Experimental device and method for simulating inclined drilling water pumping experiment

Abstract

The invention provides an experimental device and method for simulating an inclined drilling water pumping experiment, and relates to the field of hydrogeology, and the experimental device comprises a sand box part, a water tank part, a pressure measuring pipe part and a water pumping well part. The sand box part simulates an aquifer, and simulation of stratigraphic space distribution in an actual situation is realized by controlling the size and combination relation of filler particles in an experiment; the water tank part adjusts water levels at two ends of the sand box and controls the flowing state of underground water in the sand box by adjusting the relative height of the water tanks on two sides; the piezometric tube part measures the water head pressure at different positions of the aquifer in the sand box and depicts the flow field of the sand box in the water pumping experiment; according to the pumping well part, a water pump and a filter pipe form drill holes with different inclination angles according to different experimental purposes. The experiment device can be used for obtaining the water level change rate in the water-bearing layer and the scale of the falling funnel when the water pumping experiment is carried out by drilling holes with different inclination angles, and can monitor the disturbance condition of the flow field in the experiment in real time.

Description

Technical Field

[0001] The present invention relates to the field of hydrogeology, and in particular to an experimental device and method for simulating an inclined borehole pumping experiment. Background Art

[0002] The rapid development of national infrastructure construction in the new era has put forward higher requirements for hydrogeological operations. In the process of solving practical problems, hydrogeological research such as tunnel water inrush prediction and prevention, geothermal water exploitation, utilization and operation often relies on the application of geotechnical experimental technology to accurately obtain key hydrogeological parameters such as groundwater flow characteristics and rock and soil permeability, so as to provide a scientific basis for engineering decision-making. The permeability coefficient is usually obtained by drilling pumping test. Compared with vertical drilling, inclined drilling can control more strata with fewer boreholes in areas with complex geological structures; when the strata are located below rivers and streams, it is difficult to carry out vertical drilling pumping tests, while inclined drilling can drill the boreholes to the required strata on both sides of rivers and streams; for sensitive landforms, inclined wells can also be avoided accordingly. In the current technical background, the inclined hole pumping test directly uses the Dupuit and Thiem formulas of the vertical shaft pumping test for parameter calculation in the indoor calculation stage, and there is a lack of indoor experiments to effectively verify the parameter calculation method. In summary, the inclined borehole pumping test has certain research significance. Summary of the invention

[0003] Based on the actual engineering needs encountered in hydrogeological related fields such as tunnel sudden water inrush prediction and prevention, geothermal water exploitation, etc., in order to study the disturbance law of groundwater flow field caused by inclined drilling pumping test and analyze the differences between inclined well and vertical well pumping experiments, the present invention provides a conveniently adjustable, safe and reliable experimental device and experimental method for vertical well and inclined well pumping experiments.

[0004] An experimental device for simulating an inclined borehole pumping experiment, the experimental device comprising a sand box part A, a water tank part B, a pressure measuring tube part C and a water pump part D;

[0005] The sand box part A includes a sand box baffle, a sand box permeable plate, a pressure measuring point, a vertical shaft, an inclined shaft, and an isolation plate. The sand box baffle and the sand box permeable plate are located at both ends of the sand box part A, and the vertical shaft and the inclined shaft are located in the middle of the sand box part A. The sand box part A is used to simulate the aquifer, and the simulation of the spatial distribution of the stratum in the actual situation is realized by controlling the particle size and combination relationship of the filler in the sand box part A.

[0006] The water tank part B includes a left water tank B1 and a right water tank B2. The two sides of the sand box part A are connected to the left water tank B1 and the right water tank B2 respectively; the left water tank B1 includes a left water tank body, a left water tank height adjustment screw,

[0007] The left sand box water inlet valve, the right water tank B2 includes the right water tank body, the right water tank height adjustment screw, and the right sand box water inlet valve; the water level at both ends of the sand box is adjusted by the water tank part B, and the flow state of groundwater in the sand box is controlled by adjusting the relative height of the water tanks on both sides;

[0008] The piezometric tube part C is used to measure the head pressure at different positions of the aquifer in the sand box and to characterize the flow field of the sand box in the pumping experiment;

[0009] The pumping well part D includes a vertical well pumping pipe, an inclined well pumping pipe, a pumping pump, and a pumping pump outlet pipe; the pumping well part D is connected to the vertical well through the vertical well pumping pipe, and is connected to the inclined well through the inclined well pumping pipe; the pumping well part D is used to form boreholes with different inclinations by the pumping pump and the filter pipe according to different experimental purposes;

[0010] According to the lithological characteristics of the strata, sand samples with different particle size distribution and permeability characteristics are filled in the sand box, and the experimental device is used to realize the proportional reduction simulation of the strata in the project area; by obtaining the water level change rate and the size of the drop funnel in the aquifer when conducting pumping experiments with boreholes at different inclinations, the disturbance of the flow field during the experiment can be monitored in real time; by conducting sand box pumping experiments, the groundwater flow state in the sand box is monitored and analyzed, so as to obtain the dynamic distribution data of the flow field, and analyze the differences and change laws of the flow field distribution.

