摘要
以某矿多煤层下保护层急倾斜俯伪斜工作面为例,确定了沿工作面伪斜方向顶板硬岩层承受的载荷和充填体的支撑载荷的表达式.基于关键层理论和有限元数值模拟方法,确定了下保护煤层开采后上覆岩层中的关键层的位置及其破断距;得出了急倾斜煤层开采后受关键层影响下的上覆岩层移动特点和破坏形态;分析了关键层对保护层开采保护范围的影响.研究表明,距下保护层K6煤层17 m的硅质石灰岩为上覆岩层中的关键层,其破断距为30 m左右;关键层破断之前,关键层上部的被保护层卸压并不明显;关键层破断以后,保护层的保护作用逐渐明显;且被保护层的瓦斯涌出规律与关键层破断距成周期变化,倾斜上部瓦斯得到充分释放,而倾斜下部由于冒落矸石的充填导致岩层变形较小,瓦斯不能充分释放,使保护范围在倾向上部比下部大.
An oblique work face under protecting strata is used as an example for determining the load on a hard roof and the support from back filling.Key strata theory and finite numerical simulations were used to calculate the roof fracture intervals after removal of coal.Characteristics of movement of the strata were analyzed.Protection from the key stratum was studied as a function of gas flow and strata movement after coal exploitation.The key stratum was cherty limestone with hemstitch to the K6 coal seam of 17 meters and a first break interval of about 30 meters.Before the key stratum breaks there is no obvious distortion of the overlying strata and stresses in the protected coal seam could not be released.After the stratum breaks distortion and fissures occur in the overlying strata.Gas from the protected coal seam is given off from the upper side of the incline.Beneath the incline filling from caving prevents distortion of the stratum and gas is not released there.The protecting effects from the strata increases gradually and the effect is larger on the upper regions of the incline than it is on the lower regions.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2011年第1期23-28,共6页
Journal of China University of Mining & Technology
基金
国家自然科学基金项目(50774106)
国家自然科学创新群体基金项目(50621403)
国家重点基础研究发展计划(973)项目(2005CB221502)
关键词
关键层
急倾斜煤层
下保护层
破断距
key strata
steep-inclined seam
under-protecting stratum
breaking interval
