A test method for the failure of the inclined shaft shaft wall and surrounding rock considering belt vibration and seepage

Abstract

The present invention discloses a test method for the failure of the inclined shaft shaft wall and surrounding rock considering belt vibration and seepage, including laying a layer of rock-like material layer in a visualization model box, prefabricating a number of fissures, and stuffing plug pieces into the prefabricated fissures; arranging sensors; injecting water to saturate the rock-like material; repeating the above steps until the rock-like material is laid to the designed elevation; inserting freezing pipes and opening the seepage system; starting the freezing circulation system; excavating the shaft, pouring the inclined shaft shaft wall and curing; stopping freezing, installing a belt vibration load simulation system; inputting parameters into the servo controller; starting the data acquisition system and the belt vibration load simulation system, and recording test data until the inclined shaft shaft wall or surrounding rock is damaged and the test ends. The test method of the present invention considers the influence of the combined action of belt vibration load and seepage on the inclined shaft shaft wall and surrounding rock, is closer to the engineering reality, and has important significance for ensuring the safe operation of the inclined shaft.

Description

Technical Field

[0001] The present invention relates to the technical field of inclined shaft freezing tests, and particularly to a test method for the failure of the inclined shaft shaft wall and surrounding rock considering belt vibration and seepage.

[0002] The "test method for the failure of the inclined shaft shaft wall and surrounding rock considering belt vibration and seepage" of the present invention is the result of the project "Experimental study on the mechanical properties of the Luohe Formation sandstone after the thawing of the inclined shaft in the western water-rich area (12102379)" of the National Natural Science Foundation of China. Background Technique

[0003] When coal mines are exploited using inclined shafts in the western water-rich area, they often pass through fractured rock formations with abundant groundwater development. The rock mass of this formation contains discontinuity surfaces with different sizes and complex shapes, and has characteristics such as low strength and strong permeability. During the construction of inclined shafts, due to the phenomena of pore water storage and fissure water conduction, artificial freezing methods must be used for shaft sinking construction. However, during the freezing process, the water inside the fractured rock mass condenses into ice, forming a multi-phase damage medium of water-ice-rock and generating a huge frost heaving force. This uneven frost heaving and the unloading of the shaft excavation cause the further expansion of the original fissures and the initiation of new fissures in the fractured rock mass, resulting in the deterioration of its strength and the enhancement of permeability.

[0004] After the inclined shaft thaws, the groundwater level recovers. Under the action of dynamic loads such as belt (vehicle) transportation, coal seam mining, roof caving, blasting, and groundwater seepage, the original fissures and newly initiated fissures in the fractured rock mass further expand and penetrate, resulting in the continuous deterioration of the mechanical properties of the fractured rock mass and the intensification of fissure seepage, causing the instability and failure of the inclined shaft surrounding rock and the rupture of the inclined shaft shaft wall, triggering disasters such as water inrush, sand bursting, and shaft flooding, seriously threatening the safe operation of the mine and the lives of personnel.

[0005] Combined with the research results and practical experience in participating in projects in recent years, it is found that the dynamic load and seepage action are the key factors inducing the catastrophic changes of the fractured rock mass after the thawing of the inclined shaft in the water-rich area. Most of the existing research on the stress or deformation failure law of the shaft wall and surrounding rock after the thawing of the inclined shaft only considers the seepage action, and there is no report on the research of the stress or deformation failure law of the shaft wall and surrounding rock after the thawing of the inclined shaft under the combined action of belt vibration and seepage. Therefore, it is necessary in this field to conduct research on the stress or deformation failure law of the shaft wall and surrounding rock after the thawing of the inclined shaft under the combined action of belt vibration and seepage, and there is an urgent need for a test method for the failure of the inclined shaft shaft wall and surrounding rock considering belt vibration and seepage. Summary of the Invention

[0006] The purpose of the present invention is to provide a test method for the failure of the inclined shaft shaft wall and surrounding rock considering belt vibration and seepage to solve the problems raised in the background technique.

