Modern foundations for gas equipment operated under the influence of dynamic loads, including seismic ones, often turn out to have overestimated stiffness and material consumption. Reducing costs, construction time and ensuring the reliability of gas transmission system facilities is relevant. The features of the operation of the foundation with an attached special device according to the “Method of increasing the dynamic rigidity of the foundation under vibration load and a device for its implementation” under seismic influence are considered. An approach is proposed to determine the deformation energy of the foundation system - a special device from the effects of seismic load, taking into account the formation of elastic and plastic deformations. The movements of the foundation were determined using the finite difference method. Taking into account the proposed approach to determining the deformation energy of the foundation – special device system, studies have been carried out in terms of determining the energy required to destroy the connecting element in the composition of the device under consideration during seismic action. Conclusions are drawn based on the results of the research done. The performed studies have shown the effectiveness of the proposed approach to determine the deformation energy of the connecting element in the composition of the device under consideration. Since the proposed approach makes it possible to select the parameters of a special device attached to the foundation in order to increase the reliability of the foundation structure both under dynamic loads from gas equipment and under seismic influences.