One of the major issues of civil engineering in urban areas and road construction is stabilization of steep vertical soil and slopes. A method of stabilization that is now widely used is the soil nailing stabilization system. In this study, soil nailing system is examined. One of the major situation in soil nailing walls is increasing depth of the wall after designing and installation of soil nails. Since the length and places of the nails are designed according to the first length of the excavation, soil nail system can't respond to the pressure on the wall and the arrangement need to be redesigned. In this research the alternate method of using long strengthening nails has been used. The effects of some parameters such as nail length and place on the results of lateral earth pressure, nail axial force and lateral displacement of wall have been considered for wall height of 15, 21 and 25 meters. To study the behavior of the wall using the appropriate application and behavior models that can predict the behavior of soils in different directions is necessary. In this study, FLAC 3D software is an explicit finite element program capable of simulating the behavior of soil nail walls has been used. To model the behavior of soil nailing walls with the best accuracy, comparison between the two surface soil behavior model and Mohr Columb and Cam-Clay has been generally done. By comparing the results of different soil nail layout, results show the efficiency of new layout method and with comparing the results of soil behavior method, the accuracy of 2 surface model is clear. Keywords Stabilization, soil nailing, soil behavior model, optimum arrangement