Studies On Energy-based Integrated Practical Design Method For The Base-isolated Structure

After many years of theoretical research and engineering practice, isolation technology with its good energy dissipation has been widely used in the field of engineering. While the applied research of the isolation technology has become increasingly perfect, the design method of isolation structure is more and more standardized. For example, The United States, Japan, New Zealand, Italy, China and other countries have enacted the codes of building seismic isolation design. But the structure design method still exists some problems in practical application. The reasonable and efficient design method of isolation structure remains a hot spot of the isolation technology research.In this article, the important parameters of the structure design are the energy of two indicators, which are the force and the displacement. The core is the basic structure design of the additions of the natural rubber bearing and the lead rubber bearing. A series of related researches have done in the forecasting method of energetic reaction of the base-isolation structure by using MATLAB software and SAP2000 software, the additional damping ratio calculation of the base-isolation structures, and the design of isolation layer. The main results are as follows:(1) The forecasting analysis of the energetic reaction of base-isolated structures. Based on analyzing the equations of the energetic reaction of the traditional seismic structure and base-isolated structure, after analyzing the influencing factors of energetic reaction of traditional anti-seismic structure, and comparing and summarizing the influencing factors of the energetic reaction of base-isolated structures, a estimation method about the energy of base-isolation structures (especially the input energy) is put forward. Then It with the results of the analysis of the structure by using SAP2000, which shows that the forecasting method can get more reasonable results is compared.(2) The additional damping ratio calculation of the base-isolation structures. After analyzing the additional damping ratio of damping structure, the calculation formula of additional damping ratio of the base-isolation based on energy is put forward. After analyzing the total strain energy of the upper structure, the energy dissipation of isolation layer, the maximum displacement of the upper structure, and the maximum displacement of the isolation layer, which are the main influencing factors of the additional damping ratio of the base-isolation structures, the solution to those factors and the influence on the additional damping ratio which is produced by its error is got. By comparing the estimation results of the additional damping ratio of the base-isolation structure with analysis results from SAP2000, it proves that it’s safe and efficient to use this method to estimate the additional damping ratio of the base-isolation structure. And it can become a calculation method of the additional damping ratio in the integration design. The integration design of base-isolated structures can come true.(3) The design of isolation layer. This part firstly introduces the energy dissipation formula of lead rubber bearings under seismic action. After that it shows the analysis and summary of the influencing factors of the choice of bearings which contain the type of bearings, the energy consumption of bearings, and the energy dissipation of isolation layer. Finally, the preliminary screening to the arrangement scheme of bearings based on the displacement index and the verification method of response spectrum of base-isolated structure are summed up. Through comparing the calculation results of isolation structures design by using segment design method, it proves that it’s reasonable and efficient to use this method to design the isolation layer of base-isolation structures.(4) The case’s analysis of base-isolated structure based on energy design method. The segment design method and the design method based on energy which is talked about in this article are used to make a complete isolation design of a science building in a high school. Then the specification indexes of the base-isolation structure and the programs of the isolation layer layout which are designed by the two methods are compared and analyzed. It proves that the integrated design method of the base-solation structure based on energy is practical, effective, reliable.