Water pressure drop amplitude and drainage time prediction method applied to underground porous drainage

Abstract

The invention relates to the technical field of water drainage and pressure reduction of a coal mine floor aquifer, in particular to a water pressure reduction amplitude and drainage time prediction method applied to underground porous water drainage. The method comprises the following steps: delineating a water-rich abnormal area by multiple means; obtaining a water guide coefficient and an elastic water release coefficient of the target area based on the group hole water discharge test data; arranging control points at the periphery of the working face, especially at the thin position of the water-resisting layer, calculating the visual water inrush coefficient and determining the designed water level drop depth; predicting drainage time by combining the water guide coefficient and the elastic water release coefficient of each aquifer and the designed water level drop depth of the control point; according to the water-rich abnormal area, reasonably arranging drainage holes and establishing an underground porous drainage system; and the drainage system is further dynamically regulated and controlled to operate by applying the designed water level drop depth and drainage time of the control point. According to the method, the drainage time is predicted in advance, the construction progress arrangement is optimized, and the overall working efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of water drainage and pressure reduction of coal mine floor aquifers, and in particular to a method for predicting water pressure drop amplitude and drainage time for underground multi-hole water drainage. Background Art

[0002] Mine water damage is one of the most serious disasters in coal mining. With the increase of coal mining depth, the water pressure of the aquifer gradually increases, the hydrogeological conditions become increasingly complex, and the problem of deep high-pressure water damage becomes increasingly prominent. Therefore, effective water damage prevention and control measures must be taken to reduce the bottom plate pressure head and ensure that the water pressure of the working face is lower than the safe water pressure.

[0003] Traditional underground drainage systems mainly rely on single-hole or simple multi-hole drainage designs. These systems are usually inefficient in controlling water pressure and cannot accurately predict water pressure changes and drainage time. In addition, existing technologies are also deficient in real-time monitoring and data processing of water pressure changes, resulting in the inability to adjust drainage strategies in a timely manner, thereby increasing construction risks. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a method for predicting the water pressure drop and drainage time for underground multi-hole water drainage. The technical scheme adopted is as follows:

[0005] One embodiment of the present invention provides a method for predicting water pressure drop and drainage time for underground multi-hole water drainage, the method comprising:

[0006] Step S1, delineating the abnormally rich water area by multiple means; obtaining the hydraulic conductivity and elastic water release coefficient of the target area based on the group well water release test data;

[0007] Step S2, arranging control points around the working face, especially where the waterproof layer is thin, calculating the apparent water inrush coefficient and determining the designed water level drawdown;

[0008] Step S3, predicting the drainage time by combining the hydraulic conductivity, elastic water release coefficient and design water level drawdown of each aquifer and the control point;

[0009] Step S4, reasonably arrange drainage holes according to the abnormally rich water area and establish an underground multi-hole drainage system; further use the designed water level drawdown and drainage time of the control point to dynamically control the operation of the drainage system.

[0010] Preferably, the water-abnormal area is delineated, including:

[0011] Geological surveys, geophysical exploration and remote sensing technology are used to comprehensively delineate water-rich abnormal areas.

[0012] Preferably, a group well water release test is used to obtain the hydraulic conductivity and elastic water release coefficient of each aquifer in the target area, including:

[0013] The group borehole discharge test is used to obtain the hydraulic conductivity and elastic water release coefficient of each aquifer in the target area.

[0014] Preferably, calculating the apparent water inrush coefficient of the control point includes:

[0015] The apparent water inrush coefficient of the control point is the ratio of the head pressure borne by the coal seam floor aquiclude at the control point to the thickness of the effective aquiclude.

[0016] Preferably, the design water level drawdown of the control point is:

[0017]

[0018] Among them, s i represents the design water level drawdown of the ith control point; represents the apparent water inrush coefficient of the ith control point; T s represents the critical water inrush coefficient; M i It represents the thickness of the effective impermeable layer of the coal seam floor at the i-th control point.

