Seismic Performance of Precast Unbonded Prestressed Concrete Columns

摘要

Shake table testing and an analytical study were, conducted to investigate the seismic performance of unbonded prestressed hollow concrete columns constructed with precast segments. A prototype column was designed based on the current bridge specifications by AASHTO. A one-fourth-scale model column was constructed by match casting. Shake table testing that consisted of 15 runs based on the 1995 Hyogo-Ken Nanbu (Kobe) Earthquake was conducted. The specimen performed very well with essentially no residual displacement and only limited concrete spatting at the base. A parametric study was conducted using a nonlinear two-dimensioned finite element pushover analysis. An equation to estimate the strain in the prestressing strands was proposed. A simplified method to calculate the load-displacement relationship showed good correlation with the pushover analysis results. Unbonded prestress columns can be designed to provide excellent drift capacity with limited permanent displacements.