综放采场围岩复合结构力学模型及其控制研究

根据综放采场顶煤冒放形式和顶板移动结构,提出5种煤岩复合结构,研究了其形成条件,并建立了相应的力学模型:拱—拱组合模型、拱—砌体梁组合模型、拱—传递岩梁组合模型、台阶悬臂—砌体梁组合力学模型、台阶悬臂—悬臂梁组合力学模型,并由此推导其控制方程,计算支架载荷;针对不同顶板、煤层条件,运用相应力学模型分析支架—围岩关系,计算综放工作面支架载荷,确定综放采场支架合理工作阻力,从而有效控制综放采场围岩;通过对10个不同条件综放工作面支架载荷的计算与实测比较,计算值的安全系数为1.06,表明根据综放采场围岩组合结构力学模型计算支架载荷比简化的岩重计算更为合理,从而为综放采场围岩控制提供了理论基础。通过一个工程实例详细阐述了根据综放采场煤岩结构为学模型计算支架载荷的方法。图5,表2,参10。

Mechanics model of coal-rock compound structure and its control in fully mechanized longwall top-coal caving face

Top-coal caving mining method, which has its origin in Europe, has been fully developing into an important technology in thick coal seam mining by virtue of its high productivity and high efficiency, however, a support's resistance determined by traditional method is greatly different from that determined by the field measurements in fully mechanized longwall top-coal caving face. Therefore, the support-surrounding rock relation of fully mechanized mining operation with top-coal caving needs to be studied again. By means of thorough investigation and study of top-coal caving and roof moving law, five coal-rock compound structures and their relevant mechanics models are put forward, and the equilibuium forces needed by the modesl are deduced. The five mechanical models are arch-arch composite structure, arch-brick block beam structure, arch-transferring beam structure, converse step cantilever-brick block beam structure and converse step cantilever-cantilever beam structure. According to the different coal-rock compound structure under appropriate roof and coal seam condition, the relation of support and surrounding rocks of longwall top-coal caving faces can be analyzed based on the corresponding mechanics model, so the support load resistance pressure can be quantitatively calculated in line with the equilibuium force of mechanics model, which means that top-coal and roof can be efficiently controlled. Compared with the observed values of the ten top-coal caving faces, the calculated values of support load has the mean safety factor of 1. 06, so it is scientific to determine the rational resistance pressure of hydraulic support to control the surrounding rocks of longwall fully mechanized top-coal caving faces, which is the key to fulfill the highly efficient and productive in extra-thick coal seam mining in China. In this paper, the calculating of support resistance pressure of Xinzhouyao coal mine,and the hard coal and the hard roof are controlled successfully is detailed presented. 5 figs. , 2 tabs. , 10refs.