A Study On The Bearing Capacity Of Axial Compression Of Octagon-shaped Concrete-filled Double Skin Steel Tubular With Pvc-u As Its Inner Tube

The past 10-odd years has witnessed the development of the concrete-filled double skin Steel tubular (CFDSST). As a new kind of structure, it enjoys a series of advantages such as high flexural rigidity, high bearing capacity, good plasticity and toughness and convenient construction. At present, researches with regard to the behavior of Octagon-Shaped Concrete-Filled Double Skin Steel Tubular (OSCFDSST) under axial compression and under eccentric compression are available at home. The focus of this study—OSCFDSST with PVC-U as its inner tube is a new type of structure that bears the resemblance to OSCFDSST with steel tube as its inner tube. This structure features PVC-U as its inner tube and octagon-shaped steel as its outer tube with concrete sandwiched in between. In contrast with OSCFDSST with steel tube as its inner section, it is light in dead weight and low in price. Apart from that, PVC-U inner tube can also be utilized as down pipe. In the first place, relevant studies concerning CFDSST, OSCFDSST, and plastic tube material's application in the composite structure are examined and an argument for the mechanical rationality and the engineering practicability of the structure of OSCFDSST with PVC-U as its inner tube is provided.The second part is dedicated to a detailed report on the design and production, geometric dimension and material-selection of the specimens employed in the axial compression experiment. The paper then moves onto an elaborate description of the preparatory work, and the entire process of upload and destruction of the specimens. Through an analysis of the experimental results, a summary of the possible destruction configuration plus a contrastive study on the uploading process and bearing capacity are presented.In addition, this paper also attempts to conduct a computer definite element simulation analysis, which led to a summary of the impact of the specimens'diameter/thickness ratio and hollow ratio upon their bearing capacity.In this paper, a systematic study on the destruction configuration of the OSCFDSST with PVC-U as its inner tube and its influential factors is performed. Moreover, a contrastive analysis between the former and CFDSST further confirms its engineering application values. It is hoped that this new structure will be widely popularized and applied in actual construction in the future.