Identification Of Inelastic Seismic Response Behavior Of Reinforced Concrete High-rise Shear Wall Structures

Shear wall bears all vertical and horizontal loads in the cast-in-situ reinforced concrete shear wall structure.It is widely used in high-rise residential buildings and other public buildings because of the large lateral stiffness,excellent spatial integrity and no internal edges and corners.The experience of earthquake damage over the years shows that well-designed reinforced concrete shear wall structures have good seismic performance,mainly reflected in the structure damage slightly in both structural and non-structural element even if under strong earthquakes.However,there have been no careful and detailed analysis results of the inelastic seismic response performance of the shear wall under the rare earthquakes,and no effective analysis and recognition of the effectiveness of the corresponding earthquake resistance measures specified in the codes so far.In order to deeply study the seismic performance and inelastic development mechanism of reinforced concrete shear wall structures,judge the rationality of the relevant specified of China's design code,and improve the design method of shear wall structure,a non-linear model of the reinforced concrete shear wall structure in 8-degree0.2-g seismic zone which designed and constructed under country's codes was performed by PERFORM-3D analysis program,and its structural performance under the rare earthquake was evaluated.Besides,introducing the mainstream seismograph selection and calibration methods of Technical specification for concrete structures of tall building?SRCT?and ASCE 7,and comparing the mean value and dispersion of the structural main engineering demand parameters under the input of seismic records which are selected by two different selection and scaling method,and finally determining the seismic records used for subsequent analysis to eliminate the influences of selection of ground motion records and the calibration method for the results of time-history analysis.The main conclusions of this paper are as follows:?1?In selecting seismic records,SRCT method is more concerned with the fact that the selected seismic record response spectrum and the target design response spectrum are statistically equivalent.And because the dual-band method controls the deviation of the response spectrum of the selected seismic record and the target response spectrum at the major periodic points of the platform section and structure,the selected earthquake records more easily include spectral features that have a significant effect on structural response.The earthquake record selection program of ASCE 7 more hopes that the selected seismic record can meet the source and epicentral distance conditions that control the structural reaction obtained by the depolymerization analysis,this method is more in line with the actual situation In the scaling of seismic records,the SRCT require that the peak acceleration of the seismic record be adjusted to the peak ground acceleration of the corresponding intensity area.ASCE7 uses the design response spectrum as the target spectrum and requires that the average response spectrum of multiple seismic waves should not be lower than the design response spectrum in the range of 0.2T₁ to 1.5T₁.The average value of the engineering demand parameters obtained by using the SRCT method is slightly larger than the engineering demand parameters obtained by the ASCE 7 method,but the overall difference is not significant;however,the coefficient of variation obtained by using the SRCT method is smaller than that obtained by the ASCE7-10.In general,the high-level seismic record selection and scaling method have certain advantages in controlling the dispersion of time-history analysis results.However,when selecting seismic records for important projects,designers should fully investigate the seismic environment around the project site on the basis of meeting high-level requirements,and try to select the seismic record that is consistent with the seismic environment of the project site.The results of the elasto-plastic time-history analysis of the reinforced concrete shear wall structure which is mainly composed of slender coupling beams,without excessive long-walled limbs,and floor slabs and wall limbs and coupling beams are reasonably connected and in the 8 degree 0.20g seismic zone in this paper shows that the overall deformation of the structure,the plastic deformation of the coupling beam,and the normal section performance of the shear wall can meet the requirements of deformation and bearing capacity under the rare earthquake,and the plastic damage is not large;To a certain extent,it has achieved the goal of using coupling beams as the first line of earthquake resistance.However,some of the wall limbs have insufficient shear capacity.In order to prevent the shear wall from undergoing shear failure and ensure that the structure under the strong earthquake can form a good plastic distribution pattern,relevant measures must be taken to prevent shear failure,such as take a more reasonable shear wall layout;Increase the requirement of the code for the minimum horizontal reinforcement ratio of the shear wall,and appropriately enlarge the shear amplification factor of the short-wall limbThe main innovations of this paper are as follow:?1?This paper selects an engineering design example of an 8-degree 0.2-g high-rise shear wall structure residential house in Kunming area as the object of analysis.Its structural arrangement satisfies real project conditions,and the analysis results are more instructive for engineering applications.?2?According to the SRCT program and ASCE 7-10 program,7 groups of seismic records were selected and scaled.Analyzing the similarities and differences between the two methods,and comparing difference in engineering demand parameters in time history analysis of the seismic records obtained by the two methods.?3?The maximum shear force and its corresponding bending moment and axial force for each wall element in time-history analysis are used as the most unfavorable shear force internal force combinations,and calculates the shear capacity of the shear wall according to Code for design of concrete structures,the distribution characteristics of the shear capacity ratio of the shear wall under the rare earthquake excitation are obtained.Based on this,the effectiveness of shear wall shearing measures specified in codes was evaluated.