Abstract: Rock uniaxial compressive strength (UCS) is one of the most important mechanical parameters of rock, which is vital to the design of rock engineering and stability analysis of country rock. Since the rigid procedures of rock drilling and coring, sample processing and testing conditions in rock UCS test, a high-precision model is urgent required for rock UCS prediction, among which the parameters should be easy to get. Based on inherent links of rock physico-mechanical parameters, a relation between rock UCS and P-wave modulus is established. According to the test data of rock dry density, P-wave velocity and UCS from dacite-porphyrite and shale, a UCS prediction formula based on P-wave modulus is obtained by using the linear fitting method, which is verified by statistical test and compared with the traditional prediction formula based on P-wave velocity. The results show that the general prediction formula is simple in form, high in accuracy, and the modulus is easy to obtain, which can be easily applied to practice.

Key words: dacite-porphyrite, shale, uniaxial compressive strength(UCS), P-wave modulus, strength prediction