[0007] To achieve the above object, the present invention provides a test method for the failure of the inclined shaft lining and surrounding rock considering belt vibration and seepage, which is carried out using a physical simulation test device for the failure of the inclined shaft lining and surrounding rock. The test device includes a visualization model box, an inclined shaft device, a belt vibration load simulation system, a rock-like material, a seepage system, a data acquisition system, and a freezing cycle system. The inclined shaft device is a hollow cylindrical structure arranged in the visualization model box, and the opening ends of the inclined shaft device are respectively fixedly connected to the left and right plates of the visualization model box. The belt vibration load simulation system includes two groups of slideways, two load angle control rods, and a load application unit. The two groups of slideways are respectively located on the left and right sides of the visualization model box. The two load angle control rods are parallel to each other and are inclinedly arranged in the inclined shaft device. The two ends of each load angle control rod extend to the outside of the left and right sides of the visualization model box, and the two ends of each load angle control rod are respectively connected to two slideways in the same group. The load application unit includes a plurality of hydraulic jacks, a plurality of oil pumps, and a servo controller. The plurality of hydraulic jacks are divided into two groups and are respectively arranged on the two load angle control rods. Each hydraulic jack is connected to an oil pump through a hydraulic pipe, and the plurality of oil pumps are respectively connected to the servo controller through control lines. The rock-like material is densely filled in the visualization model box. The water inlet pipe of the seepage system is connected to the water inlet of the visualization model box through an osmotic pressure pump, and the water outlet pipe of the seepage system is connected to the water outlet of the visualization model box. Filters are arranged at both the water inlet and the water outlet. The data acquisition system includes a data acquisition module, a temperature sensor, a strain sensor, and a deformation monitoring sensor. The freezing cycle system includes a refrigerator and a plurality of freezing pipes. The test method includes the following steps:

[0008] Step S1: First, lay a layer of rock-like material in the visualization model box to form a rock-like material layer. Then, use fissure pieces to prefabricate several fissures in the rock-like material layer. The several fissures are symmetrically distributed at the top of the rock-like material layer and on both sides of the axis of the inclined shaft device. Then, pull out the fissure pieces and respectively insert plug pieces into the prefabricated several fissures to prevent the prefabricated fissures from collapsing.

[0009] Step S2: Arrange a temperature sensor, a stress sensor, and a deformation monitoring sensor on the rock-like material layer, and connect the leads of each sensor to the data acquisition module respectively. The data acquisition module is connected to the control module.

[0010] Step S3: Inject water into the visualization model box to fully saturate the rock-like material.

[0011] Step S4. Repeat the above steps S1 to S3 in sequence until the rock-like material is laid to the designed elevation; wherein, the thickness of each layer of the rock-like material layer is 1 / 5 to 1 / 4 of the designed elevation of the rock-like material;

[0012] Step S5. First, divide the freezing pipes into multiple rows and vertically insert them on both sides of the axis of the inclined shaft device, and then install the seepage system and open it;

[0013] Step S6. Start the freezing circulation system. When the temperature of the rock-like material reaches the designed temperature, close the two middle rows of freezing pipes;

[0014] Step S7. Excavate the shaft in the visualization model box according to the designed cross-sectional size and angle of the inclined shaft; after the shaft excavation is completed, pour the inclined shaft wall in the shaft according to the similarity ratio and cure it, thus forming the inclined shaft device; wherein, during the curing period of the inclined shaft wall, the two rows of freezing pipes on both sides always remain in the operating state;

[0015] Step S8. After the curing of the inclined shaft wall is completed, first close the freezing circulation system, then install the belt vibration load simulation system, and then adjust the load angle control rod according to the inclined shaft angle and fix it;

[0016] Step S9. According to the belt vibration load and vibration frequency on site, input the vibration load and vibration frequency converted according to the similarity ratio into the servo controller;

[0017] Step S10. Start the data acquisition system and the belt vibration load simulation system successively, and record the test data until the inclined shaft wall or the surrounding rock is damaged, and the test ends.

[0018] Further, in the step S1: the length of the crack is 30 to 50 mm, the width is 0.1 to 0.5 mm, and the depth is 1 to 2 cm; there are 3 cracks with an inclination angle of 0°, 30°, 60°, and 90° respectively on the front and back sides of the top of the rock layer material layer, and the inclination angle is the included angle between the crack and the horizontal projection of the axis of the inclined shaft device.

