Probability Distribution of Rock Salt Creep Parameters Based on Multivariate Normal Distribution

According to the rock salt creep experimental data at a would be gas storage site and their variation pattern, based on the Burgers creep model fitting, the rock salt creep parameters of the gas storage are obtained. Taking each of the creep parameters as a random variable, the influence of many random factors on the creep parameters is studied during the rock salt formation and its creep experiment process. Considering the linkages between the creep parameters, assuming a five variable overall random sample constituted by the creep parameter variables in accordance with a five variable normal distribution, the joint density function of the five variable normal distribution is obtained. Then the link between the creep parameters is revealed through the covariance matrix, and the multivariate normal distribution assumption is tested by the Q Q test method of the χ2statistics. It is shown that the five variable overall random sample constituted by the creep parameter variables can be very well represented by the five variable normal distribution. The results provide an insight for the probability distribution of rock salt creep parameters.