# Rock Mechanics Modeling Based On Soft Granulation Theory

H. Owladeghaffari Dept .Mining &Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran ABSTRACT: This paper describes application of information granulation theory, on the design of rock engineering flowcharts. Firstly, an overall flowchart, based on information granulation theory has been highlighted. Information granulation theory, in crisp (non-fuzzy) or fuzzy format, can take into account engineering experiences (especially in fuzzy shape-incomplete information or superfluous), or engineering judgments, in each step of designing procedure, while the suitable instruments modeling are employed. In this manner and to extension of soft modeling instruments, using three 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 are 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. Validations of our proposed methods, on the data set of in-situ permeability in rock masses in Shivashan dam, Iran have been highlighted. 

## 1. Introudction

In the recent years, developing new indirect analysis methods has opened new horizons in rock engineering solutions. Tendency to the micro-view of the natural events in the rock based systems, upon the high speed PC technology; behind largescale investigations, has allocated new challenges in this track. Transition from a general (overall) view in to the detailed descriptions, can be interpreted as relations (inter-extra relations) of the commuted "information packages", got from accumulations of data, experience, novelty and other effective agents. 

Such construction of the "whole" from "part" 
(granules) is the current behavior of human cognition. Among the basic concepts which underlie human cognition there are three remarkable sides, which are: granulation, organization, and causation. Granulation involves decomposition of whole into parts; organization involves integration of parts in to whole; and causation relates to association of causes with effects [1]. 

Under this view from the discritization (meshing, blocking, latticing…) of the interior or boundary of a field to the solving steps (thinking) of the problem are the perspectives of granulation. We called first level of granulation as "hard granulation", and second level as "soft granulation". To better understand of the meaning of hard and soft granulation, we reproduce the general rock engineering design flowchart in figure1 [2]. Level1 can be supposed as a hard granulation where level2 is related with soft granulation. 

Clearly, in soft granulation; we are approaching to the real human cognition, whereas in hard packing the machine computations are distinguished. Let us, consider the last class in level2 (in category D): internet based system. Interestingly, this category shows how the discriminated projects, under the virtual world, employ the distributed information granules. Plainly, the contributions of any projects and the sub-sets of granules in construction of this 