Mechanical responses and energy characteristics of the Jinping marble under the dynamic impact

Abstract

To study the dynamic responses and energy characteristics of the marble from the Jinping hydropower station, the dynamic compression tests on the rock samples are carried out using the split-Hopkinson pressure bar, and the fractal dimension of the fragments is also introduced to quantitatively characterize the relationship among the failure shape, energy consumption characteristics and strain rate of the rock samples. The results show that the initial compaction section of the stress-strain curve of the marble under dynamic loading is not obvious, and the stress-strain curve takes on a rebound phenomenon when the strain rate is low, and the peak stress of the sample increases with the rise of strain rate. The dynamic compressive strength has a linear relationship with the logarithm of strain rate, and the energy time-history curves show an "S"-shaped evolution. The incident energy, reflected energy and transmitted energy all increase with the increasing strain rate. The dynamic compressive strength has a logarithmic growth with the energy consumption density. As the energy consumption density or strain rate rises, the failure degree and the fractal dimension of the samples gradually increase. This study is of certain reference value for improving the cognition of rock damage and fracture evolution mechanism under dynamic loads such as blast.

Keywords

• marble
• dynamic impact
• mechanical responses
• energy characteristics
• fractal dimension