State-of-the-Art Review of Seismic-Resistant Precast Bridge Columns
Qi Zhang, M. Shahria Alam
Abstract
There has been significant research effort on seismic-resistant precast bridge columns; however, the research results have not been transferred into the industry to achieve their full potential. This review provides a summary of the research development and challenges for both researchers and practitioners. Applications of new materials in rocking columns are briefly discussed. Three types of rocking columns are reviewed: emulative column, simple rocking column, and hybrid rocking column. It is believed that hybrid rocking columns are the most prominent option when compared with the other two types. Its design recommendations with respect to energy dissipating bars, axial load ratios, and tendons are concluded based on the review data. The amount of energy dissipating bars should be such that its contribution to total bending moment capacity is less than 50%. In most of the cases, the energy-dissipating bar ratios are less than 1.7% of the column sectional area. Upon a careful review of existing experimental test results, an effective stiffness ratio of 20%–40% can be suggested for design. To further facilitate engineering designs, regression equations predicting residual drift to maximum drift ratios, as well as viscous damping ratios are proposed.