[0011] An experimental method for simulating an inclined borehole pumping experiment is implemented based on the experimental device, and the experimental method comprises the following steps:

[0012] ①Device installation

[0013] Connect the left water tank body to the sand box through the left water tank sand box connecting pipe; connect the right water tank body to the sand box through the right water tank sand box connecting pipe; connect the pressure measuring pipes at the pressure measuring points in the order from top to bottom and from left to right, and arrange them on the pressure measuring panel;

[0014] ②Sand sample filling

[0015] After the device is installed, sand of the required particle size for the experiment is sieved through a sand and gravel sieve, and the sand is filled into the sand box on both sides of the isolation plate (6), and the filling should be compacted layer by layer; to simulate different aquifer conditions, different sand filling methods are required. This experiment adopts three sand filling modes: sand and gravel of the same particle size are evenly spread throughout the sand box to simulate homogeneous isotropic aquifer conditions; sand and gravel of different particle sizes are layered and horizontally loaded into the sand box to simulate horizontally distributed strong and weak interlayer aquifer conditions; sand and gravel of different particle sizes are layered and tilted into the sand box to simulate non-horizontal aquifer conditions; the sand sample is bounded by the permeable plate, the panel where the pressure measuring point is located, and the isolation plate;

[0016] ③ After the sand sample is filled, adjust the height adjustment screw of the left water tank and the right water tank so that the left water tank body and the right water tank body are at the same height, and open the left sand box water inlet valve and the right sand box water inlet valve; the water tank supplies water to the left water tank body and the right water tank body through the left water tank inlet and the right water tank inlet, and the water in the water tank flows to the sand box through the left water tank sand box connecting pipe and the right water tank sand box connecting pipe respectively, and fills the sand sample aquifer with water under the control of the acrylic hole plate and the gauze of the permeable plate. When the water levels on the left and right sides of the sand box aquifer reach the heights of the overflow plate of the left water tank and the overflow plate of the right water tank respectively, the water levels of the water tanks on the left and right sides no longer rise. At this time, the water in the left and right water tanks respectively crosses the left overflow plate and the right overflow plate and flows out from the left overflow outlet and the right overflow outlet, thereby controlling the water levels on both sides of the sand box to remain constant; the permeable plates on the left and right sides are fixed head boundaries, and the isolation plate and the panel where the pressure measuring point is located are water-proof boundaries.

[0017] ④ Use a water pump to pump water from the vertical shaft and the inclined shaft, turn on the power of the water pump, insert the vertical shaft pumping pipe and the inclined shaft pumping pipe into the vertical shaft and the inclined shaft respectively, set the pumping flow rate of the water pump, start the water pump to pump water from the vertical shaft and the inclined shaft, and the water in the vertical shaft and the inclined shaft is discharged through the water outlet pipe of the water pump.

[0018] ⑤ Regularly observe the pressure measuring panel and record the water head size of the vertical well and the inclined well, analyze the similarities and differences in the water head change laws of the vertical well and the inclined well during the pumping process, and when the water level in the vertical well and the inclined well remains stable, observe the pressure measuring panel, record the water head data of the pressure measuring tube, and characterize the water head line and streamline of the sand box according to the principle of interpolation to analyze whether there is a difference in the flow field between the vertical well and the inclined well; if there is no difference, it means that the inclined well pumping experiment and the vertical well pumping experiment have the same disturbance on the sand box flow field. In this case, the actual project adopts the inclined well pumping test to obtain the permeability coefficient of the aquifer, and the vertical well pumping test parameter determination method can be directly used; if there is a difference, the difference in flow field between the vertical well pumping test and the inclined well pumping test is used to derive the correction method and correction coefficient for the inclined well pumping parameter determination; there may be differences in the corresponding correction methods and correction coefficients for different geological structures. The device is used to simulate different geological structures, and finally the laboratory model is proportionally enlarged and applied to the engineering area to realize the inclined well pumping test parameter determination work in the project;

