During processing of section deformation’s convergent data of large underground cavern group engineering

obvious regularity is found at degree of fluctuation of the time history curve. Therefore

one-dimensional box dimension is introduced to quantitative description of this feature; and then relevant mechanical meaning of properties of surrounding rock is discussed based on the testing calculation results. Furthermore

the index is used to compare variation of the results of different monitoring cross-sections; and the corresponding relationship between integrity of rock and box dimension is confirmed. Through analyzing the relationship of various sections’ spatial locations and their box dimension values

the evolution tendency of rock’s integrity on the whole region is drawn. Finally

validity of the paper’s inference is proved by surrounding rock conditions which is revealed by subsequent excavation.