عنوان مقاله [English]
The Discrete Element Method (DEM) was initiated in 1971 by Cundall, who studied the dynamic behavior of rock masses. In his method, each single particle is treated as a distinct element. The new concept of DEM, in which each block of a soil mass is considered as an element, was presented by Chang, in regard to different geotechnical problems. In this research, DEM is used to analyze metal-strip reinforced soil structures. The whole reinforced earth wall is divided into trapezoidal elements; each one containing a reinforcement. Normal and shear Winkler springs are considered at the sides of the elements to model interaction with adjacent soil blocks. Also, there are two other springs for the effects of metal strips in each element. The stiffness of the reinforcement's normal springs is calculated by considering the friction of the soil and metal strip surfaces. The shear force is obtained by considering the equation of an elastic bending and by replacing the soil with a series of elastoplastic springs. Then, the stiffness matrix can be obtained and, by applying the external force vector, displacements are found. The internal forces at the sides of each element can be calculated by multiplying the stiffness of the springs with the relative displacements of that side. A FORTRAN program is written to model different cases of reinforced earth walls. In order to verify DEM results, several examples have been analyzed and compared with other methods. In contrast with the difficulties and uncertainties of conventional methods, DEM can easily model the static and dynamic analysis of reinforced earth walls.