深部急倾斜煤层偏压巷道支护参数优化研究

Study of parameter optimization of support in deep steeply inclined roadway with unsymmetrical loadings

深部急倾斜煤层由于受特殊的地质结构和高地应力影响,煤层巷道开挖后易出现地层错动、垮塌的特点,施工中冒顶、底臌现象异常突出,巷道支护极其困难。通过对新集三矿-700 m煤探巷道进行现场勘查与试验,针对该急倾斜软岩巷道变形非对称性,底臌严重、地层错动的破坏特点,提出了可缩性U型钢全断面封闭支护和非对称性预应力锚杆(索)支护的全新支护方案,通过大型有限元软件ABAQUS建立数值分析模型,与原支护方案进行了对比分析。研究表明,采用改进支护方案巷道底臌位移量减小了66%,最大拉应力从0.58 MPa减小到0.38 MPa,塑性区较原方案更小,支护结构受力更加均匀。其结果可为同类地质条件的巷道支护设计提供一定参考。

Due to the effects of spectacular geological formations and high in-situ stress, the stratigraphic heave after excavation, roof collapse and floor heave in the coal seam roadway in deep steeply inclined soft rock masses are easy to appear, resulting in extremely difficulty in supporting. Through field exploration and tests of roadway in Xinji Coal Mine No.3-700 m, this paper proposes a new support scheme by applying steel arch of shoring and unsymmetrical prestressed anchor reinforcement in roadway supporting according to the asymmetric deformation, obvious floor heave and the stratigraphic heave deformation. A numerical model is established by finite element software ABAQUS and is compared with the original support scheme. The results show that the displacement of floor heave decreases by 66%; the largest tensile stress reduces from 0.58 MPa to 0.38 MPa, the plastic zone distribution is much smaller than the original scheme; and stress distribution of supporting structure is more uniform by using the improved support scheme. The study can provide useful references to some similar roadways in deep steeply inclined soft rock mass.