Experimental Study On Compression Behaviour Of RC Pier Retrofitted By Prestressed Steel Hoop

According to the seismic performance of defects of the existing circular piers, akind of prestressed steel hoop technology of strengthening RC circular pier isproposed. Prestressed steel hoop can avoid the problem of steel hoop stress lageffectively and improve the confinement of reinforcement material, which make thereinforcement effect improved obviously. The paper focus on the behaviour of RCcircular pier retrofitted by prestressed steel hoop under axial compressionperformance, the main research work and results are as follows:Based on the seven RC circular piers retrofitted with PSH tested under axialcompression to verify the feasibility and the reinforcement effect of PSHstrengthening RC piers. The compress resistant mechanism of PSH and the compressbearing capacity of retrofitted piers are discussed by analyzing configurationparameter of PSH and the prestressing ratio of PSH. The test result include:(1) Axialcompressive bearing capacity and limit deformation of RC pier retrofitted with PSHwere improved effectively;(2) Axial compressive bearing capacity and deformationcapacity of reinforced specimen increased with the configuration parameter of hoopand the prestressing ratio increase. In the case of the prestressing ratio is more than acertain value, the axial deformation capacity of the specimen hardly growth with theprestressing ratio increasing.The simulation of the experiment was analysed by using finite element analysissoftware-ABAQUS. The test result indicated:(1) The numerical results of axialcompression bearing capacity and related curves show well agreement with theexperimental values;(2) With the increase of the configuration parameter of PSH, thefailure modes of specimens change from a certain middle section between plate jacketto a region of damage.According to experimental study and theoretical analysis, a formula based on theexisting constraint concrete constitutive model is suggested to calculate the compressbearing capacity of the retrofitted piers. The effecting factors of the bearing capacitysuch as stirrups, PSH and longitudinal bar were considered. The calculated results show well agreement with the test results.