近浅埋煤层双关键层工作面支架阻力确定

Determination of Support Resistance of Working Face with Double Key Stratums in Nearly Shallow Coal Seam

针对近浅埋煤层双关键层破断呈现大、小周期来压现象,本文以陕北榆神府矿区某矿井42111综采工作面为工程背景,采用理论分析和现场实测相结合的方法,研究了近浅埋煤层综采工作面顶板破断特征及矿压显现规律,现场矿压观测结果显示42111工作面顶板存在上、下两层关键层,双关键层破断后形成“双砌体梁”结构,其来压具有显著的大、小周期现象;通过建立顶板来压“支架围岩”相互作用力学模型,计算得到“双砌体梁”结构大周期来压时支架阻力不应小于10241.09 kN,现场所选的ZY12000/20/40D型掩护式液压支架额定支护阻力为12000 kN>10241.09 kN,满足设计要求.42111工作面支架阻力现场实测表明:支架阻力区间呈正态分布,均位于其额定阻力范围且富裕度较大,说明选择的液压支架型号、指标较为合理,支架对采场顶板的支撑作用较好,有效保障了工作面顶板安全.

In view of the phenonmenon of large and small of periodic weighting in the fracture of double key stratums in shallow coal seam,based on the research background of the 42111 fully mechanized coal mining face in Yushenfu mining area in northern Shaanxi Province,the theoretical analysis and the in-situ observation were adopted to study the ground pressure behavior and roof movement characteristics of the double key strata.The field pressure observation results show that there are upper and lower double key stratums above the roof of the 42111 working face.After the double key stratums broken,a“double masonry beam”structure formed,and the pressure had significant large and small periodic.Combined with the characteristics of roof breaking,the mechanical model of the interaction between the roof and the surrounding rock was established.It was calculated that the resistance of the support should not be less than 10241.09 kN while the“double masonry beam”structure was compressed in a large period by the established model.The rated support resistance of the ZY12000/20/40D type shielded hydraulic support selected on site meets the design requirements,it was 12000 kN(bigger than 10241.09 kN).The in-situ observation of the support resistance of the 42111 working face shows that the support resistance interval is normally distributed,all with in its rated resistance range and the abundance is relatively large,indicating that the selected hydraulic support model and indicators were reasonable,and the support had a better supporting effect on the stope roof,which can effectively ensure the safety of the working surface roof.