Analysis of roof deformation factors in coal roadway heading face based on response surface method

The roof stability of heading face is affected by many factors and the driving speed is slow due to the unreasonable value of unsupported distance. In order to solve the problem, this paper studies the three-way stress and deformation law of coal roadway heading face roof based on response surface method through numerical simulation, and analyzes the key factors affecting the roof deformation of heading face and their interaction relationship. The results show that the stress adjustment and deformation begin to appear at about one time of hole diameter in front of the heading face, and the stress adjustment is basically stable at one time of hole diameter behind the heading face. The roof deformation is basically stable at about two times of hole diameter behind the heading face. Roof deformation is negatively correlated with roof mudstone cohesion and support strength, but positively correlated with roof mudstone thickness and unsupported distance. Multi-factor interaction analysis by response surface method is an effective means to determine the reasonable unsupported distance of heading face under specific conditions. According to the geological conditions of 33082 roadway in Zhaozhuang Coal Mine, the reasonable unsupported distance is set as 2 m, and the support strength is increased to 0.25 MPa. The application shows that the roadway stability is guaranteed, and the roadway driving speed is also increased from the original 180 m/month to 350 m/month, which significantly improves the driving speed.