Seismic Behavior Research And Seismic Fragility Analysis Of RAC Frame Structures

As the procedure of citifying is fastenning and the standards of construction industry is improving, more and more old houses facing demolition or transformation, which produces large amounts of construction waste. If the waste concrete has been crushed, screened and distributed reasonable to preduce the recycled aggregate and recycled concrete with better properties applied to the field of civil engineering, it will greatly prolong the service life of concrete material, and reduce environmental pollution and resource waste. Because the recycled concrete technology’s research and development is late, so many problems have not be solved. Especially, the seismic performance of recycled concrete aggregate frame structure research and seismic vulnerability analysis method etc still need to be included in the study, which lays a foundation for the later engineering application.First, the mechanical property tests of five groups of 60 ordinary concrete specimen and recycled concrete specimen and performed, the recycled concrete’s compressive strength,splitting tensile strength elastic modulus and the changing rule of the stress and strain,under different rate of recycled aggregate are studied. The basic mechanical properties of recycled concrete component are summarized.and the stress-strain curve of recycled concrete materials under different regeneration aggregate is filled. Then a 2 across 3 layers frame structure of recycled concrete model is made. The shaking table tests on the structure model 21 kinds of working conditions are performed.and the seismic performance of this kind of structures are studied. Then, the nonlinear dynamic time history analysis to the structure by using finite element analysis software ANSYS is done.and the result of the analysis and shaking table test data is compared. The results show good aggressive, which illustrates the rationality of the ANSYS finite element analysis result. Then 10 real seismic records are selected,based on vibration spectrum characteristics acceleration,durations and other factors, and the modulation is changed by using hunt & fill method.then 10 IDA curves are got under different ground motion records,according to the method of IDA.Finally, according to the result of the IDA curves data. We get the relation between the demanding parameters of the structure and the ground motion intensity index, the damage index of recycled concrete frame structure. The ultimate of states are defined which are immediate use, life safety and to prevent the collapse of the state etc. After obtained the failure probability of different structures limit state,the structural damping ratio of 5% value of acceleration response spectrum is defined as the horizontal, and the probability of structural failure is defined as ordinate to draw the earthquake fragility curves of recycled concrete frame structures. Seismic fragility curves structural is used to analyze the seismic vulnerability. More comprehensive descripted the safety performance of different limit state provisions of recycled concrete frame structure damage indicators and Intuitively reacted the seismic behavior of recycled concrete frame structure,provided the basis for the field of applied earthquake of recycled concrete frame structure.