[0019] Preferably, predicting the drainage time of the control point according to the hydraulic conductivity, elastic water release coefficient and design water level drawdown of each aquifer includes:

[0020] The total hydraulic conductivity of the target area is calculated based on the hydraulic conductivity of each aquifer; the total elastic water release coefficient of the target area is calculated based on the elastic water release coefficient of each aquifer;

[0021] Based on the total hydraulic conductivity and total elastic water release coefficient of the target area, a solution equation for the drainage time is established. The solution equation for the drainage time of the control point is:

[0022]

[0023] Among them, s i represents the design water level drawdown of the ith control point; n represents the number of drainage holes; r j represents the distance between the jth release hole and the i-th control point; t i represents the sparseness time of the i-th control point; y represents the integral variable;

[0024] The decentralization time equation is solved to obtain the decentralization time of the control point.

[0025] Preferably, the underground porous water discharge system comprises:

[0026] The underground porous water discharge system includes a porous water discharge device, a water pressure and flow monitoring device, and a ground control and data processing device; wherein the porous water discharge device includes a discharge hole, a water discharge pipe and a water discharge valve, and the water pressure and flow monitoring device includes a capacitive sensor and an electromagnetic flow meter.

[0027] The embodiments of the present invention have at least the following beneficial effects: the present invention delineates the abnormally rich water area; uses the group borehole water release test to obtain the water conductivity and elastic water release coefficient of each aquifer in the target area; through the comprehensive application of geological survey, geophysical exploration and remote sensing technology, it can make up for the shortcomings of a single method and improve the accuracy and reliability of the delineation results; the group borehole water release test can simulate the hydrogeological conditions in the actual mining process and provide more practical data; through the coordinated test of multiple borehole positions, the hydrogeological parameters at different positions in the region are obtained, and the characteristics of the aquifer are fully understood;

[0028] Furthermore, control points are set, and the design water level drawdown of the control points is calculated through the apparent water inrush coefficient of the control points. Then, the drainage and pressure reduction time of the control points is predicted in combination with the water conductivity and elastic water release coefficient of each aquifer. The drainage and pressure reduction time is predicted in advance, which helps to reasonably arrange the construction progress and improve the overall work efficiency.

[0029] Finally, an underground multi-porous water discharge system is established, and the underground multi-porous water discharge system is controlled to discharge water according to the designed water level drop and drainage time of the control point. This helps to systematically manage the water pressure drop at each control point underground, monitor and control the water pressure and flow changes of each drainage hole in real time, and ensure the drainage and pressure reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A method flow chart of a method for predicting water pressure drop and drainage time for underground multi-hole water drainage provided by an embodiment of the present invention;

[0032] Figure 2 A delineation diagram of abnormal water-rich areas in a coal mine for a method for predicting water pressure drop and drainage time for underground multi-hole drainage provided by an embodiment of the present invention;

[0033] Figure 3 A drainage hole layout diagram for a method for predicting water pressure drop and drainage time for multi-hole water drainage in a well provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation method, structure, features and effects of a method for predicting water pressure drop and drainage time for underground porous water drainage proposed by the present invention in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0035] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0036] The following is a detailed description of a specific scheme of a method for predicting water pressure drop and drainage time for underground multi-hole water drainage provided by the present invention in conjunction with the accompanying drawings.

[0037] Example:

[0038] The main application scenarios of the present invention are: this application delineates water-rich abnormal areas, obtains hydrogeological parameters through large-flow group hole water release tests, and then calculates the water pressure drop at the control point, and predicts the drainage and pressure reduction time at the control point; and then establishes a multi-porous drainage system through the water pressure drop at the control point and the drainage and pressure reduction time at the control point to release water. Its core advantage is that it can effectively improve the drainage and pressure reduction efficiency, which is of great significance for improving the technical means of preventing and controlling water disasters in the coal seam floor and reducing the cost of water disaster prevention and control projects.

[0039] See also Figure 1 , which shows a flow chart of a method for predicting water pressure drop and drainage time for underground multi-hole water drainage provided by an embodiment of the present invention, the method comprising the following steps:

[0040] Step S1, delineate the abnormally water-rich area; and obtain the hydraulic conductivity and elastic water release coefficient of each aquifer in the target area by means of a group well water release test.

[0041] When draining coal mines, it is necessary to obtain abnormal water-rich areas to guide the layout of drainage holes. It is necessary to comprehensively delineate abnormal water-rich areas based on a variety of methods.

