Vertical shaft and formation coordination-slip interface water conduction mechanism testing system and method

Abstract

The present invention provides a test system and method for the water conduction mechanism of the coordinated-slip interface of a vertical shaft and a formation, comprising a model box, a shaft, a formation, a water pressure control component, a horizontal ground pressure control component, a sliding control component, a data acquisition component, a data acquisition instrument and a computer, wherein the model box is used to accommodate the formation, and the shaft vertically penetrates the model box and the formation; the water pressure control component can fill water into the formation, and the water pressure control component can control the water pressure of the formation; the horizontal ground pressure control component is used to provide horizontal ground pressure for the formation; the sliding control component is used to provide downward sliding force for the shaft; the data acquisition component is connected to the data acquisition instrument, and the data acquisition instrument is connected to the computer. The test system can be used to explore the evolution characteristics of the water conduction channel and the law of groundwater seepage, and reveal the water conduction disaster mechanism of the interface of the abandoned shaft coal mining.

Description

Technical Field

[0001] The invention relates to the field of mining, and in particular to a system and method for testing a vertical shaft shaft and stratum cooperative-slip interface water conduction mechanism. Background Art

[0002] With the exploitation of coal resources, some old mining areas are facing closure or have been closed. If the mines in such old mining areas are closed directly, it will cause a waste of resources. According to the "Specifications for the Retention and Compressed Coal Mining of Coal Pillars in Buildings, Water Bodies, Railways and Main Shafts and Lanes" (2017 Edition), the protective coal pillars of the shafts that are about to be scrapped should be recovered under the conditions of safety.

[0003] In the case of compressed coal mining with thick, loose layers overlying rich water and thin bedrock, the movement of overburden caused by mining will lead to changes in the stress field between the abandoned shaft and the overlying strata, and there is a risk of triggering the discharge of water diversion channels in the thick and loose aquifers, resulting in sudden water and sand gushing and disasters. How to safely and effectively recover coal resources under abandoned shafts with thick, loose layers overlying rich water and thin bedrock has become a technical problem that needs to be solved urgently in many old mining areas waiting to be closed. At present, there is little research on the water hazards caused by compressed coal mining in abandoned shafts triggering the discharge of water diversion channels in the thick and loose aquifers to open the water-rich thick and loose layers overlying the working face, which in turn causes flooding of the well or sudden water and sand gushing to the working face.

[0004] Therefore, there is an urgent need to develop a test system for the water conduction mechanism of the coordination-slip interface between the shaft and the stratum and to determine the test method, to carry out research on the evolution mechanism of the water conduction channel between the overlying strata and the shaft in abandoned shaft coal compression mining and the water conduction disaster mechanism in abandoned shaft coal compression mining in thick loose layers, so as to ensure the safe mining of the protective coal pillar of abandoned shafts in old mining areas. Summary of the invention

[0005] The purpose of the present invention is to provide a testing system and method for the water conduction mechanism of the coordinated-slip interface of a vertical shaft and strata. The testing system and method can be used to experimentally study the evolution of the overlying strata and the water conduction channel of the shaft during the abandoned vertical shaft coal compression mining process, explore the evolution characteristics of the water conduction channel and the law of groundwater seepage, establish the relationship between the vertical sliding rate and sliding amount of the shaft and the seepage path and seepage volume of the upper aquifer, further reveal the water conduction disaster mechanism of the interface of the abandoned vertical shaft coal compression mining, and have important theoretical significance and application value for protecting the abandoned shaft from coal pillar compression, improving resource recovery rate, and extending the service life of the mining area.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A vertical shaft and formation coordination-slip interface water conduction mechanism test system, comprising a model box, a shaft, a formation, a water pressure control component, a horizontal ground pressure control component, a slip control component, a data acquisition component, a data acquisition instrument and a computer, wherein the model box is used to accommodate the formation, the shaft vertically penetrates the model box and the formation, and the shaft can move vertically; the water pressure control component can fill water into the formation, and the water pressure control component can control the water pressure of the formation; the horizontal ground pressure control component is used to provide horizontal ground pressure for the formation; the slip control component is used to provide downward sliding force for the shaft; the data acquisition component is used to collect test data, the data acquisition component is connected to the data acquisition instrument, and the data acquisition instrument is connected to the computer.

[0008] Furthermore, in the above-mentioned vertical shaft and formation coordination-slip interface water conduction mechanism test system, the model box includes a cylinder and a top cover, the bottom of the cylinder is provided with a bottom cover, the upper end of the cylinder is open, and the top cover covers the upper end of the cylinder; the top cover includes an upper section and a lower section, the lower section is a cylinder, the diameter of the cross section of the lower section is larger than the diameter of the lower surface of the upper section, the diameter of the upper surface of the upper section is smaller than the diameter of the lower surface of the upper section, the outer edge of the upper surface of the upper section and the outer edge of the lower surface of the upper section are an arc surface, the center of the arc line where the vertical section of the upper section intersects with the arc surface is outside the upper section, and the lower surface of the top cover is provided with a boss protruding below the top cover, and the diameter of the boss is the same as the inner diameter of the cylinder. The thickness H2 of the boss is 1cm~3cm. After the top cover is connected to the cylinder, the boss can apply vertical pressure to the formation; a plurality of bolt holes are arranged on the periphery of the top cover, and the bolt holes of the top cover are located on the lower section. The end of the upper end of the cylinder extends to the outside of the cylinder to form a convex edge, and a plurality of bolt holes are arranged on the convex edge. The bolts pass through the bolt holes of the top cover and the bolt holes of the convex edge in sequence to connect the top cover with the cylinder. The contact between the top cover and the cylinder is sealed by a first sealing ring; the inner empty height of the cylinder is H1; a plurality of wire outlet holes are arranged on the bottom cover, and the plurality of wire outlet holes are used to lead the data lines of the data acquisition component out of the cylinder, and each of the wire outlet holes is sealed with epoxy resin.

