Performance of ductile highway bridge piers subjected to bi-directional earthquake attack
Circular reinforced concrete highway bridge piers, designed in accordance with the requirements of Caltrans, New Zealand and Japanese specifications, are experimentally investigated to assess their seismic performance. Pseudodynamic tests are performed on 30% scaled models of the prototype bridge piers. Each specimen is subjected to a sequence of three different earthquake ground motions scaled appropriately to represent: (i) the Design Basis Earthquake (DBE) with a 90 percent confidence; (ii) the Maximum Considered Event (MCE) with a 50 percent confidence; and (iii) the MCE with a 90 percent confidence. Test results show that when bridge piers are designed to the specifications of the three countries, satisfactory performance with only slight to moderate damage can be expected for DBE. For the MCE, severe damage without collapse is likely for the Caltrans and Japanese piers. However, the NZ pier may not be able to survive MCE motions with sufficient confidence to ensure the preservation of life-safety.