Research On Supporting Characteristics And Application Of Concrete Filled Steel Tube Support In Deep Soft Rock Roadway

After the coal mine entered deep mining,a large number of difficult-to-support roadways appeared,including deep soft rock roadways,extremely soft rock roadways,loose and broken surrounding rock roadways,and high-stress roadways.In recent years,relevant scholars have done a lot of support research on the problem of deep soft rock roadway,but the problem has not been fundamentally solved,and the deep soft rock roadway cannot be maintained for long-term stability.Pouring concrete-filled steel tube support is a kind of support technology invented for deep soft rock roadways.A large number of studies have shown that the pouring concrete-filled steel tube support can form an effective support technology with the existing bolting,shotcreting,grouting,etc.Composite support scheme.In view of this,this article takes the support of the main roadway in Yangcheng coal mine as the background,and conducts a detailed research on the support characteristics of the cast-in-place concrete-filled steel tube support and its engineering application in deep soft rock roadways.The main research results are as follows:(1)Analyze the support status of the-650 main roadway in Yangcheng Coal Mine when the cast-in-place steel tube concrete support is not used,and focus on the analysis of the support difficulties of-650 south wing roadway with many faults,weak surrounding rock,and multiple repairs.Proposed a composite support scheme based on concrete-filled steel tube brackets.(2)Through experiments,the properties of the concrete inside the steel tube and the load-bearing characteristics of the cast-in-place concrete-filled steel tube support were studied,and the failure process of the horseshoe-shaped and flat-elliptic support was revealed,and the failure mechanism of the concrete-filled steel tube support under load was obtained.Through the method of numerical simulation,the influence of the support spacing on the surrounding rock deformation is quantified,and it is determined that the support spacing should be 1m under normal conditions.(3)Preliminary selection of the support type for the Yangcheng Mine-650 horizontal roadway,and design the support structure through theoretical calculations to determine the final model,and obtain the key to the Yangcheng Mine-650 South Wing Track Main Roadway and the return air main roadway.Support parameters.(4)In the support design of the main roadway and return airway in the south wing of Yangcheng Coal Mine-650 roadway,two supporting schemes,namely the non-fault fracture zone support scheme and the fault fracture zone support scheme,were proposed and successfully applied.The long-term stability of the soft rock roadway in deep mines is realized,and the maximum deformation value of the support is only 140 mm.