RU2777701C1 - Device and method for performing leepage testing under shear for a network of cracks - Google Patents

Abstract

FIELD: shear leakage tests.

SUBSTANCE: invention is intended to perform a shear leakage test for a network of fractures. The substance of the invention lies in the fact that the device contains the extreme isobaric device for water injection in the model, the extreme isobaric device for discharging water in the model, a glass model of a network of cracks, wide overlay plates and narrow overlay plates, all of which are processed to ensure water tightness in connection points. Wide overlay plates and narrow overlay plates are placed on the upper and lower parts of the glass crack network model, wherein the narrow overlay plates are placed on the shifted part of the glass crack network model, the wide overlay plates are placed on two sides of the narrow overlay plates, and the end of the wide overlay plate, which faces in the direction from the narrow overlay plate, tightly attached to the upper damper of the water inlet pipe inside the hole of the extreme isobaric device for water injection in the model. Using the length direction of the glass fracture network model as the x-axis and its width direction as the y-axis, a coordinate system is set, and the glass fracture network model can move in the x-axis or y-axis direction. In the apparatus and method for conducting a shear leakage test for a fracture network of the present invention, a laboratory test is implemented with a physical model of shear leakage for a fracture network.

EFFECT: enabling reliable and simple shear leakage tests for the fracture network.

6 cl, 5 dwg

Description

FIELD OF TECHNOLOGY

[0001] The present invention relates to the technical field of fluid mechanics and rock mechanics, and more specifically, it relates to an apparatus and method for conducting a shear leakage test for a fracture network.

BACKGROUND OF THE INVENTION

[0002] In engineering geology, there is a possibility of shear and disturbance of the rock mass under the influence of an earthquake, mining, and other factors, which leads to a relative displacement of the network of cracks within the rock mass along shear cracks. This situation leads to more complex channels for the passage of water or other harmful substances, further increasing the permeability of the rock mass and deteriorating its physical and mechanical properties. Implementation of a laboratory test with a physical model of shear infiltration for a fracture network can reveal the mechanism of shear infiltration in a fracture network, and can also provide a reliable basis for safe evaluation of engineering technology.

[0003] Statistically, more than 90% of shaft damage in rock is due to groundwater permeability, 60% of mine accidents are due to groundwater, and 30% to 40% of dam failures in hydroelectric projects are caused by seepage. Thus, there is an urgent need in this field to study the mechanism of shear infiltration in a fracture network, with the implementation of a test with a physical model of shear infiltration for a fracture network being the most effective and important step. Testing with a physical model of seepage in shear for a fracture network is mainly difficult due to ensuring equal values of water pressure on all fractures and faults, as well as due to the development of a network of fractures where shear displacement occurs.

[0004] Patent Application No. 201410140674.1 discloses a method for conducting a seepage-shear bond test in rock, during which the following problems occur: (1) when the test specimen is sheared and damaged, all shear cracks and cracks in the crack network are deformed , causing changes in the degree of opening and permeability, thereby separately determining the effect of shear fractures on the penetration characteristics of the entire fracture network of the test sample. (2) During the test, the water pressure at the measurement point is constantly changing and refers to the dynamic water pressure, thus not simulating the hydrostatic pressure of the steady flow on the object.

DISCLOSURE OF THE INVENTION

[0005] The present invention provides an apparatus and method for conducting a shear leakage test for a fracture network, which implements a laboratory test with a physical model of shear leakage for a fracture network, and which has the advantages of low cost and ease of implementation.

[0006] To solve technical problems, the present invention uses the technical solutions presented below. A device for carrying out a shear leakage test is presented, which contains: the model outer isobaric water injection device, the model outer isobaric water outlet device and the glass model of the fracture network, and the model outer isobaric water injection device has a c-shaped section and its opening faces the test environment;

the extreme isobaric device for water outlet in the model has a c-shaped section and its hole faces the test environment; and the opening of the extreme isobaric water outlet device in the model and the opening of the extreme isobaric water injection device in the model are oriented opposite each other;

the glass model of the crack network is formed by two separable halves of the model, with the side of one of the two separable halves of the model, which is facing away from the test environment, installed in the hole of the isobaric device for water injection, which is the outermost in the model, and the side of the other separable half of the model, which is facing into in the direction from the test medium, installed in the hole of the outermost isobaric device for water release in the model; and

using the length direction of the glass crack network model as the x-axis and its width direction as the y-axis, a coordinate system is specified; in this case, the two detachable halves of the model can be moved in the direction of the x-axis or the y-axis, and the offset in the direction of the x-axis must be greater than 0.

[0007] As a further preferred feature of the present invention, the device further comprises wide overlay plates and narrow overlay plates, wherein the narrow overlay plates are placed respectively at the top and bottom of the tight junction of the two detachable halves of the model, and the wide overlay plates are tightly attached to narrow overlay plates and placed in the upper and lower parts of the two detachable halves of the model in the direction from the test environment.