[0019] Further, in the step S5: the multiple rows of freezing pipes are arranged at intervals in the front-back direction, and each row of freezing pipes includes multiple freezing pipes arranged at intervals in the left-right direction; the row spacing between two adjacent rows of freezing pipes is 200 mm, and the spacing between two adjacent freezing pipes in each row of freezing pipes is 100 mm.

[0020] Further, the inclined shaft device includes an inclined shaft roof, an inclined shaft floor, and two inclined shaft side plates. The inclined shaft roof and the inclined shaft floor are parallel to each other and are inclined relative to the horizontal direction; a plurality of mounting holes are formed in each load angle control rod, and a hydraulic jack is disposed in each mounting hole; the cylinder body of the hydraulic jack penetrates through the mounting hole and is fixedly disposed on the load angle control rod, and the free end of the piston rod of the hydraulic jack abuts against the inclined shaft floor.

[0021] Further, the two sets of slideways are arranged at intervals, and each set of slideways includes a first slideway and a second slideway. The first slideway and the second slideway are arranged in parallel and opposite to each other on two opposite sides of the visualization model box; a plurality of first positioning holes are formed in both the first slideway and the second slideway, and the plurality of first positioning holes are evenly spaced along the length direction of the slideway, and the first positioning holes on the first slideway and the second slideway are arranged in a staggered manner.

[0022] Further, second positioning holes are respectively formed at both ends of the load angle control rod; both ends of the load angle control rod are detachably connected to the first slideway and the second slideway through bolts.

[0023] Further, two side plates of the visualization model box where the two ends of the inclined shaft device are connected are respectively provided with two through holes for adjusting the inclination angles of the two load angle control rods; the two through holes respectively match the two ends of the inclined shaft device, or the two through holes are long holes adapted to the inclination angle range of the load angle control rod; the inclination angle range of the load angle control rod is 15° to 45°.

[0024] Further, the seepage pressure of the seepage system is 0 - 3 MPa.

[0025] Further, the positions of the water inlet and the water outlet are at least 25 cm higher than the higher end of the inclined shaft wall.

[0026] Further, the length of the load angle control rod is adjustable and includes a telescopic sleeve and two telescopic rods movably inserted into both ends of the telescopic sleeve. Positioning screws are respectively threadedly connected to both ends of the side wall of the telescopic sleeve, and the two telescopic rods are respectively positioned inside both ends of the telescopic sleeve through the corresponding positioning screws.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1). A test method for the failure of the inclined shaft wall and surrounding rock considering belt vibration and seepage of the present invention is carried out using a physical simulation test device for the failure of the inclined shaft wall and surrounding rock. The test device includes a visualization model box, an inclined shaft device, a belt vibration load simulation system, a rock-like material, a seepage system, a data acquisition system, and a freezing cycle system; the present invention considers the combined action of belt vibration load and seepage on the inclined shaft wall and surrounding rock, analyzes the stress law of the shaft wall and surrounding rock after the inclined shaft thaws under the influence of belt vibration load and seepage, is closer to the engineering reality, and has important significance for ensuring the safe operation of the inclined shaft.

[0029] (2). A test method for the failure of the inclined shaft wall and surrounding rock considering belt vibration and seepage of the present invention can realize the three-dimensional physical simulation of the deformation and failure of the shaft wall and surrounding rock after the inclined shaft thaws under the combined action of belt vibration and seepage under different inclined shaft angles, different inclined shaft cross-sectional sizes, different burial depths, and different geological conditions. It has important theoretical significance and application value for mastering the stress law of the shaft wall and surrounding rock after the inclined shaft thaws under the influence of belt vibration load and seepage, revealing the structural fracture evolution law of the shaft wall and surrounding rock after the inclined shaft thaws under the action of belt vibration and seepage load, exploring the deformation and failure mechanism of the shaft wall and surrounding rock after the inclined shaft thaws under the action of belt vibration load and seepage, as well as the long-term stability analysis and evaluation and disaster prevention of the inclined shaft in the water-rich area after thawing.

