Research on Mechanical Behaviour of High-rise Diagonal Grid Tube Structure and Case study

Abstract

In order to obtain the mechanical characteristics of high-rise diagonal grid tube structure under horizontal and/or vertical loads, three types of structure model, which were diagonal grid tube structure, diagonal grid–frame tube and framed tube structure, were established by the finite element software Etabs. The laws of internal force distribution, interstory displacement, base shear and shear hysteresis effect, were analysed deeply. The results from three-model showed that compared with the framed tube structure, the diagonal grid tube structure had the larger stiffness and the shorter period. Under the horizontal seismic load, the total shear force of the diagonal grid tube structure improved 20% by that of the conventional framed tube structure, with the interlayer shear force and the interlayer displacement angle distribution keeping basically the same. The inclining column to the diagonal grid structure could enhance the lateral stiffness in its plane effectively, but hardly improve the lateral stiffness out of its plane. Then, the performance under the vertical load was also discussed. Under the action of the vertical load, the shear hysteresis effect appeared, especially for the flange inclined column. Subsequently, the feasibility of the diagonal grid tube in the engineering projects was evaluated. The finite element software ABAQUS was used to analyse the dynamic elastoplastic time history performance of a one-way oblique grid system high-rise building under rare earthquakes. The results showed that the maximum interlayer displacement of the structure was less than the limit of Chinese codes and standards, and the structure could achieve the goal of anti-seismic fortification without collapse under strong earthquakes. There was a conclusion that the diagonal grid tube could be applied as a part of the overall structure for high-rise or super-tall buildings in the zones with seismic design intensity of 7 degree.