Abstract:
To investigate customized governance schemes for surrounding rock deformation in roadways under different geological and stress conditions, we take the immediate severe floor heave phenomenon in the return airway of Working Face I040205 in Hongliu Coal Mine, CHN Energy Ningxia Coal Industry, as an example (pressure relief measures were continuously implemented during the working face advancement, but with insignificant effects, and serious floor heave formed in adjacent roadways). The borehole water pressure fracturing technology was adopted to carry out roof pressure relief research. It is revealed that the mining-induced stress concentration in adjacent working faces and the roof cantilever beam effect are the main causes of floor heave. Field measurements show that the severity of floor heave exhibits certain periodic variations, with deformation lagging behind the stress peak and having creep characteristics. The water pressure fracturing parameters were optimized, a "borehole-ramp section" matching model was established, and dynamic spacing arrangement and high-pressure water pump staged fracturing were applied. The research shows that the optimized fracturing scheme can effectively reduce floor stress, decrease the frequency of floor heave, improve roadway stability, and reduce maintenance costs.