Research on the occurrence mechanism of coal burst near graben mining based on cusp catastrophe theory

Purpose From the perspective of composite structure, this paper takes the working face graben mining as the research background, and analyzes the characteristics of overlying strata sliding instability along the fault. Design/methodology/approach The Weibull distribution function was adopted to describe the constitutive relationship of the overlying strata. Based on the principle of total potential energy, the cusp catastrophe model was established, and the mechanical criterion of the overlying strata instability was derived. The roof subsidence monitoring data and the cusp catastrophe model were effectively integrated, yielding a roof stability criterion. Taking the 3,307 working face of Yiqiao coal mine as an example, the monitoring data before the obvious instability symptom was selected for verification. Findings The mechanism of rock burst in near-graben mining was revealed, and the main influencing factors of rock burst instability were analyzed. Based on the effective fusion of the monitoring data of ground settlement and cusp catastrophe model, the prediction model of tunnel surrounding rock stability was established, and the discriminant of surrounding rock stability was derived. Taking the 3,307 working face of Yiqiao coal mine as an example, the monitoring data before the obvious instability symptom was selected for verification. The results show that the roof instability is related to the strain softening degree and stiffness ratio of the overlying strata. The discriminant results of the instability mechanical criterion and stability discriminant of roof instability are consistent with the actual situation on site. Originality/value Based on the particularity of the graben structure, as well as the occurrence and instability characteristics of the overlying rock, the Weibull distribution function was adopted to describe the constitutive relationship of the overlying strata above the working face. Based on the principle of total potential energy, the cusp catastrophe model of surrounding rock instability was established, and the mechanical criterion of surrounding rock instability was derived. The mechanism of rock burst in near-graben mining was revealed, and the main influencing factors of rock burst instability were analyzed. Based on the effective fusion of the monitoring data of ground settlement and the cusp catastrophe model, the prediction model of tunnel surrounding rock stability was established, and the discriminant of surrounding rock stability was derived.