Effective identification method for water-preserving coal mining area in weathered bedrock aquifer

Abstract

The present application relates to the field of geological mining. Disclosed is an effective identification method for a water-preserving coal mining area in a weathered bedrock aquifer. The method comprises: classifying the types of stratum structures; when a target stratum area belongs to a first type, and the invasion degree of burnt rock in an aquitard is greater than or equal to a first set threshold value, making a determination on the basis of an initial hydraulic gradient of the aquitard, the hydraulic head height of an unconsolidated sand aquifer and the effective thickness of the aquitard; when the target stratum area belongs to a second type, and the invasion degree of burnt rock in a weathered bedrock aquifer is greater than or equal to a second set threshold value, making a determination on the basis of the water retention capacity and water abundance of the burnt rock in the weathered bedrock aquifer; when the target stratum area belongs to a third type, making a determination on the basis of the invasion degree of the burnt rock in the weathered bedrock aquifer and surface water bodies; and when the target stratum area belongs to a fourth type, directly making a determination. The present application realizes the effective identification of a water-preserving coal mining area in a weathered bedrock aquifer.

Description

An effective method for identifying water-retaining coal mining areas in weathered bedrock aquifers. Technical Field

[0001] This application relates to the field of geological and mining technology, and in particular to an effective method for identifying water-retaining coal mining areas in weathered bedrock aquifers. Background Technology

[0002] Currently, in some regions, the conflict between coal mining and water resources and ecological environmental protection is prominent, making it necessary to carry out water-conserving coal mining. The main target stratum for traditional water-conserving coal mining is the loose sand layer. Since the loose sand layer is located at the top of the strata and is directly related to the surface ecology, areas where coal mining affects the water in the sand layer are considered water-conserving coal mining areas.

[0003] Weathered bedrock is also an important water resource, but since it is not directly exposed on the surface, areas with water-retaining coal mining significance need further identification. Compared with the traditional identification of water-retaining coal mining areas, the identification of water-retaining coal mining areas in weathered bedrock aquifers has the following problems: (1) Compared with loose sand aquifers, weathered bedrock aquifers have more varied lithology, and their water-holding capacity in the dry season is an important factor in the identification of water-retaining coal mining areas, which has not been considered in previous identifications; (2) There may be hydraulic connection between weathered bedrock aquifers and loose sand aquifers. Hydraulic connection is an important indicator for evaluating water-retaining coal mining areas in weathered bedrock, which has not been considered in previous identifications.

[0004] Furthermore, the degree of intrusion of sintered rock also has a significant impact on the identification of water-retaining coal mining areas in weathered bedrock aquifers. Sintered rock is a special type of rock mass formed by the spontaneous combustion of thick coal seams near the surface during geological history, which baked or scorched the surrounding rocks. According to outcrop observations and drilling data in sintered rock areas, the three zones of sintered rock are often incomplete and irregularly distributed, thus causing a certain degree of intrusion into weathered bedrock or impermeable soil layers, thereby affecting the identification and determination of water-retaining coal mining areas. Summary of the Invention

[0005] The purpose of this application is to provide an effective method for identifying water-retaining coal mining areas in weathered bedrock aquifers. This method can effectively identify water-retaining coal mining areas in weathered bedrock aquifers, and protect water resources and the ecological environment while assisting in coal mining, thereby achieving green mining of coal resources.

[0006] To achieve the above objectives, this application provides the following solution:

[0007] This application provides an effective method for identifying water-retaining coal mining areas in weathered bedrock aquifers. The effective method for identifying water-retaining coal mining areas in weathered bedrock aquifers specifically includes:

[0008] Stratigraphic structure types are classified; these types include: Type I, Type II, Type III, and Type IV.

