Water-resisting performance testing system for water-resisting layer of coal mine

Abstract

The utility model relates to the technical field of soil layer permeability test, especially to a kind of water-resisting layer water-resisting performance test system for coal mine, including measured hole and test hole;Measured hole is vertically penetrated upper aquifer from ground and extends to the top of water-resisting layer;Test hole is set up in the side of measured hole, and sequentially through upper aquifer and water-resisting layer, and extend to lower aquifer and extend first depth;It further includes pumping device and first water level testing device, pumping device is suitable for pumping groundwater in test hole, and first water level testing device is used to test the water level height of measured hole when pumping device pumps and / or after pumping, its beneficial effect is through the test system, realizes in situ, dynamic continuous water-resisting performance test, can more truly reflect the overall sealing characteristic of water-resisting layer in complex stratum structure.

Description

Technical Field

[0001] This utility model relates to the field of soil permeability testing technology, and in particular to a water-impermeable performance testing system for a water-impermeable layer in a coal mine. Background Technology

[0002] In the field of mine safety assessment, such as coal mining, accurately determining the water-retaining performance of the overlying water-retaining layer is of great significance for water-conserving coal mining and operational safety.

[0003] Traditional testing methods often rely on laboratory sample analysis or large-scale drilling operations. These methods are not only costly and complex to operate, but also fail to fully reflect the true working state of the aquitard under natural geological conditions.

[0004] Therefore, how to design a test system for the water-tightness performance of aquitards in coal mines that can simulate the real seepage behavior of groundwater when the aquitard is disturbed is an urgent problem to be solved in this field. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, this utility model provides a water-tightness performance testing system for water-tight layers in coal mines. It solves the technical problem that the testing methods in the prior art often rely on sample analysis in the laboratory or large-scale drilling operations. These methods are not only costly and complicated to operate, but also difficult to fully reflect the actual working state of the water-tight layer under natural geological conditions.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the main technical solutions adopted by this utility model include:

[0009] In a first aspect, this utility model provides a water-tightness testing system for aquitards in coal mines, suitable for determining the water-tightness of aquitards on a foundation consisting of an upper aquifer, an aquitard, and a lower aquifer from top to bottom. The system includes a test borehole and a test borehole; the test borehole vertically penetrates the upper aquifer from the ground surface and extends to the top of the aquitard; the test borehole is located on one side of the test borehole, passes through the upper aquifer and the aquitard in sequence, and extends to the lower aquifer to a first depth; it also includes a pumping device and a first water level testing device, the pumping device being suitable for pumping groundwater from the test borehole, and the first water level testing device being used to test the water level height of the test borehole during and / or after pumping.

[0010] In one technical solution of this utility model, the wall of the test hole is made of a water-permeable material; the wall of the test hole corresponding to the upper aquifer and the water-resistant layer is made of a water-resistant material, and the wall of the test hole corresponding to the lower aquifer is made of a water-permeable material.

[0011] In one technical solution of this utility model, the test hole wall corresponding to the lower aquifer is a perforated pipe wall; the test hole wall corresponding to the upper aquifer and the water barrier is a water barrier pipe wall; and the test hole wall corresponding to the lower aquifer is a perforated pipe wall or a bare hole.

[0012] In one technical solution of this utility model, the test hole extends exactly to the waterproof layer.

[0013] In one technical solution of this utility model, the test hole extends to a second depth into the waterproof layer.

[0014] In one technical solution of this utility model, the test holes are configured as multiple holes circumferentially distributed outside the test hole.

[0015] In one technical solution of this utility model, the testing system is set up in multiple groups at intervals within the foundation.

[0016] In one technical solution of this utility model, a second water level testing device is also included for testing the water level height of the hole;

[0017] When the water level in the test well reaches the threshold, the pumping device extracts the groundwater in the test well and lowers it to the second threshold.

[0018] In one technical solution of this utility model, a processing and storage unit is also included. The processing and storage unit is connected to the first water level testing device and the pumping device to control the operation of the pumping device and record the test values ​​of the first water level testing device.

[0019] In one technical solution of this utility model, the waterproof layer is a red clay layer.

[0020] (III) Beneficial Effects

[0021] The beneficial effects of this utility model are: the water-proofing performance testing system for water-proofing layers in coal mines of this utility model, by setting up interconnected test holes and test holes in the foundation, constructs a dynamic monitoring system that can truly reflect the working performance of the water-proofing layer under actual geological conditions.

