Research On Wave-selection And Shear Wall Tensile Stress Problem Of High-rise Design In High Seismic Intensity Area

In recent years, with the development of China’s economy, the raise of aesthetic requirement of buildings and the pursuance in building configurations of proprietors, beyond-code tall buildings has increased rapidly. Because of its specificity and importance, the design and calculation of these buildings need to meet requirements beyond what the current construction standards require. Above all, problems in beyond-code tall buildings are increasing.In high-intensity areas, Haikou(8degrees,0.30g), for instance, for beyond-code buildings mostly featured with an excess height, the problems of design and calculation in which mainly exist in their seismic design. Compared with tall buildings, the additional calculations in seismic design for beyond-code high-rise include:(1)Elastic Time-history AnalysisIn the seismic design of multi-earthquake for beyond-code high-rise, elastic time-history analysis is needed. Response spectrum method is the traditional calculation method used in the seismic design of multi-earthquake, whose response spectrums are acquired from the Code for Seismic Design of Buildings, thus only the average spectral characteristics and vibration intensity are considered. As the additional calculation in multi-earthquake, elastic time-history analysis exerts time integration to input seismic waves and artificial waves, which can fully reflect the duration of earthquake, ground motion intensity and spectral characteristics.To reflect the duration of earthquake, ground motion intensity and spectral characteristics correctly, the measured waves and artificial waves used in elastic time-history analysis must meet the requirements in5.1.2in the Code for Seismic Design of Buildings.(2)Tensile Stress CheckingIn the calculation of seismic precautionary intensity, shear walls in beyond-code high-rise need to meet certain targets. Specific requirements are:in seismic precautionary intensity unyielding design, for shear walls with an average tensile stress more than one time the standard value of corresponding concrete tensile strength, structure steel is needed to bear the tension; for those with two times and more, in the calculation of average tensile stress, the section of steel can be transformed to concrete section according to the modulus ratio of steel and concrete.The two extra problems above in beyond-code high-rise design is studied in this paper, a practical wave-selection method is put forward, the calculation and treatment methods of tensile stress problem are elaborated. Meanwhile, actual projects in Haikou is introduced and analyzed to illustrate the problems above, which would provide a reference for similar projects.