[0042] Geological surveys, geophysical exploration and remote sensing technology are used to comprehensively delineate water-rich abnormal areas.

[0043] (1) Geological survey method, including lithology analysis, structural analysis and topography analysis. It was found that the distance between the Cambrian limestone aquifer and the coal seam is between 28.06 and 87.92 m, the water pressure is between 1.78 and 2.71 MPa, and the apparent water inrush coefficient is between 0.024 and 0.077 MPa / m. The Cambrian limestone aquifer is threatened during mining;

[0044] (2) Geophysical exploration method: On the ground, controlled source audio frequency magnetotelluric sounding and transient electromagnetic method are used to conduct geophysical exploration of water in the working face, and to explore the abnormal water-rich areas 10m, 50m, and 80m below the Cambrian limestone on the bottom of the coal seam; transient electromagnetic exploration is used underground to delineate the scope of the water-rich area;

[0045] (3) Using satellite remote sensing images, we analyzed information such as surface temperature, vegetation coverage, and water body distribution to indirectly infer the enrichment of groundwater. The results showed that the target area is a flood and alluvial inclined plain in front of the mountain, with high terrain in the north and low terrain in the south, and well-developed gullies. Part of the atmospheric precipitation is collected in the gullies in the form of surface runoff, and flows out of the well field from north to south; the other part infiltrates into the ground, flows along the gap runoff of flood and alluvial materials, and discharges in the form of springs at the gully cutting part or the Jinghe River Valley. In summary, a comprehensive analysis using a variety of methods was performed, and 38 water-rich anomaly areas were divided according to the different locations of the water-rich areas in the upper Cambrian limestone, such as Figure 2 shown.

[0046] Furthermore, after delineating the abnormally rich water area, it is necessary to obtain the hydrogeological parameters of the target area, and use the group hole water release test to obtain the hydraulic conductivity and elastic water release coefficient of each aquifer in the target area; specifically, a preset number of hydrological holes are designed and constructed to conduct the underground group hole water release test, and two drop-through water release tests are carried out. The total flow rate of the first drop-through water release is 350m 3 / h, the total flow rate of the second drop is 450m 3 / h. Preferably, in the embodiment of the present invention, the number of hydrological holes is 10. The implementer can determine the number of hydrological holes according to actual conditions. When conducting a water release test, the number of drop paths needs to be determined according to actual conditions.

[0047] The group hole water release test is carried out underground, and the equipment includes drilling holes, valves, and common tools include filters, flow meters (or weir boxes), water level meters, water thermometers, timers, etc.

[0048] When conducting a group-hole water release test, the hydrological holes are divided into observation holes and release holes. The water pressure and flow of the observation holes and the release holes are observed synchronously. The observation interval is dense at first and then sparse. From the start of the test, measurements are taken every 1 minute from the 1st to 10th minute, every 2 minutes from the 10th to 20th minute, every 10 minutes from the 20th to 120th minute, and every 30 minutes thereafter.

[0049] A large-scale group-hole drainage test was conducted underground to determine the water conductivity of the first aquifer to be 64.729m 2 / d, the conductivity of the second aquifer is 65.875m 2 / d. The elastic water release coefficient of the first aquifer is 0.000425, and the elastic water release coefficient of the second aquifer is 0.000211. At the same time, the borehole hydrophobicity coefficient of the target area is also obtained to be 35.199min / m 2 , based on this, it can be judged that the limestone aquifer in the bottom of the coal seam is easy to drain.

[0050] Step S2, arrange control points around the working surface and at places where the waterproof layer is thinner, calculate the apparent water inrush coefficient of the control points; and obtain the designed water level drawdown of the control points according to the apparent water inrush coefficient.

[0051] During the coal mining process, stress changes in the goaf will cause the coal seam floor to be damaged, forming a floor disturbance damage zone. The depth of the floor disturbance damage zone directly affects the water pressure requirement of the confined aquifer. The deeper the floor disturbance damage zone, the more the water pressure needs to be reduced to ensure that water does not penetrate into the coal mining area through the damage zone.

[0052] Furthermore, control points are arranged around the working face and at places where the waterproof layer is thinner, and the apparent water inrush coefficient of the control points is calculated. The water pressure drop at the control points is designed based on the standard when the apparent water inrush coefficient drops below the safe value.