[0009] Identify the target stratigraphic region of the mining area;

[0010] When the target stratum area belongs to the first type, the intrusion degree of the igneous rock in the impermeable soil layer is determined; if the intrusion degree of the igneous rock in the impermeable soil layer is less than the first set threshold, then the target stratum area is judged as a water-retaining coal mining area of ​​weathered bedrock aquifer based on the initial hydraulic gradient of the impermeable soil layer, the water head height of the loose sand aquifer, and the actual thickness of the impermeable soil layer; if the intrusion degree of the igneous rock in the impermeable soil layer is greater than or equal to the first set threshold, then the effective thickness of the impermeable soil layer is first determined based on the actual thickness of the impermeable soil layer and the intrusion degree of the igneous rock, and then the target stratum area is judged as a water-retaining coal mining area of ​​weathered bedrock aquifer based on the initial hydraulic gradient of the impermeable soil layer, the water head height of the loose sand aquifer, and the effective thickness of the impermeable soil layer.

[0011] When the target stratum area belongs to the second type, the intrusion degree of the igneous rock in the weathered bedrock aquifer is determined; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is less than the second set threshold, the target stratum area is judged as a water-retaining coal mining area based on the water holding capacity and water-bearing capacity of the weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is greater than or equal to the second set threshold, the target stratum area is judged as a water-retaining coal mining area based on the water holding capacity and water-bearing capacity of the igneous rock in the weathered bedrock aquifer.

[0012] When the target stratum area belongs to type III, determine the intrusion degree of the igneous rock in the weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is less than or equal to 0, and there is no surface water, then the target stratum area is determined to be a water-retaining coal mining area in the non-weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is greater than 0, and there is surface water, then the target stratum area is determined to be a water-retaining coal mining area in the weathered bedrock aquifer.

[0013] When the target stratum area belongs to the fourth type, the target stratum area is determined to be a water-retaining coal mining area in the weathered bedrock aquifer.

[0014] According to the specific embodiments provided in this application, the following technical effects are disclosed:

[0015] This application classifies the stratigraphic structure of mining areas into four types. By determining the stratigraphic structure type of the target stratigraphic region, it is possible to further identify water-conserving coal mining areas with weathered bedrock aquifers. For the first type, since the loose sand aquifer is exposed at the surface, it has significant ecological and water supply value; therefore, it is crucial to prevent the weathered bedrock aquifer from plundering the water from the loose sand aquifer. For the second type, since the impermeable soil layer is directly exposed at the surface, recharge is generally very difficult, but due to the overlying impermeable soil layer, evaporation from the weathered bedrock aquifer is relatively low, thus mining is permissible. For the third type, since the weathered bedrock aquifer has no overlying strata and is directly exposed at the surface, this type generally occurs at the bottom of gullies, and both water supply and ecological environment supply are mainly affected during the dry season. For the fourth type, the weathered bedrock aquifer is overlying a loose sand aquifer, and these two aquifers have a close hydraulic connection; therefore, to protect the ecologically significant loose sand aquifer, the weathered bedrock aquifer must be protected. Through further analysis of the above four types, the effective identification of water-retaining coal mining areas in weathered bedrock aquifers was achieved. Detailed Implementation

[0016] [Corrected according to Rule 91, 03.11.2025] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0017] [Correction 03.11.2025 based on Rule 91] To make the above-mentioned objects, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to specific embodiments.

[0018] [Corrected from Rule 91, 03.11.2025] This embodiment provides an effective method for identifying water-retaining coal mining areas in weathered bedrock aquifers, specifically including:

[0019] Step S1: Classify the stratigraphic structure types; the stratigraphic structure types include: Type I, Type II, Type III and Type IV; Type I is a weathered bedrock aquifer overlaid with an impermeable soil layer, and the impermeable soil layer is overlaid with a loose sand aquifer; Type II is a weathered bedrock aquifer overlaid with an impermeable soil layer, and the impermeable soil layer is exposed at the surface; Type III is a weathered bedrock aquifer directly exposed at the surface; Type IV is a weathered bedrock aquifer overlaid with a loose sand aquifer.

[0020] Step S2: Determine the target stratigraphic region of the mining area.

[0021] In this embodiment, borehole columnar section diagrams are used to identify the target stratum region of the mining area.

