Grouted Splice Sleeve Connection Alternatives for Precast Reinforced Concrete Bridge Piers in Moderate-to-High Seismic Regions

Abstract

Connections between precast concrete bridge elements of the substructure and superstructure are some of the most critical components in bridges constructed using accelerated bridge construction. Researchers are in the process of investigating the suitability of various connection configurations in moderate-to-high seismic regions. These connections, not only have to resist high levels of earthquake-induced deformations and stresses, but also must expedite the overall construction delivery time. Load capacity, ductility levels, and repairability are three significant acceptance criteria for any connection considered in earthquake-prone regions. A research program was developed at University of Utah to study the seismic performance of four half-scale bridge components connected by means of Grouted Splice Sleeves (GSS). The specimens were designed so that flexure would dominate the response. Cyclic quasi-static loading was applied to two pier-to-footing and two pier-to-cap beam connections. The pier-to-footing connections incorporated one splice sleeve type with both bars grouted at both ends (GGSS); the pier-to-cap beam connections used one bar fastened to one end and the other bar grouted in the opposite end (FGSS). Splice sleeves were located in the column ends for each connection category in the first phase of the research, i.e. GGSS-1 and FGSS-1. In the second phase, the splice sleeves were located in the top of the footing (GGSS-2) and the top of the cap beam (FGSS-2), in order to investigate the effect of the splice sleeve location in the overall response of the test specimens under seismic loading. Results of the four tests are presented including failure modes and load-displacement response, displacement capacity, dissipated energy, equivalent viscous damping ratio, and strength and stiffness degradation. Moreover, the distribution of strain along the main bars, together with the rotation capacity of each test specimen is presented. The performance of the four specimens is compared in terms of strength, ductility, and energy dissipation capacity to highlight the properties of each connection type. An improvement of displacement ductility of 3% and 20% was observed in the pier-to-footing and pier-to-cap beam connections, respectively, when sleeves were placed in the footing and the cap beam. The overall response of the test specimens was found to be satisfactory and the connections are viable.