Improvement Of Anti-seismic Calculation Method For Maritime Structure And Research Of Parameters For Seabed Subsoil Of Nuclear Power Plants

Structure form, design and construction of the maritime structure in nuclear power plants is similar to ordinary hydraulic and port and waterway engineering. Since safety importance of nuclear power project is much higher than the general buildings, the seismic fortification criterion of maritime structure is much higher too. the pseudo static method and dynamic finite element method should be combined to check seismic stability of seismic Ⅰ,Ⅱ items according to the current code.However, not all the provisions for pseudo static approach in current code is reasonable, both for the calculation theory and the calculating result. Based on the project undertaken by our research group over the years, the actual section is calculated, the dynamic response acceleration distribution is found, an improved method is proposed for calculating safety factor, and the applicability for improved method is proved.Parameter selection affects more than model selection in the numerical seismic analysis of maritime structure of nuclear power plants.There is another work in the thesis. The geotechnical test data of projects undertaken by our research group are summarized, strength and deformation parameters are paid special attention, static and dynamic modulus, static and dynamic strength and the relationship between them was discussed,some rules are obtained refer to relevant research results.The main content of this thesis include:(1) The acceleration response of nearly30sections of practical engineering is counted, the magnificatio of acceleration at different height relative to the ground acceleration is calculated in all the sections depend on different working conditions, envelope is done and a new graphic acceleration distribution will be suggested.(2) An improved method is put forward that the seismic coefficient is get by improving one level site seismic fortification intensity, instead of the current method that bedrock acceleration is used to do pseudo static analysis.The new graphic acceleration distribution is also used in the improved method, and a new safety coefficient is suggested.The engineering section is checked that the minimum safety factor and the corresponding slip surface is compared. (3) The sections that don’t meet the requirement of safety coefficient of pseudo static approach is calculated by using dynamic finite element method and permanent deformation in turn if needed.(4) The strength and deformation parameters of subsoil of all the nuclear power projects obtained from the static and dynamic triaxial test are counted, and static and dynamic modulus, static and dynamic strength and the relationship between them was discussed,which will be the reference for the future experimental parameters sorting.