[0030] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The present invention will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0032] Figure 1 is a flow chart of a test method for the failure of the inclined shaft wall and surrounding rock considering belt vibration and seepage of the present invention;

[0033] Figure 2 is a horizontal end view schematic diagram of a physical simulation test system for the failure of the inclined shaft wall and surrounding rock of the present invention;

[0034] Figure 3 is a longitudinal sectional structure schematic diagram of a physical simulation test system for the failure of the inclined shaft wall and surrounding rock of the present invention (the seepage system is shown in the figure);

[0035] Figure 4 is a top view structure schematic diagram of a layer of rock-like material prefabricated with cracks in the present invention;

[0036] Figure 5It is a top - view structural schematic diagram of the cooperation between the freezing pipes and the rock - like material in the present invention;

[0037] Among them, 1 - base, 2 - visualization model box, 3 - inclined - shaft device, 3.1 - inclined - shaft roof, 3.2 - inclined - shaft floor, 3.3 - inclined - shaft side plate, 4 - belt vibration load simulation system, 4.1 - slideway, 4.11 - first slideway, 4.12 - second slideway, 4.1a - first positioning hole, 4.2 - load - angle control rod, 4.3 - hydraulic jack, 4.4 - hydraulic pipe, 4.5 - oil pump, 4.6 - control line, 4.7 - servo controller, 4.8 - bolt, 5 - rock - like material, 6 - seepage system, 6.1 - water storage tank, 6.2 - water inlet pipe, 6.3 - water outlet pipe, 6.4 - osmotic pressure pump, 7 - filter screen, 8 - crack, 9 - freezing pipe. Specific implementation manners

[0038] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the claims.

[0039] Please refer to Figures 1 to 3, this embodiment provides a test method for the failure of the inclined shaft shaft wall and surrounding rock considering belt vibration and seepage, which is carried out using a physical simulation test device for the failure of the inclined shaft shaft wall and surrounding rock. The test device includes a base 1, a visualization model box 2, an inclined shaft device 3, a belt vibration load simulation system 4, a rock-like material 5, a seepage system 6, a data acquisition system, and a freezing cycle system. The inclined shaft device is a hollow cylindrical structure arranged in the visualization model box, and the two open ends of the inclined shaft device are respectively fixedly connected to the two opposite side plates of the visualization model box; the belt vibration load simulation system includes two groups of slideways 4.1, two load angle control rods 4.2, and a load application unit. The two groups of slideways are respectively located on the two opposite sides of the visualization model box. The two load angle control rods are parallel to each other and are inclinedly arranged in the inclined shaft device. The two ends of each load angle control rod extend out of the visualization model box, and both ends of each load angle control rod are respectively connected to two slideways in the same group; the load application unit includes a plurality of hydraulic jacks 4.3, a plurality of oil pumps 4.5, and a servo controller 4.7. The plurality of hydraulic jacks are divided into two groups and are respectively arranged on the two load angle control rods. Each hydraulic jack is connected to an oil pump 4.5 through a hydraulic pipe 4.4, and the plurality of oil pumps are respectively connected to the servo controller 4.7 through control lines 4.6; the rock-like material is densely filled in the visualization model box; the seepage system includes a water storage tank 6.1, a water inlet pipe 6.2, a water outlet pipe 6.3, and an osmotic pressure pump 6.4. One end of the water inlet pipe is connected to the water storage tank, and the other end of the water inlet pipe is connected to the water inlet of the visualization model box. One end of the water outlet pipe is connected to the water outlet of the visualization model box, and the other end of the water outlet pipe is connected to the water storage tank. The osmotic pressure pump 6.4 injects water with different seepage pressures into the visualization model box, flows through the rock-like material, and then returns to the water storage tank through the water outlet pipe. Among them, the seepage pressure of the seepage system 6 is 0 - 3 MPa. By adjusting the seepage pressure of the seepage system, the seepage pressure at different depths within the range of 0 to -300 m can be simulated. The data acquisition system includes a data acquisition module, a temperature sensor, a strain sensor, and a deformation monitoring sensor; the freezing cycle system includes a refrigerator and a plurality of freezing pipes.

