Abstarct: Due to the development of the tunneling industry in the last century and due to the high tunneling speed and proper safety conditions, the Tunnel Boring Machines (TBM) are widespread used for boring the long mountain tunnels, urban tunnels, infrastructure tunnels and even underground mines. Since the investment cost of the TBM tunneling is higher than other common tunneling methods, it is necessary to consider various issues to predict future costs so that unexpected and unforeseen problems do not affect the performance of TBM and ultimately project planning. One of the most important and effective issues on the TBM performance is the normal wear of the TBM disc cutters during the boring process of the abrasive and strong rocks. Disc cutter’s normal wear is defined as a gradual and uniform decreasing in the disc diameter due to the rock-TBM interaction. Different factors may worsen this condition and reduce the wear life of the disc cuter. Rock joint properties are one of the most important factors that, if considered in theoretical and experimental relationships, can modify the conservative results of the life predicting models. In this research, baxsed on the databaxse obtained from the Kerman water conveyance tunnel project, the effect of the different properties of the jointed rocks on the life of the disc cutter has been studied. In the first part of this study, various factors in the databaxse were statistically analyzed and finally the parameters that had the highest correlation with the life of the disc cutter were selected to provide an experimental model for predicting the life of the disc cutter using multivariate nonlinear regression. These parameters include the total fracturing factor of the rock mass, the rock mass strength and the Cerchar abrasivity index. According to the proposed empirical model with a correlation coefficient of 0.800, the life of the disc cutter is directly related to the fracturing factor of the rock mass and is inversely related to the rock mass strength and Cerchar abrasivity index. The validation of this model is baxsed on the available data in two geological sections of the headrace tunnel in the Uma Oya multipurpose project in Sri Lanka which has shown that the predicted results has good agreement with the actual recorded results, especially in severely fractured and fully jointed rocks. In the second part of this research and as the first step of the numerical modeling, the effect of the different parameters on the life of the disc cutter and the rock crushing mechanism has been investigated by 3DEC commercial software developed by Itasca. For validating, the numerical results of the dynamic boring of a single disc in the intact rock (without joints) have been compared with the results of CSM theoretical model. This comparison shows negligible differences between numerical and theoretical approaches. After this validation and as the second step of the numerical modeling, the joints are added to the numerical model and the sensitivity analyses have been executed on the TBM operational parameters, rock joints and disc cutter geometry. As results, increasing the disc cutter penetration rate, cutterhead RPM, installation radius of the disc cutter on the cutterhead as well as decreasing joints’ spacing may increase TBM penetration into the rock and improve its performance. Also, the normal wear of the disc cutter increases by increasing the penetration rate, cutterhead RPM, joints’ spacing, and bluntness of the disc cutter and also by decreasing the installation radius of the disc cutter on the cutterhead. In this model, the joints with angle of 45 to 60 degrees’ respect to the direction of the disc cutter penetration have the greatest effect on increasing the crushing of the rock and reducing the induced von Mises stress in the disc cutter. In other words, in such joint conditions, the TBM advances rapidly and the disc cutters wear out slower. In the final step of the numerical modeling, the operation of the TBM in Kerman water conveyance tunnel was modeled numerically in real scale which shows rocks with more fracturing conditions, the induced von Mises stresses in disc cutters are less and as a result, normal wear of disc cutters will be less. In addition, the study of rock failure mechanism shows that the initiation and extension of the plastic zones in the rock due to the application of the disc cutter forces occurred due to shear yield firstly and then, by continuing boring process, the tensile yield in addition to shear yield lead to the rock fragmentation and TBM advancement.