[0019] ⑥ Stop pumping, and when the sand box reaches the initial state again, modify the pumping flow rate of the pump and start pumping. When the water level in the vertical and inclined wells remains stable, observe the pressure measuring panel, record the water head data of the pressure measuring tube, and characterize the water head line and streamline of the sand box according to the principle of interpolation to analyze whether there is any difference in the flow field between the vertical and inclined wells;

[0020] ⑦ Adjust the height adjustment screw of the left water tank to lower the height of the left water tank, so that the water level on the left side of the sand box drops. After the water level remains stable, repeat steps ④-⑥; Adjust the height adjustment screw of the left water tank to restore the water level of the left water tank to be flush with the right side, adjust the height adjustment screw of the right water tank to lower the height of the right water tank, so that the water level on the right side of the sand box drops, and repeat steps ④-⑥;

[0021] Taking into account the actual needs of hydrogeological engineering, sand samples with different particle size distribution and permeability characteristics are filled in the sand box according to the lithological characteristics of the strata, and the experimental device is used to realize the proportional reduction simulation of the strata in the engineering area; by carrying out sand box pumping experiments, the groundwater flow state in the sand box is monitored and analyzed, so as to obtain the dynamic distribution data of the flow field, and analyze the differences and changing laws of the flow field distribution.

[0022] The beneficial effects of the present invention are as follows: the present invention takes into account the actual needs of hydrogeological engineering, utilizes the geological profile data obtained by geophysical exploration (geophysical exploration) and drilling technology, and fills sand samples with different particle size distributions and permeability characteristics in the sand box according to the lithological characteristics of the strata, so as to realize the proportional reduction simulation of the strata in the engineering area. By controlling the size and combination relationship of the filling particles, the simulation of the spatial distribution of the strata in the actual situation is realized; the water tank part adjusts the water level at both ends of the sand box, and controls the flow state of groundwater in the sand box by adjusting the relative height of the water tanks on both sides; the pressure measuring tube part measures the head pressure at different positions of the aquifer in the sand box, and depicts the flow field of the sand box in the pumping experiment; the pumping well part is composed of a pump and a filter tube to form boreholes with different inclinations according to different experimental purposes, which is used to obtain the water level change rate and the scale of the drop funnel in the aquifer when the pumping experiment is carried out in boreholes with different inclinations, and can monitor the disturbance of the flow field in the experiment in real time. By conducting sand box pumping experiments, monitoring and analyzing the groundwater flow state in the sand box, the dynamic distribution data of the flow field is obtained, which is further expanded to the entire project area through scale conversion and spatial interpolation technology, providing more accurate simulation results for hydrogeological analysis and engineering geological evaluation; it provides scientific and quantitative decision-making support for engineering hydrogeological risk assessment, groundwater resource management, and anti-seepage design. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of an experimental device and method for simulating an inclined borehole water pumping experiment proposed by the present invention.

[0024] Figure 2 A top view of an experimental device and method for simulating an inclined borehole water pumping experiment proposed by the present invention.

[0025] Figure 3 A three-dimensional diagram of an experimental device and method for simulating an inclined borehole water pumping experiment proposed by the present invention.

[0026] Figure 4This is a two-layer structure diagram of the water-permeable board in the present invention.

[0027] Figure 5 It is a mean isotropic uniform sand filling method.

[0028] Figure 6 It is an anisotropic horizontal sand filling method.

[0029] Figure 7 It is an anisotropic inclined sand filling method. DETAILED DESCRIPTION

[0030] Example 1

[0031] An experimental device simulating an inclined borehole pumping experiment Figure 1 As shown, the experimental device includes a sand box part A, a water tank part B, a pressure measuring tube part C and a water pump part D; the sand box part A includes a sand box baffle 1, a sand box permeable plate 2, a pressure measuring point 3, a vertical shaft 4, an inclined shaft 5, an isolation plate 6, and a moving wheel 7; the water tank part B includes a left water tank B1 and a right water tank B2, the left water tank B1 includes a left water tank body 8, a left water tank height adjustment screw 9, and a left sand box water inlet valve 10, and the right water tank B2 is the same as the left water tank B1, including a right water tank body 11, a right water tank height adjustment screw 12, and a right sand box water inlet valve 13; the pressure measuring tube part C includes a pressure measuring panel 14 and a pressure measuring tube 15; the water pumping well part D includes a vertical shaft water pumping pipe 16, an inclined shaft water pumping pipe 17, a water pump 18, and a water pump outlet pipe 19.

