Application research on composite support technology of concrete-filled steel tube support in high stress and large deformation soft rock roadway: A case study

Aiming at the surrounding rock control problem of high stress and large deformation soft rock roadway. This article takes the 141712 coal haulage uphill as the engineering background in Guizhou Panjiang Mining Area. Through field investigation, theoretical calculation, numerical simulation, and industrial tests, the deformation characteristics of surrounding rock and the mechanism of roadway instability and failure were revealed. And a composite support scheme of "bolt (cable) + grouting + concrete-filled steel tube support" was designed. A strengthening support mechanical model of "Three-arch" based on the concrete-filled steel tube support technology was established. The ultimate bearing capacity of the design scheme above is calculated, which meets the support load and can maintain the stability of the soft rock roadway. Through numerical simulation analysis, the distribution characteristics of the plastic zone, stress field and displacement field of the design scheme are obtained, and the rationality of the scheme is verified. The industrial tests were successfully applied and the field monitoring results show that the deformation is within the controllable range, effectively controls the deformation of the 141712 roadway. The research results can provide a reference case for the control of soft rock roadway with high stress and large deformation under similar complex conditions.