The Research On The Composite Seismic Isolation Pier

The concept of base isolation was first proposed by Japanese scholar KawaiHirohide in1881. Base isolation theory opens up a new and effective way toalleviate the damage caused by earthquakes to buildings. After numerous scholars、continuous development and improvement during over one hundreds years, baseisolation technology has been developed from the stage of theoretical research to thestage of engineering application. The base isolation technology has now become themain developing direction of structural seismic technology.Since the early studies on seismic waves were not deep enough, it is generallybelieved that the influence of vertical seismic component on ordinary buildings canbe neglected in the seismic design，because vertical seismic component is only1/2-2/3of horizontal seismic component. As a result, during the past one hundredyears, the studies of the base isolation technology were all focused on how to reducethe influence of the horizontal earthquake on the upper parts of buildings. With thedevelopments of the science and technology, people have a deeper understandingtowards the vertical earthquake, and find that it can’t be ignored that the influence ofvertical seismic action on the structure, especially in the areas near the epicenter.Considering the current situation that the existing shock isolation device has noeffects on isolating vertical seismic loading, according to the theory of the baseisolation, this thesis develops a new three-dimensional seismic isolation device,composite isolation pier, which is based on the existing isolation technology-steel-asphalt composite isolation layer. The device has good capacity ofthree-dimensional seismic isolation, it can also reduce the influences of thehorizontal and vertical seismic action on the upper structure. Besides，it has theadvantages such as a simple structure, low cost, durability, and industrializedproduction. All these advantages determine that the composite isolation pier hasgood social and economic benefits.The thesis firstly introduces the seismic isolation’s theory and characteristicsof the composite isolation pier, and then focuses on introducing the compositeisolation pier structure, the calculation model and the design method. The criteria ofthe composite isolation pier design followed has been found through calculation andanalysis, and also introduces the design process of the composite isolation pier by calculating an example. Finally conducting the vibration table simulation test withquality of reinforced concrete block instead of the building with bigger stiffness. Byarranging the counterweight block on the isolation pier and arranging vibration tableof mesa vibration pickup, measured the peak acceleration of isolation pier output andvibration table input, and measuring isolation effects by its ratio. The results of theexperiment showed that no matter the vibration table input is vertical vibration orhorizontal vibration, the acceleration transmitted to the upper structure by isolationpier are40%-60%reduction, the composite isolation pier has good dimensionalisolation pier isolation effect, it provides a theoretical basis for promoting the use ofcomposite isolation pier.