Abstract: The application of rock-filled concrete (RFC) technology in high dams and other large-scale projects is on the rise. Given the elevated seismic fortification intensity at certain project sites is relatively high, there emerges a pressing need for enhanced structural design consideration for RFC dams, necessitating comprehensive research on the dynamic performance of RFC. This study employs a scaled-down testing approach to conduct a series of uniaxial and triaxial compression tests on RFC specimens subjected to varying confining pressures and strain rates. The results indicate that the uniaxial strength of RFC is positively correlated with the strain rate, while it will decline to some extent as the size of coarse aggregates or the dimension of the specimen increases. Confining pressure significantly increases the dynamic strength of RFC. Under the same confining pressure, specimens containing larger aggregates demonstrate lower uniaxial strength but exhibit higher triaxial strength. This observation suggests the mesoscopic characteristics of the self-sustaining skeleton formed by coarse aggregates play a crucial role in the strength of RFC. Based on the test results, a failure criterion is established using the octahedral stress, thereby providing experimental evidence for the seismic design of RFC structures.

Key words: rock-filled concrete, dynamic strength, strain rate, confining pressure, failure criterion