（1. 深部岩土力学与地下工程国家重点实验室，北京 100003; 2. 中国矿业大学（北京） 力学与建筑工程学院，北京 100003;）
中图分类号：TD 322 文献标识码：A
Key Parameters of the Gob-side Entry Retaining Formed by Roof Cutting and Pressure Releasing in Deep Medium-thickness Coal Seam
(1. State key laboratory for Geomechanics & Deep Underground Engineering, Beijing 100003, China ; 2.School of Mechanics and civil Engineering, China University of Mining & Technology (Beijing), Beijing 100003, China;)
Abstract: In order to ensure the first successful application of gob side entry retaining technology by roof cutting and pressure releasing in deep medium-thickness coal seam, the key parameters were studied by theoretical analysis, field measurement and numerical simulation. The results show that: When the buried depth exceeds the first critical depth, the surrounding rock of the roadway will exhibit a nonlinear and large deformation mechanical phenomenon. It shows that the deformation of roadway surrounding rock is large and stable for a long time, and the gangue presents rheological characteristics. At the same time, pre-split blasting will cause disturbance damage to the original support and roof. On this basis, the hole was 600mm spacing with 8m depth and 15 ° angle, charge structure was 4+3+2+0. The constant resistance cable was arranged in two rows near the cutting line, and the length is 10m; The advanced supporting distance was 40m and the lagging temporary supporting distance was 240m. In addition, through the optimization of the original gangue retaining structure, a new type of retractable U steel retaining structure was designed. Finally, the research results are successfully applied at No. 21300 working face in Chengjiao coal mine. The deformation is controllable, and the effect is good.
Keywords: Deep mining; Medium-thickness coal seam; Roof cutting and pressure releasing; Gob side entry retaining; Key parameters;