A hybrid tubular standing support for underground mines: Compressive behaviour

This paper presents the development of an innovative standing support for underground mines. The main feature of this standing support is its exterior container, a combination of polyvinyl chloride (PVC) with large rupture strain and fibre-reinforced polymer (FRP) with high strength-to-weight ratio. To demonstrate the advantages of this cementitious grout filled PVC-FRP tubular (PFT) standing support, a series of compression tests were conducted. Test variables included the strength of cementitious grout infill material and the thickness of FRP jacket. Compression tests were also conducted on cementitious grout-filled PVC tubular (PT) support and cementitious grout-filled FRP tubular (FT) support. These tests showed that PFT support presents a typical strain-hardening behaviour together with an outstanding axial deformation ability (>20% of the overall height of the support). In addition, the maximum compressive strength of PFT support is much higher than that of the corresponding PT support and FT support. Furthermore, using thicker FRP jacket or high strength cementitious grout material can enhance the load carrying capacity of PFT support. These comparative results indicated that the high performance of PFT support is mainly attributed to the combination of confining constituents (i.e. PVC and FRP) and infill material.