[0040] Referring to Figure 3 shown, a test method for the failure of the inclined shaft shaft wall and surrounding rock considering belt vibration and seepage of the present invention includes the following steps:

[0041] Step S1: First, lay a layer of rock-like material 5 in the visualization model box 2 to form a rock-like material layer. Then, use fissure pieces to prefabricate several fissures 8 in the rock-like material layer. The several fissures are symmetrically distributed on the front and back sides of the rock material layer. Then pull out the fissure pieces. To prevent the prefabricated fissures from collapsing, insert plug pieces into the several prefabricated fissures respectively. Preferably, the length of the fissure is 30 - 50 mm, the width is 0.1 - 0.5 mm, and the depth is 1 - 2 cm. There are 3 fissures with angles of 0°, 30°, 60°, and 90° respectively on the front and back sides of the top of the rock layer material layer. The angle is the included angle between the fissure and the horizontal projection of the axis of the inclined shaft device. The distance between adjacent two fissures is 100 - 300 mm. Specifically, as Figure 4 shown, the 4 kinds of fissures with angles of 0°, 30°, 60°, and 90° can be arranged in rows in sequence along the left and right directions of the box body, or can be arranged according to requirements. Preferably, the three rows of fissures on the same side of the axis of the inclined shaft device are arranged staggeredly in sequence. The row distance between adjacent two rows of fissures is 100 - 300 mm, and the distance between adjacent two fissures in the same row is 100 - 300 mm. The rock-like material is prepared according to the material ratio of cement: water: quartz sand = 1: 0.25: 1.25. The plug piece can be selected as a hard paper sheet.

[0042] Step S2: Install temperature sensors, stress sensors, and deformation monitoring sensors on the rock-like material layer, and connect the leads of each sensor to the data acquisition module respectively. The data acquisition module is connected to the control module. The control module can be a computer, etc. In this step, the temperature sensors, stress sensors, and deformation monitoring sensors are arranged according to the cross-sectional size and angle of the inclined shaft of the shaft to be excavated, etc., and these temperature sensors, stress sensors, and deformation monitoring sensors do not interfere with the excavated shaft. This is understandable to those skilled in the art.

[0043] Step S3: Inject water into the visualization model box 2 to fully saturate the rock-like material 5.

[0044] Step S4: Repeat the above steps S1 - S3 in sequence until the rock-like material 5 is laid to the design elevation. Among them, the thickness of each layer of the rock-like material layer is 1 / 5 - 1 / 4 of the design elevation of the rock-like material 5.

[0045] Step S5: First, divide several freezing pipes 9 into four rows and vertically insert them into the rock-like material 5. Then install the seepage system 6 and turn it on. Preferably, the multi-row freezing pipes 9 are arranged at intervals in the front and back directions, and each row of freezing pipes 9 includes multiple freezing pipes arranged at intervals in the left and right directions. The row distance between adjacent two rows of freezing pipes is 200 mm, and the distance between adjacent two freezing pipes in each row is 100 mm. Specifically, as Figure 5 shown.

[0046] Step S6: Turn on the freezing circulation system. After the temperature of the rock-like material 5 reaches the designed temperature, close the two middle rows of freezing pipes 9.

[0047] Step S7: Excavate the shaft in the visualization model box 2 according to the designed inclined shaft cross-sectional dimensions and angles; after the shaft excavation is completed, pour and cure the inclined shaft wall in the shaft according to the similarity ratio, thus forming the inclined shaft device 3; among them, the two rows of freezing pipes on both sides always remain in the operating state during the curing period of the inclined shaft wall. In this step, the two middle rows of freezing pipes need to be truncated during shaft excavation, and the two rows of freezing pipes on both sides are reserved and continuously provide the freezing function.

[0048] Step S8: After the curing of the inclined shaft wall is completed, first turn off the freezing circulation system, then install the belt vibration load simulation system 4, and then adjust the load angle control rod 4.2 according to the inclined shaft angle and fix it.