[0053] The design of water pressure (level) drop at the control point should use the apparent water inrush coefficient as an important reference for judging the depth of water level drop design. Specifically, control points are arranged around the planned mining working face and where the thickness of the impermeable layer is thin. The distribution of control points is as follows: Figure 3 As shown, A, B, C, D, E, F, G, and H are the control points arranged respectively, and the water level drawdown design of the control points is calculated according to the following formula:

[0054]

[0055] Among them, s i represents the design water level drawdown of the ith control point; represents the apparent water inrush coefficient of the ith control point; T s represents the critical water inrush coefficient; M i T represents the effective waterproof layer thickness of the coal seam floor at the ith control point. s is the critical water inrush coefficient, which is 0.06MPa / m in areas where the bottom plate is structurally damaged, and 0.1MPa / m in areas where the aquiclude is intact and has no fractures or structural damage.

[0056] The apparent water inrush coefficient of the ith control point is the ratio of the water head pressure borne by the aquifer of the coal seam floor at the ith control point to the thickness of the effective aquifer of the coal seam floor at the ith control point. The specific calculation formula is:

[0057]

[0058] in, represents the apparent water inrush coefficient of the ith control point; M i P represents the effective waterproof layer thickness of the coal seam floor at the i-th control point; i It represents the head pressure borne by the aquiclude of coal seam floor at the i-th control point.

[0059] The empirical formula for the thickness of the effective waterproof layer of the coal seam floor at the control point is: M i =M 0i -max(0.7007+0.1079L, 0.303L 0.8 ), where M 0i is the thickness of the coal seam floor impermeable layer at the i-th control point; max(0.7007+0.1079L, 0.303L 0.8 ) is the disturbance damage depth of the bottom plate, L is the width of the working surface, and 1m water column = 0.00981Mpa.

[0060] like Figure 3 As shown, the widths of the working faces 12010, 12030, and 12050 in the present invention are 220m, 200m, and 150m, respectively, using max (0.7007+0.1079L, 0.303L 0.8 ) calculated that the depths of the disturbance and damage zones of the coal seam floor are 23.34m, 21.28m, and 16.68m respectively.

[0061] Considering the depth of coal seam and the thickness of floor waterproof layer, the control points are selected around the working face, and the max(0.7007+0.1079L, 0.303L 0.8 ) The depth of the disturbance and damage zone of the coal seam floor was calculated to be between 14.88 and 23.34 m, with an average of 19.02 m.

[0062] With the apparent water inrush coefficient no greater than 0.06M MPa / m as the goal, control points are arranged around the working face. The designed water level drawdown of each control point is shown in Table 1.

[0063] Table 1 Design of water pressure drop at control point

[0064]

[0065] At this point, the designed water level drawdown of each control point is obtained.

[0066] Step S3, predicting the drainage time of the control point according to the hydraulic conductivity, elastic water release coefficient and designed water level drawdown of each aquifer.

[0067] Next, the Theis formula of unsteady flow is adopted, and the fsolve function in Python is used to solve the group hole drainage and pressure reduction time through a numerical method, and a numerical solution is obtained to predict the drainage and pressure reduction time of the control point. In the embodiment of the present invention, the aquifer is divided into two layers, namely the first aquifer and the second aquifer. In step S1, the hydraulic conductivity of the first aquifer and the second aquifer in the target area, and the elastic water release coefficient of the first aquifer and the second aquifer are obtained; it should be noted that the number of aquifer layers is determined based on the actual geological conditions on site. In the embodiment of the present invention, two aquifer layers are used as an example for explanation. In actual implementation, the number of aquifer layers needs to be determined according to the geological conditions on site.

[0068] Based on the hydraulic conductivity and elastic water release coefficient of the first and second aquifers and the Theis formula, the drainage time of each control point under the group borehole release is calculated.

