R&D and Application of Curved D-Shape Concrete-Filled Steel Tube Support in Roadway Support

The concrete-filled steel tube support (CFSTS) has been proposed as a new passive support form for controlling the stability of surrounding rock in underground structures, especially for the case of high ground stress. In order to improve the application of the CFSTS in the high stress soft rock roadway, this paper made a comparison between the commonly used U36 steel support and the CFSTS, and the advantages of the CFSTS were determined by theoretical calculation; By using the numerical simulation to optimize the ordinary CFSTS, the D-shape concrete-filled steel tube support (D-CFSTS) was designed, then the compression analysis was carried out; Based on the engineering background of the Pingdingshan ten mines, the D-CFSTS was applied to the support of the soft rock roadway. The results show: The supporting force of the CFSTS is far greater than that of the U-steel support. Under the same load, the deformation of the D-CFSTS is smaller than that of the circular CFSTS, especially D-CFSTS is more suitable for the deep roadway where the horizontal stress is greater than the vertical stress. In the Pingdingshan ten mines, the U-steel support was damaged prematurely, but the D-CFSTS had good effect and could maintain long-term stability.