Issue 73

Z. Xiong et alii, Fracture and Structural Integrity, 73 (2025) 267-284; DOI: 10.3221/IGF-ESIS.73.18

notable [2]. In the United States, at least 27 states have recognized the cost-effectiveness of jointless bridges [3], which provide improved seismic resistance and superior performance under extreme conditions due to their enhanced structural redundancy. Seismic fragility curves and evaluations for the hybrid concrete-steel frame were reported in [4]. H-shaped steel piles are widely used in IABs due to their flexibility, high strength, and ability to accommodate horizontal deformation. Arsoy et al. [5] demonstrated that H-shaped steel piles are the optimal choice for IABs. In terms of soil structure interactions of IABs under seismic action, parametric studies indicated that low friction and dilatancy angles in granular fill resulted in unfavorable settlement patterns [6]. Shaking table tests demonstrated that compressible inclusions between the abutment and backfill effectively reduce seismic accelerations transmitted to the bridge deck and mitigate settlements [7]. The girder-abutment joint is a critical component of composite girder integral bridges. In steel-concrete composite girders, shear connectors are essential for transmitting shear forces and preventing relative slip at the steel-concrete interface. This ensures effective composite action between the two materials. Kim et al. [8] investigated the bearing capacity of joints, demonstrating that installing welded nail connectors and stiffener connectors enhances joint stiffness, bearing capacity, and crack resistance. Conventional shear connectors, such as stud connectors and perfobond strip connectors, are widely employed in steel concrete composite girders. However, perfobond connectors encounter challenges related to rebar penetration. In contrast, composite dowels overcome these limitations by eliminating the need for specialized welding and delivering robust performance even with lower-strength materials [9], which stimulates this work using the composite dowels as connectors. With regarding to the fatigue performance of composite dowels, we [10-11] analyzed composite dowels crack propagation under flexural/pure shear, revealing the relationships between stress intensity factor and crack length. The European Design Manual for Integral Composite Girder Bridges [12] proposes a joint configuration as shown in Fig.1(a) wherein steel girders are directly placed on steel piles. This design eliminates batch casting requirements, transmits shear forces via weld studs, and transfers compressive forces to the bridge abutment through a bottom flange bearing plate. Ashiduka et al. [13] introduced an alternative joint design as shown in Fig.1(b), utilizing direct holes in the girder’s flange and web to accommodate perforated steel bars. Riches et al. [14] proposed a configuration as shown in Fig.1(c) incorporating a bottom flange end plate to disperse concentrated loads, with tensile forces transmitted by steel reinforcement. The Japan Road Research Laboratory [15] conducted experimental and numerical studies on steel-concrete composite girder joints as shown in Fig.1(d), analyzing component-level load distribution. Briseghella et al. [16]] developed a design as shown in Fig.1(e) experimentally validated for hysteretic behavior, employing headless weld studs to transfer vertical shear forces, while tensile and compressive forces are transmitted through deck reinforcement and a bearing plate. Despite their merits, these configurations face practical challenges, including stud welding complexities, rebar penetration issues, concrete casting dead zones, and welding fatigue. To address these limitations, this study proposes a novel integral bridge abutment incorporating composite dowels girders as demonstrated in Fig 1(f), which is elaborated in the following sections.

Simplicity of structure

Rebar

Stud

Construction efficiency

Composite dowels

(a)[12]

(c)[14]

(b)[13]

(d)[15]

(f)

(e)[16]

Figure 1: Structural details of the joints.

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