**6.6 Cyclic test setup**

As depicted in **Figure 8**, the ballast box device is used at IUST University to simulate rolling stock forces applied to the track. The device includes power supplier, pump, and piston to provide vertical forces, computer software, sensors to measure displacements and calculate them, and a box to hold ballast specimens. The dimension of ballast box and piston is 0.7 m (l) 0.45 m (h) 0.3 m (w) and 0.22 0.22 m, respectively. Using the hydraulic pump power controlled by software in terms of applied force and frequency, the piston applies vertical force to specimen in box. This process continues to 100,000 cycles. In this research, the vertical force of 27 kN and frequency of 3 Hz in 100,000 cycles were applied to the specimens.
