complex internal space. In the event of an earthquake, the damage to the masonry material will lead to the collapse of the entire pagoda body, threatening the safety of human life and property. The limit analysis is considered to be the most appropriate technique for analyzing this kind of problem. This paper presents a novel limit analysis method to discretize a masonry pagoda through infinite resistant hexahedrons ad dissipation at the interfaces. It assumes that the interface material obeys a Mohr-Coulomb failure criterion with tension and compression cutoff. Considering the relationship between the jump of velocities and plastic multipliers on all interfaces, the normalization condition of the failure mechanism, boundary conditions, and the objective function to minimize, it uses standard linear programming to estimate the collapse multiplier and failure mechanism active. The problem obtained is self-dual, and it cannot be considered belonging to either the upper or the lower bound limit analysis families. The paper considered a case study - Zhongjiang south pagoda in China. The limit analysis assumes two cohesion conditions (0.05 MPa, 0.20 MPa), and studies the collapse mechanism under G1 and G2 distributions. The direction of the horizontal load applied comprises four angles. With the aim to study how the damage spreads within the structure and demonstrate the accuracy of the approach proposed, several simulations are also performed by a Finite Element-based software (Abaqus) for comparison. The results of the study are in good agreement with other simulation methods and the post-earthquake conditions observed.