The height of the super high-rise building-China International Silk Road Center is 498 m. The building is located in Xi'an Shaanxi province, where the seismic intensity is 8 degree, and the lateral deformation and load bearing capacity of the structure are both controlled by the seismic load. In order to solve the problem of insufficient lateral stiffness of the structure, the use of an outrigger truss strengthened storey was considered. However, the traditional outrigger truss often leads to an abrupt change in the stiffness and bearing capacity of the structure. To address this issue, the hybrid outrigger technology involving both rigid and viscous damping outriggers was applied to the building design. The optimum position and efficiency of the outrigger truss arrangement were investigated through calculation and analysis, taking into consideration the structural index, structural energy dissipation, member stress and economic aspects. The layout of viscous damping outrigger truss in the upper two refuge areas and the rigid outrigger truss in the lower two refuge areas was proposed. From the aspects of structural response and structural damage, the seismic performance of the structure under different levels of earthquake was analyzed, and the finite element analysis of the key joints of the outrigger truss was carried out. The results show that, by using the hybrid outrigger truss technique, the energy dissipation mechanism of the structure can be improved, the seismic response and member damage can be reduced, and the outrigger truss is safe and reliable. © 2021, Editorial Office of Journal of Building Structures. All right reserved.
