Abstract: Rock mechanics is based on rock mechanics test, which is one of the most important methods in studying rock mechanics and engineering. But the experimental results of rock mechanics test are always influenced by many factors and the discrete experimental results are ubiquitous. Those bring some inaccurate or even reverse results. Based on the relationship among ultrasonic velocity, rebound value and strength of rock, the ultrasonic-rebound comprehensive method was applied to the rock sample selection which has the advantages of two methods. In order to get the accurate results, the rock specimens which may cause discrete results can be selected out first before the laboratory test. Practice shows that such a comprehensive sampling method has good applicability. It is quite convenient to distinguish the rock specimens with interior defects and has no injury. At the same time, the ultrasonic-rebound method is quite useful to predict the compressive strength. So the application of this method in sampling of rock mechanics test and strength prediction is worth using for reference.

Key words: ultrasonic velocity, rebound method, interior defects, sampling, strength prediction