###### Abstract
Modeling, as is done in this paper, can provide the ability to predict the additional stresses and save a large amount money compared with any sort of test [25]. There are some published works that used theoretical, experimental, and modeling methods as follows. Depending on the experiments, the low value of track stiffness could lead to low compactness of ballast and track settlement [26]. The relationship between the applied force and rail displacement reaction is known as track stiffness. However, the compactness is related to soil disinfection by decreasing the volume of air voids. Thus, by increasing the compactness, the soil properties will be improved, including track stiffness. Additionally, it concluded that settlement values increased by raising the water level in ballastless tracks. It could reach 30 times the  
Figure 1: Two-dimensional (2D) longitudinal section of ballasted track: (**a**) track structure; (**b**) effect of pipe settlement. settlement values before the water level starts rising [17]. On the other side, the results of applying insufficient stiffness to subgrade soil were investigated based on FEM. It was found that unequal settlement in ballast could exist in different gaps beneath sleepers. That would lead to increasing the dynamic stresses by 75.3%, 50.7%, and 61.1% for the roadbed surface, the subgrade surface, and the subsoil surface, respectively [27]. Although there are many published works of railway track settlement, there is a lack of publications in studying the effect of soil settlement on additional stresses in ballasted track elements. In Egypt, settlement is an essential problem that faces the ballasted tracks. There are two periodical activities of maintenance through the summer and winter to cover the problems of settlement and misalignment. Thus, studying the impact of settlement is the main focus of this paper by introducing settlement of a sewer pipeline beneath ballasted track. Therefore, the FE model is proposed to analyze and help to predict the additional stresses in track elements due to settlement in the subgrade layer. By predicting the effect of the settlement, planning of the maintenance process will be more accurate. It could be managed well in different aspects, such as defining the schedule of the maintenance process of railway tracks and the predicted cost of that process. It would help to control the maintenance process and then decrease the paid costs depending on the rate of interest of the maintenance budget. Additionally, it will be helpful to determine the service lifetime of track elements according to the condition of settlement. That would decrease the possibility of failure of any element driving to decrease the possibility of accidents. The 2D analysis can add enough details or several types of materials within a short time of solving models. It has a lower computational cost compared to 3D analysis, especially for dynamic analysis. Thus, 2D analysis is applied to the longitudinal section of ballasted track. Firstly, a dynamic wheel load on the track structure without settlement of subgrade layer is applied after building the model. Then, the model is verified with the Zimmermann method and the [PERSON]'s circle theory to know the percentage of agreement with them. Secondly, we studied the effect of changing the contact types between track elements. This study investigates three different cases with regards to stresses and deformation results without settlement in the subgrade layer. The first case is a theoretical case that has bonded contacts between all track elements. The second case introduces the status of new tracks, where the fasteners are tied tightly with rail, rail pad, tie plate, and sleeper. Thus, the contacts between the last-mentioned elements are bonded. The second case has bonded contacts between all track elements, with a 0.7 friction coefficient between sleepers and ballast stones. The third case introduces the status of operated tracks where the fasteners are not tied tightly to the rail.