Effect Of The Ⅲ Site Soil In Kunming On Structure With Tower Under Earthquake

Presently, when design the structure with tower, the interaction of Soil-Structure is not full considered according to the Code for seismic design of building, there are some differences compared to the actual seismic response. To accurately calculate the seismic response of structure with tower, obtain the actual vibration modes of tower, improve the seismic performance of the structure with tower, we should accurately consider the interaction of Soil-Structure.In this paper, through ABAQUS to establish three-dimensional solid finite element model that include the soil and structure with tower, and proceed modal analysis、 elasto-plastic time history analysis. The main works of this paper include the following aspects:(1) Summaries were made on the seismic analysis of the basic theory、Soil-Structure interaction theory、contact problems fundamentals between pile and soil、 modal analysis theory and elasto-plastic time history analysis theory. And select the appropriate calculation method and calculation model combined with the special nature of the object studied in this paper.(2) It is been explained the engineering parameters, defined the constitutive model of soil、steel and concrete, given the key points of the modeling, choosen the right type of unit and unit size.Then establish three-dimensional solid finite element model that consider the interaction between soil and structure, and establish three-dimensional solid finite element model that only include the structure.(3) The two finite element models were carried on modal analysis, then compare with the natural frequency and mode shapes of the two models.The main conclusions were:After considering interactions, the vibration period of each vibration mode was increased, and greater impact on the structure of higher modes; The first three Modes were similar, but there were quite differents between higher modes, and the modes for local vibration of tower were not appearance.(4) Four natural waves and an artificial wave were selected basis on the code, which conform the conditions of I side,the five waves were inputted at the bottom of soil in the model that consider the interaction; The five surface waves can obtaion by the analysis of free field, and the five surface waves were inputted at the bottom of column in the model that only include the structure.First, the stress of soil was analyzed,and then elasto-plastic time history analysis were carried on the two finite element model. Then compare with the seismic response indicators of the structure with tower that include the peak acceleration of each floors, the maximum displacement of each floors, the maximum displacement of interlayer and maximum shear of each floors column. And summaries were carried on for results of the analysis.