Issue 73

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

Figure 16: Plastic strain contour of steel girder. Fig. 16 presents the plastic strain contours of steel girders for ex = 200 mm and ex = 600 mm when the joint reaches its ultimate bearing capacity, highlighting the failure modes. As ex increases, the plastic region at the interface between the embedded steel girder section and the extended section expands from the web to the bottom plate, creating a weakened section. Additionally, the tooth joints yield, and local crushing of concrete under the steel girder occurs once the weakened section reaches full plasticity. According to the failure patterns of the concrete component shown in Fig. 17, tensile cracks initially develop at the top of the rear abutment due to its high stiffness and the rotation of the extended steel girder section. As loading continues, these cracks propagate, particularly in the concrete surrounding the composite dowels, caused by the rotation of the steel girder and concrete compression between the dowels. These cracks gradually extend toward the deck. With further loading, tensile stresses induce cracking in the deck, which spreads at an inclined angle toward the junction of the main girder and steel piles. The cracks on the abutment are shown in Fig. 18.

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Figure 17: Failure mode.

Figure 18: Crack distribution.

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