[0022] The pumping device is connected to the test well and can continuously or intermittently extract groundwater from the well under set operating conditions, thereby creating a hydraulic gradient in a local area to simulate the seepage behavior of groundwater below the aquitard when disturbed. At the same time, the first water level testing device monitors the water level fluctuations in the test well in real time, especially during the pumping process and the recovery phase after pumping stops, recording the time series data of the water level drop rate, stable water level value, and water level recovery process.

[0023] Since the test well penetrates the aquitard and extends into the bedrock aquifer, pumping operations will primarily cause the flow of deep groundwater. If the aquitard has good impermeability, its effect on water flow will be significant, resulting in slow changes in the water level in the test well, a small drop, or even a near-stable level. Conversely, if the aquitard has defects such as fissures, weakened zones, or poor continuity, water will more easily seep into the test well's influence area through vertical infiltration, leading to a significant drop in the water level. Through quantitative analysis of the hydraulic response relationship between the two wells, the actual permeability coefficient, conductivity, and sealing effectiveness of the aquitard can be calculated.

[0024] This testing system enables in-situ, dynamic, and continuous testing of the water-tightness performance, providing a more realistic reflection of the overall sealing characteristics of the water-tight layer in complex geological structures. Furthermore, the testing process does not rely on large-scale drilling or destructive coring, is simple to implement, has low cost, and can be repeated multiple times as needed to improve data reliability.

[0025] The water-tight layer is the laterite layer, which is a key water-tight layer overlying the coal seam. By testing the water-tightness of this laterite layer, the safety threshold of the water-tightness of the upper layer of the coal mine can be determined, thereby improving the safety and reliability of coal mine operations. Attached Figure Description

[0026] Figure 1 This is one of the structural schematic diagrams of the water-proofing performance testing system for water-proofing layers in coal mines according to this utility model;

[0027] Figure 2 This is the second schematic diagram of the structure of the water-proofing performance testing system for the water-proofing layer in coal mines according to this utility model;

[0028] Figure 3 This is a system block diagram of the storage unit, pumping device, and first water level testing device of this utility model.

[0029] [Explanation of Labels in the Attached Image]

[0030] 100, Upper aquifer; 200, Impermeable layer; 300, Lower aquifer;

[0031] 1: The hole to be measured;

[0032] 2: Test hole; A. Perforated pipe wall; B. Waterproof pipe wall;

[0033] 3. Pumping device;

[0034] 4. First water level testing device;

[0035] 5. Process storage units. Detailed Implementation

[0036] To better explain and facilitate understanding of this utility model, the following description is provided in conjunction with the appendix. Figures 1-3 This invention will be described in detail through specific embodiments. Wherein, directional terms such as "upper" and "lower" are used in this document. Figure 1 The orientation is used as a reference.

[0037] Example 1:

[0038] Reference Figures 1-3 This utility model provides a water-tightness performance testing system for an aquifer 200, suitable for measuring the water-tightness performance of an aquifer 200 on a foundation consisting of an upper aquifer 100, an aquifer 200, and a lower aquifer 300 from top to bottom. The system includes a test hole 1 and a test hole 2. The test hole 1 vertically penetrates the upper aquifer 100 from the ground and extends to the top of the aquifer 200. The test hole 2 is located on one side of the test hole 1, passes through the upper aquifer 100 and the aquifer 200 in sequence, and extends to the lower aquifer 300 to a first depth. The system also includes a pumping device 3 and a first water level testing device 4. The pumping device 3 is adapted to pump groundwater from the test hole 2, and the first water level testing device 4 is used to test the water level height of the test hole 1 during and / or after pumping by the pumping device 3.

[0039] Water rich in the upper aquifer 100 can enter the test well 1 through the side wall of the test well 1 and be stored in the test well 1; groundwater contained in the lower aquifer 300 will enter the test well 2 and be stored in the test well 2.

[0040] In this embodiment, the water-proofing performance testing system of the water-proofing layer 200 constructs a dynamic monitoring system that can truly reflect the working performance of the water-proofing layer 200 under actual geological conditions by setting up interrelated test holes 1 and test holes 2 in the foundation.