[0069] First, the total hydraulic conductivity of the target area is calculated according to the hydraulic conductivity of the first aquifer and the second aquifer, where the total hydraulic conductivity of the target area is the weighted sum of the hydraulic conductivity of each aquifer, and the calculation formula is:

[0070] T total =b1T1+b2T2,

[0071] Where T1 and T2 represent the hydraulic conductivity of the first aquifer and the second aquifer, respectively; b1 and b2 represent the first weight coefficient and the second weight coefficient, respectively. Substituting T1 = 64.729 and T2 = 65.875 into the total hydraulic conductivity T total 65.302m 2 / d, the values ​​of the first weight coefficient and the second weight coefficient are both 0.5, and the implementer can adjust them according to the actual situation.

[0072] Then, the total elastic water release coefficient of the target area is calculated according to the elastic water release coefficients of the first aquifer and the second aquifer. The calculation method of the total elastic water release coefficient of the target area is the same as that of the total hydraulic conductivity, which is the weighted sum of the elastic water release coefficients of each aquifer. The calculation formula is:

[0073]

[0074] in, and Respectively represent the elastic water release coefficients of the first aquifer and the second aquifer; a1 and a2 represent the third weight coefficient and the fourth weight coefficient. and The values ​​are 0.000425 and 0.000211 respectively, and the values ​​of a1 and a2 are both 0.5, so the total elastic water release coefficient is 0.000318.

[0075] Then, based on the Theis formula for unsteady flow, the equation for solving the drainage time is constructed by combining the total hydraulic conductivity and the total elastic water release coefficient.

[0076] According to the Theis formula for unsteady flow, the water level drop caused by the drainage hole at any point (observation hole) in the single-hole water discharge test is:

[0077]

[0078] Among them, s represents the water level drawdown generated at any point (observation hole), and W(u) represents the well function.

[0079] According to the superposition principle, the total depth reduction caused by group hole water release at any control point is: Then the equation for solving the sparseness time is:

[0080]

[0081] Among them, s i represents the design water level drawdown of the ith control point; n represents the number of drainage holes; r j represents the distance between the jth release hole and the i-th control point; t i It represents the time taken for the water pressure at the ith control point to reach safety, that is, the drainage time of the ith control point; y represents the integral variable.

[0082] Since the Theis formula contains the exponential integral function W(u), it cannot be solved directly analytically, so the Python "fsolve" function is used to numerically solve the drainage time equation. The time when the water pressure at each control point drops to a safe value is obtained, which is also the drainage time of each control point.

[0083] Combined with the group hole water discharge test, the flow configuration of each discharge hole is shown in Table 2. The drainage time equation is solved to obtain the drainage time of each control point, as shown in Table 3.

[0084] Table 2 Flow configuration of drainage holes (m 3 / h)

[0085] Release hole G1 G2 G3 G4 G5 flow 60 50 60 50 60

[0086] Table 3 Estimated evacuation time of each control point (d)

[0087] Control Points A B C D E F G H Evacuation time 58.416 23.941 40.966 20.028 36.441 40.508 11.628 35.525

[0088] Obviously, the water discharge volume of the group holes is 280m 3 / h, the estimated evacuation time for each control point on the working face is between 11.628 and 58.416 d.

[0089] Step S4, arranging drainage holes according to the abnormally rich water area and establishing an underground multi-porous drainage system; controlling the drainage of the underground multi-porous drainage system based on the designed water level drawdown and drainage drawdown time of the control point.

[0090] Establish an underground porous water discharge system, including: porous water discharge device, water pressure and flow monitoring device, ground control and data processing device.

[0091] The multi-hole drainage device includes: drainage holes, drainage pipes, and drainage valves. The drainage holes are connected to the drainage pipes, and drainage gates are installed on the drainage pipes. The drainage pipes are connected to the underground drainage tunnels. The drainage holes are distributed in different locations underground. The number, diameter, and layout design of the drainage holes are optimized according to the groundwater pressure, rock formation conditions, and drainage requirements; the pipes connecting the drainage holes and the underground drainage system are used to guide the groundwater to be discharged from the drainage holes to the ground or designated drainage locations. The drainage valve is installed on the drainage hole or pipe to control the switch and flow of the water flow.

[0092] Water pressure and flow monitoring device: The water pressure monitoring device uses a capacitive sensor, the flow uses an electromagnetic flowmeter, and the water temperature monitoring device uses a thermal resistor sensor. It centrally collects data from pressure, flow, and water temperature, converts analog signals into digital signals, and transmits and stores them. The water pressure and flow monitoring device is installed at the drainage hole and other key locations to monitor the pressure and flow changes of the drainage hole in real time.

