| The problem of structure-foundation dynamic interaction is raised to follow the advance of practice. By the earthquake engineering practice, it is realized that structure-foundation dynamic interaction has important influence to the seismic response of building more and more. The thesis takes silo, stock, pile, and foundation as the spatial structure. Based on the finite element theory, calculation model of three dimension silo-stock-pile-foundation dynamic interaction system is set up. By means of the finite element method and pseudo excitation method, the studies on dynamic interaction problem of silo-stock-pile-foundation under the stochastic earthquake exciation are developed, more deeply and systematically, and some worthy results are obtained in the paper. Main reseach work and get main conclusions as follows:1. The author analyzed the present research condition and the development levels of the soil- structure dynamic interaction completely, on the foundation of looking up a great deal of documents at home and abroad, and pointed out the deficiency of the existing research. Because the earthquake exciation is a kind of random load, therefore, the response of the structure on the earthquake load should be studied by the standpoint of stochastic process, which matches the engineering practice.2. Through checking the documents lately, pseudo excitation method is applied to the random seismic response research of the three-dimension pile-soil-structure dynamic interaction system in the paper at the first time, which extends the applied range of pseudo excitation method.3. Dynamic characteristics of the space free field foundation and soil-pile-raft dynamic interaction system are studied. Numerical value calculation results show thatafter establishing pile foundation on the free field foundation, the natural frequency of the original foundation soil is enlarged and the natural period is shorten. The main affection is that the influence of the pile foundation to the ex-3 natural frequency of the foundation is small, the opposite error margin is in 10%. Along with the natural frequency of the system enlarging, the influence trend of the pile foundation to the frequency enlarges too. But after the natural frequency of the system enlarging the some value, the influence of the pile foundation upon the natural frequency will basically keep constant. Using the pseudo excitation method, random seismic responses of free field foundation and pile-soil interaction system are studied. It is found that soil-pile dynamic interaction can reduce the random seismic response of the free field foundation obviously.4. Three dimension finite element calculation models of silo, silo-stock interaction system are established in a systematic way. Dynamic characteristics of silo, silo-stock interaction system are separately studied under the condition of rigid foundation. Numerical value calculation result shows that the natural frequency of the empty silo is bigger than that of silo-stock interaction system. Using the pseudo excitation method, random seismic responses of empty silo and silo-stock interaction system are studied, the influence of the stock to the silo dynamic response is analyzed also. The result from the study indicates that the displacement response power spectral density peak value of silo-stock interaction system is bigger than that of empty silo on rigid foundation, the reducing vibration effect of the stock to silo vibration is not very obvious.5. Three dimension finite element calculation models of empty silo-foundation, silo-stock-foundation spatial interaction system are established in a systematic way. Dynamic characteristics of empty silo-foundation, silb-stock-foundation spatial interaction system are separately studied. The result from the study indicates that fundamental frequency of silo-stock-foundation spatial interaction system is less than that of empty silo-foundation, the range of lowering is about 20%. However, along with the natural frequency increasing, the frequency of the silo-stock-foundation interaction system increases a little by the empty silo. Using the pseudo excitation method, random seismic responses of empty silo-foundation and silo-stock-foundation spatial interaction system are studied. The result from the study indicates that the displacement response power spectral density peak value of silo-stock-foundation spatial interaction system is less than that of empty silo-foundation, the reducing vibration effect of the stock to silo is obvious.6. Three dimension finite element calculation model of silo-stock-pile-foundation spatial interaction system is established in a systematic way. Dynamic characteristic ofsilo-stock-pile-foundation spatial interaction system is studied. Numerical value calculation result shows that the natural frequency of silo-stock-pile-foundation interaction system is bigger than that of silo-stock-foundation interaction system, the increasing range of fundamental frequency is about 55%. Using the pseudo excitation method, random seismic response of silo-stock-pile-foundation interaction system is studied, the influence of the stock and pile to the interaction system dynamic response is analyzed also. The result from the study indicates that the pile foundation can reduce the random seismic response of the silo-stock-pile-foundation interaction system obviously. Pile foundation can not only increase the strength of the foundation soil, but also decrease deformation of the foundation soil, meanwhile, under the earthquake excitation, pile foundation can also be taken as the component of eliminating energy and vibration absorber which can be used in the structure anti- earthquake.
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