[0009] Furthermore, in the above-mentioned vertical shaft and formation coordination-slip interface water conduction mechanism test system, the formation in the model box includes, from bottom to top, a lower aquifer, an impermeable layer and an upper aquifer, the upper aquifer and the lower aquifer are both paved with sand, and the impermeable layer is paved with clay; the sand gaps in the upper aquifer and the lower aquifer are filled with water, and the impermeable layer has a fixed water content; red ink is added to the upper aquifer for tracing.

[0010] Furthermore, in the above-mentioned vertical shaft and formation coordination-slip interface water conduction mechanism test system, the shaft is a hollow cylindrical structure, the lower end of the shaft is open, and the upper end of the shaft is sealed with a cover, and the material of the shaft is a transparent acrylic material; a first through hole is provided at the center of the bottom cover, and a second through hole is provided at the center of the top cover, the apertures of the first through hole and the second through hole are the same, and the center line of the first through hole and the second through hole is colinear with the axis of the cylinder, and the first through hole and the second through hole are for the shaft to pass through; the contact points between the first through hole and the second through hole and the cylinder are sealed by a second sealing ring.

[0011] Furthermore, in the above-mentioned vertical shaft and formation coordination-slip interface water conduction mechanism test system, the water pressure control component includes a first water pressure pump and a second water pressure pump, the bottom cover is provided with a first through hole, the first through hole is equipped with a seepage joint, the seepage joint of the first through hole is connected to the first water pressure pump through a pipeline, and the first water pressure pump can fill water into the lower aquifer and control the water pressure in the lower aquifer; the top cover is provided with a second through hole, the second through hole is equipped with a seepage joint, the seepage joint of the second through hole is connected to the second water pressure pump through a pipeline, and the second water pressure pump can fill water into the upper aquifer and control the water pressure in the upper aquifer.

[0012] Furthermore, in the above-mentioned vertical shaft and formation coordination-slip interface water conduction mechanism test system, the horizontal ground pressure control component includes a third water pressure pump and an inner sleeve, the material of the inner sleeve is rubber, the inner sleeve is a cylindrical structure, the outer wall of the inner sleeve is in contact with the inner wall of the cylinder, and the space enclosed by the inner wall of the inner sleeve is used to fill the formation; a closed cavity is provided between the inner wall and the outer wall of the inner sleeve, a third through hole is provided on the side wall of the cylinder, a seepage joint is installed in the third through hole, the seepage joint of the third through hole is connected to the third water pressure pump, and the third water pressure pump can fill water into the cavity of the inner sleeve and provide horizontal ground pressure to the formation; the height of the inner sleeve is H3, H3=H1-H2.

[0013] Furthermore, in the above-mentioned vertical shaft and formation coordination-slip interface water conduction mechanism test system, the slip control component includes a slip controller, an oil cylinder, a reaction frame, a steel plate and a constraint screw, the reaction frame is arranged above the model box, and a plurality of constraint screws are arranged, the lower end of the constraint screw is fixed to the ground, and the upper end of each constraint screw is provided with a nut, and the upper end of the constraint screw passes through the reaction frame and is fixed by the nut; the steel plate is connected to the lower surface of the reaction frame, the oil cylinder is located between the steel plate and the shaft, and the oil cylinder can provide downward sliding force for the shaft; the oil cylinder is connected to the slip controller via a data cable; the pressure value of the oil cylinder is 5t~8t.

[0014] Furthermore, in the above-mentioned vertical shaft and formation coordination-slip interface water conduction mechanism test system, the data acquisition component includes a first water pressure sensor, a second water pressure sensor, a first flow sensor, a second flow sensor and a dual-lens endoscope, a number of the first water pressure sensors are arranged at the junction of the lower aquifer and the aquiclude, the first water pressure sensors are arranged vertically, the first water pressure sensors are evenly arranged in 3 to 5 circles along the radial direction of the lower aquifer, and 4 first water pressure sensors are evenly arranged in each circle, and the data line of the first water pressure sensor is led out of the cylinder through the outlet hole set on the cylinder; a number of the second water pressure sensors are arranged at the junction of the lower aquifer and the shaft, the second water pressure sensors are arranged horizontally, and the first The second water pressure sensors are evenly arranged in 3 to 5 circles along the axial direction of the lower aquifer, and 4 second water pressure sensors are evenly arranged in each circle. The data line of the second water pressure sensor is led out of the cylinder through the wire outlet hole arranged on the cylinder; the first flow sensor is arranged on the pipeline between the first through hole and the first water pressure pump, and the second flow sensor is arranged on the pipeline between the second through hole and the second water pressure pump; the dual-lens endoscope is arranged in the wellbore, the dual-lens endoscope is arranged on the axis of the wellbore, and the dual-lens endoscope is located in the waterproof layer; the first water pressure sensor, the second water pressure sensor, the first flow sensor, the second flow sensor and the dual-lens endoscope are all connected to the data acquisition instrument.

