大倾角近距离煤层开采覆岩运移及顶板破坏特征

(1.西安科技大学 西部矿井开采及灾害防治教育部重点实验室,陕西 西安 710054; 2.西安科技大学 能源学院,陕西 西安 710054; 3.西安科技大学 理学院,陕西 西安 710054; 4.陕西延长石油巴拉素煤业有限公司,陕西 榆林 719000)

大倾角煤层; 近距离煤层; 覆岩运移规律; 顶板破坏特征

Overburden movement and roof failure characteristics in steeply dipping and close distance coal seam mining
WU Yong-ping1,2,HUANGFU Jing-yu1,2 ,LUO Sheng-hu1,3,WU Yong-qiang4,LIU Bao-heng1,2,LIU Wang-hai1,2

(1.Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi'an University of Science and Technology,Xi'an 710054,China; 2.College of Energy Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 3.College of Sciences,Xi'an University of Science and Technology,Xi'an 710054,China;4.Shaanxi Yanchang Petroleum Balasu Coal Industry Co.,Ltd.,Yulin 719000,China

steeply dipping seam; close distance coal seam; overburden movement law; roof failure characteristics

备注

大倾角近距离煤层采场的矿压显现规律较大倾角单一煤层长壁采场更为复杂,需进行深入的研究。以2130煤矿4#煤和5#煤近距离大倾角煤层开采为背景,采用物理相似材料模拟实验、数值计算、理论分析和现场试验相结合的研究方法,系统研究了大倾角近距离煤层采场的覆岩运移及顶板破坏特征。结果 表明,大倾角近距离煤层的连续开采,影响采场的覆岩垮落规律、围岩应力分布、顶底板变形破坏特征; 近距离煤层两工作面不同的位置关系导致下煤层工作面顶板形成不同的力学结构、发生不同的变形破坏及位移,影响下层煤开采的矿压显现; 25221工作面的基本顶岩梁首先于上端处发生破断,并在之后的运移中于中部再次发生破断,影响了工作面支架载荷与稳定性,使工作面支架呈现出倾斜中部受载较大、下部次之、上部最小和中下部支架受载稳定、中上部受载多变的非对称特征。研究结果可为大倾角近距离煤层开采提供理论依据,并为2130煤矿的后续开采提供参考。

The strata behavior regularity in steeply dipping and close distance coal seam is more complicated than that in single long wall coal seam with steeply dipping,which needs to be studied in depth.Based on the geological conditions and characteristics of strata behaviors at No.5 coal seam and No.4 coal seam in 2130 Coal Mine,the overburden movement and roof failure characteristics of the stope with steeply dipping and close distance are investigated by theoretical analysis,numerical simulation,physical analogue material simulation,and field test.The results show that continuous mining of steeply dipping and close distance coal seam will affect the overlying strata migration law,stresses of surrounding rock,the deformation and breakage law of upper and lower floor.And the different positions,between the two working faces lead to different mechanical structure,different deformation,failure and displacement of the roof of the lower coal seam working face,which affects the rock pressure appearance of the lower coal seam mining.The basic roof rock beam of 25221 working face first broke at the upper end,and then did again in the middle during the later migration,which affected the support load and the stability of working face support.Therefore,the support presents asymmetric characteristics of large load in the middle of inclination,followed by the lower part,minimum load in the upper part and stable load in the middle and lower part,and variable load in the middle and upper part.The research results can provide an important theoretical basis for the mining of steeply dipping and close distance coal seam,a reference for the follow-up mining of 2130 coal mine.