Experimental study on seismic performance of abnormal interior joints in steel reinforced concrete hybrid structure for main building in thermal power plants

Split-level, variable beams and columns in main building structure in the thermal power plants bring a large number of abnormal interior joints. The quasi-static test for five typical specimens in 1/5 scale of the prototype model were carried out, to study the hysteretic performance, energy dissipation capacity, ductility, stiffness characteristics and bearing capacity of this kind of abnormal joints. The results show that: the dominant failure mode is plastic hinges failure at column ends for four steel reinforced concrete abnormal interior joints which is not good for seismic resistance, while the failure mode mainly the shear damage in core area for the reinforced concrete abnormal interior joint because the beam-column stiffness ratio is quite large. The height of split-level which is caused by the large beam and small beam has certain influence on the bearing capacity, ductility capacity and stiffness characteristics of steel reinforced concrete abnormal interior joints, but the influence law is not obvious. The dissipation capacity of steel reinforced concrete column-reinforced concrete beam abnormal interior joints is better than the reinforced concrete abnormal interior joint. For the limitation of failure mode, however, the bearing capacity, ductility, stiffness characteristics of steel reinforced concrete column-reinforced concrete beam abnormal interior joints are lower than the reinforced concrete abnormal interior joints'. Compared with the steel reinforced concrete abnormal interior joint with reinforced concrete beams, the initial cracking bearing capacity of steel reinforced concrete abnormal joint with steel reinforced concrete beam is higher, and its stiffness characteristic is better, but its bearing capacity, ductility performance and energy dissipation do not enhance obviously.