Study On Pile-Soil-Superstructure Elasto-plastic Dynamic Interaction Under The Horizontal Earthquake Action

In order to avoid the damage of the building during the earthquake, the seismic design of building must be done. The interaction between foundation and super-structure will be appeared in the period of the earthquake, some building can be considered the interaction by decreasing the shear force and the story drift. The elastio-plastic deformation of some building must be calculated. The conclusion about the interaction is gotten in the condition of the elasticity and the elastio-plastic deformation is computed in the condition of the assumption of rigid ground. The study of the soil-structure interaction under strong earthquake and the analysis of the elastio-plastic deformation considered soil-structure interaction are very lack. The piles are applied if the ground is very deep. So the study of pile-soil- structure elastio-plastic dynamic interaction is very important.The model of pile-soil- structure elastio-plastic dynamic interaction has been analyzed and the property of pile-soil- structure elastio-plastic dynamic interaction has been studied in the paper. The elastio-plastic deformation considered the interaction is computed. The results can be used for seismic design.The finite element method is adopted in the study of pile-soil- structure elastio-plastic dynamic interaction. The analysis model is regarded as: the super-structure is the reinforced concrete plane frame of beams and column, the foundation is piles, the soil around the pile is simulated by plane strain elements. The main contents are as follows: The elastio-plastic constitutive equation for pile-soil-structure is selected. The bilinear isotropic constitutive model based on the Von Mises yield criterion is used for super-structure, and the parameters for this constitutive model are computed. The elastio-plastic constitutive model based on Drucker-Prager yield criterion is used for the soil. The finite element method is modified for the study of elastio-plastic pile-soil-super-structure dynamic interaction. The solution of motion equation, the finite element, the boundary of soil, the means for input of the earthquake wave, the dimension of mesh and the gravity load of system are researched in this part. The validity of the finite element method using ANSYS is validated. The responses of the horizontal layered soil under the earthquake are studied. This work is very important for next study, such as the responses of pile-soil system and pile-soil-structure system under the earthquake. The elastio-plastic responses of pile-soil system under the horizontal earthquake are studied. The elastio-plastic pile-soil-structure dynamic interaction hehorizontal earthquake are studied. The four super-structure which built in two sites areanalyzed. The super-structure is 5 stories, 10 stories, 15 stories or 20 stories, the sites isII and III. Based on the analysis above, the main achievements are as follows:(1) The finite element method can be used for the analysis of the elastio-plastic pile-soil- structure dynamic interaction. In this method, the elastio-plastic property of soil and super-structure has been considered, the beam elements are applied for super-structure.(2) Used the APDL, the transmitting boundary applied for the soil boundary in the program ANSYS.(3) Under horizontal earthquake, the peak value of the relative displacement on the surface of free field may be increased and the peak value of the absolute acceleration on the surface of free field may be decreased, if there are soft layer in the free field. Under horizontal earthquake, the peak value of the relative displacement on the surface of free field may be decreased and the peak value of the absolute acceleration on the surface of free field may be increased, if there are hard layer in the free field. In the elastio-plastic analysis, the peak value of the relative displacement and the absolute acceleration on the surface of free field may be increased, if there are soft layer in the free field.(4) Under horizontal earthquake, the peak value of the relative displa...