Analyses of mitigation effects of isolation structure considering additional wind-resistant support of variable stiffness

Wind-resistant in isolation layer is a design challenge if basic wind pressure of the isolated structure is relatively large. The program of setting steel plate wind-resistant support of variable stiffness on the isolation layer is proposed to reduce the number of the lead-rubber support and improve the damping effect. Based on practical engineering background, the horizontal damping coefficients are set less than 0.53, 0.40 and 0.27, respectively, to establish three contrast structure models and make time-history analyses. The result shows that, the isolation layer form combined with rubber isolation support and steel plate wind-resistant support of variable stiffness is reasonable to reduce the seismic response, improve the isolation effect and meet the wind-resistant design objective. However, the number of the rubber isolation support and the wind-resistant support requires optimization design. Furthermore, to ensure the normal use of the structure, it is proposed that the lead support horizontal design value is close to the isolation layer horizontal shear standard value under wind load. The working mechanism of the wind-resistant support of variable stiffness is clarified by conducting structural simulation and static loading shear test over wind-resistant support. The result shows that the wind-resistant support works well and provides horizontal support under normal working conditions and small earthquakes. When suffering moderate earthquakes, the wind-resistant support will yield and be destroyed before stopping working, making the damping effect unchangeable. © 2016, Nanjing Univ. of Aeronautics an Astronautics. All right reserved.