Study On Seismic Analysis Model Of Reinforced Concrete Structure Based On Envelope Circle Method

Earthquake is a kind of natural phenomenon with great destructive force.The accurate response calculation results and reasonable and safe reinforcement design of the building structure under the action of earthquake play a key role in the seismic capacity of the structure.The existing code uses the mode decomposition response spectrum method to calculate the internal force response of the structure.This method is to directly take the maximum value of each internal force for combination and take the combination as the calculation result for reinforcement design,without considering the correlation between each internal force,so the calculation result is more conservative.Some scholars put forward a new calculation method of structural seismic response envelope circle method,which can consider the correlation between the internal forces,and the calculation results are more accurate.This paper focuses on the application of envelope circle method in aseismic analysis and calculation of steel-concrete structures,discusses the margin saving of reinforcement ratio in reinforcement design by using this method compared with the traditional mode decomposition response spectrum method,and introduces the differential evolution algorithm discrete envelope circle to improve the existing discrete method.The main work of this paper is as follows:(1)The envelope circle method is applied to calculate the response results of axial force N and bending moment M of eccentrically compressed(tension)members of steel-concrete structures under earthquake action,and the response results are brought into the reinforcement formula in code for design of concrete structures(GB50010-2010)to calculate the reinforcement ratio.The results are compared with the axial force and bending force obtained by the mode decomposition response spectrum method The reinforcement ratio obtained from the moment results is compared to check the amount of reinforcement saved,discuss the factors that affect the size of the reinforcement ratio saved,and discuss the law of the reinforcement ratio saved;(2)The envelope circle method is applied to calculate the response results of bending moment M and shear V of steel-concrete structure under earthquake action,and the corresponding formula in the code is used to calculate the reinforcement ratio results.Compared with the reinforcement ratio results under the mode decomposition response spectrum method,the margin to save the reinforcement ratio in the calculation process of bending resistance and shear resistance of steel-concrete structure is obtained The factors,rules and sizes that affect the ratio of reinforcement saving are discussed;(3)The envelope circle method is applied to the calculation of the plane shear reinforcement of the shear wall of the steel-concrete structure.The response results of the axial forces N11,N22 and V12 under the earthquake action are calculated and brought into the corresponding formula in the code to calculate the reinforcement ratio.Compared with the reinforcement ratio results under the mode decomposition response spectrum method,the margin of saving the reinforcement ratio in the shear calculation of the shear wall is obtained and discussed On the factors,rules and sizes that affect the reinforcement ratio;(4)The existing methods of discrete envelope circle mainly include enumeration method and virtual mode method.When the above two methods are used to solve the point on the envelope circle where the calculation result of structural reinforcement ratio is the largest,there are some problems such as the calculation result is not accurate enough and the calculation amount is large.Now,DE algorithm is introduced into the discrete process of envelope circle,this method will improve the calculation efficiency and get more accurate results The virtual mode method is compared with the de method in the process of discrete envelope circle,and the essence of the virtual mode method is discussed.The two methods are combined to solve the maximum reinforcement ratio point on the envelope circle.