北方岩溶陷落柱的充水特征及水文地质模型

WATER-BEARING CHARACTERISTICS AND HYDRO-GEOLOGICAL MODELS OF KARSTIC COLLAPSE COLUMNS IN NORTH CHINA

岩溶陷落柱是中国北方型石炭二迭纪煤田的一种特殊隐伏垂向构造,广泛分布于20个煤田45个煤矿区,对煤矿安全生产危害极大。为实现岩溶陷落柱的数学模拟并准确预测其涌(突)水量,进行了其充水特征及受控机制的研究,并建立了水文地质模型。研究表明,陷落柱的充水受地质构造运动、地下水径流条件、柱体内物质组成、压实和胶结情况以及承受水压大小等多种条件与因素的控制和影响,而各种因素又彼此促进和相互制约,只有处在现代岩溶水强径流带和集中排泄带并隐伏埋藏在地下水水位以下者,才能构成突水的潜在威胁。真正造成突水危害的还需要其他条件的配合,这就决定了绝大部分北方岩溶陷落柱并不充水也不导水。若岩溶陷落柱一旦突水,水量大且迅猛,预测及防治难度极大。按照系统论的观点,灰岩地下水是其补给源,柱体本身是充水通道,井巷或采煤工作面是其排泄点,岩溶陷落柱作为矿井地下水广义三重介质渗流系统的一类介质,自身又构成了独特的岩溶陷落柱水文地质子系统。对于子系统内部特征的详细深入研究,可将陷落柱划分为全充水强导水型、边缘充水导水型和不导水或微弱导水疏干型等3种类型,在地下水系统中相应地概化为垂向管道、主干裂隙或垂向越流介质、隔水体或无影响介质,通过数学模型的解算实现矿井涌(突)水量的?

Karstic collapse column is a kind of vertical structure typically formed at Carboniferous-Permian coalfields of north China, and widely distributed in 45 coal mine areas of 20 coalfields. Water inrush from the karstic collapse columns is harmful to mining safety. For simulating them and forecasting water volume with mathematic models, their properties and controlling mechanisms of water-bearing are studied, and hydro-geological models are set up. The study shows that the water-bearing properties of karstic collapse columns are controlled and influenced by several conditions and factors, such as tectonic movements, groundwater flow conditions, substance, solid and cementation in the columns, as well as confining pressure. All factors promote and restrict each other, so that only in karstic runoff or discharged zones or under water table, there could be danger of water inrush. But if water inrush from them happens unexpectedly, water volume will be destructive, and it is difficult to forecast and prevent. According to viewpoint of systems, karstic collapse column is one kind of media in a mine groundwater system with generalized multiple porous media seepage, and are also special hydro-geological subsystems where karstic groundwater is recharge source, columns are flow pathways, and roadways or working faces are their discharge points. Three kinds of patterns can be classified by interior properties, complete strong water bearing pattern, brim water bearing pattern, and weakly penetrated and run pattern. Accordingly, karstic collapse columns are generalized as vertical pipelines, main fractures or vertical! cross-stream media, and water barrier or media of aquifer uninfluenced. The mining water volume can be) accurately forecast with mathematic models of mine groundwater systems.