Simulation of Distinct Element Joint Stiffness of the Historical Masonry Structure Model by Micro-Tremor Measurement

Historical masonry structures are generally vulnerable to unsettlement and earthquake ground motion. It is desirable to evaluate their static and dynamic mechanisms by a numerical method to preserve and reinforce them. We studied a reduced-scale corbel arch model of the part of the Bayon temple in Angkor, Cambodia. Two dimensional DEM (Discrete Element Method) was used to simulate the experimental displacement at the top due to the enforced unsettlement. Friction angle and contact parameters estimated in preliminary experiments were adapted in DEM simulation. For the static unsettlement simulation DEM worked well; however, the simulation for the fundamental frequency and the mode shape in micro-tremor simulation with the same parameters depicted the much higher fundamental frequency. We reassessed a friction angle, joint normal and joint shear stiffness and found that the constraint on joint stiffness imposed by the static experiment was not sensitive enough for the dynamic case and search of the parameters in broad extents were necessary. The reevaluated contact parameters for the static experiment were effective for the dynamic experiment as well.