[0022] Step S3: When the target stratum area belongs to the first type, determine the intrusion degree of the igneous rock in the impermeable soil layer; if the intrusion degree of the igneous rock in the impermeable soil layer is less than 10%, then determine whether the target stratum area is a water-retaining coal mining area of ​​weathered bedrock aquifer based on the initial hydraulic gradient of the impermeable soil layer, the water head height of the loose sand aquifer, and the actual thickness of the impermeable soil layer; if the intrusion degree of the igneous rock in the impermeable soil layer is greater than or equal to 10%, then first determine the effective thickness of the impermeable soil layer based on the actual thickness of the impermeable soil layer and the intrusion degree of the igneous rock, and then determine whether the target stratum area is a water-retaining coal mining area of ​​weathered bedrock aquifer based on the initial hydraulic gradient of the impermeable soil layer, the water head height of the loose sand aquifer, and the effective thickness of the impermeable soil layer.

[0023] In this embodiment, if the intrusion degree of the igneous rock in the impermeable soil layer is greater than or equal to 10%, the following steps are specifically performed:

[0024] The intrusion thickness of the igneous rock is calculated based on the degree of intrusion of the igneous rock in the impermeable soil layer.

[0025] The difference between the actual thickness of the impermeable soil layer and the intrusion thickness of the pyrometallurgical rock is determined as the effective thickness of the impermeable soil layer.

[0026] The seepage ratio is obtained by calculating the ratio of the water head height of the loose sand aquifer to the effective thickness of the impermeable soil layer.

[0027] When the initial hydraulic gradient of the impermeable soil layer is less than or equal to the seepage ratio, the target stratum area is determined to be a water-retaining coal mining area in the weathered bedrock aquifer.

[0028] When the initial hydraulic gradient of the impermeable soil layer is greater than the seepage ratio, the target stratum area is determined to be a water-retaining coal mining area in a non-weathered bedrock aquifer.

[0029] Step S4: When the target stratum area belongs to the second type, determine the intrusion degree of the igneous rock in the weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is less than 5%, then determine whether the target stratum area is a water-retaining coal mining area of ​​the weathered bedrock aquifer based on the water holding capacity and water-bearing capacity of the weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is greater than or equal to 5%, then determine whether the target stratum area is a water-retaining coal mining area of ​​the weathered bedrock aquifer based on the water holding capacity and water-bearing capacity of the igneous rock in the weathered bedrock aquifer.

[0030] In this embodiment, the process for determining water holding capacity and water abundance is as follows:

[0031] When the water holding capacity of the calcined rock in the weathered bedrock aquifer is greater than or equal to 15%, the target stratum area is determined as a water-retaining coal mining area in the non-weathered bedrock aquifer.

[0032] When the water holding capacity of the igneous rock in the weathered bedrock aquifer is less than 15%, determine whether the water-bearing capacity of the igneous rock in the weathered bedrock aquifer is weakly water-bearing or below; if yes, then the target stratum area is determined to be a water-retaining coal mining area in the non-weathered bedrock aquifer; if no, then the target stratum area is determined to be a water-retaining coal mining area in the weathered bedrock aquifer.

[0033] Step S5: When the target stratum area belongs to the third type, determine the intrusion degree of the igneous rock in the weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is less than or equal to 0 and there is no surface water (dry season), then the target stratum area is determined to be a water-retaining coal mining area in the non-weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is greater than 0 and there is surface water (dry season), then the target stratum area is determined to be a water-retaining coal mining area in the weathered bedrock aquifer.

[0034] Step S6: When the target stratum area belongs to the fourth type, the target stratum area is determined to be a water-retaining coal mining area in the weathered bedrock aquifer.

[0035] In addition, this embodiment also provides a coal mining method, which mainly uses the above-mentioned effective identification method of water-retaining coal mining area in weathered bedrock aquifer to determine the water-retaining coal mining area in the mining area, and takes water-retaining coal mining measures for the water-retaining coal mining area in weathered bedrock aquifer.