[0032] like Figure 2 , Figure 3 As shown, the left water tank body 8 includes a left water tank water inlet 20, a left water tank sand box connecting pipe 21, a left overflow plate 22, and a left overflow outlet 23; the right water tank body 11 includes a right water tank water inlet 24, a right water tank sand box connecting pipe 25, a right overflow plate 26, and a right overflow outlet 27; the water trough is connected to the water tank water inlet through a water pipe to replenish water to the water tank, and the water tank is connected to the sand box through the water tank sand box connecting pipe, and the sand box water inlet valve is controlled to store water in the sand box. The water level in the water tank stops rising when it reaches the overflow plate, and the overflow water flows out from the overflow outlet, thereby controlling the water head of the water tank to remain unchanged.

[0033] like Figure 3 As shown, the height of the water tanks on the left and right sides is controlled by the left water tank height adjusting screw 9 and the right water tank height adjusting screw 12, which are marked with scales. By adjusting the height of the water tanks on both sides, the distribution and change law of the flow field in the sand box after pumping under different conditions are simulated, and the difference in flow field of the sand box between the vertical well pumping experiment and the inclined well pumping experiment is compared.

[0034] like Figure 4As shown, the sand box water-permeable plate 2 includes an acrylic perforated plate 28 and a gauze 29 , wherein the gauze allows water to pass but not sand, thereby ensuring that the sand can be sealed in the sand box, while water can enter the sand box through the sand box water-permeable plate 2 .

[0035] Pressure measuring points 3 are evenly set on the front and back of the sand box. Pressure measuring points are connected to pressure measuring tubes. The water head values ​​at different depths and sections in the sand box are obtained by reading the pressure measuring tubes, which can describe the flow field distribution in the sand box. The pressure measuring tube connection method is: connect the pressure measuring tubes in the order from top to bottom and from left to right. Figure 1 This is the connection method of the first column of pressure measuring points; after connection, the pressure measuring tubes connected to a column of pressure measuring points in the pressure measuring panel are a group, each representing the water head on a section. The water head value of the pressure measuring points on a certain plane in different groups from left to right can reflect the distribution of the flow field in the sand box; pressure measuring points are set along a straight line at the bottom of the sand box, one of which passes through the bottom of the pumping well and is used to measure the well water level. The pressure measuring tube connected to the pressure measuring point at the bottom of the sand box is placed at the end of the pressure measuring panel.

[0036] The sand box is divided into two parts by a partition plate 6, a vertical shaft pumping sand box and an inclined shaft pumping sand box; pressure measuring points are set on both sides of the vertical shaft and the inclined shaft and connected to pressure measuring tubes. The pressure tube water head can characterize the flow field and can be used to test the flow field distribution of the vertical shaft and inclined shaft pumping experiments.

[0037] By changing the particle size of the sand sample filled in the sand box and the filling method, different aquifer conditions can be simulated. Figure 5 Sand and gravel of the same particle size are evenly spread throughout the sand box to simulate homogeneous isotropic aquifer conditions;

[0038] Figure 6 Sand and gravel with different particle sizes are loaded horizontally into a sand box to simulate the conditions of horizontally distributed strong and weak interbedded aquifers;

[0039] Figure 7 Sand and gravel of different particle sizes were loaded into the sand box in layers and tilted to simulate the conditions of non-horizontal aquifers.

[0040] Example 2

[0041] Follow the steps below to simulate the inclined borehole pumping experiment:

[0042] ① Such as Figure 1 As shown, prepare the experimental device, connect the left water tank body 8 to the sand box through the left water tank sand box connecting pipe 16; connect the right water tank body 11 to the sand box through the right water tank sand box connecting pipe 25; connect the pressure measuring pipes at the pressure measuring point 3 in the order from top to bottom and from left to right, as shown in FIG. Figure 1 This is the connection method for the first column of pressure measuring points. Use this connection method to connect the pressure measuring points of all columns in sequence.

