Abstract:

Mechanical property experiment is designed to compare the performance of straightwall semicirclearch concretefilled steel tube support and that of Ushaped steel support, so as to solve the instability problem of the support for roadways with conventional straightwall semicirclearch crosssection. In the experiment, the load bearing capacity, displacement and strain of the concretefilled steel tube support are measured and analyzed, and the influence of the roasted bend on the antitensioning property of the raw material of the steel tubes, as well as the rationality of the mixing ratio of the C60 concrete, are analyzed. The experiment shows that the concretefilled steel tube support has outstanding loadbearing advantages. Guided by the experiment results, straightwall semicirclearch concretefilled steel tube support is designed and applied for the 1100 horizontal dynamic pressure roadway of Huafeng coal mine and the 450level new east wing high stress roadway of Dashucun coal mine. The practice shows that the concretefilled steel tube support has good supporting effect and is superior to the Ushaped steel support with the same profile. It is also found that the foot corners of the closed straightwall semicirclearch support are weak points and need to be improved and strengthened.

Key words: concretefilled steel tube support, straightwall semicirclearch crosssection, mechanical property experiment, roadway support