Transverse - longitudinal flexural performance of steel tube slab composite slabs: A novel pipe roofing system for metro station

摘要

? 2023 Elsevier LtdThe steel tube slab (STS) structure is a novel pipe-roofing structure, which is used as the support system for underground stations. The pipe-roofing structure is generally assumed as a beam structure in previous research, which is questionable, because the transverse and longitudinal coupling force mechanism is ignored. Hence, this work aims to investigate the flexural performance of STS composite slab through experimental test and establish a design approach for STS structure. Firstly, based on six tests on flexural performance of the STS composite slabs, the crack development, failure mode and deformation mechanism were analysed. Each of the specimens demonstrated a high bearing capacity that exceeded 3000 kN. Furthermore, the specimens exhibited ductility during testing with the failure occurring at either the flange or concrete between the steel tubes. Subsequently, the effect of the length–width ratio and spacing between the tubes on the flexural performance of the tested specimens were examined. The result indicated that the length–width ratio and the spacing between the tubes significantly affected the flexural stiffness, but had limited effects on the flexural capacity. Finally, a design approach was proposed to estimate the elastic capacity of STS composite slabs, and finite element (FE) models validated by the test results were established to increase the general applicability of the theoretical model. The predicted outcomes demonstrated a satisfactory correlation with both the test and FE results, with an average relative error of 9.8%. The study's findings are anticipated to serve as a dependable resource for the design and application of STS structures.