Experimental study on seismic behavior of earthquake-resilient prefabricated column foot joint with lateral force-resisting energy-consuming devices
Based on the design concepts of plastic damage control,replaceable energy dissipated elements and separation of lateral stiffness,a type of restorable prefabricated column foot joint with lateral force-resisting energy-consuming devices(LRECD)was proposed.It was composed of a square steel tube column hinged at the bottom and the LRECD through high-strength bolts.To investigate the seismic performance,repairable performance and low cycle fatigue performance of the column foot joint,pseudo static tests were conducted on three side column foot joints and one middle column foot joint.Performance indexes such as hysteretic curves,skeleton curves,stress curves,ductility and energy dissipation capacity were obtained.The results show that the column foot joint has good bearing capacity,energy dissipation capacity,seismic performance and repairable performance after the earthquake.The design enables concentration of the plastic damage of the structure on the LRECD.After the earthquake,the function of the joint can be restored only by replacing the LRECD and high-strength bolts.The repaired joint has similar properties to the original joint,which provides the possibility of multiple repairs.At the same time,the foot joint exhibits stable performance after 30 cycles of low-cycle fatigue loading,and the LRECD can be used as a displacement related damper.The seismic performance of the middle column foot joint has significant advantages over the side column foot joint,but the quality of the weld at the square steel tube column joint area should be guaranteed.