Bridges, Tunnels and other Transportation Structures
Full Session with Abstracts
Bridge construction can be expedited substantially by the use of prefabricated elements and systems that are connected in place. This approach is known as accelerated bridge construction (ABC). Although ABC methods have been widely used in bridge superstructures for some time, the requirement to maintain integrity of the structure on the connections subjected to moderate and severe earthquakes has restrained ABC deployment when earthquake forces are significant. Component-level tests have been conducted to study the seismic performance of many ABC connections; however, they these connections not been studied when integrated into a bridge system. A 0.35-scale, two-span, concrete bridge model with six ABC connection types was designed, constructed and tested under bi-directional ground motions simulated on shake tables at the Earthquake Engineering Laboratory of the University of Nevada, Reno. The connections integrated into the system consisted of: (1) deck panel-to-girder connection using shear connectors embedded in grout-filled deck pockets and ultra-high performance concrete (UHPC) shear keys, (2) deck panel-to-deck panel connection using UHPC shear keys with spliced reinforcement, (3) column-to-footing connection employing pipe-pin connections, (4) column-to-cap beam connection with grouted duct connections, (5) steel girder-to-cap beam connection for positive moment demands using dowel bars, and (6) deck connection above pier achieved by lap-spliced straight bars embedded in a UHPC layer. Nine bi-axial tests with earthquake amplitudes ranging from 20% to 225% of the design level earthquake (DE) were conducted. The main test results obtained for the 100% and 225% design level earthquakes are presented in this paper. The bridge performance and all of its connections types were satisfactory. This was concluded based on the fact that capacity-protected connections remained damage free, while column plastic hinges dissipated the earthquake energy through substantial nonlinear action.