Abstract: This article points out each of the current analytical methods used in rock and soil mechanics through CT number research avail of observation, wasting the precious quantitative information of CT datum. Utilizing the CT number, the perfect degree and the damage-fracture degree of a point inside the rock sample are defined; the level perfect field, the level damage-fracture field and the ( — )level intercepted section are defined according to the level perfect degree and the level damage-fracture degree and the set theory; the size of the level perfect field, the level damage-fracture field and the( — )level intercepted section can be accurately calculated avail of the measure theory; based on these conceptions of the rock and soil media perfect space and damage-fracture space are established, paving a new way for the quantitative analysis of the rock and soil mechanics by means of the CT datum. If the level is magnified from the mesomechanics value to the macroscopic one, this method is suitable for the macroscopic geotechnical mechanics, realizing the unified description of the macroscopic mechanics and the mesomechanics, the unified description of the continuum mechanics and porous media or crannied media mechanics comes true, too.

Key words: damage-fracture degree, level damage-fracture field, ( &mdash, )level intercepted section, measure, damage-fracture space