Study On Seismic Intensity Measures And Isolation Bearing Displacement For Three-Dimensional Isolated Single-layer Reticulated Domes

Incremental dynamic analysis is widely used in the analyses of seismic responses of structures.For three-dimensional isolated single layer reticulated domes,effective descriptions of the seismic intensity is the basis of the incremental dynamic analysis.At the same time,the displacement response and damage of the isolation layer that influence the overall reliability of the isolated structures are the key points of the seismic dynamic response analysis.Based on numerical simulation,the dynamic responses of three dimensional isolated single-layer reticulated domes under the excitation of near and far fault earthquakes are compared,then this thesis analyzes intensity measures applicable to three-dimensional isolated single-layer reticulated domes,and a displacement predication formula of the isolation layer is proposed.The main research contents are follows.(1)Firstly,taking a three-dimensional isolated Kiewitt-8 single-layer reticulated dome as object of research,this thesis compares the dynamic responses of the reticulated dome and the isolation layer under far and near fault excitation.The results show that the three-dimensional isolation bearing can reduce the acceleration response and overall deformation of the reticulated domes.However,compared with the far-field earthquakes,the near-field earthquakes containing long-period pulses can increase the displacement of isolation significantly.(2)Then this thesis analyzes the influence of pulse contents,period of pulse,threedimensional ground motion etc.,on the application of intensity measures under the excitation of near-fault earthquake,and the selection method of efficient intensity measures of three-dimensional isolated reticulated domes is discussed.Considering the anisotropic properties of structure,an vector-valued intensity measure [ DMASIx,DMASIy,Saz] is proposed,and it is evaluated in terms of correlation and efficiency.(3)Based on IM selected from Part(2),the influence of design parameters on the displacement response is studied by using non-dimensional analysis.Then the displacement predication formula of the three-dimensional isolation bearing is proposed through statistical analysis of numerical simulations.Its accuracy is verified by the validation model.