[0041] Among them, borehole 1 extends vertically downwards from the surface through the upper aquifer 100 and terminates above the impermeable layer 200, mainly used to observe water level changes in the sandy aquifer. Test borehole 2 is located at a certain lateral distance from it. Ideally, the distance between the two should be as close as possible, such as 5 meters. Test borehole 2 traverses the upper aquifer 100 and the impermeable layer 200, and further penetrates to the first depth within the lower aquifer 300, forming a pumping channel that can actively intervene in the groundwater condition.

[0042] The pumping device 3 is connected to the test well 2 and can continuously or intermittently pump groundwater from the test well 2 under set operating conditions, thereby creating a hydraulic gradient in a local area to simulate the seepage behavior of groundwater when the aquitard 200 is disturbed. At the same time, the first water level testing device 4 monitors the water level fluctuations in the test well 1 in real time, especially during the pumping process and the recovery phase after pumping stops, recording the water level drop rate, stable water level value, and time series data of the water level recovery process.

[0043] Since test well 2 penetrates the impermeable layer 200 and extends into the bedrock aquifer, the pumping operation will primarily cause the flow of deep groundwater. If the impermeable layer 200 has good impermeability, its obstruction effect on water flow will be significant, resulting in slow water level changes, small drops, or even near-stability in test well 1. Conversely, if the impermeable layer 200 has defects such as fissures, weakened zones, or poor continuity, water will more easily seep into the influence area of ​​test well 2 through vertical infiltration, leading to a significant drop in the water level of test well 1. Through quantitative analysis of the hydraulic response relationship between the two wells, the actual permeability coefficient, water conductivity, and sealing effectiveness of the impermeable layer 200 can be calculated.

[0044] This testing system enables in-situ, dynamic, and continuous testing of the water-tightness performance, providing a more realistic reflection of the overall sealing characteristics of the water-tight layer 200 in complex geological structures. Furthermore, the testing process does not rely on large-scale drilling or destructive coring, making construction simple and cost-effective. Multiple rounds of pumping-recovery tests can be repeated as needed, improving data reliability.

[0045] The water-tight layer 200 is a laterite layer, which is a key water-tight layer 200 overlying the coal seam. By testing the water-tightness of this laterite layer, the safety threshold of the water-tightness of the upper layer of the coal mine can be obtained, thereby improving the reliability of coal mine operations.

[0046] In an environment where the aquifer 200 is a laterite layer, the upper aquifer 100 is generally a sandy soil layer, and the lower aquifer 300 is generally a bedrock layer.

[0047] Specifically, the first depth can be 20-100m. After testing, the red soil layer, as a water-resistant layer, has a suitable thickness of about 5m.

[0048] More specifically, the first water level testing device 4 can be a water level sensor. Other methods that can measure water level height should also be within the scope of the first water level testing device 4, such as methods that allow workers to directly observe water level height.

[0049] Example 2:

[0050] Reference Figures 1-3 In addition to possessing all the technical solutions of the above embodiments, the embodiments of this utility model further possess the following technical solutions:

[0051] The wall of test hole 1 is made of a permeable material; the wall of test hole 2 corresponding to the upper aquifer 100 and the water-resistant layer 200 is made of a water-resistant material, while the wall of test hole 2 corresponding to the lower aquifer 300 is made of a permeable material.

[0052] The borehole wall of test hole 2 corresponding to the lower aquifer 300 is a perforated pipe wall A; the borehole wall of test hole 2 corresponding to the upper aquifer 100 and the aquitard 200 is an aquitard pipe wall B; the borehole wall corresponding to the lower aquifer 300 is a perforated pipe wall A or a bare hole.

[0053] In this embodiment, the borehole wall of the test borehole 1 is designed with a permeable material to enable it to achieve full hydraulic connection with the free water in the upper aquifer 100. The structure of the test borehole 2 is designed differently according to the characteristics of the different strata it traverses: in the section passing through the upper aquifer 100 and the aquitard 200, its borehole wall is made of a waterproof material, such as a well-sealed waterproof pipe wall B, to effectively block the hydraulic connection between the test borehole 2 and the upper aquifer 100 and the aquitard 200, preventing the shallow groundwater from being directly disturbed or short-circuited during pumping, and ensuring that the pumping action is mainly concentrated at the target depth.

[0054] The portion of test borehole 2 extending into the lower aquifer 300 uses a perforated pipe wall A or remains a bare borehole. This structure has good permeability, allowing bedrock fissure water to freely enter test borehole 2, forming an effective water collection channel. This enables the pumping device 3 to concentrate the extraction of deep groundwater from the lower aquifer 300, thereby creating a controllable hydraulic gradient at the bottom of the impermeable layer 200.

