Analysis of dynamic energy dissipation mechanism of post-tensioned prestressed rocking wall

Abstract:

The energy dissipation contribution of wall-base rocking impact damping of post-tensioned prestressed rocking walls with ground motion energy input was analyzed. A refined finite element model of the rocking wall was established based on ABAQUS. The dynamic characteristics of the rocking wall structure was determined using modal analysis, and the free damping vibration of the rocking wall under large lateral displacement was simulated. The dynamic time history response of the wall top displacement, velocity, and acceleration was obtained. Taking the restitution coefficient of the rocking wall as a quantitative index of impact damping, the energy dissipation capacity of rocking walls with different aspect ratios and prestress levels was comprehensively evaluated, which contains multiple mechanisms of impact energy dissipation. Results show that the proposed model could accurately reflect the dynamic response of the rocking wall. The aspect ratio had great impact on the dynamic characteristics of the rocking wall. With the decrease in the aspect ratio, the proportion of impact energy dissipation increased significantly, up to 78.3%. The initial prestress level had no obvious influence on the dynamic characteristics and free damping vibration response of the rocking wall, but it significantly improved the energy dissipation capacity and increased the energy dissipation ratio to 36.8%.