The specialized instruments installed in earth dams play a crucial and vital role in monitoring, controlling, and managing the structural stability of these dams against applied forces and destructive natural factors. In this study, the Shiadeh earth dam, Currently, all precision instruments installed on the dam are out of order, rendering it impossible to record any potential deformations or settlements. Therefore, this research focuses on predicting the dam’s settlement during its operational phase, using historical data from the period when the instruments were fully functional and reliable. The prediction process was carried out using the advanced Radial Basis Function (RBF) algorithm. Within the scope of this study, both static and dynamic analyses were performed using the advanced PLAXIS 3D software to model the dam’s behavior and evaluate its settlement along the crest. The settlement prediction results obtained through the RBF algorithm, when compared with ground survey data from micro-geodetic points located on the downstream slope of the dam, show acceptable agreement, confirming the validity and accuracy of the modeling approach employed. The analysis of crest settlement using PLAXIS 3D modeling indicates that throughout various reservoir impoundment conditions across different seasons, the dam maintained a high safety factor and demonstrated stable performance. The maximum recorded deformation at the dam crest was found to be 0.789 meters. In the three-dimensional PLAXIS model, the effect of the strike-slip fault was also taken into account, which led to intensified deformation.