[0008] As a further preferred feature of the present invention, the apparatus further comprises a water inlet, a lower water inlet shutter, an upper water inlet shutter, and a hydrostatic test port on the water inlet, wherein the water inlet and the port for hydrostatic testing on the water inlet, they are made in a row on the top of the extreme isobaric water injection device in the model; the lower damper of the inlet pipe for water and the upper damper of the inlet pipe for water are placed inside the hole of the extreme isobaric device for water injection in the model; the lower water inlet flap is located under the water inlet and the hydrostatic test port on the water inlet; and the upper water inlet flap is located on the upper part of the contact point between the extreme isobaric water injection device in the model and the glass fracture network model.

[0009] As a further preferred feature of the present invention, the apparatus further comprises a water outlet, a hydrostatic test port on the water outlet, and a top flap of the water outlet, the water outlet and the hydrostatic test port on the water outlet for water is made on the upper part of the isobaric device for water release, which is extreme in the model; and the upper damper of the water outlet is located inside the hole of the isobaric device for water outlet, which is the outermost in the model, and on the upper part of the contact point between the outermost isobaric device for water outlet in the model and the glass fracture network model.

[0010] As a further advantageous feature of the present invention, the model extreme isobaric water injection device, the model extreme isobaric water outlet device, wide cover plates and narrow cover plates are subjected to a sealing treatment at the joint edges.

[0011] The present invention also provides a method for conducting a shear leakage test for a fracture network, which includes the following steps, in which:

step 1: determining the size of the narrow overlay plates: making narrow overlay plates of the appropriate size in accordance with the required amount and direction of the shear displacement;

Step 2: Assemble the test device: Assemble the outer model isobaric water injection device, the outermost isobaric water outlet device and the glass fracture network model, and connect them by using wide patch plates and narrow patch plates;

step 3: prepare for testing: start the water source and inject water through the water inlet in the model isobaric water injection device until the water flow exits from the water outlet in the model isobaric water outlet; and

step 4: measure the water pressure values at the water inlet and outlet for water: after ensuring the stability of the entire water flow in step 3, use a differential pressure gauge to measure the hydrostatic pressure values of the water inlet and water outlet, respectively, at the hydrostatic test port on the water inlet and a hydrostatic test port on the water outlet.

[0012] Due to the above technical solutions, the present invention has the following beneficial effects compared to the prior art:

[0013] 1. The model extreme isobaric water injection device according to the present invention provides equal water pressures in all cracks and fractures, and the model extreme isobaric water outlet provides equal water pressures at the water outlet, so that the hydrostatic pressure of a steady flow is reached in the simulated area.

[0014] 2. The glass model of the fracture network in the present invention is formed by two detachable model halves, and a laboratory test with a physical model of shear leakage for the fracture network is realized by moving one detachable model half in the x-axis or y-axis direction.

[0015] 3. The crack network in the glass model of the crack network according to the present invention is obtained by machining a glass plate, making it easy to implement and low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0017] FIG. 1 is a plan view of the entire structure of the present invention;

[0018] FIG. 2 is a front view of the entire structure of the present invention;

[0019] FIG. 3 is a front view of the modeled isobaric water injection device of the present invention;

[0020] FIG. 4 is a front view of a glass crack network model in the present invention; and

[0021] FIG. 5 is a front view of the model's outermost isobaric water outlet device in the present invention.

Explanation of reference designations: 10. Extreme isobaric device for water injection in the model; 11. Water inlet; 12. Bottom damper for water inlet; 13. Upper damper for water inlet; 14. Hydrostatic test port on water inlet; 20. Extreme in the model isobaric device for the release of water; 21. Water outlet; 22. Hydrostatic test port on water outlet; 23. Upper damper for water outlet; 30. Glass model of a network of cracks; 40. Wide patch plate; and 50. Narrow patch plate.

DETAILED DESCRIPTION OF IMPLEMENTATION OPTIONS

[0022] Further detailed description of the present invention is presented below with reference to the accompanying drawings. These accompanying drawings are simplified schematic views and only schematically depict the basic structure of the present invention. Thus, only those components that are relevant to the present invention are shown.

[0023] Laboratory testing with a physical model of shear infiltration for a fracture network can reveal the mechanism of shear infiltration in a fracture network, and can also provide a reliable basis for safe evaluation of engineering technology. There are some shortcomings in the prior art. For example, when a test piece is sheared and damaged, all shear fractures and fractures in the fracture network deform, causing changes in the opening degree and permeability, thereby separately determining the effect of shear fractures on the penetration characteristics of the entire fracture network of the test piece. Moreover, during the test, the water pressure at the measurement point is constantly changing and refers to the dynamic pressure of the water, thus not simulating the hydrostatic pressure of the steady flow on the object.

