Study On Base Isolated Structure Considering Soil-Structure Dynamic Interaction

In this thesis, the structure which was wrecked in the wenchuan-earthquake is studied. we build a soil-structure dynamic interaction model of this structure with the Penzien model and analyse four conditions of this structure.1.unconsidering soil-structure dynamic interaction before strengthening.2.considering soil-structure dynamic interaction before strengthening.3.unconsidering soil-structure dynamic interaction after base isolated strengthening.4.considering soil-structure dynamic interaction after base isolated strengthening. Four conditions of this structure are analysed by using ELCENTRO wave, TAFT wave and ARTIFICIAL wave. We get some results about period, story shear, story displacement, story acceleration, shear of vibration cushion, displacement of vibration cushion and hysteretic characteristics of vibration cushion. The same structure, base isolated or not, is discussed with two conditions which the soil-structure dynamic interaction is consider or not in three type of site soils.We come to some following conclusions:1 Base isolated structure is not as sensitive as the ordinary structure in respects of period, shear, displacement and acceleration.2 After considering soil-structure dynamic interaction, the stiffness of structure is changed and the period of structure is longer with the stiffing of site soil.3 The structure's displacement of considering soil-structure dynamic interaction is bigger than the structure's displacement of unconsidering soil-structure dynamic interaction.4 Whether the structure is base isolated strengthening or not, story shear and story acceleration will change un-orderly. Some story's shear and acceleration will increase and other's shear and acceleration will decrease.5 For Base isolated structure, after considering soil-structure dynamic interaction, shear and displacement will decrease and hysteretic characteristics of vibration cushion will decline.6 For Base isolated structure,the energy which is exhausted by the vibration cushion is abundant and changed by the different site conditions.When the site become stiffer, the energy which is exhausted by the vibration cushion is more than before.