Shaking Table Model Test And Seismic Evaluation Of Reinforced Concrete Frames

The damage caused by earthquakes at home and abroad indicates that building structures would go through enormous nonlinear deformations and even collapse under medium or strong earthquakes. Because the current seismic design theory could not effectively reduce the damage, the performance-based seismic design theory was recognized step by step in recent years, the study of this has now become the present hot spot of earthquake engineering. On the basis of Benchmark Test of 12-story Reinforced Concrete Frame Model, the performance based seismic theory and assessment of R.C. structures is studied in this paper by means of combining theory with experiments. So the study will be of great importance in theory and of practical values.Based on the shaking table test on a 12 story R.C. frame model with scale of 1/10, which is done in Tongji university National key lab, the seismic performance and damage characteristic of R.C frame are studied. Furthermore, seismic performance of R.C frame is evaluated based on the performance-based seismic design theory. According to nonlinear stactic push-over analysis method, nonlinear responses of structures, the internal force, deformation and position of plastic hinge in every phase are analyzed. The weak positions of structures can be easily found by using this method. Based on different lateral load pattern, shear and top displacement curves are derived. All of results calculated above are compared with the test results, it is shown that calculations are well coincided with tests. According to the performance-based seismic design theory, capacity spectrum method and improved capacity spectrum method are applied to evaluate the seismic performance of structures. The results shows that capacity spectrum method maybe not converge in calculating the target displacement, while the improved capacity spectrum method can evaluated the target displacement when the frame in elastic stage or nonlinear stage. Based on the shaking tablemodel test of the 12 stories frame and the nonlinear time history analysis of the frame, the top displacement of structures calculated by improved capacity spectrum method is compared with that of the test and nonlinear time history analysis. It is shown that improved capacity spectrum method may overrate the seismic performance of the frame. However, improved capacity spectrum method may be used to evaluate the seismic performance of tall buildings, but it should be noted that proper measures must be taken to eliminate errors.