[0055] When pumping begins, if the impermeable layer 200 has good sealing properties and low permeability, its ability to block the upward movement of deep water will be significant, and the water level in the measured well 1 will remain basically stable or only experience slight fluctuations. Conversely, if the impermeable layer 200 has seepage channels or its integrity is compromised, changes in the hydraulic head pressure of the lower aquifer 300 will be transmitted upwards through the seepage of the impermeable layer 200, causing a significant drop in the water level in the measured well 1. By analyzing the time lag, amplitude variation, and recovery rate of this hydraulic response process, the actual water-blocking capacity of the impermeable layer 200 can be quantitatively assessed.

[0056] In this technical solution, the waterproof sealing of test well 2 at a non-target layer avoids the mixing of shallow and deep water, improving the targeting and accuracy of the test; the fully permeable structure of the test well 1 ensures the sensitivity and representativeness of the observation data. Furthermore, by setting a permeable section only in the lower aquifer 300, the source of pumping water can be clearly identified, concentrating the energy of hydraulic disturbance on the bottom of the waterproof layer 200, amplifying the observation effect of differences in its waterproof performance, and improving the test resolution.

[0057] Example 3:

[0058] Reference Figures 1-3 In addition to possessing all the technical solutions of the above embodiments, the embodiments of this utility model further possess the following technical solutions:

[0059] The test hole 1 extends exactly to the waterproof layer 200; or, the test hole 1 extends to a second depth into the waterproof layer 200.

[0060] In this embodiment, the bottom position of the test hole 1 can be optimized according to the actual geological conditions and test objectives. Its bottom end can extend exactly to the top surface of the waterproof layer 200, or be drilled further down to extend a second depth in the waterproof layer 200.

[0061] When the test borehole 1 terminates precisely at the top surface of the impermeable layer 200, the effective depth of the impermeable layer 200 is the total depth of the impermeable layer 200. Under this arrangement, if the test borehole 2 pumps water from the lower aquifer 300 and causes a drop in the deep water head, but the water level in the test borehole 1 does not change significantly, it indicates that the impermeable layer 200 has a good barrier effect against vertical seepage; conversely, if the water level drops rapidly, it indicates that the impermeable layer 200 may have seepage channels or insufficient impermeability.

[0062] When the test well 1 continues to extend downwards to a second depth, entering the interior of the impermeable layer 200, the effective depth of the impermeable layer 200 is the difference between the total depth and the second depth. Under this arrangement, if the test well 2 pumps water from the lower aquifer 300, causing a drop in the deep water head, and the water level in the test well 1 does not change significantly, it indicates that the impermeable layer 200, representing the difference in the second depth, has a good barrier effect against vertical seepage; conversely, if the water level drops rapidly, it indicates the possible existence of a seepage channel.

[0063] By adjusting the value of the second depth, the water-proof threshold of the 200-meter water-proof layer can be tested, thus obtaining more accurate limit data.

[0064] Example 4:

[0065] Reference Figures 1-3 In addition to possessing all the technical solutions of the above embodiments, the embodiments of this utility model further possess the following technical solutions:

[0066] Test holes 2 are configured as multiple holes circumferentially distributed outside the test hole 1.

[0067] In this embodiment, the test wells 2 are no longer limited to a single well arrangement, but are set as multiple wells, evenly distributed around the periphery of the well 1 being tested, forming a ring-shaped or multi-point surrounding layout centered on the well 1 being tested. This allows for more comprehensive application of hydraulic excitation, resulting in a more uniform and symmetrical seepage field during pumping, effectively avoiding problems such as flow direction deviation or uneven local disturbance that may occur with unilateral pumping. Each test well 2 is constructed according to the same structural standard, that is, in the upper aquifer 100 and aquitard 200 section, an aquitard wall B is used to block the hydraulic connection with the shallow aquifer medium, while in the section extending into the lower aquifer 300, a perforated wall A or a bare hole structure is used to ensure effective communication with the bedrock fissure water, thereby ensuring that each test well 2 can stably extract deep groundwater.

