Research on the Fracture Mechanism of Bridge Piers Damaged by Jointed Rolling Stones

This paper investigates rockfalls, focusing on their interaction with bridge piers through physical experiments and numerical simulations. It analyzes the instability and breakage of fissured rock masses, often triggered by earthquakes, and their effects on bridge structures. By employing the discrete-element method, the study explores the dynamic responses of bridge piers to rock impacts and offers insights for mitigating rockfall hazards. Results showed that, first, increasing preexisting cracks in rolling stones leads to increased damage, with the most severe damage observed at slope angles between 60° and 75°. Second, as slope angle increases, bridge pier damage becomes more severe. At 60°, the depth of surface damage to the bridge pier was the greatest, with the pier experiencing its maximum lateral displacement. At 75°, the average length of concrete cracks and indentations on the pier surface reached a maximum of 2.95 cm. Third, the fragmentation of rolling stones increases their speed and reduces their potential energy, and the slope angle increases the kinetic energy and velocity of the rolling stones, reaching a peak at 75° for moderately and weakly bonded stones. Finally, the fragmentation of rolling stones significantly reduces their impact force. Hence, the effects of stone fragmentation cannot be overlooked in practical scenarios. Damage to bridge piers increases with the slope angle.