[0049] Step S9: According to the belt vibration load and vibration frequency on site, input the vibration load and vibration frequency converted according to the similarity ratio into the servo controller 4.7.

[0050] Step S10: Turn on the data acquisition system and the belt vibration load simulation system 4 successively, and record the test data until the inclined shaft wall or the surrounding rock is damaged, and the test ends.

[0051] In this embodiment, the visualization model box is fixedly arranged on the top of the base. Water inlets and outlets are respectively arranged on the front and rear side plates of the visualization model box, and filters 7 are arranged at both the water inlets and outlets. Preferably, the filters are fixedly arranged on the inner wall surfaces of the front and rear side plates of the visualization model box. The inclined shaft device includes an inclined shaft roof 3.1 on the upper side, an inclined shaft bottom plate 3.2 on the lower side, and two inclined shaft side plates 3.3 on both sides. The inclined shaft roof and the inclined shaft bottom plate are parallel to each other and are inclined with respect to the horizontal direction. The two open ends of the inclined shaft device are respectively connected to the left and right side plates of the visualization model box; specifically, the inclined shaft device is inclined downward from one opening end to the other opening end.

[0052] Two groups of slideways are vertically and fixedly arranged at intervals on the top of the base. Each group of slideways includes a first slideway 4.11 and a second slideway 4.12 which are arranged oppositely. The first slideway is located on the left side of the visualization model box, and the second slideway is located on the right side of the visualization model box. The two groups of slideways are respectively matched with two load angle control rods one by one. The length of the load angle control rod is adjustable. The two ends of the two load angle control rods respectively extend to the outside of the left and right sides of the visualization model box. The left and right ends of each load angle control rod are respectively detachably connected to the first slideway and the second slideway in the same group. The load application unit is used to apply different magnitudes of loads to the inclined shaft floor. The belt vibration load simulation system can simulate the vibration load transmitted to the inclined shaft floor during belt transportation through servo pressure adjustment. The rock-like material is densely filled in the visualization model box, that is, the inclined shaft device is buried in the rock-like material.

[0053] In this embodiment, the positions of the water inlet and the water outlet are both at least 25 cm higher than the higher end of the inclined shaft roof (i.e., the upper shaft wall of the inclined shaft wall); preferably, the positions of the water inlet and the water outlet are both 30 cm higher than the higher end of the inclined shaft roof.

[0054] In this embodiment, the load angle control rod includes a telescopic sleeve and two telescopic rods movably inserted into both ends of the telescopic sleeve. Positioning screws are respectively threadedly connected to both ends of the side wall of the telescopic sleeve. The two telescopic rods are respectively positioned inside both ends of the telescopic sleeve through the corresponding positioning screws. A plurality of mounting holes are formed in the telescopic sleeve of each load angle control rod, and a hydraulic jack is arranged in each mounting hole. Preferably, the number of mounting holes on each load angle control rod is equal, and the positions of the plurality of mounting holes on the two load angle control rods are also the same. Specifically, the cylinder body of the hydraulic jack penetrates through the mounting hole and is fixedly arranged on the load angle control rod. The free end of the piston rod of the hydraulic jack abuts against the inclined shaft floor. The servo controller respectively controls each oil pump to move according to the signals of the control system. Each oil pump supplies oil to the corresponding hydraulic jack to control the extension length of the piston rod of the hydraulic jack, thereby realizing the simulation of the force on the inclined shaft wall under different inclined shaft angles.

[0055] In this embodiment, a plurality of first positioning holes 4.1a are formed on both the first slideway and the second slideway. The plurality of first positioning holes are evenly spaced along the long direction of the slideway, and the first positioning holes on the first slideway and the second slideway are arranged in a staggered manner; that is, a row of first positioning holes is provided on each of the first slideway and the second slideway, and the two rows of first positioning holes are arranged in a staggered manner. Correspondingly, second positioning holes are respectively formed on the two telescopic rods of each load angle control rod; the two telescopic rods of each load angle control rod are respectively detachably connected to the first slideway and the second slideway through bolts 4.8; that is, the load angle control rod is detachably connected to the slideway through bolts. Specifically, first, the second positioning holes at both ends of the load angle control rod are respectively aligned with the first positioning holes at appropriate positions on the first slideway and the second slideway, and then the bolts are inserted into the positioning holes to position the load angle control rod.

