Investigation of the stability of arch dam abutments is one of the most important aspects in the analysis of this type of dams. To this end, the Bakhtiari dam, a doubly curved arch dam having six wedges at each of its abutments, is selected. The seismic safety of dam abutments is studied through time history analysis using the design-based earthquake (DBE) and maximum credible earthquake (MCE) hazard levels. Londe limit equilibrium method is used to calculate the stability of wedges in abutments. The thrust forces are obtained using ABAQUS, and stability of wedges is calculated using the code written within MATLAB. Effects of foundation flexibility, grout curtain performance, vertical component of earthquake, nonlinear behavior of materials, and geometrical nonlinearity on the safety factor of the abutments are scrutinized. The results show that the grout curtain performance is the main affecting factor on the stability of the abutments, while nonlinear behavior of the materials is the least affecting factor amongst others. Also, it is resulted that increasing number of the contraction joints can improve the seismic stability of dam. A cap is observed on the number of joints, above which the safety factor does not change incredibly. Moreover, the seismic stability of arch dam abutments is investigated within the framework of probabilistic method. The seismic safety of the dam abutments is studied with quasi-static analysis for different hazard levels using the Londe limit equilibrium method. As the finite element method is time-consuming, the neural network is used as an alternative for calculating the wedge safety factor. For training the neural network, 1000 random samples are generated and the dam response is calculated. The direction of applied acceleration is changed within 5-degree intervals to reveal the critical direction corresponding to minimum safety factor. The Latin Hypercube Sampling (LHS) is employed for sample generation, and the safety level is determined with the reliability analysis. Three sample numbers of 1000, 2000 and 4000 are used to examine the average and standard deviation of the results. The global sensitivity analysis is used to identify the effects of random variables on the abutment stability. It is shown that friction, cohesion and uplift pressure have most significant effects on the wedge stability variance. Aftrerwards, the seismic stability of the rock wedges in the foundation of the Bakhtiari arch dam is studied with limit state and finite element methods. The dam abutment seismic safety is analyzed by utilizing the time history analysis along with Londe method. Subsequently, the wedges that are close to critical state are identified. Afterwards, the joints of the critical wedges are analyzed via FEM and the damage propagation in the dam body is investigated. Moreover, the effects of the grout curtain efficiency and hazard level on the nonlinear behavior of the arch dam with integrated foundation and foundation with joints are studied. The results show that considering the joints in foundation has a significant effect on the dam behavior.