Effects of the Hinge Restrainers on the Response of the Aptos Creek Bridge during the 1989 Loma Prieta Earthquake

This paper presents the results of a study for the effects of the cable restrainers on the nonlinear seismic response of the Aptos Creek Bridge during the 1989 Loma Prieta earthquake. The earthquake analyses focus on the relative displacements of the hinge, the absolute displacements of the bridge, the restrainer force levels, the shear key and the shear pipe forces, the hinge impact, and the abutment and pile forces in both the longitudinal and the transverse directions. At the estimated earthquake excitation levels at the bridge site, it was found that the restrainers did not play a major role on the overall structural response. However, at higher acceleration levels they contributed significantly to the reduction of displacement and force responses.