开滦范各庄井田突水特征及煤层底板 突水地质条件分析

 煤层顶底板突水危险性预测与评价是煤矿突水灾害防治的基础和依据，以开滦范各庄井田为依托，从促发与阻抗突水2方面系统分析矿井突水特征和12～14煤层间砂岩裂隙含水层厚度及其特征、突水介质条件(岩性、层间距)和突水构造条件，建立煤层底板突水与地质条件之间的相关关系和模型，并探讨控制机制。研究结果表明，本区发生突水的水源以12～14煤层间砂岩裂隙承压含水层为主，其砂岩裂隙含水层的厚度由井田的浅部向深部增厚；含水层水压随其埋藏深度的增加而增高，呈线性相关关系，且富水性增强。煤层底板隔水性能取决于隔水层厚度及其泥岩百分比含量，底板泥岩极限厚度与水压之间呈正相关关系，随着底板泥岩厚度的增加，泥岩层抵抗水压的能力增强，隔水性能变好，且完整底板泥岩层的抗水能力明显大于含裂隙的底板泥岩层。突水与构造密切相关，突水点最大涌水量与断层密度呈正相关关系。断层突水是由于断层对煤岩层的破坏作用导致在断层附近煤岩层裂隙和孔隙增加，力学强度大幅度降低的结果，且受控于区域构造和现代构造应力环境。这些成果为井田12煤层底板突水危险性评价与预测和井下突水防治提供理论依据。

WATER INRUSH CHARACTERISTICS OF FANGEZHUANG COALMINE FIELD IN KAILUAN AND ITS GEOLOGICAL CONDITION ANALYSIS OF WATER INRUSH FROM COAL SEAM FLOOR

Water inrush risk forecasting and evaluation of coal roof and floor are the basic issues of water inrush disasters prevention in coalmine field. Based on Fangezhuang coalmine field in Kailuan，water inrush characteristics and the sandstone fracture aquifer thickness of coal seams from No.12 to No.14，water inrush medium conditions(lithology，interlayer distance)，and water inrush structure conditions，are all analyzed from the two aspects of promotion and treatment of water inrush. Correlation and models between water inrush of coal seam floor and geological conditions are established. And also，the controlling mechanism is discussed. It is shown that water source that induces water inrush in this area takes the confined aquifer of sandstone fracture of coal seams from No.12 to No.14 as the main body. The thickness of sandstone fracture aquifer becomes thicker from the shallow to the depth of the mine field；and water abundance enhancement presents linear correlation. Water isolation of coal floor depends on the thickness of aquifuge and its shale percentage content. Limit thickness of floor mudstone has a positive correlation with water pressure；the abilities of mudstone layer¢s resisting water pressure enhance and water isolation becomes better with the increase of mudstone thickness of coal floor. Thus，the mudstone layer with intact structure floor has obviously larger ability of resisting water pressure than that of mudstone layer with fracture. Water inrush is closely related to the structures. Maximum water emission of water inrush point has positive correlation with fault density. Water inrush from fault is attributed to destructive effect of fault to coal and rock seams，resulting in the increase of its fracture，porosity and the considerable decrease of the mechanical strength around fault. Also，it is controlled by regional tectonic and modern tectonic stress environment. Those achievements provide theoretical basis for water inrush risk evaluation and forecast of floor of coalmine field No.12 and underground water inrush prevention.