The Interaction Analysis Of High Frame Strcture-pile Raft Foundation-soil

Since the reform and opening up to the outside world, China’s urbanization processhas been rapidly developing. More and more people are flooding into cities, leading torapid population growth in cities. Consequently, people need more places to work andlive in. Thus, we should build more buildings, but now the urban land is in a very tightsituation. The high cost of land forces us can only develop high-rise buildings in orderto solve the shortage of land conflicts. In such a big situation, the development of bigcities can’t get rid of the construction of high-rise buildings, and they have graduallybecome the symbol of a city’s development, which also promotes researches oninteraction analysis.However, the existing design method for high-rise buildings does not consider theinteraction of superstructure-foundation-soil, which is not consistent to the actual results.On the one hand, analysis without consideration of interaction leads to the foundationdesign conservative, resulting in material waste and construction costs higher. On theother hand, differential settlement of the foundation causes the inner structural stress ofsuperstructure redistributes, which may lead to the insecurity of the superstructure.Overall, considering the effect of interaction undoubtedly can make the design of thebuilding safe and economical. There has been many theoretical researches on interaction,and has developed into different analysis methods. Among them, substructure method iswidely used and recognized by most researchers. With the development of the computer,the finite element method is used gradually, which provides a convenient method for theresearch on interaction.In this thesis, I use the widely used finite element software ABAQUS tonumerically simulate a frame-piled raft foundation structure. The soil model is set aselastic-plastic Mohr-Coulomb model, and the concrete material is assumed staying inthe elastic state, using elastic model. By setting contact pair between piles and soil, themodel can consider the force and relative slip between them. Loads on thesuperstructure include gravity、floor dead loads、floor live loads and horizontal seismicaction. By analyzing the results of models, I research the difference betweenconsidering interaction and not considering interaction, such as the effect on the innerforce and displacement of superstructure and the uneven settlement and inner force ofthe foundation. On the base of these studies, then by changing the soil’s elasticmodulus、the length of piles、the diameter of piles、the thickness of the raft、the storyof the superstructure and other factors, we get the effect of these factors on the innerforce and displacement of the whole model, in order to arrive at some qualitative and quantitative conclusions to provide some guidance and reference on the future design ofhigh-rise buildings.