A method for determining the minimum number of times of cyclic loading and unloading for compaction of an infilled jointed rock mass

A method for determining the minimum number of times of cyclic loading and unloading for compaction of an infilled jointed rock mass is disclosed. The method includes following steps: preparing an infilled jointed rock mass test piece; subjecting the test piece to a plurality of times of cyclic loading and unloading tests, and after each time of cyclic loading and unloading, measuring gas permeability of the test piece under different confining pressure and different osmotic pressure, and mapping a changing curve showing that the gas permeability of the test piece under different osmotic pressure changes along with confining pressure cyclic loading and unloading; mapping a changing curve showing that the gas permeability of the test piece changes along with the number of times of cyclic loading and unloading, and performing curve fitting; predicting permeability of the infilled jointed rock mass after more times of cyclic loading and unloading through a fitting function; and when the permeability decreasing rate of the infilled jointed rock mass after the number i times of cyclic loading and unloading is greater than 80%, determining that the compactness of the infilled jointed rock mass is substantially stable and the corresponding number of times of cyclic loading and unloading is the needed minimum number of times of cyclic loading and unloading for compaction. The method issimple, rapid and economical, and can greatly improve safety and stability of oil storage, gas storage and water storage related projects.