REDUCTION OF DYNAMIC RESPONSE OF BUILDINGS, EQUIPMENT AND PIPE NETWORKS USING SERB-SITON METHOD TO INCREASE NPP SAFETY MARGINS

摘要

Buildings, equipment and pipe networks, herein below called "structures", within nuclear and classic objectives are affected by the dynamic actions of earthquake, shocks and vibrations type, herein below called" excitations". The repeated action of excitations on structures most often lead to important built-up of kinetic and potential energy in oscillating systems made-up of such structures. Such a built-up is leading to tens of times increase of the amplitude of the dynamic response in accelerations and displacements of structures as to the excitation amplitude. In its turn, such an increase is leading to the exceeding of the efforts and distortions of the structures material, accompanied by the occurrence of damages or destroy. Because in most cases the excitation cannot be reduced or eliminated, the only technical solution available for the engineers is to reduce the dynamic response of the structures on the existing excitations. The innovative SERB-SITON solution developed and applied within the Subsidiary of Technology and Engineering for Nuclear Projects (SITON) is based on the use of SERB-SITON isolation behavior devices with low friction and controlled stiffness on horizontal plane to cut-off the dynamic action transfer from the excitation to the structure and telescopic devices with controlled elasticity and damping both to reduce the dynamic response of the structures, as well as the dissipation of the energy transferred to the structure or the limitation of structure distortion upon the dynamic actions. The paper presents the performances of SERB-SITON mechanical devices used to protect buildings, equipment and pipe networks against dynamic actions and an adequate method to evaluate the dynamic response of structures (by using SERB-SITON devices), in real time inclusively. For large-size buildings such as nuclear power plants, old buildings, churches, bridges, etc., SERB-SITON isolation devices with friction by sliding or rolling with a very small and adjustable, stiffness installed under the structure on any horizontal direction, are presented. For reinforced concrete or metal framework buildings such as high buildings, industrial halls, towers, etc., SERB-SITON telescopic devices with controlled stiffness and damping large, force inclusively are presented. For equipment and pipe networks, SERB-SITON supports that are capable to overtake large permanent loads with relative displacements on two directions for thermal displacements, and also capable to elastically overtake and damp dynamic actions, are presented.