[0068] When multiple test wells 2 are pumped simultaneously, a stable, axisymmetric low-potential zone is formed around the test well 1, significantly enhancing the intensity and range of head disturbance at the bottom of the impermeable layer 200. If the impermeable layer 200 has good overall impermeability, its blocking effect on the upward migration of deep water will keep the water level in the test well 1 relatively stable; conversely, if the impermeable layer 200 has local weak areas, fissures, or seepage channels, the water level in the test well 1 will drop significantly. Since the multiple test wells 2 are circumferentially distributed, their combined effect can amplify the overall response signal of the impermeable layer 200, improving the accuracy and comprehensiveness of the test.

[0069] Differential pumping tests can also be conducted by grouping or individually activating test wells 2 in different orientations. By comparing the differences in water level response of the test wells 1 under different directional excitations, the flexibility and comprehensiveness of the test can be improved.

[0070] Example 5:

[0071] Reference Figures 1-3 In addition to possessing all the technical solutions of the above embodiments, the embodiments of this utility model further possess the following technical solutions:

[0072] The testing system is set up at intervals within the foundation.

[0073] In this embodiment, the testing system can be set up in multiple groups at intervals along key areas or potential risk paths within the foundation area to form a spatially discrete but functionally unified monitoring network. This allows the evaluation of the waterproofing performance to no longer be limited to a single location, but to cover a larger area of ​​the foundation, enabling a systematic comparison and comprehensive analysis of the performance differences of the waterproofing layer 200 in different geographical locations and geological microenvironments.

[0074] Each test system operates independently, and each can pump water from its corresponding test well 2 using its own pumping device 3. The first water level testing device 4 records the water level response process of the test well 1 in real time. Because each group maintains a certain distance from the others, their hydraulic influence zones are independent or only slightly overlap, avoiding signal interference during the test process and ensuring the authenticity and resolvability of each group's data.

[0075] Example 6:

[0076] Reference Figures 1-3 In addition to possessing all the technical solutions of the above embodiments, the embodiments of this utility model further possess the following technical solutions:

[0077] The testing system also includes a second water level testing device for testing the water level height of borehole 2; when the water level height of borehole 2 reaches a threshold, the pumping device 3 extracts the groundwater in borehole 2 and lowers it to the second threshold.

[0078] In this embodiment, the second water level testing device is used to monitor the groundwater level in the test well 2 in real time, forming a closed-loop feedback control for the pumping process.

[0079] This device works in conjunction with the pumping unit 3 to dynamically monitor the water level changes in test well 2 during the pumping process, serving as a key input signal for automatic control of pumping behavior. When the groundwater level in test well 2 rises to a preset first threshold, it indicates that the water supply from the lower aquifer 300 to test well 2 has reached the set monitoring or operational standard. At this point, the system automatically starts the pumping unit 3 to begin pumping groundwater from test well 2, continuing operation until the water level drops to a preset second threshold. Subsequently, the pumping unit 3 stops working and enters a monitoring standby state. This process can be repeated periodically, enabling intermittent and controllable pumping operations for deep groundwater.

[0080] This dual-threshold control-based pumping mode effectively avoids problems such as energy waste, equipment overload, or borehole instability that may occur with traditional continuous pumping. It also ensures consistency in the intensity and duration of each pumping event, improving the comparability and repeatability of data across multiple tests. By confining the pumping behavior to two clearly defined water level intervals, a series of regular hydraulic pulse disturbances can be generated in the tested borehole 1, simulating periodic load changes that may occur in actual engineering, such as rainfall infiltration, tidal effects, or artificial drainage. The first water level testing device 4 in the tested borehole 1 simultaneously records the response characteristics of the water level above the impermeable layer 200 under these pulse disturbances, including parameters such as delay time, fluctuation amplitude, attenuation rate, and recovery speed, thereby more comprehensively revealing the dynamic water-blocking capacity of the impermeable layer 200.

[0081] By setting a reasonable threshold range, the system can automatically adjust the pumping frequency and duration according to the actual replenishment situation, ensuring that effective hydraulic excitation is continuously applied to the bottom of the impermeable layer 200 while preventing local vacuum or soil structure damage caused by excessive pumping. In scenarios where multiple test systems operate in parallel, each test well 2 can independently set threshold parameters to achieve differentiated control and adapt to the differences in formation permeability at different locations.

[0082] Example 7:

[0083] Reference Figures 1-3 In addition to possessing all the technical solutions of the above embodiments, the embodiments of this utility model further possess the following technical solutions:

[0084] The testing system also includes a processing and storage unit 5, which is connected to the first water level testing device 4 and the pumping device 3 to control the operation of the pumping device 3 and record the test values ​​of the first water level testing device 4.