[0015] On the other hand, a method for testing the water conduction mechanism of the vertical shaft shaft and the formation cooperative-slip interface using the above-mentioned vertical shaft shaft and the formation cooperative-slip interface water conduction mechanism testing system is provided, comprising the following steps:

[0016] S1 Determine the similarity criterion, and use the equation analysis method and dimensional analysis method to derive the similarity criterion of the vertical shaft and formation synergy-slip interface water conduction test;

[0017] S2 configures stratum similar materials, and prepares similar materials for the upper aquifer, aquiclude and lower aquifer according to similarity criteria and actual geological conditions;

[0018] S3 installs a horizontal ground pressure control assembly, installs an inner sleeve along the inner wall of the cylinder, the inner sleeve is connected to a third hydraulic pump through a pipeline via a seepage joint of a third through hole, and the inner sleeve is filled with water through the third hydraulic pump;

[0019] S4: placing the wellbore, installing the wellbore through the first perforation at the bottom of the wellbore, placing the dual-lens endoscope in the wellbore through the lower end of the wellbore, and connecting the data line of the dual-lens endoscope to the data collector after being led out through the lower end of the wellbore;

[0020] S5: laying the strata, laying the lower aquifer, the aquiclude and the upper aquifer in the cylinder from bottom to top in sequence, burying the first water pressure sensor and the second water pressure sensor in the lower aquifer while laying the lower aquifer, and connecting the data cables of the first water pressure sensor and the second water pressure sensor to the data acquisition device after being led out of the cylinder through the outlet holes on the cylinder;

[0021] S6 installs the top cover of the model box, passes the upper end of the wellbore through the second through hole of the top cover, and fixes the top cover to the upper end of the cylinder with bolts;

[0022] S7 applies horizontal ground pressure, applies water pressure to the inner sleeve through a third hydraulic pump, and then applies horizontal ground pressure to the formation;

[0023] S8: filling and pressurizing the aquifer, filling the lower aquifer with water and providing a constant water pressure through the first water pressure pump, and filling the upper aquifer with water and providing a constant water pressure through the second water pressure pump;

[0024] S9 installs the sliding control assembly, fixes the constraint screws on the ground around the model box, places the oil cylinder at the upper end of the wellbore, places the reaction frame fixedly connected with the steel plate above the oil cylinder, passes the upper end of the constraint screw through the reaction frame and fixes it with a nut;

[0025] S10 vertical shaft and formation coordination - slip interface water conduction test, under the control of the slip controller, the wellbore is pushed downward at a constant rate by the oil cylinder, and the water pressure of the lower aquifer is reduced by the second water pressure pump. The data of the first water pressure sensor, the second water pressure sensor, the first flow sensor and the second flow sensor, as well as the image of the dual-lens endoscope are collected by the data acquisition instrument.

[0026] Furthermore, in the above-mentioned method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface, in the step S5, the lower aquifer is formed by laying sand in layers and compacting, and the laying thickness of each layer of sand in the lower aquifer is 5cm~10cm, and each layer of sand is leveled and compacted after laying; the waterproof layer is formed by laying clay in layers and compacting, and the laying thickness of each layer of clay in the waterproof layer is 2cm~3cm, and each layer of clay is leveled and compacted after laying; the upper aquifer is formed by laying sand in layers and compacting The thickness of each layer of sand in the upper aquifer is 5cm~10cm, and each layer of sand is leveled and compacted after laying; after the stratum is laid, a counterweight is piled on the upper surface of the upper aquifer, and the stratum is loaded and compacted by the counterweight until the consolidation tends to be stable; the time for the stratum to be compacted by the counterweight is greater than or equal to 24 hours. When the compaction deformation of the stratum is too large, the upper aquifer needs to be laid; in the step S8, the water pressure of the upper aquifer and the lower aquifer are both P1, P1=1MPa~2MPa; in the step S10, the water pressure of the lower aquifer is reduced by the second hydraulic pump , =20kPa~100kPa; in the step S10, by collecting data from the first water pressure sensor, the second water pressure sensor, the first flow sensor and the second flow sensor, the vertical slip rate and slip amount of the wellbore during the relative slip between the wellbore and the formation are analyzed, and the relationship between the seepage volume of the wellbore and the formation interface is analyzed. Combined with the image collected by the dual-lens endoscope, the vertical wellbore and formation coordination-slip interface water conduction mechanism is obtained.

[0027] Analysis shows that the present invention discloses a testing system and method for the water conduction mechanism of the interface between the vertical shaft and the stratum in cooperation and sliding, which fills the gap of the testing system and method that currently considers the evolution mechanism of the water conduction channel of the thick loose aquifer triggered by the abandoned vertical shaft coal compression mining and then triggers the downward discharge of the thick loose aquifer and the research on the interface water conduction disaster mechanism. By using this testing system, by reducing the water pressure of the lower aquifer, when the oil cylinder pushes the shaft to slide downward at a constant rate, the influence of the mining disturbance on the sliding and seepage of the interface between the overlying stratum and the shaft can be realized in the actual abandoned shaft coal compression mining process, and the evolution characteristics of the interface water conduction channel and the groundwater seepage law during the cooperation and sliding of the vertical shaft and the stratum are explored, which is of great significance to further revealing the interface water conduction disaster mechanism of abandoned vertical shaft coal compression mining, and is an important research basis for the subsequent abandoned shaft protective coal pillar coal compression. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0029] Figure 1 It is a structural schematic diagram of an embodiment of the present invention.

[0030] Figure 2 The figure is a schematic diagram of the explosion structure of a cylinder according to an embodiment of the present invention.

[0031] Figure 3 This is a schematic structural diagram of a first water pressure sensor arranged in a lower aquifer according to an embodiment of the present invention.

[0032] Figure 4 This is a schematic structural diagram of a second water pressure sensor arranged in a lower aquifer according to an embodiment of the present invention.

[0033] Figure 5 The present invention is a flowchart of a method for testing the water conduction mechanism of the vertical shaft and formation cooperation-slip interface according to an embodiment of the present invention.

