Response Characteristics Of Steel Reticulated Shells-concrete Frame Structure Under Earthquake And Reliability Design Of Column Bearing Capacity

Steel roof-concrete frame hybrid structure is widely used in large-span public buildings with its good performance and beautiful architectural style.Therefore,the study of steel roof-concrete frame structure has important engineering significance.In this paper,the seismic performance of steel frame-concrete frame structure is mainly divided into two parts,one is the response analysis of steel roof-concrete frame under earthquake effect,and the other is to analyze the reliability of the frame column on the basis of response analysis.In this paper,we first propose a refined method to calculate the fine resistance of columns with stochastic eccentricity and tensile failure.The refined probabilistic model of resistance of column under large eccentric compression,bound state and small eccentric compression is analyzed respectively.Then a finite element analysis model is established for an actual project by ANSYS.The modal analysis is carried out to obtain the natural frequency of the structure and the vibration law under the low-order vibration mode,determine the integration step of the time history analysis.Then,the response spectrum analysis of the structure is carried out,and the internal force and displacement response of the structure are obtained by inputting the ground motion in different directions.The seismic characteristics of the structure are obtained.Then,the time-history analysis of the structure is carried out,and there are nine seismic waves that meet the requirements are determined after screening.The axial force and moment of the support column are recorded at each point in the whole earthquake.By calculating the correlation coefficient between the bending moment and the axial force,it is found that there is a great correlation between the axial force and the bending moment.The calculated axial force and the moment variation coefficient,the value obtained is higher than the value taken by the specification.On the basis of time history analysis,the frame column is calculated for reliability.Reliability is an important index to measure the safety of the structure.The reliability coefficient of the variance coefficient calculated by time history analysis is low,and the proportion of earthquake effect is bigger and the reliability is lower.Finally,the parameters of column reliability are analyzed,and the variation law of column reliability under low variation and high variability earthquake effect is studied,and the improvement design of column bearing capacity is put forward.