[0085] In this embodiment, the processing and storage unit 5 is connected to the first water level testing device 4 and the pumping device 3 via wired or wireless means to achieve integrated management of data acquisition, process control, and information storage. The processing and storage unit 5 receives water level monitoring signals from the first water level testing device 4 in real time and continuously records the water level changes of the tested well 1 during the pumping process and recovery phase, generating a high-time-resolution water level response curve. Simultaneously, this unit is also linked with the pumping device 3, automatically controlling its start / stop, pumping duration, pumping rate, and other operating parameters based on preset programs or real-time data analysis results, thus achieving intelligent operation of the testing process.

[0086] Under this architecture, the system can autonomously execute a complete test cycle according to a set time series or water level threshold conditions. For example, when the water level of test well 2 reported by the second water level testing device reaches the first threshold, the processing and storage unit 5 receives the signal and immediately triggers the pumping device 3 to start; at the same time, the unit begins high-frequency acquisition of data from the first water level testing device 4, capturing the transient response of the water level of the tested well 1 in the initial stage of the disturbance. After pumping is completed, the system continues to record the recovery process of the water level of the tested well 1, completely saving the full cycle data from the drop to the rise, providing sufficient basis for subsequent analysis.

[0087] It can be understood that, except for conflicting parts, the above embodiments 1-7 can be freely combined to form other embodiments of this utility model.

[0088] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0089] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0090] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0091] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to those processes, articles, or apparatus / devices.

[0092] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

Claims

1. A water-tightness testing system for aquifers in coal mines, suitable for construction on a foundation consisting of an upper aquifer (100), a water-tight layer (200), and a lower aquifer (300) from top to bottom, characterized in that: It includes a test hole (1) and a test hole (2); the test hole (1) extends vertically from the ground through the upper aquifer (100) and to the top of the waterproof layer (200); the test hole (2) is opened on one side of the test hole (1), and passes through the upper aquifer (100) and the waterproof layer (200) in sequence and extends to a first depth in the lower aquifer (300); It also includes a pumping device (3) and a first water level testing device (4), wherein the pumping device (3) is adapted to pump groundwater in the test hole (2), and the first water level testing device (4) is used to test the water level height of the test hole (1) when and / or after the pumping device (3) pumps water.

2. The water-tightness testing system for water-tight layers in coal mines as described in claim 1, characterized in that: The wall of the test hole (1) is made of a water-permeable material; the wall of the test hole (2) corresponding to the upper aquifer (100) and the water-proof layer (200) is made of a water-proof material, and the wall of the test hole corresponding to the lower aquifer (300) is made of a water-permeable material.

3. The water-tightness testing system for water-tight layers in coal mines as described in claim 2, characterized in that: The test hole (2) has a perforated pipe wall (A) corresponding to the lower aquifer (300). The test hole (2) has a water-resistant pipe wall (B) corresponding to the upper aquifer (100) and the water-resistant layer (200); the test hole wall corresponding to the lower aquifer (300) is a perforated pipe wall (A) or a bare hole.

4. The water-tightness testing system for water-tight layers in coal mines as described in claim 1, characterized in that: The test hole (1) extends exactly to the waterproof layer (200).

5. The water-tightness testing system for water-tight layers in coal mines as described in claim 1, characterized in that: The test hole (1) extends to a second depth within the waterproof layer (200).

6. The water-tightness testing system for water-tight layers in coal mines as described in claim 1, characterized in that: The test holes (2) are configured to be multiple and circumferentially distributed outside the test hole (1).

7. The water-tightness testing system for water-tight layers in coal mines as described in claim 1, characterized in that: The testing system is set up in multiple groups at intervals within the foundation.

8. The water-tightness testing system for water-tight layers in coal mines as described in claim 1, characterized in that: It also includes a second water level testing device for testing the water level height of the test hole (2); When the water level in the test hole (2) reaches a threshold, the pumping device (3) extracts the groundwater in the test hole (2) and lowers it to a second threshold.

9. The water-tightness testing system for water-tight layers in coal mines as described in claim 1, characterized in that: It also includes a processing and storage unit (5), which is connected to the first water level testing device (4) and the pumping device (3).

10. The water-tightness testing system for water-tight layers in coal mines as described in any one of claims 1-9, characterized in that: The waterproof layer (200) is a red soil layer.

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