[0034] Explanation of the reference numerals: 1 cylinder; 2 top cover; 3 boss; 4 wellbore; 5 flange; 6 bolt; 7 first sealing ring; 8 outlet hole; 9 lower aquifer; 10 aquiclude; 11 upper aquifer; 12 first perforation; 13 second perforation; 14 second sealing ring; 15 first hydraulic pump; 16 second hydraulic pump; 17 third hydraulic pump; 18 inner sleeve; 19 first through hole; 20 second through hole; 21 third through hole; 22 seepage joint; 23 sliding controller; 24 oil cylinder; 25 reaction frame; 26 steel plate; 27 constraint screw; 28 nut; 29 first water pressure sensor; 30 second water pressure sensor; 31 first flow sensor; 32 second flow sensor; 33 dual-lens endoscope; 34 data acquisition instrument; 35 sealing cover; 36 bolt hole; 37 bottom cover; 38 upper section; 39 lower section. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. Each example is provided by way of explanation of the present invention and does not limit the present invention. In fact, it will be clear to those skilled in the art that modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as a part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desired that the present invention encompasses such modifications and variations within the scope of the appended claims and their equivalents.

[0036] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. The terms "connected", "connected" and "set" used in the present invention should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component; it can be a wired electrical connection, a radio connection, or a wireless communication signal connection. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0037] One or more examples of the present invention are shown in the accompanying drawings. The detailed description uses numbers and letter labels to refer to features in the drawings. Like or similar labels in the drawings and description have been used to refer to like or similar parts of the present invention. As used herein, the terms "first", "second", "third", etc. are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components.

[0038] like Figures 1 to 5 As shown, according to an embodiment of the present invention, a vertical shaft and formation cooperation-slip interface water conduction mechanism testing system is provided, such as Figure 1 As shown, the test system includes a model box, a wellbore 4, a formation, a water pressure control component, a horizontal ground pressure control component, a sliding control component, a data acquisition component, a data acquisition instrument 34 and a computer, wherein the model box is used to accommodate the formation, the wellbore 4 vertically penetrates the model box and the formation, and the wellbore 4 can move vertically; the water pressure control component can fill water into the formation, and the water pressure control component can control the water pressure of the formation; the horizontal ground pressure control component is used to provide horizontal ground pressure for the formation; the sliding control component is used to provide downward sliding force for the wellbore 4; the data acquisition component is used to collect test data, the data acquisition component is connected to the data acquisition instrument 34, and the data acquisition instrument 34 is connected to the computer.

[0039] Furthermore, if Figure 2As shown, the model box includes a cylinder 1 and a top cover 2, the bottom of the cylinder 1 is provided with a bottom cover 37, the upper end of the cylinder 1 is open, and the top cover 2 covers the upper end of the cylinder 1; the top cover 2 includes an upper section 38 and a lower section 39, the lower section 39 is a cylinder, the diameter of the cross section of the lower section 39 is larger than the diameter of the lower surface of the upper section 38, the diameter of the upper surface of the upper section 38 is smaller than the diameter of the lower surface of the upper section 38, the outer edge of the upper surface of the upper section 38 and the outer edge of the lower surface of the upper section 38 are arc surfaces, and the center of the arc line where the vertical section of the upper section 38 intersects with the arc surface is outside the upper section 38; the lower surface of the top cover 2 is provided with a boss 3 protruding below the top cover 2, the diameter of the boss 3 is consistent with the inner diameter of the cylinder 1, and the thickness H2 of the boss 3 is 1cm~3cm. After the top cover 2 is connected to the cylinder 1, the boss 3 can apply vertical pressure to the formation. A plurality of bolt holes 36 are provided on the outer periphery of the top cover 2, and the bolt holes 36 of the top cover 2 are located on the lower section 39. The upper end of the cylinder body 1 extends toward the outside of the cylinder body 1 to form a flange 5, and a plurality of bolt holes 36 are provided on the flange 5. Bolts 6 pass through the bolt holes 36 of the top cover 2 and the bolt holes 36 of the flange 5 in sequence to connect the top cover 2 with the cylinder body 1, and the contact between the top cover 2 and the cylinder body 1 is sealed by a first sealing ring 7; the inner space height of the cylinder body 1 is H1; a plurality of wire outlet holes 8 are provided on the bottom cover 37, and the plurality of wire outlet holes 8 are used to lead the data cables of the data acquisition component out of the cylinder body 1, and each wire outlet hole 8 is sealed with epoxy resin on the surface of the bottom cover 37.

[0040] Furthermore, the strata in the model box include, from bottom to top, a lower aquifer 9, an aquiclude 10 and an upper aquifer 11, to simulate the strata in actual engineering projects. The upper aquifer 11 and the lower aquifer 9 are both paved with sand, and the aquiclude 10 is paved with clay. The sand gaps in the upper aquifer 11 and the lower aquifer 9 are filled with water, and the aquiclude 10 has a fixed moisture content. The moisture content of the aquiclude 10 needs to be determined based on the actual strata, and the moisture content of the aquiclude 10 can be one of 12%, 14%, 16% and 18%. Red ink is added to the upper aquifer 11 for tracing, so as to facilitate the observation of the shear water conduction law of the interface between the wellbore 4 and the stratum during the sliding of the wellbore 4 through a dual-lens endoscope 33. When the shaft 4 does not move, the contact surface between the aquiclude 10 and the shaft 4 is a non-water-conducting channel. During the test, the sliding control component pushes the shaft 4 to slide downward. During the sliding process of the shaft 4, a water-conducting channel is gradually formed between the aquiclude 10 and the shaft 4. The water in the upper aquifer 11 seeps downward through the water-conducting channel formed by the contact surface between the aquiclude 10 and the shaft 4. By collecting test data through the data acquisition component, the activation process of the water-conducting channel at the contact surface between the aquiclude 10 and the shaft 4 and the law of groundwater seepage can be explored, thereby revealing the water-conducting disaster mechanism at the interface of abandoned vertical shaft compressed coal mining.

