Reserach On The Mechanical Performance Of Unbonded Post-tensioned Precast Walls

In the modern construction industry,prefabricated construction has been paid more and more attention because of its unique superiority.As a new assembly-type RC structure,at present,unbonded post-tensioned precast walls have been studied increasingly abroad,some work has been done in this area as well.But overall,it is still lack of systematic research.Compared with the general shear wall structure,unbonded post-tensioned precast walls can be undergone large lateral drift with little damage.The walls have good self-centering performance.They can undergo lager drift,but accumulate significantly smaller residual drift during an earthquake.The structure is studied by theoretical analysis firstly.The thesis introduces and compares the characteristics of two theoretical analysis methods.Then an example is calculated using the more appropriate method of the two methods and the load-displacement curve is obtained.Finite element analysis software ABAQUS is used to analyzed the above example under monotonic load.The numerical simulation results agree well with the theoretical results.The feasibility of numerical simulation is examined.According to the front conclusions,the paper carries out a series of FEA analysis of different parameters including the arrangements of prestressed reinforcing steels and the distribution steel bars,axial compression ratio and strength of concrete to get factors which influencing the structural behavior.A comparision is also made between two kinds of prestressed concret structures with bonded and unbonded tendons.Finally,the dissipation energy ability of unbonded post-tensioned precast walls are discussed.Against the deficiency in the performance of energy dissipation under earthquake,energy-dissipating bars are suggested to place at the bottom of the walls.Then the thesis analyzes and discusses the reasonable layout principle of energy-dissipating bars.