STUDY OF FATIGUE PROPERTIES AND CRITICAL STRESS MEASUREMENT METHOD OF ROCK
FENG Chunlin1，WU Yongfeng2，FENG Fuxian1
(1. Faculty of Nuclear Resources and Safety Engineering，University of South China，Hengyang，Hunan 421001，China； 2. Nuclear Industry of Gansu 219 Team，Tianshui，Gansu 741025，China)
Abstract：For seeking a solution to solve of the discreteness of rock parameters，on the basis of the testing results of uniaxial compression，fatigue deformation properties of granite and white sandstone，a new measurement method of the critical stress of rock is put forward. The method is first based on the different peak stress-stain curves，which is grouped，and then fatigue testing is performed at different heights，at low stress levels. According to testing results，steady and unsteady state curves can be drawn and both curves crossover point is found. Its two important parameters，i.e. stress and strain，are the critical stress and strain. The grouping method is even more exactness，more corresponding to facts，more economic and safe than the tradition method. It would have practical value in the rock base engineering.