[0043] ② After the device is installed, use the sand and gravel sieve to sift the sand of the required particle size for the experiment, and fill the sand into the sand box on both sides of the isolation plate 6. Pay attention to compacting layer by layer when filling; to simulate different aquifer conditions, different sand filling methods are required. This experiment uses three sand filling modes: evenly spread the sand and gravel of the same particle size throughout the sand box to simulate the homogeneous isotropic aquifer conditions; load sand and gravel of different particle sizes into the sand box in layers and horizontally to simulate the horizontally distributed strong and weak interlayer aquifer conditions; load sand and gravel of different particle sizes into the sand box in layers and tilted to simulate the non-horizontal aquifer conditions. The sand sample is bounded by the permeable plate 2, the panel where the pressure measuring point 3 is located, and the isolation plate 6;

[0044] ③ After the sand sample is filled, adjust the height adjustment screw 9 of the left water tank and the height adjustment screw 12 of the right water tank so that the left water tank body 8 and the right water tank body 11 are at the same height, open the left sand box water inlet valve 10 and the right sand box water inlet valve 13; the water tank supplies water to the left water tank body 8 and the right water tank body 11 through the left water tank water inlet 20 and the right water tank water inlet 24, and the water in the water tank is respectively supplied to the left water tank sand box connecting pipe 21 and the right water tank sand box connecting pipe 25. The sand box flows, and the sand sample aquifer is filled with water under the control of the acrylic hole plate 28 and the gauze 29 of the permeable plate 2. When the water levels on the left and right sides of the sand box aquifer reach the heights of the overflow plate 22 and the overflow plate 26 of the left and right water tanks, respectively, the water levels of the left and right water tanks no longer rise. At this time, the water in the left and right water tanks respectively crosses the left overflow plate 22 and the right overflow plate 26 and flows out from the left overflow outlet 23 and the right overflow outlet 27, thereby controlling the water levels on both sides of the sand box to remain constant. The permeable plates 2 on the left and right sides are the fixed head boundaries, and the isolation plate 6 and the panel where the pressure measuring point 3 is located are the water-proof boundaries.

[0045] ④ Use the water pump 18 to pump water from the vertical shaft and the inclined shaft, turn on the power of the water pump, insert the vertical shaft pumping pipe 16 and the inclined shaft pumping pipe 17 into the vertical shaft and the inclined shaft respectively, set the water flow rate of the water pump, start the water pump to pump water from the vertical shaft and the inclined shaft, and the water in the vertical shaft and the inclined shaft is discharged through the water pump outlet pipe 19.

[0046] ⑤ When the water level in the vertical well and the inclined well remains stable, observe the pressure measuring panel, record the water head data of the pressure measuring tube, characterize the water head line and streamline of the sand box according to the principle of interpolation, and analyze whether there is a difference in the flow field between the vertical well and the inclined well; if there is no difference, it means that the disturbance of the sand box flow field by the inclined well pumping experiment and the vertical well pumping experiment is consistent. In this case, the vertical well pumping test method can be directly used to obtain the permeability coefficient of the aquifer in the actual project; if there is a difference, the correction method and correction coefficient of the inclined well pumping test are derived by using the flow field difference between the vertical well pumping test and the inclined well pumping test; there may be differences in the correction method and correction coefficient corresponding to different geological structures. The device is used to simulate different geological structures, and finally the laboratory model is proportionally enlarged and applied to the engineering area to realize the work of obtaining the parameters of the inclined well pumping test in the project.

[0047] When there are differences, on the basis of the vertical shaft parameter, the device is used to correct the vertical shaft parameter, so as to obtain accurate relevant parameters. For example, after filling the sand, the vertical shaft pumping formula is used to obtain the permeability coefficient of the sand sample, and then the vertical shaft parameter method is directly used to obtain the permeability coefficient of the sand box sand sample of the inclined well experiment. Because different sand samples may have different differences (or there may be no differences), it is necessary to conduct multiple experiments to find the corresponding rules, and use this rule in combination with the vertical shaft parameter to obtain the final required parameters. For example, when a certain type of sand sample is used to obtain parameters using the inclined well experiment, it is necessary to multiply it by a certain multiple after obtaining it using the vertical shaft formula, but the specific multiple is unknown before the experiment. After multiple experiments using this device, the corresponding multiple rule can be obtained, and the final parameters of the inclined well pumping test can be obtained by multiplying the vertical shaft formula by this multiple.

[0048] ⑥ Stop pumping, and when the sand box reaches the initial state again, modify the pumping flow rate of the pump and start pumping. When the water level in the vertical and inclined wells remains stable, observe the pressure measuring panel, record the water head data of the pressure measuring tube, and characterize the water head lines and streamlines of the sand box based on the principle of interpolation to analyze whether there are differences in the flow fields of the vertical and inclined wells.

[0049] ⑦ Adjust the left water tank height adjustment screw 9 to lower the left water tank height and lower the water level on the left side of the sand box. After the water level remains stable, repeat steps ④-⑥. Adjust the left water tank height adjustment screw 9 to restore the water level of the left water tank to the same level as the right side. Adjust the right water tank height adjustment screw 11 to lower the right water tank height and lower the water level on the right side of the sand box. Repeat steps ④-⑥.

