| As one of the most serious sudden natural disasters,earthquakes endanger the safety of human life and property.The earthquake damage caused by the Mexico Earthquake in 1985,the Hanshin Earthquake in 1995 and the Haiti Earthquake in 2010 all showed that the structure on soft soil sites,especially on soft soil in coastal areas,is easier to be affected by soil-structure interaction than other sites.And a variety of failure modes may appear in the structure under the action of an earthquake.Our country,located in the west of the Pacific Rim Seismic Belt,and the southwest and northwest are located on the Eurasian Seismic Belt,has been a country with severe earthquake disasters since ancient times.At the same time,there are many coastal cities in our country,and some of them have high seismic fortification intensity.It is of great significance to fully consider the mechanism of structures response in these areas under earthquake action.This paper mainly uses a numerical model to study the influence of the soil-structure interaction of coastal soft soil sites on the seismic response of pile-supported high-rise structures and the influence of different system parameters on the effect of soil-structure interaction.The main research contents and results are as follows:1.With the aid of the finite element software MSC.Marc,a numerical model suitable for seismic analysis of the soil-structure coupling system of pile-supported high-rise structures on coastal soft soil sites is established.Combined with the special nature of the research object,in-depth research is carried out in four aspects: artificial boundary,calculation range of soil domain,soil element size and soil-structure contact interface setting.Finally,the Drucker-Prager soil constitutive,layered constrained artificial boundary,10 times the superstructure size of the soil domain calculation range,3m side length of the soil element mesh size,soil-pile contact analysis and equivalent two-dimensional modeling Method are adopted to establish a numerical model.2.The main analysis object of this paper is designed,and the influence of soil-structure interaction on the structure is further studied based on its response under earthquake.The main results show that the filtering effect of the foundation soil can amplify the intensity of the seismic waves transmitted to the surface of the soil on the one hand,and reduce it on the other hand.It is mainly affected by the input seismic wave frequency spectrum and the natural frequency of the site.After the interaction,the intensity of the seismic wave transmitted to the top surface of the foundation will slightly decrease.The superstructure of the soil-structure coupling system has the possibility and tendency of large swing under the action of earthquake.This tendency will greatly increase the response of superstructure acceleration,foundation shear and interlayer lateral angle in some cases.3.Through parametric analysis,study the change law of the influence of each element on the soil-structure interaction on the seismic response of the structure,and on the basis of the current code,point out that the soil-structure interaction may cause the pile-supported highrise structure on the coastal soft soil foundation.The adverse effects.The main results show that,different from the calculation method in the code,after considering the soil-structure interaction,the calculation results of the foundation shear force of the pile-supported highrise structure on the coastal soft soil foundation under the seismic action may increase.And when the rigidity of the structure is larger,the rigidity of the soil is smaller,and the longer friction piles are used,the adverse effect becomes more prominent. |
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