钢-预制 HSC 组合梁群钉连接件受剪性能研究

To study the failure mechanism of grouped studs in steel-precast high-strength concrete (HSC) composite beams, eight push-out specimens were employed to study the influences of stud diameter, infilling concrete strength, and casting method of the shear pocket on the shear performance. The typical failure mode of specimens is dominated by stud fracture and concrete crushing near the stud root. Due to the welding defect of individual studs, the shear failure occurs in the weld zone. The shear behavior of grouped studs is mainly affected by the stud diameter and infilling concrete strength of the shear pocket. The precast method of the shear pocket has no reduction in the shear bearing capacity compared to the cast-in-place method. Parametric studies were conducted using ABAQUS to explore the factors on the shear capacity of grouped studs. The shear capacity of grouped studs almost increases by 104% as the stud diameter increases from 19 mm to 30 mm. Increasing the tensile strength of head studs from 400 MPa to 550 MPa, the shear capacity of grouped studs improves by 27% . However, the stud height and concrete strength have little effect on the shear capacity. Parametric analysis results were compared with the predicted results calculated by the formulas recommended in EN 1994-1-1, AISC 360-05, and GB 50017―2017, and it is found that the shear capacities of grouped studs are conservatively predicted. These design provisions conservatively predict the shear capacity of grouped studs. The proposed formula for predicting the shear capacity on the seam of grouped studs in steel-precast HSC composite beams agrees well with the test results, which provides reference for the application of grouped studs in steel-precast HSC composite beams.