Taking the skarn specimens extracted near the deep ore drift in Dongguashan copper mine as the research object

a modified split Hopkinson pressure bar (SHPB) system was used to investigate dynamic characteristics of deep skarn under the combined action of high axial pressure and confining pressure under frequent dynamic disturbance. The results show that internal microcracks in specimens were closed due to high pre-loaded axial pressure and confining pressure

which results in no concave phenomenon at the initial stage of dynamic stress-strain curves during the impact load

i.e. no compaction stage. After peak stress

the phenomenon of reduced strain rebound occurs when the elastic force stored in the specimen is greater than the impact load during unloading. Otherwise

the compressive strain increases until the specimen breaks. The accumulative impact disturbance times rises while with increasing confining pressure

and it reduces due to the increased axial compression. Furthermore

the growth or decreasing rate is influenced by the confining pressure and axial pressure. The dynamic deformation modulus and peak stress decrease with the increase of impact disturbance times

but the maximum strain and dynamic peak strain grow up. Moreover

the average of dynamic strength has been cut down with the rising axial pressure

but it decreases firstly and then increases with the increase of confining pressure. The dynamic deformation of rock is accompanied by elastic deformation

the strain rebound generally increases firstly and then decreases with increasing impact disturbance times on the whole.