深部中厚煤层切顶留巷关键技术参数研究

（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;）

摘要：为保证切顶卸压沿空留巷技术在深部中厚煤层的首次应用取得成功，结合理论分析、数值模拟及现场实测等方法对深部高应力复合破碎顶板切顶留巷关键参数展开研究，研究结果表明：当埋深超过第一临界深度后，巷道围岩将呈现出非线性大变形的力学现象，表现在巷道围岩变形量大且稳定时间长，冒落矸石呈现流变特征，同时，预裂爆破会对原有支护和顶板造成扰动破坏。在此基础上确定了切缝钻孔间距为600mm，深度8m，角度15°，切缝孔装药结构为4+3+2+0；恒阻锚索靠近切缝线分两列布置，长10m；超前支护距离40m，滞后临时支护距离240m。此外通过对原有挡矸结构进行优化，设计了一种新型可缩U型钢挡矸结构。最终研究成果在城郊煤矿21300工作面成功实施，总体变形可控，成巷效果好。

关键词：深部开采；中厚煤层；切顶卸压；沿空留巷；关键参数；

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 Ming

(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;