Super-tall Connected Structure Under Typical Long-period Ground Motion Seismic Analysis

The high-rise connected structure refers to a type of complex high-rise structure formed by connecting connectors between two or more adjacent buildings.Its main features are as follows: the connection between adjacent buildings is strengthened through the installation of connectors to improve the integrity of the complex structure is changed and the dynamic characteristics of the high-rise connected structure are changed.According to recent earthquake disaster reports,it can be concluded that there is a typical type of long-period ground motion that may cause serious damage to long-period structures.Therefore,the seismic analysis of the super high-rise connected structure as a kind of special long-period structure under the action of long-period ground motion is of great significance.In this paper,taking an actual biaxially symmetric super high-rise conjoined structure as an example,the large-scale general finite element software ABAQUS is used to calculate and analyze its seismic performance and damage evolution law under the action of typical long-period ground motion.The main research contents are as follows:(1)Based on the three-dimensional dynamic finite element equation,a basic format for the whole process analysis of large-scale structures is established.According to the geometric characteristics of the components,fiber beam elements are selected to simulate beam-column elements,and layered shell elements are selected to simulate wall panel elements.By comparing and analyzing the characteristics of the implicit method and the explicit method,the explicit integration algorithm does not need to be solved iteratively,and it can bettersimulate the discontinuous problems such as material damage,failure and damage,and it is selected as the numerical solution method of the model.(2)Based on the user subroutine of the ABAQUS general finite element platform,the elastoplastic damage constitutive model relationship is embedded in the structural finite element analysis model,so that the structure can more objectively reflect the nonlinear characteristics of the concrete structure.(3)On the basis of the above pre-processing flow,finite element format and elastoplastic damage constitutive model,a finite element model of a biaxially symmetric super high-rise connected structure in Wuhan was established by using the general finite element software ABAQUS,and the dynamic time history analysis under the action of frequently occurred earthquakes and rare occurrence earthquakes is provided.Based on the spectral characteristics of long-period ground motions,it is proved that the energy of far field-like harmonic ground motions mainly accumulates in the middle and late periods,and it is easy to resonate with long-period structures,and it is easy to cause cumulative damage to the structure.The near-fault pulse like ground motion energy will quickly accumulate to the maximum,which may cause the first crossing of the structure to fail at the bottom and affect the stability of the overall structure.(4)The comparative analysis method is used to discuss the post-processing results of structural response characteristics,base shear and elastoplastic damage evolution,and the analysis results show that under the action of four kinds of ground motions,the displacement angle curves of the super high-rise connected structure’s phenomenon of inward shrinkage are more obvious in the x-direction than that of the y-direction in the connection body,which shows that the presence of the connection body enhances the deformation coordination between the two towers;further research shows that the long-span high-rise super high-rise connected structure under the dynamic action of the typical long-period earthquakes may be over-limit,the connectors may be severely damaged,or even collapse.