[0050] Considering the actual needs of hydrogeological engineering, the experimental device can use the geological profile data obtained by geophysical exploration (geophysical exploration) and drilling technology, fill the sand box with sand samples of different particle size distribution and permeability characteristics according to the lithological characteristics of the stratum, and realize the proportional reduction simulation of the stratum in the engineering area. By controlling the particle size and combination relationship of the filler, the irregular wedge-shaped impermeable material is placed in the sand sample of the sand box to simulate the situation when there is an impermeable layer in the actual geological structure, so as to realize the simulation of the spatial distribution of the stratum in the actual situation; by carrying out the sand box pumping experiment, the groundwater flow state in the sand box is monitored and analyzed, so as to obtain the dynamic distribution data of the flow field, and further expand it to the entire engineering area through scale conversion and spatial interpolation technology, so as to provide more accurate simulation results for hydrogeological analysis and engineering geological evaluation; and provide scientific and quantitative decision support for engineering hydrogeological risk assessment, groundwater resource management and anti-seepage design.

[0051] 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. An experimental device for simulating inclined borehole pumping experiment, characterized in that: The experimental device includes a sand box part A, a water tank part B, a pressure measuring tube part C and a water pump part D; The sand box part A comprises a sand box baffle (1), a sand box permeable plate (2), a pressure measuring point (3), a vertical shaft (4), an inclined shaft (5), and an isolation plate (6). The sand box baffle (1) and the sand box permeable plate (2) are located at two ends of the sand box part A, and the vertical shaft (4) and the inclined shaft (5) are located in the middle of the sand box part A. The sand box part A is used to simulate an aquifer, and by controlling the particle size and combination relationship of the filler in the sand box part A, the simulation of the spatial distribution of the strata in the actual situation is realized. The water tank part B comprises a left water tank B1 and a right water tank B2, and the two sides of the sand box part A are respectively connected to the left water tank B1 and the right water tank B2; the left water tank B1 comprises a left water tank body (8), a left water tank height adjustment screw rod (9), and a left sand box water inlet valve (10); the right water tank B2 comprises a right water tank body (11), a right water tank height adjustment screw rod (12), and a right sand box water inlet valve (13); the water levels at both ends of the sand box are adjusted by the water tank part B, and the flow state of groundwater in the sand box is controlled by adjusting the relative heights of the water tanks on both sides; The piezometric tube part C is used to measure the head pressure at different positions of the aquifer in the sand box and to characterize the flow field of the sand box in the pumping experiment; The pumping well portion D comprises a vertical well pumping pipe (16), an inclined well pumping pipe (17), a pumping pump (18), and a pumping pump outlet pipe (19); the pumping well portion D is connected to the vertical well (4) through the vertical well pumping pipe (16), and is connected to the inclined well (5) through the inclined well pumping pipe (17); the pumping well portion D is used to form boreholes with different inclinations by the pumping pump and the filter pipe according to different experimental purposes; According to the lithological characteristics of the strata, sand samples with different particle size distribution and permeability characteristics are filled in the sand box, and the experimental device is used to realize the proportional reduction simulation of the strata in the project area; by obtaining the water level change rate and the size of the drop funnel in the aquifer when conducting pumping experiments with boreholes at different inclinations, the disturbance of the flow field during the experiment can be monitored in real time; by conducting sand box pumping experiments, the groundwater flow state in the sand box is monitored and analyzed, so as to obtain the dynamic distribution data of the flow field, and analyze the differences and change laws of the flow field distribution.

2. The experimental device for simulating inclined borehole pumping experiment according to claim 1, characterized in that: The left water tank body (8) comprises a left water tank water inlet (20), a left water tank sand box connecting pipe (21), a left overflow plate (22), and a left overflow outlet (23). The left overflow plate (22) is located between the left water tank water inlet (20) and the left overflow outlet (23). The left water tank body (8) is connected to the sand box part A via the left water tank sand box connecting pipe (21). The left water tank sand box connecting pipe (21) is provided with a left sand box water inlet valve (10). The right water tank body (11) comprises a right water tank water inlet (24), a right water tank sand box connecting pipe (25), a right overflow plate (26), and a right overflow outlet (27); the right overflow plate (26) is located between the right water tank water inlet (24) and the right overflow outlet (27); the right water tank body (11) is connected to the sand box part A through the right water tank sand box connecting pipe (25); and a right sand box water inlet valve (13) is provided on the right water tank sand box connecting pipe (25); The water tank is connected to the water inlet of the water tank through a water pipe to replenish water to the water tank. The water tank is connected to the sand box through the water tank sand box connecting pipe. The sand box water inlet valve is controlled to store water in the sand box. After the water level in the water tank reaches the height of the overflow plate, it will no longer rise, and the overflow water will flow out from the overflow outlet, thereby controlling the water head of the water tank to remain unchanged.