[0041] Furthermore, the wellbore 4 is a hollow cylindrical structure, the upper end of the wellbore 4 is sealed by a sealing cover 35, and the lower end of the wellbore 4 is open. The material of the wellbore 4 is a transparent acrylic material, which is convenient for real-time viewing of the situation in the wellbore 4 during the test process; a first through hole 12 is provided at the center of the bottom cover 37, and a second through hole 13 is provided at the center of the top cover 2. The apertures of the first through hole 12 and the second through hole 13 are the same, and the center line of the first through hole 12 and the second through hole 13 is colinear with the axis of the cylinder 1. The first through hole 12 and the second through hole 13 are for the wellbore 4 to pass through; the contact points between the first through hole 12 and the second through hole 13 and the cylinder 1 are sealed by a second sealing ring 14.

[0042] Furthermore, the water pressure control component includes a first water pressure pump 15 and a second water pressure pump 16. A first through hole 19 is provided on the bottom cover 37. A seepage joint 22 is installed in the first through hole 19. The seepage joint 22 of the first through hole 19 is connected to the first water pressure pump 15 through a pipeline. The first water pressure pump 15 can fill water into the lower aquifer 9 and provide a constant water pressure, thereby controlling the water pressure in the lower aquifer 9; a second through hole 20 is provided on the top cover 2. A seepage joint 22 is installed in the second through hole 20. The seepage joint 22 of the second through hole 20 is connected to the second water pressure pump 16 through a pipeline. The second water pressure pump 16 can fill water into the upper aquifer 11 and provide a constant water pressure, thereby controlling the water pressure in the upper aquifer 11.

[0043] Further, the horizontal ground pressure control assembly includes a third hydraulic pump 17 and an inner sleeve 18, the material of the inner sleeve 18 is rubber, the inner sleeve 18 is a cylindrical structure, the outer wall of the inner sleeve 18 is in contact with the inner wall of the cylinder 1, and the space surrounded by the inner wall of the inner sleeve 18 is used to fill the formation; a closed cavity is provided between the inner wall and the outer wall of the inner sleeve 18, a third through hole 21 is provided on the side wall of the cylinder 1, a seepage joint 22 is installed in the third through hole 21, and the seepage joint 22 of the third through hole 21 is connected to the third hydraulic pump 17, and the third hydraulic pump 17 can fill water into the cavity of the inner sleeve 18 and provide constant water pressure, thereby providing horizontal ground pressure to the formation; the height of the inner sleeve 18 is H3, H3=H1-H2. Such a setting can make the formation truly simulate the formation conditions in the actual project and ensure the accuracy of the test results.

[0044] Furthermore, the sliding control component includes a sliding controller 23, a cylinder 24, a reaction frame 25, a steel plate 26 and a constraint screw 27. The reaction frame 25 is arranged above the model box. A plurality of constraint screws 27 are arranged. The lower end of the constraint screw 27 is fixed to the ground. The upper end of each constraint screw 27 is provided with a nut 28. The upper end of the constraint screw 27 passes through the reaction frame 25 and is fixed by the nut 28; the steel plate 26 is connected to the lower surface of the reaction frame 25, and the cylinder 24 is located between the steel plate 26 and the wellbore 4. The cylinder 24 can provide a downward sliding force for the wellbore 4; the cylinder 24 is connected to the sliding controller 23 through a data cable; the pressure value of the cylinder 24 is 5t~8t, and the sliding controller 23 can control the vertical sliding rate and sliding amount of the wellbore 4 through the cylinder 24. The oil cylinder 24 is used to provide a downward sliding force for the shaft 4 to slide downward, so as to simulate the movement process of the shaft 4 in the actual project, and then study the evolution mechanism of the overlying strata and the shaft water conduction channel in the abandoned vertical shaft coal compression mining and the water conduction disaster mechanism of the abandoned vertical shaft coal compression mining in thick loose layers to ensure the safe mining of the abandoned shaft protection coal pillar.

[0045] Furthermore, the data acquisition component includes a first water pressure sensor 29, a second water pressure sensor 30, a first flow sensor 31, a second flow sensor 32 and a dual-lens endoscope 33, as shown in FIG. Figure 3 As shown, a plurality of first water pressure sensors 29 are arranged at the junction of the lower aquifer 9 and the aquiclude 10, the first water pressure sensors 29 are arranged vertically, and the first water pressure sensors 29 are evenly arranged in 3 to 5 circles along the radial direction of the lower aquifer 9 and around the wellbore 4, and each circle is evenly arranged with 4 first water pressure sensors 29, and the data lines of the first water pressure sensors 29 are led out of the cylinder 1 through the outlet holes 8 arranged on the bottom cover 37. In one embodiment of the present invention, the first water pressure sensors 29 are arranged in 4 circles; Figure 4As shown, a plurality of second water pressure sensors 30 are arranged at the junction of the lower aquifer 9 and the wellbore 4, the second water pressure sensors 30 are arranged horizontally, and the second water pressure sensors 30 are evenly arranged in 3 to 5 circles along the axial direction of the lower aquifer 9 and around the wellbore 4, and each circle is evenly arranged with 4 second water pressure sensors 30, and the data lines of the second water pressure sensors 30 are led out of the cylinder body 1 through the outlet holes 8 arranged on the bottom cover 37; the first flow sensor 31 is arranged on the pipeline between the first through hole 19 and the first water pressure pump 15, and the second flow sensor 32 is arranged on the pipeline between the second through hole 20 and the second water pressure pump 16; the double-lens endoscope 33 is arranged in the wellbore 4, the double-lens endoscope 33 is arranged on the axis of the wellbore 4, and the double-lens endoscope 33 is located in the waterproof layer 10. The image taken by the double-lens endoscope 33 can observe the shear water conduction law of the interface between the wellbore 4 and the formation during the sliding process. The first water pressure sensor 29 , the second water pressure sensor 30 , the first flow sensor 31 , the second flow sensor 32 and the dual-lens endoscope 33 are all connected to the data acquisition device 34 via data cables.