[0093] Ground control and data processing device: The ground control and data processing device is used to centrally manage the operation of the entire multi-hole drainage system, monitor the water pressure and flow of each drainage hole in real time, adjust the switch of the drainage valve and the amount of water released, and predict the water level drop and drainage pressure reduction time of each control point. The operator can use the system to monitor the water pressure and flow data in real time, adjust the switch of the drainage valve and the amount of water released, view the prediction results, and make corresponding operational decisions. Then, the drainage of the underground multi-hole drainage system is controlled in combination with the designed water level drop and drainage time of the control point.

[0094] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The above is a description of a specific embodiment of this specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0095] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for predicting water pressure drop and drainage time for underground multi-hole water drainage, characterized in that: The method includes: Step S1, delineating the abnormally rich water area by multiple means; obtaining the hydraulic conductivity and elastic water release coefficient of the target area based on the group well water release test data; Step S2, arranging control points around the working face, especially where the waterproof layer is thin, calculating the apparent water inrush coefficient and determining the designed water level drawdown; Step S3, predicting the drainage time by combining the hydraulic conductivity, elastic water release coefficient and design water level drawdown of each aquifer and the control point; Step S4, reasonably arrange drainage holes according to the abnormally rich water area and establish an underground multi-hole drainage system; further use the designed water level drawdown and drainage time of the control point to dynamically control the operation of the drainage system.

2. The method for predicting water pressure drop and drainage time for underground multi-hole drainage according to claim 1, characterized in that: The delineated water-abnormal area includes: Geological surveys, geophysical exploration and remote sensing technology are used to comprehensively delineate water-rich abnormal areas.

3. The method for predicting water pressure drop and drainage time for underground multi-hole drainage according to claim 1, characterized in that: The water conductivity and elastic water release coefficient of each aquifer in the target area are obtained by using the group well water release test, including: The group borehole discharge test is used to obtain the hydraulic conductivity and elastic water release coefficient of each aquifer in the target area.

4. The method for predicting water pressure drop and drainage time for underground multi-hole drainage according to claim 1, characterized in that: The calculation of the apparent water inrush coefficient of the control point includes: The apparent water inrush coefficient of the control point is the ratio of the head pressure borne by the coal seam floor aquiclude at the control point to the thickness of the effective aquiclude.

5. The method for predicting water pressure drop and drainage time for underground multi-hole drainage according to claim 1, characterized in that: The design water level drawdown of the control point is: Among them, s i represents the design water level drawdown of the ith control point; represents the apparent water inrush coefficient of the ith control point; T s represents the critical water inrush coefficient; M i It represents the thickness of the effective impermeable layer of the coal seam floor at the i-th control point.

6. The method for predicting water pressure drop and drainage time for underground multi-hole drainage according to claim 1, characterized in that: The method of predicting the drainage time of the control point according to the hydraulic conductivity, elastic water release coefficient and design water level drawdown of each aquifer includes: The total hydraulic conductivity of the target area is calculated based on the hydraulic conductivity of each aquifer; the total elastic water release coefficient of the target area is calculated based on the elastic water release coefficient of each aquifer; Based on the total hydraulic conductivity and total elastic water release coefficient of the target area, a solution equation for the drainage time is established. The solution equation for the drainage time of the control point is: Among them, s i represents the design water level drawdown of the ith control point; n represents the number of drainage holes; r j represents the distance between the jth release hole and the i-th control point; t i represents the sparseness time of the i-th control point; y represents the integral variable; The decentralization time equation is solved to obtain the decentralization time of the control point.

7. The method for predicting water pressure drop and drainage time for underground multi-hole drainage according to claim 1, characterized in that: The underground porous water discharge system comprises: The underground porous water discharge system includes a porous water discharge device, a water pressure and flow monitoring device, and a ground control and data processing device; wherein the porous water discharge device includes a discharge hole, a water discharge pipe and a water discharge valve, and the water pressure and flow monitoring device includes a capacitive sensor and an electromagnetic flow meter.

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