奥陶系灰岩+厚隔水层夹薄层灰岩+煤层的地层结构模式是我国石炭二叠系煤田带压开采的典型存在形式。尽管隔水层巨厚,由于其中夹有薄层灰岩含水层,导致深部开采时突水灾害仍然频发。由于突水系数的局限性,依据隔水层厚度、底板破坏带高度与奥灰导升带高度之和、突水系数将底板隔水层类型综合划分为极薄、薄、中、厚及巨厚5种类型,淡化突水系数在极薄、厚及巨厚隔水层中的应用。

阐述了薄层灰岩在串连奥灰与煤层形成水害的独特作用,定义了深部底板奥灰及薄灰水害概念及突水模式,总结了其五维度特征,概括为充水水源的总源递进、充水通道的面状分散、充水强度的台阶增长、充水时间的滞后出水、充水水源水质的交换吸附,阐明了奥灰水渗透、扩容、压裂、导升经薄灰中转储运形成面状散流的突水机理,提出了相应的突水危险性评价公式P₀>3σ₃-σ₁-P_p+R_m。

针对巨厚隔水层且传统井下底板加固甚至区域治理仍无法完全控制深部突水的现状,创新了全时域与全空域四维度奥灰及薄灰水害的“全时空”综合防治理念,空域上井上下相结合、奥灰及薄灰多层次区域治理与井下薄灰钻孔探治验相结合的全空间多层次立体网状防控布局,创建了全空域立体交叉网络探查、治理、验证、补充的“全空域”立体防治模式,形成了条件评估、探治验补、检验评价、监测保障的全时域“四位一体”技术质量控制流程,创立了“四位一体”立体网状全时空深部底板奥灰及薄灰水害防治方法。

以邯邢矿区梧桐庄井田2603工作面为工程案例,确定奥灰顶面以下40~60 m和20~30 m、薄灰大青和山伏青灰岩为目标实施多层段地面超前区域治理及补充治理,配合野青和山伏青为目标井下补充治理和验证,形成立体网络治理;采用奥灰薄灰水文地质条件评估确定治理目标,用地面区域探查治理、补充探查治理以及传统井下查缺补漏验证前期治理效果,以治理效果检验、底板完整性评价、突水危险性评价、涌水量预测、排水能力评价等全面评估能否回采工作面,回采过程中采取水文监测、微震系统、矿压系统等综合监测手段紧盯薄层灰岩关键层,实现了工作面安全回采。

The rock structure model of Ordovician limestone +thin limestone placed in between thick aquifuges+coal seam is the typical existence form of Permo-Carboniferous coalfields mining under pressure in China. Although the aquifuge is extremely thick,it is frequently affected by water inrush in deep mining because of the thin limestone aqui- fer. Due to the limitation of the water inrush coefficient,based on the thickness of the aquifuge,the height of the floor damage zone as well as the height of fracturing belt of the Ordovician Limestone,and the water inrush coefficient,this paper classifies the floor aquifuge into five categories:extremely thin,thin,medium,thick and extremely thick,and re- duces the application role of water inrush coefficient in extremely thin,thick and extremely thick aquifuge. This paper describes the unique role of thin Limestone in the formation of water disaster in series between Ordovician Limestone and coal seams,defines the concept of water disaster and water inrush pattern of deep floor Ordovician Limestone and thin Limestone. The characteristics of its five dimensions are also summarized as the total source progression of the wa- ter filling source,the planar dispersion of the water filling channel,the step increase of the water filling intensity,the hysteretic effluent of the water filling time,and the exchange and adsorption of the water quality of the water filling source. The water inrush mechanism is clarified that the permeability, dilatancy, fracturing, and rise of Ordovician Limestone water form a planar and divergent flow by the transfer,storage and transportation of thin Limestone,and the corresponding water inrush risk evaluation formula P0 >3σ3 -σ1 -Pp +Rm is also proposed. The water inrush cannot be completely controlled by the traditional underground floor reinforcement or even the regional treatment under extremely thick aquifuge,the “whole time-space” comprehensive prevention and control concept of the four-dimensional Ordovi- cian Limestone and thin Limestone water disaster in whole time and space domain is innovated,and in the space,a full-space multi-layer three-dimensional network prevention and control layout is formed,which combines the top and bottom of the mine,the combination of multi-level regional treatment of Ordovician Limestone and thin Limestone,and the exploration,treatment and verification of underground thin Limestone drilling,creating the " whole space" tridimen- sional prevention and control model of whole space three-dimensional crossover network exploration,treatment,verifi- cation,and supplement,forming a whole time domain “ Four-in-One” technology quality control process of condition assessment,and exploration,treatment,verification as well as supplement,and inspection evaluation,and monitoring and guarantee,and establishing a deep floor Ordovician Limestone and thin Limestone water disaster prevention meth- od with “Four-in-One” whole time-space tridimensional network. Taking the 2603 working face of Wutongzhuang mine field in the Hanxing mine area as an engineering case,the paper determined that 40-60 m and 20-30 m below the top surface of the Ordovician Limestone,and the Daqing thin Limestone and Shanfuqing Limestone were the targets to car- ry out the advanced regional treatment and supplementary treatment of the multi-layer section,and formed a three-di- mensional network treatment with Yeqing and Shanfuqing Limestone as the target of underground supplementary treat- ment and verification. The Ordovician Limestone and thin Limestone hydrogeological condition assessment is used to determine the treatment goal in the paper,and the surface area exploration and treatment,supplementary exploration and treatment,as well as traditional underground inspection are used to verify the preliminary treatment effect,and the comprehensive evaluation of whether the working face can be mined with the verification of treatment effect,the evalu- ation of the integrity of the floor,the evaluation of water inrush risk,the prediction of water inflow,and the evaluation of the drainage capacity. In the process of coal mining,the hydrologic monitoring,micro seismic system,mine pressure monitoring system and other comprehensive means are adopted to pay close attention to the key stratum of the thin Limestone,so as to realize the safe mining of the working face.