Seismic Design of Circular Concrete Filled Tube Bridge Pier Connections for Accelerated Bridge Construction

Abstract

Concrete filled tubes (CFTs) consist of a steel tube with concrete infill. CFT columns offer an efficient and economical alternative to conventional reinforced concrete bridge columns, in that CFT columns can offer larger strength and stiffness and facilitate rapid construction. This report is the second in a series. The prior report focused on engineering methods for CFT components and seismically resilient CFT column-to-foundation connections. This report focuses on CFT column-to-cap beam connections. In contrast to column-to-footing connections the cap-beam connection has unique design considerations including inverted construction and geometric limitations. The research project uses experimental methods to develop design procedures for various CFT column-to-cap beam connections. Three connections were studied,namely: (1) an embedded flange connection in which the CFT is embedded in the cap beam, (2) a welded dowel connection in which a series of headed dowels is welded inside the tube and embedded into the cap beam (both fully bonded and partially deboned conditions were studied), and (3) a dowel connection in which an independent cage of headed dowels and transverse reinforcing is developed into the CFT and embedded into the cap beam. All specimens were constructed using precast cap-beam components to demonstrate the feasibility of using these connections for accelerated bridge construction (ABC). The experimental program included specimens that simulated either the transverse or longitudinal direction of the bridge. Results showed that the three connection types provide excellent ductility under reversed-cyclic loading while all superstructure elements remained essentially elastic. The report provides design expressions, a design example and proposed codified language to facilitate immediate implementation of the research results into practice.

Behavior study of precast pier of bridge for its various shape

“…Bar fracture revealed that the connector's tensile capacity was larger than the capacity of the reinforcing bar. Finally, they concluded that the diameter of the sleeve and the length of the bar would be the sole factors affecting how well the grouted splice sleeve connection performs [25] [26].…”

Precast bridge piers: Construction techniques, structural systems, and seismic response

“…This resulted in different types of column-footing connections, as shown in Figure 6. Non-prestressed connections include, pocket connections, as shown in Figure 6(c) (Stephens et al, 2014), socket connection, as shown in Figure 6(b) (Abdelkarim et al, 2017; Abdulazeez and ElGawady, 2017; Haraldsson et al, 2013; Shen, et al, 2022), grouted rebar duct connection, as shown in Figure 6(d) (Belleri and Riva 2012; Tazarv and Saiidi, 2016; Tong et al, 2022; Zhanghua et al, 2020), splice sleeve bar coupler connection, as shown in Figure 6(a) (Ameli and Pantelides, 2016; Li et al, 2018; Qu et al, 2018; Wang et al, 2018; Zhanghua et al, 2020; Yu et al, 2022; Zhanghua et al, 2020), and emerging type connections (Kim et al, 2015), as shown in Figure 6(e).…”

“…Recently, hybrid rocking-bar-pocket connections have been presented to connect pre-tensioned precast column to the cap beam as shown in Figure 7(d) Davis et al (2017) and Mantawy et al (2016). The second type of column to cap-beam connections used non-prestressed connections including pocket connections, as shown in Figure 8(a) Mehrsoroush and Saiidi (2014), and Stephens et al (2014), grouted ducts connections, as shown in Figure 8(e) Wolf and Friedman (1994), Matsumoto et al (2002), Mandawe et al, (2002), and Qu et al (2018), bar couplers connections, as shown in Figure 8(d) Qu et al (2018), emerging connections, as shown in Figure 8(f) Kim et al (2015), and bar splice using ultrahigh-performance concrete (see Figure 8(g)) Shafieifar et al (2020). Zaghi et al (2010) proposed a pipe-pin two-way hinge connection to connect the column with the cap beam (see Figure 8(c)).…”

“…In this technique, the bridge column is prefabricated in a factory and then assembled on-site with the footing and the cap-beam through a seismic connection. Many seismic connections between columns and cap-beams and between column and footing have been studied (i.e., pocket connection (Stephens et al, 2014), socket connection (Abdelkarim et al, 2017; Han, et al, 2021; Jin, et al, 2022; Yang & Okumus, 2021), bar coupler connection (Qu et al, 2021; Wang et al, 2018), grouted duct connection (Tazarv and Saiidi, 2016; Zhanghua et al, 2020; Zhanghua et al, 2021), ultra-high-performance concrete UHPC connection (Geng et al, 2022; Xu et al, 2021, etc.). Under lateral loads, the performance of these piers is comparable to that of traditional monolithic RC piers in terms of high energy dissipation capacity, large residual displacement, and serious damage in the plastic hinge region that is difficult to repair or irreparable (Li et al, 2018; Wang et al, 2018).…”

Cyclic Test of Concrete Bridge Column Utilizing Ultra-High Performance Concrete Shell

“…Even though these elements could offer efficient and economical alternatives in construction of bridge columns, their field implementation is limited because of unreliable connections, especially in seismic zones. CFST is also susceptible to rapid corrosion because of the use of steel tubes in aggressive environments ( 10 , 11 ). The FRP tubes have the advantage of being lightweight, corrosion-resistant and high strength, but the weak interface between the FRP tube and the conventional concrete shows signs of concrete shrinkage and inadequate concrete compaction, reducing its load-bearing capacity ( 12 , 13 ).…”