Design Research and Application of D-shape Expansive Concrete-filled Steel Tube Supports in Roadway Support

Abstract

In order to perfect the application of concrete-filled steel tube support (CFSTS) in roadway support, aiming at the shortcomings of the existing common CFSTS, this paper put forward the D-shape expansive concrete-filled steel tube support (D-ECFSTS). Firstly, this article uses the numerical simulation to carry on the optimization of circular steel tube, designs the D-shape steel tube, and carries on the comparative analysis of D-shape concrete-filled steel tube support (D-CFSTS) and circular concrete-filled steel tube support (CFSTS). Then, the scheme of expansive concrete is put forward, and the ratio of expansive concrete is tested by the test method. Finally, the D-ECFSTS was made by D-CFSTS and expansive concrete, then used in roadway support. The results show: The deformation of D-CFSTS is much smaller than that of circular CFSTS under the same load; The best ratio of expansive concrete includes that the ratio of cement, sand, gravel is 1:1.31:2.65, water cement ratio is 0.41, expansion agent ratio is 11% and water-reducing agent ratio is 0.5%; In the support of Pingdingshan coal mine roadway, the supporting effect of D-ECFSTS is much better than that of U36 support. So, D-ECFSTS is a good roadway support method.