(1. State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China；2. University of Chinese Academy of Science，Beijing 100049，China；3. State Key Laboratory of Isotope Geochemistry，Guangzhou Institute of Geochemistry，Chinese Academy of Sciences，Guangzhou，Guangdong 510640，China；4. School of Civil Engineering and Architecture，Wuhan University，Wuhan，Hubei 430072，China；5. Key Laboratory of Geotechnical and Structural Safety Engineering of Hubei Province，Wuhan University，Wuhan，Hubei 430072，China)
Abstract：We propose a method to transform the ultrasonic velocity of the drilling core to seismic velocity of the corresponding strata beneath the surface. Firstly，according to the rock type，we convert the ultrasonic velocity of rock block to the seismic wave velocity using different conversion coefficients. Then we modify this velocity using an empirical equation，which consider effects of water saturation，temperature and pressure. Finally，rock body seismic wave velocity is obtained from seismic wave velocity of rock block，by using rock mass integrity coefficient Kv and rock body volume joint number Jv. To testify this method，we choose 5 drilling cores in Huayangchuanpolymetallic deposit，measure ultrasonic velocities of the samples，and convert them into seismic velocities according to our method. When comparing them with the real seismic velocity obtained from ambient noise seismic inversion，we find that the two sets of velocities are very well correlated in terms of the depth change.