[0046] The present invention also discloses a method for testing the water conduction mechanism of the vertical shaft and the formation in a coordinated-slip interface by using the vertical shaft and the formation coordinated-slip interface water conduction mechanism testing system, such as Figure 4 As shown, the following steps are included:

[0047] S1 Determine the similarity criterion, and use the equation analysis method and dimensional analysis method to derive the similarity criterion of the vertical shaft and the formation synergy-slip interface water conduction test. For example: select the geometric similarity ratio α l =50, the calculated time similarity ratio is α t =7.07, the severe similarity ratio is α γ =1.67, the stress similarity ratio is α σ =83.5.

[0048] S2 configures formation similar materials, and prepares similar materials for the upper aquifer 11, the aquiclude 10 and the lower aquifer 9 according to similarity criteria and actual geological conditions.

[0049] S3 installs a horizontal ground pressure control assembly, installs an inner sleeve 18 along the inner wall of the cylinder 1, and the inner sleeve 18 is connected to the third water pressure pump 17 through a pipeline via a seepage joint 22 of a third through hole 21, and the inner sleeve 18 is filled with water through the third water pressure pump 17.

[0050] S4 places the wellbore 4, installs the wellbore 4 through the first through-hole 12 at the bottom of the cylinder 1, places the dual-lens endoscope 33 in the wellbore 4 through the lower end of the wellbore 4, and the data line of the dual-lens endoscope 33 is led out through the lower end of the wellbore 4 and connected to the data acquisition device.

[0051] S5 lays the strata, and lays the lower aquifer 9, the aquiclude 10 and the upper aquifer 11 in sequence from bottom to top in the cylinder 1. While the lower aquifer 9 is being laid, the first water pressure sensor 29 and the second water pressure sensor 30 are buried in the lower aquifer 9. The data cables of the first water pressure sensor 29 and the second water pressure sensor 30 are led out of the cylinder 1 through the outlet holes 8 on the bottom cover 37 and connected to the data collector.

[0052] The lower aquifer 9 is formed by laying sand in layers and compacting. The thickness of each layer of sand in the lower aquifer 9 is 5cm~10cm, and each layer of sand is leveled and compacted after laying. The waterproof layer 10 is formed by laying clay in layers and compacting. The thickness of each layer of clay in the waterproof layer 10 is 2cm~3cm, and each layer of clay is leveled and compacted after laying. The upper aquifer 11 is formed by laying sand in layers and compacting. The thickness of each layer of sand in the upper aquifer 11 is 5cm~10cm, and each layer of sand is leveled and compacted after laying. After the stratum is laid, counterweights are piled on the upper surface of the upper aquifer 11, and the stratum is loaded and compacted by the counterweights until the consolidation tends to be stable; the time for the stratum to be compacted by the counterweights is greater than or equal to 24 hours. When the compaction and deformation of the stratum is too large, the upper aquifer 11 needs to be laid.

[0053] S6 installs the top cover 2 of the model box, removes the counterweight, passes the upper end of the wellbore 4 through the second through hole 13 of the top cover 2, and fixes the top cover 2 to the upper end of the cylinder 1 with bolts 6.

[0054] S7 applies horizontal ground pressure, applies water pressure to the inner sleeve 18 through the third hydraulic pump 17, and then applies horizontal ground pressure to the formation.

[0055] The S8 aquifer is filled with water and pressurized, and the lower aquifer 9 is filled with water and provided with a constant water pressure through the first hydraulic pump 15, and the upper aquifer 11 is filled with water and provided with a constant water pressure through the second hydraulic pump 16. The water pressure of the upper aquifer 11 and the lower aquifer 9 is P1, P1 = 1MPa ~ 2MPa.

[0056] S9 installs the sliding control component, fixes the constraint screw 27 on the ground around the model box, places the oil cylinder 24 at the upper end of the wellbore 4, places the reaction frame 25 fixedly connected with the steel plate 26 above the oil cylinder 24, passes the upper end of the constraint screw 27 through the reaction frame 25 and fixes it with the nut 28.

[0057] S10 Vertical shaft and formation coordination - slip interface water conduction test, under the control of the slip controller 23, the shaft 4 is pushed downward at a constant rate by the oil cylinder 24, and at the same time the water pressure of the lower aquifer 9 is reduced by the second hydraulic pump 16, and the data of the first water pressure sensor 29, the second water pressure sensor 30, the first flow sensor 31 and the second flow sensor 32, as well as the image of the dual-lens endoscope 33 are collected by the data acquisition instrument 34.

[0058] The water pressure of the lower aquifer 9 is reduced by the second hydraulic pump 16 to , =20kPa~100kPa, by reducing the water pressure of the lower aquifer 9, when the cylinder 24 pushes the wellbore 4 to slide downward at a constant rate, the water in the upper aquifer 11 seeps downward through the contact surface between the aquiclude 10 and the wellbore 4, which can simulate the actual mining process of abandoned wellbore compressed coal, and then study the influence of the mining disturbance of abandoned wellbore compressed coal on the sliding and seepage of the interface between the overlying stratum and the wellbore, and explore the evolution characteristics of the interface water conduction channel and the law of groundwater seepage during the coordinated sliding of the vertical wellbore and the stratum. By collecting data from the first water pressure sensor 29, the second water pressure sensor 30, the first flow sensor 31 and the second flow sensor 32, the vertical sliding rate and sliding amount of the wellbore 4 in the process of relative sliding between the wellbore 4 and the stratum are analyzed, and the relationship between the seepage volume of the wellbore 4 and the stratum interface is analyzed, and the image collected by the dual-lens endoscope 33 is combined to obtain the water conduction mechanism of the coordinated sliding interface between the vertical wellbore and the stratum.

