The common failure mechanism for brittle rocks is known to be axial splittingwhich happens parallel to the direction of maximum compression. One of themechanisms proposed for modelling of axial splitting is the sliding crack or socalled, "wing crack" model. Fairhurst-Cook model explains this specific type offailure which starts by a pre-crack and finally breaks the rock by propagating 2-Dcracks under uniaxial compression. In this paper, optimization of this model hasbeen considered and the process has been done by a complete sensitivity analysison the main parameters of the model and excluding the trends of their changes andalso their limits and "peak points". Later on this paper, three artificial intelligencealgorithms including Particle Swarm Intelligence (PSO), Ant Colony Optimization(ACO) and genetic algorithm (GA) has been used and compared in order toachieve optimized sets of parameters resulting in near-maximum or near-minimumamounts of wedging forces creating a wing crack.

Hossein Jalalifar. He has accomplished his doctoral degree in Rock Mechanics from the University of Wollongong Australia and is currently working as a professor at Kerman University in Iran. He is working for several journals such as Journal of Tunnels and underground spaces and Journal of petroleum Geomechanics as the member of editors. His main research topics include Rock Mechanics, Fracture Mechanics, Tunnelling, Hydraulic Fracturing and Numerical Analyses. He has published a number of academic articles on international journals related to above research topics. Within the last twenty years, he has successfully published more than 200 articles on Elsevier , Springer Journals and International Conferences.