Abstract:
A new type of anchor cable box beam high-strength support system (RFPAA system) has been developed to address the characteristics of low roof strength, easy deformation, and large crushing range of roadway with complex conditions. The ultimate bearing capacity of this support system is 1.5 times that of channel steel beam under unit steel quantity, and it can achieve 50 mm yielding deformation, with high bearing performance, quantitative yielding pressure and good surface protection ability. The influence mechanism of the load-bearing performance of the anchor cable box beam support system was studied through theoretical analysis and numerical simulation. The results show that the height of the web plate of the box support beam has the most significant impact on the load-bearing performance, while the width of the upper and lower flanges has a lower impact, and the spacing between the web plates has no effect. Moreover, the design parameters of anchor cable box beam were optimized by multi-variable comprehensive evaluation method, and the optimal support design scheme was selected by combining with the comprehensive evaluation index comparison. On this basis, the optimal support design parameters of anchor cable box beam were designed by taking Dongtan Coal Mine as the engineering background. The maximum settlement of roadway roof in the field test section was 22 cm, which verified the effectiveness of the anchor cable box beam support system.