Method Of Seismic Design Based On Theexpected Damage Of Reinforced Concrete Frame Structure

The performance-based seismic design method is to design a structure based on the principle of designing under frequent earthquake and checking under rare earthquake, but it is difficult to grasp the perf ormance of structure under rare earthquake. Therefore, this dissertation adopts the idea of seismic design based on the nonlinear stage. It is analyzed that the damage mode and internal force distribution of RC frame structures under rare earthquake, and study on how the ratio of flexural bearing capacity, known as η, influence damage mode. It is made clear that the relationship between the optimal damage mode control ling index and its affecting factors. Finally, it is presented that the seismic design method of RC frame structure based on the expected damage.Study on damage mode. In the consideration of the influence of floor, the refined ABAQUS model of RC frame structure is established. It is to analyze the rule of distribution of damage, and to dete rmine de reasonable value of η, based on the results of elastic-plastic analysis. By comparing with the structure designed through the specification, it is verified that the damage mode can be optimized by η.Study on the controlling index of optimal damage mode. Column members are classified according to the importance of them. Based on the structures that have been designed by reasonable damage mode control index, η, the distribution of internal forces of the structures are analyzed when the structures are in nonlinear stage. It is made clear that the relationship between the internal forces distribution coefficients and the relative height of the floors, and the computational formulas are given. Thus, the optimal damage mode of RC frame structures is realized.Seismic design method based on the expected damage of RC frame structures is proposed. On the basis of the former research, the bearing capacity of the expected is determined by using inelastic response spectra based on the damage. The design method of controlling expected damage of structures is realized by the ratio of flexural bearing capacity and the internal forces distribution coefficients. Finally, the process of seismic design method based on the expected damage is given.The superiority is verified of the seismic design method based on the expected damage. A RC frame structure is designed by using the proposed method in this paper and the code method, then the results of dynamic history analysis of the two structures are obtained by input a number of seismic waves. Comparing several indexes of the two structures under the rare earthquake, the superiority of the design method proposed by this paper is verified.