[0056] In this embodiment, two through holes for adjusting the inclination angles of the two load angle control rods are respectively formed on the left and right side plates of the visualization model box. The two through holes are respectively adapted to the openings at both ends of the inclined shaft device, or the two through holes are long holes adapted to the inclination angle range of the load angle control rod. Preferably, the inclination angle range of the load angle control rod is 15° to 45°. This structure facilitates the two ends of the load angle control rod to extend out of the visualization model box by providing two through holes; at the same time, it is suitable for adjusting the inclination angle of the load angle control rod, so that the load angle control rod does not interfere with the side wall of the visualization model box, and the structure is reasonably arranged.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A test method for the failure of the inclined shaft lining and surrounding rock considering belt vibration and seepage, characterized in that, It is carried out by using a physical simulation test device for the failure of the inclined shaft wall and surrounding rock. The test device includes a visualization model box (2), an inclined shaft device (3), a belt vibration load simulation system (4), a rock-like material (5), a seepage system (6), a data acquisition system, and a freezing cycle system. The inclined shaft device is a hollow cylindrical structure arranged in the visualization model box. The opening ends of the inclined shaft device are respectively fixedly connected to the left and right side plates of the visualization model box. The belt vibration load simulation system includes two groups of slideways (4.1), two load angle control rods (4.2), and a load application unit. The two groups of slideways are respectively located on the left and right sides of the visualization model box. The two load angle control rods are parallel to each other and are inclinedly arranged in the inclined shaft device. The two ends of each load angle control rod respectively extend to the outside of the left and right sides of the visualization model box. The two ends of each load angle control rod are respectively connected to two slideways in the same group. The load application unit includes a plurality of hydraulic jacks (4.3), a plurality of oil pumps (4.5), and a servo controller (4.7). The plurality of hydraulic jacks are divided into two groups and are respectively arranged on the two load angle control rods. Each hydraulic jack is connected to an oil pump (4.5) through a hydraulic pipe (4.4). The plurality of oil pumps are respectively connected to the servo controller (4.7) through control lines (4.6). The rock-like material is densely filled in the visualization model box. The water inlet pipe (6.2) of the seepage system is connected to the water inlet of the visualization model box through an osmotic pressure pump (6.4). The water outlet pipe (6.3) of the seepage system is connected to the water outlet of the visualization model box. Filters (7) are arranged at both the water inlet and the water outlet. The data acquisition system includes a data acquisition module, a temperature sensor, a strain sensor, and a deformation monitoring sensor. The freezing cycle system includes a refrigerator and a plurality of freezing pipes. The test method includes the following steps: Step S1: First, lay a layer of rock-like material (5) in the visualization model box (2) to form a rock-like material layer. Then, use fissure plates to prefabricate several fissures (8) in the rock-like material layer. The several fissures are symmetrically distributed at the top of the rock-like material layer and on both sides of the axis of the inclined shaft device (3). Then, pull out the fissure plates and respectively insert plug pieces into the prefabricated several fissures to prevent the prefabricated fissures (8) from collapsing. Step S2: Arrange a temperature sensor, a stress sensor, and a deformation monitoring sensor on the rock-like material layer, and respectively connect the leads of each sensor to the data acquisition module. The data acquisition module is connected to the control module. Step S3: Inject water into the visualization model box (2) to fully saturate the rock-like material (5). Step S4: Repeat the above steps S1 to S3 in sequence until the rock-like material (5) is laid to the design elevation. Among them, the thickness of each layer of the rock-like material layer is 1 / 5 to 1 / 4 of the design elevation of the rock-like material (5). Step S5: First, divide the freezing pipes (9) into multiple rows and vertically insert them on both sides of the axis of the inclined shaft device, and then install the seepage system (6) and turn it on; Step S6: Turn on the freezing circulation system. After the temperature of the rock-like material (5) reaches the designed temperature, close the two middle rows of freezing pipes (9); Step S7: Excavate the shaft in the visualization model box (2) according to the designed cross-sectional size and angle of the inclined shaft; after the shaft excavation is completed, pour the inclined shaft wall in the shaft according to the similarity ratio and cure it, thus forming the inclined shaft device (3); among them, the two rows of freezing pipes on both sides always remain in the operating state during the curing period of the inclined shaft wall; Step S8: After the curing of the inclined shaft wall is completed, first turn off the freezing circulation system, then install the belt vibration load simulation system (4), and then adjust the load angle control rod (4.2) according to the inclined shaft angle and fix it; Step S9: According to the belt vibration load and vibration frequency on site, input the vibration load and vibration frequency converted according to the similarity ratio into the servo controller (4.7); Step S10: Turn on the data acquisition system and the belt vibration load simulation system (4) successively, and record the test data until the inclined shaft wall or the surrounding rock is damaged, and the test ends.

