Experimental Study On Seismic Performance Of An Innovative Resilient Rocking Column

To achieve performance restoration of structures after major earthquake,an innovative resilient rocking column(IRR column)technology is proposed.This IRR column is composed of a rocking steel column,several steel slit dampers,T-shaped connecting plates and a number of high-strength bolts.It can be prefabricated in factory and assembled in-field with ease and convenience.Under major earthquake,the rocking steel column maintains elastic and the plastic deformation is concentrated on the steel slit dampers,which can be disassembled and replaced on site.To study the seismic performance of the IRR column and the corresponding design method,full-scale column test was carried out.The main works completed are as follows:(1)Cyclic loading test of 10 sets of full-scale IRR columns was prefabricated and tested.The main research parameters are: axial compression ratio n,steel plate damper thickness t and damper arrangement.The results show that all the test specimens possess stable hysteretic performance,good deformation capability,high strength and initial stiffness.(2)Designed according to the "strong-column/weak-damper " principle,the plastic deformation of all specimens is concentrated on the horizontal struts of steel slit dampers,while the other components stayed mainly elastic.After the test,the damaged dampers can be easily disassembled and replaced with new one,which makes the performance of the specimens fully recovered.(3)The horizontal load carrying capacity of the specimens increases with the increase of the thickness of the steel slit dampers and the axial compression ratio.The load carrying capacity of the specimens increased by 42.2% and 18.9%,when the thickness of the dampers increased from 8mm to 14 mm and the axial compression ratio increased from 0.1 to 0.2,respectively.(4)The bearing capacity of the test piece is mainly provided by the steel slit dampers arranged in the parallel loading direction.The contribution of the steel slit dampers in the vertical loading direction is lower compared with that of theaforementioned dampers,while the proportion is between 12.1% to 14.7%.(5)With the increase of the axial compression ratio,the uplift of the bottom face of the IRR columns under maximum drift is reduced as well as the corresponding residual deformation dose under 0 load.It is thus concluded that the performance of self-centering of specimens is improved with the increase of the axial load.(6)The horizontal load carrying capacity of the IRR column is calculated based on a simplified analysis method and the plastic limit analysis method.Comparing with the experimental results,it can be seen that the calculation results of the simplified method are conservative,and those of the plastic limit analysis method are in good agreement with the test results.It can be referenced for future research work and design practice.