Mechanism analysis and design of full-length anchoring bolt in rectangular roadway

Abstract

Rectangular roadways are widely used in coal mine development. The traditional bolt design method is to analyze surrounding rock deformation by equating rectangular roadways to circular roadways. However, the surrounding rock deformation law of circular roadway is different from that of rectangular roadway, which leads to errors in support design. Based on the monitoring results of roof deformation of transport roadway of S12001 working face in Shenmu Ningtiaota Coal Mine, Shaanxi Province, the roof beam model was established, and the calculation formula of roof deformation of rectangular roadway was derived based on the elastic-plastic theory. The results show that the vertical displacement on the surface of the roadway roof is the largest, and the vertical displacement decreases gradually towards the inside of the rock mass and the two sides of the roadway. The shear stress of the bolt is bounded by the neutral point, and the shear stress at both ends is opposite. The maximum shear stress occurs at the orifice, and the axial tensile stress of the bolt is the maximum at the neutral point, with zero at both ends. By carrying on the support design to the roof of the transportation roadway in the S12001 working face, it is found that all the supporting parameters meet the production requirements, and the deformation of the roof surrounding rock calculated theoretically is compared with the field monitoring results, and the reliability of the model is verified.

Keywords

• rectangular roadway
• full length bolt design
• internal force distribution of bolt
• elastic-plastic analysis
• neutral point theory