Stability analysis on bearing structure in the surrounding rock between staggered roadways

To overcome the common problems of surrounding rock stability and supporting in staggered roadways,the stability discriminant equation on the surrounding rock between staggered roadways was established by the limit equi- librium analysis and the elastic-plastic mechanics. Also,the main influencing factors on the surrounding rock stability in staggered roadways were discussed,and the industrial experiment was conducted. The result shows that the sur- rounding rock body between staggered roadways is affected by the superposition of the horizontal stress concentration. The failure of the surrounding rock between staggered roadways extends from the upper and lower surfaces of surround- ing rock body to the deep rock strata,coupled with the finite size of the surrounding rock between staggered roadways. The fracture coalescence of the surrounding rock between staggered roadways could lead to a potential instability of the staggered roadways. The small distance between staggered roadways and the almost parallel staggered-roadways ar- rangement can aggravate the failure of roadway surrounding rock and induce the fracture coalescence of the surround- ing rock between staggered roadways. The reasonable section size and supporting strength of roadway could effectivelycontrol and maintain the stability of staggered roadways. After adopting the combined support scheme of staggered roadways in the field,the sections of staggered roadways are intact and have no obvious deformation,and the maximum deformation of surrounding rock next to the lower staggered roadway is less than 100 mm,and the supporting effect on staggered roadways is obvious.