Study On Nonlinear Seismic Analytic Method Of Reinforced Concrete Tubing Structures

Based on available dynamic finite element theories, considering the influence of geometrical and material nonlinearity, the spatial elastic-plastic time-history analysis methods of reinforced concrete tubing structures under major earthquake excitation are studied combined with the actual seismic code.Based on the Timoshenko beam theory, three dimension integration is receded to unidimensional integration through the sectional analytic integration of beam. With the axial, shearing, bending and torsional deformation effects being included, the geometrical stiffness matrix is obtained. Then it's practicability in the geometrical nonlinear analysis is conclued.Expanding the conception of the "storey model", from which the beams and columns are discarded, with the floors being formed super-element(storey model), a new type of spatial member-storey model with elastic and elastic-plastic division is raised based on the substructure technique. This new type of model can reduce the degrees of freedom and the time of digital iteration obviously. So the engineering calculation on computer can be controlled in available run time.According to a 29-storey( 100.5m in height) reinforced concrete tube building, a spatial member-storey model is built up. The displacement, axial force, shear force and time-history curve in displacement, velocity, acceleration is obtained by perform the seismic response analysis under major earthquake excitation using mode-superposition response spectrum method and elastic-plastic time-history analysis method. Some observation and discussion are given.When three kinds of strengthened storeys are set to concrete tubing structures, we get the seismic response and compare the results using above modal and method. The changing of internal force and the aseismatic performance are studied by comparing the three kinds of structures with different arrangement. Some studies are given to the design and construct measure of this kind of structures.The example shows that this new type of spatial member-storey model based on the substructure technique is a feasible and practical one for engineering structures. The model and the method used in this thesis has provided a effective reference for the nonlinear seismic response analysis of large-scale complicated tall building.