2. The test method according to claim 1, characterized in that In the said Step S1: The length of the crack is 30 - 50 mm, the width is 0.1 - 0.5 mm, and the depth is 1 - 2 cm; on the front and back sides of the top of the rock layer material layer, there are 3 cracks each with an inclination angle of 0°, 30°, 60° and 90°, and the inclination angle is the included angle between the crack and the horizontal projection of the axis of the inclined shaft device (3).

3. The test method according to claim 1, characterized in that, In the said Step S5: The multiple rows of freezing pipes are arranged at intervals in the front-back direction, and each row of freezing pipes includes a plurality of freezing pipes arranged at intervals in the left-right direction; the row spacing between two adjacent rows of freezing pipes is 200 mm, and the spacing between two adjacent freezing pipes in each row of freezing pipes is 100 mm.

4. The test method according to claim 1, characterized in that, The inclined shaft device includes an inclined shaft roof (3.1), an inclined shaft floor (3.2) and two inclined shaft side plates (3.3), the inclined shaft roof and the inclined shaft floor are parallel to each other and are inclined relative to the horizontal direction; a plurality of mounting holes are formed on each load angle control rod, and a hydraulic jack is arranged in each mounting hole; the cylinder body of the hydraulic jack passes through the mounting hole and is fixedly arranged on the load angle control rod, and the free end of the piston rod of the hydraulic jack abuts against the inclined shaft floor.

5. The test method according to claim 1, characterized in that, The two groups of slideways are arranged at intervals, and each group of slideways includes a first slideway (4.11) and a second slideway (4.12), the first slideway and the second slideway are arranged in parallel and opposite on two opposite sides of the visualization model box; a plurality of first positioning holes (4.1a) are formed on both the first slideway and the second slideway, the plurality of first positioning holes are evenly arranged at intervals along the length direction of the slideway, and the first positioning holes on the first slideway and the second slideway are arranged in a staggered manner.

6. The test method according to claim 5, wherein Second positioning holes are respectively formed at both ends of the load angle control rod; both ends of the load angle control rod are detachably connected to the first slideway and the second slideway through bolts (4.8).

7. The test method according to claim 1, wherein On two side plates at the two ends of the visualization model box, which are connected to the inclined shaft device with openings at both ends, there are respectively two through holes for adjusting the inclination angles of the two load angle control rods; the two through holes are respectively adapted to the openings at the two ends of the inclined shaft device, or the two through holes are long strip holes adapted to the inclination angle range of the load angle control rods; the inclination angle range of the load angle control rods is 15° to 45°.

8. The test method according to claim 1, characterized in that, The seepage pressure of the seepage system (6) is 0 - 3 MPa.

9. The test method according to claim 1, characterized in that The positions of the water inlet and the water outlet are both at least 25 cm higher than the higher end of the inclined shaft wall.

10. The test method according to claim 1, wherein The length of the load angle control rod is adjustable and includes a telescopic sleeve and two telescopic rods movably inserted at both ends of the telescopic sleeve. At both ends of the side wall of the telescopic sleeve, there are respectively screwed positioning screws, and the two telescopic rods are respectively positioned inside both ends of the telescopic sleeve through the corresponding positioning screws.

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