Mechanism and experiment of self-stress grouting reinforcement for fractured rock mass of underground engineering

•An new self-stress grouting reinforcement method for fractured rock mass was proposed.•The reinforcement mechanism of the self-stress grouting for fractured rock mass were investigated by theoretical analysis.•The reinforcement effects of self-stress grouting and ordinary grouting on fractured sandstones were compared through physical experiments.•The self-stress grouting reinforcement method was used to control the surrounding rock of the substation roadway of Pingmei No.10 Mine.