3. The experimental device for simulating inclined borehole pumping experiment according to claim 1, characterized in that: The heights of the water tanks on the left and right sides are controlled by a left water tank height adjustment screw rod (9) and a right water tank height adjustment screw rod (12), which are marked with scales. The heights of the water tanks on the two sides are adjusted to simulate the distribution and change law of the flow field in the sand box after pumping water under different initial conditions, and then compare the flow field differences between the vertical well pumping experiment and the inclined well pumping experiment.

4. The experimental device for simulating inclined borehole pumping experiment according to claim 1, characterized in that: The sand box part A is provided with sand box water-permeable plates (2) on both sides. The sand box water-permeable plates (2) include acrylic perforated plates (28) and gauze (29). The gauze (29) allows water to pass but not sand to pass, so as to ensure that the sand is sealed in the sand box, while water can enter the sand box through the sand box water-permeable plates (2); water in the water tanks on the left and right sides enters the sand box part A through the left water tank sand box connecting pipe (21) and the right water tank sand box connecting pipe (25), and fills the sand sample in the sand box with water through the sand box water-permeable plates (2).

5. The experimental device for simulating inclined borehole pumping experiment according to claim 1, characterized in that: The pressure measuring tube part C comprises a pressure measuring panel (14) and a pressure measuring tube (15); a plurality of pressure measuring points (3) are arranged on the front, back and bottom of the sand box, and the pressure measuring points (3) are connected with pressure measuring tubes (15) and are arranged in order in the pressure measuring panel (14). By reading the data of the pressure measuring tubes, the water head values ​​of different pressure measuring points (3) are obtained, and the flow field of the sand box in the pumping test is described.

6. The experimental device for simulating inclined borehole pumping experiment as claimed in claim 5, characterized in that: The isolation plate (6) separates the sand box part A into two parts: a vertical shaft pumping sand box and an inclined shaft pumping sand box; the water head value of the pressure measuring tube (15) connected to the sand box for the pressure measuring point is read to obtain the flow field distribution of the vertical shaft and inclined shaft pumping experiments, which is used to analyze the difference and change law of the flow field distribution of the vertical shaft pumping sand box and the inclined shaft pumping sand box.

7. The experimental device for simulating inclined borehole pumping experiment as claimed in claim 6, characterized in that: The sand box simulates different aquifer conditions through different sand filling methods. Sand and gravel of the same particle size are evenly spread throughout the sand box to simulate the homogeneous isotropic aquifer conditions; sand and gravel of different particle sizes are loaded horizontally into the sand box in layers to simulate the horizontally distributed strong and weak interlayered aquifer conditions; sand and gravel of different particle sizes are loaded obliquely into the sand box in layers to simulate the non-horizontal aquifer conditions.

8. The experimental device for simulating inclined borehole pumping experiment according to claim 1, characterized in that: The sand box part A also includes a moving wheel (7), through which the sand box part A can be freely moved so as to adjust the distance between the experimental devices at any time and conduct experiments better.

