Research On Rock Stability Based On Ultrasound Technique

Ultrasonic wave attenuation measure is an important method of researching the energy absorptance of rock. It relates with the variation of rock microcrack and is one of subjects to be researched continuously in rock area .On analyzing the results of other researchers, the author of this paper assembles a set of ultrasonic wave attenuation measure system of rock crack spread under untaxed pressure, makes up data program, using pulse transmition technique and spectral ratio method, with perfect and analogous crack basalt samples, performs experiment research in the relation of the attenuation and the crack spread, and obtains some of value data.The experiment results demonstrate that longitudinal on the variation of rock ultrasonic wave goodness. At first, Qp increases with pressure. When the pressure attains certain value, it change into reduce. Before the sample is broken up, longitudinal splitting Qp reduces gradually. But, shear glie Qp does not vary obviously and the sample occurs sharp destruction. The discussion of attenuation mechanism of ultrasonic wave transimtion in rock is performed. The viscosity friction of mineral grain and microcrack surface, and the scatter effect of macrocrack, are considered an prevailing attenuation mechanism. In application, rock ultrasonic wave measure system is reformed. It is fulfilled to detect large pollster layer concrete sample. The results show that the system can elementally satisfy the measure requirement of the acoustic quality of mine rock, and it is adaptable to the wave velocity and the attenuation measure of the loose area of rock, of weak layers under dam base.