Abstract:
After 25 cycles of loads (the lower limit of load is 140 kN, the upper limit of load is 260 kN, the frequency is 0.1 Hz), the triaxial compression tests for different confining pressures (0, 2, 5, 10 MPa) of water saturated concrete under different loading rates (the response range of strain rate of concrete under seismic load is 10
-5/s~10
-2/s) are carried out, and the peak stress and peak strain of concrete and damage characteristics are analyzed in this study. The analysis results show that after cyclic loading: ① with the increase of the loading rates, the peak stress and the peak strain of concrete increase gradually, and the growth rate of damage variables slows down; ② with the increase of the confining pressures, the peak stress and the peak strain of concrete increase gradually. The growth rate of the damage variables is slowing down, but the
D-value of damage limit is becoming larger. Based on the experimental results mentioned above, an empirical formula for the dynamic peak stress of concrete with the confining pressures and loading rates after cyclic loading is obtained from the experimental tests. And an empirical formula for the dynamic peak strain of concrete with the confining pressures and loading rates after cyclic loading has also been got based on the above test results.