[0059] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0060] A testing system and method for the water conduction mechanism of the interface of the vertical shaft and the stratum in cooperation-sliding fills the gap of the testing system and method that currently considers the evolution mechanism of the water conduction channel of the thick loose aquifer triggered by the abandoned vertical shaft coal compression mining and the research on the interface water conduction disaster mechanism. By using this testing system, by reducing the water pressure of the lower aquifer 9, the cylinder 24 pushes the shaft 4 to slide downward at a constant rate. In the actual abandoned shaft coal compression mining process, the influence of the mining disturbance on the sliding and seepage of the interface between the overlying stratum and the shaft can be realized, and the evolution characteristics of the interface water conduction channel and the groundwater seepage law during the cooperation-sliding of the vertical shaft and the stratum are explored, which is of great significance to further revealing the interface water conduction disaster mechanism of abandoned vertical shaft coal compression mining, and is an important research basis for the subsequent abandoned shaft protective coal pillar coal compression.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface, characterized in that: The test is conducted using a vertical shaft and formation coordination-slip interface water conduction mechanism test system, the test system comprising a model box, a shaft, a formation, a water pressure control component, a horizontal ground pressure control component, a slip control component, a data acquisition component, a data acquisition instrument and a computer, wherein: The model box includes a cylinder and a top cover, the model box is used to accommodate the formation, the wellbore vertically penetrates the model box and the formation, and the wellbore can move vertically; The horizontal ground pressure control assembly comprises a third hydraulic pump and an inner sleeve, a third through hole is arranged on the side wall of the cylinder, a seepage joint is installed in the third through hole, and the horizontal ground pressure control assembly is used to provide horizontal ground pressure for the formation; The water pressure control assembly comprises a first water pressure pump and a second water pressure pump, the water pressure control assembly can fill water into the formation, and the water pressure control assembly can control the water pressure of the formation; The sliding control assembly includes a sliding controller, an oil cylinder, a reaction frame, a steel plate and a restraining screw, and the sliding control assembly is used to provide a downward sliding force for the wellbore; The data acquisition component includes a first water pressure sensor, a second water pressure sensor, a first flow sensor, a second flow sensor and a dual-lens endoscope, and the data acquisition component is used to collect test data, the data acquisition component is connected to the data acquisition instrument, and the data acquisition instrument is connected to the computer; The testing method comprises the following steps: S1 Determine the similarity criterion, and use the equation analysis method and dimensional analysis method to derive the similarity criterion of the vertical shaft and formation synergy-slip interface water conduction test; S2 configures similar materials for the formation, and configures similar materials for the upper aquifer, aquiclude and lower aquifer according to similarity criteria and actual geological conditions; S3 installs a horizontal ground pressure control assembly, installs an inner sleeve along the inner wall of the cylinder, the inner sleeve is connected to a third hydraulic pump through a pipeline via a seepage joint of a third through hole, and the inner sleeve is filled with water through the third hydraulic pump; S4: placing the wellbore, installing the wellbore through the first perforation at the bottom of the wellbore, placing the dual-lens endoscope in the wellbore through the lower end of the wellbore, and connecting the data line of the dual-lens endoscope to the data collector after being led out through the lower end of the wellbore; S5: laying the strata, laying the lower aquifer, the aquiclude and the upper aquifer in the cylinder from bottom to top in sequence, burying the first water pressure sensor and the second water pressure sensor in the lower aquifer while laying the lower aquifer, and connecting the data cables of the first water pressure sensor and the second water pressure sensor to the data acquisition device after being led out of the cylinder through the outlet holes on the cylinder; S6 installs the top cover of the model box, passes the upper end of the wellbore through the second through hole of the top cover, and fixes the top cover to the upper end of the cylinder with bolts; S7 applies horizontal ground pressure, applies water pressure to the inner sleeve through a third hydraulic pump, and then applies horizontal ground pressure to the formation; S8: filling and pressurizing the aquifer, filling the lower aquifer with water and providing a constant water pressure through the first water pressure pump, and filling the upper aquifer with water and providing a constant water pressure through the second water pressure pump; S9 installs the sliding control assembly, fixes the constraint screws on the ground around the model box, places the oil cylinder at the upper end of the wellbore, places the reaction frame fixedly connected with the steel plate above the oil cylinder, passes the upper end of the constraint screw through the reaction frame and fixes it with a nut; S10 vertical shaft and formation coordination - slip interface water conduction test, under the control of the slip controller, the wellbore is pushed downward at a constant rate by the oil cylinder, and the water pressure of the lower aquifer is reduced by the second hydraulic pump. The data of the first water pressure sensor, the second water pressure sensor, the first flow sensor and the second flow sensor, as well as the image of the dual-lens endoscope are collected by the data acquisition instrument. Analyze the relationship between the vertical sliding rate and sliding amount of the wellbore and the seepage volume at the interface of the wellbore and the formation during the relative sliding between the wellbore and the formation, Combined with the images collected by the dual-lens endoscope, the water conduction mechanism of the vertical shaft and the formation synergy-slip interface is obtained.

2. The method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface according to claim 1 is characterized in that: The bottom of the cylinder is provided with a bottom cover, the upper end of the cylinder is open, and the top cover covers the upper end of the cylinder; The top cover comprises an upper section and a lower section, the lower section is a cylinder, and the diameter of the cross section of the lower section is larger than the diameter of the lower surface of the upper section. The diameter of the upper surface of the upper section is smaller than the diameter of the lower surface of the upper section, An arc surface is formed between the outer edge of the upper surface of the upper segment and the outer edge of the lower surface of the upper segment, and the center of the arc line where the vertical section of the upper segment intersects with the arc surface is outside the upper segment. The lower surface of the top cover is provided with a boss protruding downward from the top cover, the diameter of the boss is consistent with the inner diameter of the cylinder, the thickness H2 of the boss is 1 cm to 3 cm, and after the top cover is connected to the cylinder, the boss can apply vertical pressure to the formation; The outer periphery of the top cover is provided with a plurality of bolt holes, the bolt holes of the top cover are located on the lower section, the end of the upper end of the cylinder extends toward the outer side of the cylinder to form a convex edge, the convex edge is provided with a plurality of bolt holes, bolts pass through the bolt holes of the top cover and the bolt holes of the convex edge in sequence to connect the top cover with the cylinder, and the contact between the top cover and the cylinder is sealed by a first sealing ring; The inner space height of the cylinder is H1; The bottom cover is provided with a plurality of wire outlet holes, which are used to lead the data wires of the data acquisition component out of the cylinder body, and each of the wire outlet holes is sealed with epoxy resin.

