Seismic Design And Analysis Of A Tall Building Structure Beyond The Code-specification

The performance-based seismic design method was formally adopted in the Chinese Code for Seismic Design of Buiidings(GB50011-2010 version).Compared with the existing conventional methods,this method has some significant advantages.For instance,quantifying specifically the capability targets and standards for three-level seismic design requirements,emphasizing the choose of discrimination criteria and capability targets for implementation of three-level seismic design,and analyzing and demonstrating deeply in practice.At present,it is feasible in over-limit high-rise building structures to adopt the concepts and methods of performance-based design,which is beneficial to the technological progress and innovation in the design of high-rise building structures.The application of the performance-based seismic design method in the seismic design of exceed-code high-rise building residence irregularity structure is a trend of the seismic design method.In view of lacking of perfect and uniform standard for the seismic design of exceed-code high-rise building residence irregularity structure,it is necessary to study the seismic behavior of exceed-code high-rise building residence irregularity structure under earthquake.Combined with a practical project,this study expounds the basic methods and procedure of seismic resistant designing of exceed-code high-rise building residence irregularity structure.The example project is located in the low-intensity area of seismic fortification(six degree zone).Simulation analysis under minor earthquake is carrying on with ground motion parameters provided by the safety assessment mechanism.However,the parameters under middle and rare earthquake adopted from norm because of much bigger parameters provided by the safety assessment mechanism than the norm.Determining the performance targets under the design seismic based on the routinely specifications,which may cause the performance design under the action of the fortification earthquake to fail to improve the bearing capacity of the structure.This paper analyzes the two design methods of elasticity and non-yield under design earthquake based on the current domestic norms,and combined with the increase coefficient of the earthquake-resistant grade and the adjustment coefficient of strong columns and weak beams,comparing analysis the adjustment coefficient of the elasticity and non-yield methods.The comparison of the adjustment coefficient of the design internal force of the minor earthquake and the middle earthquake is given after the theoretical analysis.The comparison results show that the bearing capacity after the earthquake using not-yield under middle earthquake method may be less than the conventional design of a minor earthquake.Thereafter,it fails to improve the bearing capacity of the structure.Taking into account the structural safety,the structural seismic-resisting performance targets are enhanced.According to the adjusted performance targets,the seismic performance design of the engineering example project was designed.First of all,setting corresponding seismic resistant targets according to the type and the degree of rules of exceed-code high-rise building residence irregularity structure.Getting the status of the project by adopting the modal decomposition response spectrum method and elastic time-history analysis under minor earthquakes using PKPM-SATWE and MIDAS Building,the results obtained from these two finite element analysis softwares are compared to ensure the reliability of simulation results,and to achieve elastic seismic design under minor earthquake.Secondly,structural analysis under design earthquake was carried out.The seismic performance of the member was checked up according to the requirements of seismic performance targets under the fortification intensity,and static elasto-plastic analysis was carried out.The results of static elasto-plastic analysis show that the entire structure is in the state of elasticity,and the bearing capacity has not decreased,achieving the estimated performance targets.Finally,elastic-plastic dynamic time-history analysis under rare earthquake was carried out,through analyzing and judging the rationality of the calculation results,and checking whether the floor drift satisfies the requirements of the specification limits.Then,based on the degree of structural plasticity development and trend of development,the strengthening measures for the important and weakness partsare presented.After the above analysis procedure,it is concluded that the structure can meet the current three-level design requirements.