Seismic Response Analysis Of Nuclear Containment Under The Condition Of Oblique Incidence Of Seismic Wave

The unlimited desire for energy promotes the development of nuclear energy. Nuclear energy has received considerable attention due to its low pollution and high efficiency. However, the disaster caused by nuclear accident in recent years cannot be ignored. By investigating thoroughly the inducing factors of the nuclear accident, the earthquake disaster is one of the major reasons. Though the earthquake occurred by accident, our country suffered great damage from earthquakes in recent years. At present, a large number of researchers at domestic and abroad focused on the seismic response and performance of the nuclear island. However, those researchers generally assumed that the input of the seismic waves is vertical in shear at the bottom of the model or the compression of seismic waves. In fact, it is clear from researches that only seismic source, which is very far away from the building site, makes seismic waves refracted constantly and therefore the assumption about normal incidence is acceptable. Hence, when the focal distance is close to the building site, we can’t only assume that it is perpendicular to the direction of the incident instead of a spread angle of incidence to the site structure having spatial varying characteristics. Due to the inconsistent changes of the movement of the earth caused by oblique incidence seismic waves, dynamic response of large buildings such as nuclear power plant, dam, tunnel and subway station is greatly affected. In order to ensure the safety of these large structures, we must consider the problem of incident angle of seismic wave when we design the structure, particularly for a large earthquake occurring in the near field. The main contents are as follows:Firstly, the paper establishes the soil model including viscoelastic artificial boundaries and uses the wave field decomposition principle to realize the transformation of the equivalent seismic load on the boundary. The correctness of the input method of the wave field decomposition is verified by numerical examples.Secondly, based on the general finite element software ABAQUS establishing the fine nuclear containment structure, the SSI model including the interaction between the nuclear containment structure and the soil is completed.Thirdly, we select two types of seismic waves(P wave and SV wave) with different incident angle to analyze the seismic dynamic response of the nuclear containment structure. The research presents some important conclusions: compared with vertical incidence of seismic wave, dynamic response of nuclear containment structure under the condition of oblique incidence of seismic wave is apparently different. So when performing the safety assessment or the designing of the nuclear containment structure, it is necessary to consider the effect of seismic waves caused by oblique incidence.