9. An experimental method for simulating an inclined borehole pumping experiment, implemented based on the experimental device according to any one of claims 1 to 8, characterized in that: The experimental method includes the following steps: ①Device installation The left water tank body (8) is connected to the sand box via the left water tank sand box connecting pipe (16); the right water tank body (11) is connected to the sand box via the right water tank sand box connecting pipe (25); the pressure measuring pipe (15) is connected to the pressure measuring point (3) in the order from top to bottom and from left to right, and arranged on the pressure measuring panel (14); ②Sand sample filling After the device is installed, sand of the required particle size for the experiment is sieved through a sand and gravel sieve, and the sand is filled into the sand box on both sides of the isolation plate (6), and the filling should be compacted layer by layer; to simulate different aquifer conditions, different sand filling methods are required. This experiment adopts three sand filling modes: sand and gravel of the same particle size are evenly spread throughout the sand box to simulate homogeneous isotropic aquifer conditions; sand and gravel of different particle sizes are layered and horizontally loaded into the sand box to simulate horizontally distributed strong and weak interlayer aquifer conditions; sand and gravel of different particle sizes are layered and tilted into the sand box to simulate non-horizontal aquifer conditions; the sand sample is bounded by the permeable plate (2), the panel where the pressure measuring point (3) is located, and the isolation plate (6); ③ After the sand sample is loaded, the left water tank height adjustment screw rod (9) and the right water tank height adjustment screw rod (12) are adjusted so that the left water tank body (8) and the right water tank body (11) are at the same height, and the left sand box water inlet valve (10) and the right sand box water inlet valve (13) are opened; the water tank supplies water to the left water tank body (8) and the right water tank body (11) through the left water tank water inlet (20) and the right water tank water inlet (24), and the water in the water tank flows to the sand box through the left water tank sand box connecting pipe (21) and the right water tank sand box connecting pipe (25), and flows into the sand box through the acrylic on the permeable plate (2). The sand sample aquifer is filled with water under the control of the perforated plate (28) and the gauze (29). When the water levels on the left and right sides of the sand box aquifer reach the heights of the overflow plate (22) of the left water tank and the overflow plate (26) of the right water tank, respectively, the water levels of the water tanks on the left and right sides no longer rise. At this time, the water in the water tanks on the left and right sides respectively flows over the overflow plate (22) of the left side and the overflow plate (26) of the right side and flows out from the overflow outlet (23) of the left side and the overflow outlet (27) of the right side, thereby controlling the water levels on both sides of the sand box to remain constant. The permeable plates (2) on the left and right sides are the fixed water head boundaries, and the isolation plate (6) and the panel where the pressure measuring point (3) is located are the water-proof boundaries. ④ Use a water pump (18) to pump water from the vertical shaft and the inclined shaft, connect the water pump power supply, insert the vertical shaft water pumping pipe (16) and the inclined shaft water pumping pipe (17) into the vertical shaft and the inclined shaft respectively, set the water pumping flow rate of the water pump, start the water pump to pump water from the vertical shaft and the inclined shaft, and the water in the vertical shaft and the inclined shaft is discharged through the water pump outlet pipe (19); ⑤ Regularly observe the pressure measuring panel (14) and record the water head size of the vertical well and the inclined well, analyze the similarities and differences in the water head change rules of the vertical well and the inclined well during the pumping process, and when the water level in the vertical well and the inclined well remains stable, observe the pressure measuring panel, record the water head data of the pressure measuring tube, and characterize the water head line and streamline of the sand box according to the principle of interpolation to analyze whether there is a difference in the flow field between the vertical well and the inclined well; if there is no difference, it means that the disturbance of the sand box flow field by the inclined well pumping experiment and the vertical well pumping experiment is consistent, and the actual project adopts the inclined well pumping test to obtain the permeability coefficient of the aquifer, and the vertical well pumping test parameter determination method can be directly used; if there is a difference, the correction method and correction coefficient of the inclined well pumping test are derived by using the flow field difference between the vertical well pumping test and the inclined well pumping test; the correction method and correction coefficient corresponding to different geological structures may be different, and the device is used to simulate different geological structures, and finally the laboratory model is scaled up and applied to the engineering area to realize the inclined well pumping test parameter determination work in the engineering; ⑥ Stop pumping water, and when the sand box reaches the initial state again, modify the pumping flow rate of the pump and start pumping water. When the water level in the vertical well and the inclined well remains stable, observe the pressure measuring panel (14), record the water head data of the pressure measuring tube (15), and characterize the water head line and streamline of the sand box according to the principle of interpolation to analyze whether there is any difference in the flow field between the vertical well and the inclined well; ⑦ Adjust the left water tank height adjustment screw (9) to lower the left water tank height so that the water level on the left side of the sand box drops. After the water level remains stable, repeat steps ④-⑥; Adjust the left water tank height adjustment screw (9) to restore the water level on the left water tank to be flush with the right side, adjust the right water tank height adjustment screw (11) to lower the right water tank height so that the water level on the right side of the sand box drops, and repeat steps ④-⑥; Taking into account the actual needs of hydrogeological engineering, sand samples with different particle size distribution and permeability characteristics are filled in the sand box according to the lithological characteristics of the strata, and the experimental device is used to realize the proportional reduction simulation of the strata in the engineering area; by carrying out sand box pumping experiments, the groundwater flow state in the sand box is monitored and analyzed, so as to obtain the dynamic distribution data of the flow field, and analyze the differences and changing laws of the flow field distribution.

Images