STRUCTURAL DETAILS TO ACCOMMODATE SEISMIC MOVEMENTS OF HIGHWAY BRIDGES AND RETAINING WALLS

This report describes datailing for structural movements for bridges and retaining walls for new construction in the western and eastern U.S. Bridge retaining devices such as longitudinal joint restrainers, vertical motion restrainers, shear keys, and integral superstructure ti substructure connections are described. Many of these details are traditional methods that have been used in new bridge construction to limit displacements for seismic events. Sacrificial elements, which include abutments and joints, are also described. These types of details have been used in new seismic designs within the last two decades. An introduction to passive energy dissipating devices and isolation bearing systems is provided as well as recommendations for detailing. Both devices are relatively new as a method to limit displacements in bridges within the U.S. In fact, isolation bearing systems have just emerged for new bridge construction within the last few years. The minimun support length requirements are reviewed. The current practice for designing earth retaining systems for seismic displacements is reviewed and some recommendations for detailing are provided. The effects of substructure flexibility on the isolation system is documented. An example study and comparison is given to illustrate the impact of substructure flexibility.(AU)