Application of soft granulation theory to permeability analysis

In this paper, information granulation theory is applied to the design of rock engineering flowcharts. Firstly, an overall flowchart based on information granulation theory has been proposed. Information granulation theory, in crisp (non-fuzzy) or fuzzy format, can take into account engineering experiences (especially in fuzzy shape—incomplete or/and superfluous information), or engineering judgments, in each step of design procedure, while the suitable modeling instruments are employed. In this manner and to extension of soft modeling instruments, using combinations of self-organizing map (SOM), neuro-fuzzy inference system (NFIS) and rough set theory (RST) crisp and fuzzy granules, from monitored data sets are obtained. The main underlined core of our algorithms is balancing of crisp (rough or non-fuzzy) granules and sub-fuzzy granules, within non-fuzzy information (initial granulation) upon the “open–close iterations”. Using different criteria on balancing best granules (information pockets) are obtained. The method has been illustrated on a data set of in-situ permeability measurements in rock masses in Shivashan dam, Iran.