Research On Horizontal Seismic Action Of Buildings Structure Considering Soil-Structure Interaction

High-rise building structure is the product of economic development and technological change.The main characters of high-rise structure are big number of piles, tall flexible, highload, and high reqirement of seismic-resistant ability. At present, horizontal earthquake action is based on the presumption of rigid foundation in our country code for seismic design of buildings. However, the presumption of rigid foundation isn't consistent with the fact, because soil-structure interaction is objective fact. The soil-strcture interaction can reduce the system's frequency, enlarge the system's equivalent damping, magnify the effect of input wave of bedrock. These interaction effects will obviously change the property and characteristic of dynamic response of system. Therefore,when soil-structure system was analyzed dynamically, the influence of interaction can not be neglected.Aiming at the objective fact, the main researches are outlined as following:In view of the mass shearing model, using modal analysis method and not considering soil-structure interaction, earthquake action, interbed shear and frame pole of moment were calculated of the building in this paper by software of matlab. Correspondingly, using modal analysis method and considering soil-structure interaction, earthquake action, interbed shear and frame pole of moment were also calculated by software of matlab environment compilation. Using finite element method,not considering and considering soil-structure interaction. earthquake action, interbed shear and frame column of moment were calculated by softsare of ANSYS.According to the two methods of modal analysis method and finite element method, the structure was calculated considering SSI and not. And the results of the two cased were compared. The results indicated:after considering the SSI effect, the internal force of frame column changed largely. In the five kinds of different grounds, the fifth one was the softest, the SSI effect was also the most obvious and the internal force of frame column was smallest. The internal force of frame column considering SSI which was calculated by modal analysis method was smaller 28 percent than that not considering SSI. The first one is hardest, and the internal force of frame column was largest in the five types ground. And the internal force of frame column considering SSI which was calculated by modal analysis method was smaller 19 percent than that not considering SSI. So the Internal force of frame column considering SSI was smaller than that not considering SSI. The internal force of frame column using finite element method was smaller than the one using modal analysis method. These proved that the horizontal earthquake action calculated by modal analysis method in our country seismic design code was not very precise, as a result of ignorance of SSI effect, especially in the softer ground. Therefore the SSI effect should not be neglected.In this paper, the internal force of frame column of a concrete modal in the horizontal earthquake action was analyzed. In fact, the influence on structure of SSI effect was very complicated. For improving the quality of seismic design, the research was done further and perfected continuously.