摘要
根据煤炭地下气化场实际地质结构,考虑高温对燃空区上覆岩层物理力学特性的影响,采用RFPA建立模型分析燃空区覆岩结构运动及"三带"分布规律,结果表明:①燃空区上覆岩层出现明显的"三带"特征。燃空区老顶关键层初次来压步距约为42m,周期来压步距约为12m。②随着燃空区扩展,燃烧煤壁前方形成剪应力集中区,由下向上发展成拱形分布;煤壁前方形成应力增高区,煤层支承压力增高系数为2.0～2.3。③随着燃空区扩展,上覆岩层的移动范围及下沉量逐步增大;老顶关键层出现初次破断及周期来压后,厚硬岩层下沉量明显增大;同一时刻距离煤层越近的顶板,其垂直位移越大;上覆岩层位移下沉曲线基本呈对称分布。
According to the actual geological structure of the underground coal gasification filed, in consideration of the high temperature affected to the physical mechanics features of the overburden strata above the combusted cave area, a model established by a RFPA was applied to analyze overburden strata movement law above the combusted cave are and a three zone distribution law. The results showed that （~） the overburden strata above the eombusted cave area would have obvious three zone features. The initial weighting step distance of the key layer in the main roof above combusted cave area was about 42m and the periodical weighting step distance was 12m. With the combusted cave area expanded, a shear stress concentrated area would be formed in a front of the combustion coal wall and a arch distribution would be developed from bottom to top. A stress increased zone would be formed in a front of the coal wall and the support pressure increased coefficient of the seam would be 2. 0 2. 3. With the combusted cave area expanded, the movement scope and the subsidence value of the overburden strata would be steadily increased. After the initial broken and periodical weighting occurred in the key layer of the main roof, the subsidence value of the thick and hard strata would be increased obviously. The roof more closer to the seam at the same time, the higher vertical displacement would be. The displacement subsidence curve of the overburden strata would be in a symmetrical distribution.
出处
《煤炭工程》
北大核心
2013年第5期79-82,共4页
Coal Engineering
基金
国家自然科学基金(51204159)
中央高校基本科研业务费专项资金(2011QNB05)
教育部新世纪优秀人才支持计划项目(NCET-10-0770)
关键词
煤炭地下气化
燃空区
覆岩运动
三带
underground coal gasification
combusted cave area
overburden strata movement
three zones
