Since the mechanical test on rock is a kind of destructive test, it is difficult to derive massive sample data for determining mechanics parameters. The credibility of the prior information should be considered at first in estimating rock mechanics parameters by the Bayes method. The formulas for calculating the compatibility and credibility of the pre-information and post-information under the condition of normal distribution are developed based on the assumption of second kind-mistake theory of statistics. This result provides the theoretical basis of utilizing the prior information to carry...
