Research On The Suitability Of Foundation For Weak Interlayer Of Nuclear Island At Jingyu Nuclear Power Plant In Jilin

The proposed Jilin Jingyu nuclear power station is designed according to a 2 x 1000MW PWR unit,and the planning capacity is considered at a capacity of 4 x 1000MW capacity units.The site is located in the Songhua River Baishan reservoir on the left bank of the basalt platform,between the plant within the scope of the surface elevation is generally between520⁵30m,flat open.The stratum lithology in the 100m area is mainly composed of Quaternary basalt,silty clay,Jurassic mudstone,siltstone,conglomerate and Archean mixed granites.The faults in the vicinity of the site belong to the pre quaternary faults.There is no active fault.The geological structure of the whole site is not developed.There are only small scale joints,fractures,basalt layers and columnar joints.The area is located in the Northeast seismic area with low seismic activity,and the number of earthquakes is very small and the magnitude is low.According to the relevant regulations of the nuclear power station and the range of SL-2 value of the seismic regulation site 0.160g.Nuclear island related important items are built on the basis of Aeolian basalt.The stability under static state is safe.However,the dynamic characteristics of soft interlayer under the consideration of seismic dynamic action need to be studied.Therefore,the relevant research work on the dynamic characteristics of the weak interlayer of the site is of great significance to the safety of the project and to the reference of similar projects.The main contents and results of this paper are as follows:1.To enrich the field of Surveying and mapping,exploration,testing,test data,analysis of the structural conditions and seismic conditions,engineering geological conditions,hydrogeological conditions,the construction of the nuclear island foundation that basalt in the breeze on the ground under the static state is stable and suitable for construction.However,the calculation and study of the dynamic characteristics of the soft foundation under the consideration of the suitability of seismic dynamic action should be carried out.2.A comprehensive comparative study of various methods.?1?through the field of wave velocity test?single hole and cross hole method?and indoor dynamic test?dynamic three axis,Gong Zhenzhu test?,mainly for the foundation of the existing plant area of weak interlayer?silty clay and weathered rock layer?study characteristics were obtained,the kinetic parameters of the calculation and analysis of work;?2?by ultrasonic wave test,a large number of standard penetration test?SPT?,the static cone penetration test?CPT?,dynamic penetration test?DPT?,the test results of conventional rock point load test,indoor soil test,statics,applicability of each test method on the comprehensive analysis of different rock and soil,combined with the actual condition of the investigation site site master lithology,soil physics and the rocks provide static parameters;?3?the distribution range,weak interlayer thickness and buried depth,statics and The dynamic characteristics are summed up and the possible effects on the engineering site are preliminarily evaluated.3.Through the detailed engineering geology and measurement data,scientific,reasonable and effective boundary conditions are selected to establish the actual 3D geological model.?1?by means of the finite difference software FLAC^3D nonlinear dynamic calculation module,through the establishment of different thickness,the depth of soft interlayer under the condition of different site profiles,the intensity of earthquake input under the conditions of nuclear power and dynamic characteristics of weak interlayer foundation weak interlayer thickness,buried depth effect on the dynamic characteristics of the foundation;?2?based on FLAC^3D the software,under the condition of various factors containing soft interlayer foundation dynamic response was simulated by using the principle of orthogonal test,and using methods of range analysis on the influence factors of the sensitivity analysis;?3?through the numerical simulation software FLAC^3D,the research of acceleration,displacement and stress of the earthquake and the variation characteristics of plastic the dynamic stability of the foundation to further explore the soft interlayer.4.For the first time,the extension theory is applied to the comprehensive evaluation of the suitability of the weak intercalation of the nuclear island foundation,and the calculation method of the classical domain,the segment domain and the correlation degree is determined,and the angle of internal friction of the weak intercalation,the dynamic shear modulus,and the dynamic shear modulus are selected.Seven factors,such as peak acceleration of ground motion,weathering degree of rock,topographic elevation,precipitation and influence of slope,were used as evaluation indexes,and the final results were ranked.Different degrees of influence factors on the suitability of nuclear power plant foundation are obtained,and the weight is calculated by the combination of entropy method and analytic hierarchy process?AHP?.The calculated results are more accurate.Based on an example of the suitability evaluation of the weak intercalation of nuclear island foundation in nuclear power plant,it is considered that it is reasonable to apply extenics to the evaluation of this project.Feasible.The application of extenics in the study of the suitability of weak intercalation on nuclear island foundation of nuclear power station has not been attempted,and its related preliminary research results need to be improved.The application prospect in the foundation suitability study of nuclear power station is broad and worthy of further study.