[0036] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An effective method for identifying water-retaining coal mining areas in weathered bedrock aquifers, characterized in that, Effective methods for identifying water-retaining coal mining areas in weathered bedrock aquifers include: Stratigraphic structure types are classified as follows: Type I, Type II, Type III, and Type IV. Type I consists of a weathered bedrock aquifer overlaid with an impermeable soil layer, which in turn is overlaid with a loose sand aquifer. Type II consists of a weathered bedrock aquifer overlaid with an impermeable soil layer, which is exposed at the surface. Type III consists of a weathered bedrock aquifer directly exposed at the surface. Type IV consists of a weathered bedrock aquifer overlaid with a loose sand aquifer. Identify the target stratigraphic region of the mining area; When the target stratum area belongs to the first type, the intrusion degree of the igneous rock in the impermeable soil layer is determined; if the intrusion degree of the igneous rock in the impermeable soil layer is less than the first set threshold, then the target stratum area is judged as a water-retaining coal mining area of ​​weathered bedrock aquifer based on the initial hydraulic gradient of the impermeable soil layer, the water head height of the loose sand aquifer, and the actual thickness of the impermeable soil layer; if the intrusion degree of the igneous rock in the impermeable soil layer is greater than or equal to the first set threshold, then the effective thickness of the impermeable soil layer is first determined based on the actual thickness of the impermeable soil layer and the intrusion degree of the igneous rock, and then the target stratum area is judged as a water-retaining coal mining area of ​​weathered bedrock aquifer based on the initial hydraulic gradient of the impermeable soil layer, the water head height of the loose sand aquifer, and the effective thickness of the impermeable soil layer. When the target stratum area belongs to the second type, the intrusion degree of the igneous rock in the weathered bedrock aquifer is determined; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is less than the second set threshold, the target stratum area is judged as a water-retaining coal mining area based on the water holding capacity and water-bearing capacity of the weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is greater than or equal to the second set threshold, the target stratum area is judged as a water-retaining coal mining area based on the water holding capacity and water-bearing capacity of the igneous rock in the weathered bedrock aquifer. When the target stratum area belongs to type III, determine the intrusion degree of the igneous rock in the weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is less than or equal to 0 and there is no surface water, then the target stratum area is determined to be a water-retaining coal mining area in the non-weathered bedrock aquifer; if the intrusion degree of the igneous rock in the weathered bedrock aquifer is greater than 0 and there is surface water, then the target stratum area is determined to be a water-retaining coal mining area in the weathered bedrock aquifer. When the target stratum area belongs to the fourth type, the target stratum area is determined to be a water-retaining coal mining area in the weathered bedrock aquifer; If the intrusion degree of the igneous rock in the impermeable soil layer is greater than or equal to the first set threshold, then the effective thickness of the impermeable soil layer is first determined based on the actual thickness of the impermeable soil layer and the intrusion degree of the igneous rock. Then, based on the initial hydraulic gradient of the impermeable soil layer, the hydraulic head height of the loose sand aquifer, and the effective thickness of the impermeable soil layer, it is determined whether the target stratum area is a water-retaining coal mining area in a weathered bedrock aquifer. Specifically, this includes: The intrusion thickness of the igneous rock is calculated based on the degree of intrusion of the igneous rock in the impermeable soil layer. The difference between the actual thickness of the impermeable soil layer and the intrusion thickness of the pyrometallurgical rock is determined as the effective thickness of the impermeable soil layer. The seepage ratio is obtained by calculating the ratio of the water head height of the loose sand aquifer to the effective thickness of the impermeable soil layer. When the initial hydraulic gradient of the impermeable soil layer is less than or equal to the seepage ratio, the target stratum area is determined to be a water-retaining coal mining area in the weathered bedrock aquifer. When the initial hydraulic gradient of the impermeable soil layer is greater than the seepage ratio, the target stratum area is determined to be a water-retaining coal mining area in a non-weathered bedrock aquifer.

2. The effective identification method for water-retaining coal mining areas in weathered bedrock aquifers according to claim 1, characterized in that, Target stratigraphic regions in the mining area are identified using borehole columnar sections.

3. The effective identification method for water-retaining coal mining areas in weathered bedrock aquifers according to claim 1, characterized in that, When the target stratigraphic region belongs to the third type, it is necessary to obtain the surface water body of the target stratigraphic region during the dry season.