3. The method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface according to claim 2 is characterized in that: The strata in the model box include, from bottom to top, a lower aquifer, an impermeable layer and an upper aquifer, the upper aquifer and the lower aquifer are both paved with sand, and the impermeable layer is paved with clay; The sand and soil gaps in the upper aquifer and the lower aquifer are filled with water, and the aquiclude has a fixed moisture content; Red ink is added into the upper aquifer for tracing.

4. The method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface according to claim 2 is characterized in that: The shaft is a hollow cylindrical structure, the lower end of the shaft is open, the upper end of the shaft is sealed by a cover, and the shaft is made of transparent acrylic material; A first through hole is provided at the center of the bottom cover, and a second through hole is provided at the center of the top cover. The first through hole and the second through hole have the same aperture. The center line of the first through hole and the second through hole is colinear with the axis of the cylinder. The first through hole and the second through hole are for the wellbore to pass through. The contact points between the first through hole and the second through hole and the cylinder are sealed by a second sealing ring.

5. The method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface according to claim 2 is characterized in that: The bottom cover is provided with a first through hole, a seepage joint is installed in the first through hole, the seepage joint of the first through hole is connected to the first hydraulic pump through a pipeline, and the first hydraulic pump can fill water into the lower aquifer and control the water pressure in the lower aquifer; The top cover is provided with a second through hole, a seepage joint is installed in the second through hole, the seepage joint of the second through hole is connected to the second water pressure pump through a pipeline, and the second water pressure pump can fill water into the upper aquifer and control the water pressure in the upper aquifer.

6. The method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface according to claim 2 is characterized in that: The inner sleeve is made of rubber and is a cylindrical structure. The outer wall of the inner sleeve contacts the inner wall of the cylinder, and the space enclosed by the inner wall of the inner sleeve is used to fill the formation. A closed cavity is provided between the inner wall and the outer wall of the inner sleeve, the seepage joint of the third through hole is connected to the third water pressure pump, and the third water pressure pump can fill water into the cavity of the inner sleeve and provide horizontal ground pressure to the formation; The height of the inner sleeve is H3, H3=H1-H2.

7. The method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface according to claim 1 is characterized in that: The reaction frame is arranged above the model box, a plurality of constraint screws are arranged, the lower ends of the constraint screws are fixed to the ground, a nut is arranged at the upper end of each constraint screw, and the upper end of the constraint screw passes through the reaction frame and is fixed by the nut; The steel plate is connected to the lower surface of the reaction frame, and the oil cylinder is located between the steel plate and the wellbore, and the oil cylinder can provide downward sliding force for the wellbore; The oil cylinder is connected to the sliding controller via a data line; The pressure value of the oil cylinder is 5t~8t.

8. The method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface according to claim 5 is characterized in that: A plurality of the first water pressure sensors are arranged at the junction of the lower aquifer and the aquiclude, the first water pressure sensors are arranged vertically, the first water pressure sensors are evenly arranged in 3 to 5 circles along the radial direction of the lower aquifer, and each circle is evenly arranged with 4 first water pressure sensors, and the data lines of the first water pressure sensors are led out of the cylinder through the outlet holes arranged on the cylinder; A plurality of the second water pressure sensors are arranged at the junction of the lower aquifer and the wellbore, the second water pressure sensors are arranged transversely, the second water pressure sensors are evenly arranged in 3 to 5 circles along the axial direction of the lower aquifer, and each circle is evenly arranged with 4 second water pressure sensors, and the data lines of the second water pressure sensors are led out of the cylinder through the outlet holes arranged on the cylinder; The first flow sensor is arranged on the pipeline between the first through hole and the first water pressure pump, and the second flow sensor is arranged on the pipeline between the second through hole and the second water pressure pump; The dual-lens endoscope is arranged in the wellbore, the dual-lens endoscope is arranged on the axis of the wellbore, and the dual-lens endoscope is located in the waterproof layer; The first water pressure sensor, the second water pressure sensor, the first flow sensor, the second flow sensor and the dual-lens endoscope are all connected to the data acquisition instrument.

9. The method for testing the water conduction mechanism of the vertical shaft and the formation synergy-slip interface according to claim 1, characterized in that: In the step S5, the lower aquifer is formed by laying sand in layers and compacting it. The laying thickness of each layer of sand in the lower aquifer is 5 cm to 10 cm. After each layer of sand is laid, it is leveled and compacted. The waterproof layer is formed by laying clay in layers and compacting it. The thickness of each layer of clay in the waterproof layer is 2cm~3cm. After each layer of clay is laid, it is leveled and compacted. The upper aquifer is formed by laying sand in layers and compacting it. The thickness of each layer of sand in the upper aquifer is 5cm~10cm. After each layer of sand is laid, it is leveled and compacted. After the stratum is laid, a counterweight is piled on the upper surface of the upper aquifer, and the stratum is compacted by the counterweight until it becomes stable. The time for the stratum to be compacted by the weight pile is greater than or equal to 24 hours. When the stratum is compacted and deformed too much, the upper aquifer needs to be added; In step S8, the water pressure of the upper aquifer and the lower aquifer is P1, P1=1MPa~2MPa; In step S10, the water pressure of the lower aquifer is reduced by the second hydraulic pump. , =20kPa~100kPa.

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