[0024] Based on the above problems, the present application provides a device for conducting a shear leakage test for a network of cracks, which contains, as shown in FIG. 2, the model outermost isobaric water injection device 10, the modelmost isobaric water outlet device 20, and the glass model 30 of the crack network. The model's outermost isobaric water injection device 10 has a c-section and its opening faces the test environment. The model's outermost isobaric water outlet 20 has a c-section and its opening faces the test environment. The hole of the outermost isobaric device 20 in the model for discharging water and the hole of the outermost isobaric device 10 in the model for water injection are oriented opposite each other. The glass model 30 of the crack network is formed by two detachable halves of the model, wherein the side of one of the two detachable halves of the model, which faces away from the test environment, is installed in the hole of the isobaric device 10 for water injection, which is the outermost in the model, and the side of the other detachable half of the model, which facing away from the test environment, installed in the hole of the extreme isobaric device 20 in the model for water release. As shown in FIG. 1, using the length direction of the glass crack pattern 30 as the x-axis and its width direction as the y-axis, a coordinate system is set. The two detachable halves of the model can be moved in the x-direction or y-direction, and the offset in the x-direction must be greater than 0.

[0025] Glass model crack network 30 crack networks are prepared by cutting with a water jet, carving with a glass cutter, or physically striking a glass plate. The required degree of opening and displacement during shearing can be provided by the need to move only one of the two separable halves of the model in the direction of the x-axis or y-axis without the need to move both halves of the model.

[0026] As shown in FIG. 4, the present application further comprises wide appliqué plates 40 and narrow appliqué plates 50, wherein the narrow applier plates 50 are located respectively at the top and bottom (namely, the top and bottom of the shifted and offset portions) of the tight connection between two separable halves of the model, and the wide overlay plates 40 are tightly attached to the narrow overlay plates 50 and are placed at the top and bottom of the two detachable halves of the model in the direction from the test environment.

[0027] The wide overlay plates 40 are used to secure the glass fracture network model 30, and the narrow overlay plates 50 are used to secure the shifted portion of the glass fracture network model 30, the narrow overlay plate 50 being sized according to the magnitude and direction of the shear displacement. The outermost isobaric water injection device 10 in the model, the outermost isobaric water outlet device 20 in the model, wide overlay plates 40 and narrow overhead plates 50 are subjected to sealing treatment at the edges of the joint.

[0028] As shown in FIG. 1, the present application further comprises a water inlet 11, a lower water inlet flap 12, an upper water inlet flap 13, and a hydrostatic test port 14 on the water inlet, wherein the water inlet 11 and the water inlet port 14 The hydrostatic water inlet test is performed at the upper end of the model's outermost isobaric water injection device 10, which faces away from the test medium. As shown in FIG. 3, the lower water inlet damper 12 and the upper water inlet damper 13 are placed inside the hole of the model's isobaric water injection device 10. The lower water inlet flap 12 is located under the water inlet 11 and the hydrostatic test hole 14 on the water inlet, and the upper water inlet flap 14 is located at the top of the contact between the model's outermost isobaric water injection device 10 and glass model 30 network of cracks.

[0029] The positions of the water inlet 11 and the hydrostatic test port 14 on the water inlet at the top of the end of the model isobaric water injection device 10, which faces away from the test environment, are not limited and are not affected on the test result in any position.

[0030] As shown in FIG. 1, the present application further comprises a water outlet 21, a hydrostatic test port 22 on the water outlet, and a top flap 23 on the water outlet, wherein the water outlet 21 and the hydrostatic test port 22 on the water outlet are on the top of the end of the model's extreme isobaric water outlet 20, which faces away from the test environment. As shown in FIG. 5, the upper damper 23 of the water outlet is placed inside the hole of the model-outlet isobaric water outlet 20 and at the top of the contact between the model-outlet isobaric water outlet 20 and the glass fracture network model 30.

[0031] The positions of the water outlet 21 and the hydrostatic test port 22 on the water outlet at the top end of the model isobaric water outlet 20, which faces away from the test environment, are not restricted and are not affected on the test result in any position.

Implementation Option 1

[0032] In the present application, the preferred embodiment 1 shown in FIG. 2, and the device in this implementation scheme is formed by three parts: the model isobaric water injection device 10, the model isobaric water outlet device 20, and the glass model 30 of the crack network. After assembling the three parts, wide patch plates 40 are placed on the top and bottom of the crack network glass model 30, respectively, and narrow patch plates 50 are placed on the top and bottom of the shear and offset of the crack network glass model 30, respectively. Wide patch plates 40 and narrow patch plates 50 are tightly attached, and the end of the wide patch plate 40, which faces away from the narrow patch plate 50, is tightly attached to the upper damper 13 of the water inlet pipe inside the hole of the extreme isobaric device 10 for water injection in the model . The outermost isobaric water injection device 10 in the model, the outermost isobaric water outlet device 20 in the model, the wide cover plates 40 and the narrow cover plates 50 are subjected to sealing treatment at the joint edges. The glass model 30 of the crack network can move in the direction of the x-axis or the y-axis.

[0033] As shown in FIG. 2, after water is injected through the water inlet 11, the water first enters the cavity defined by the lower water inlet flap 13 and the inner walls of the model-bound isobaric water injection device 10, thereby providing a certain degree of buffering effect. After the water flows through the lower water inlet flap 13, the pressure of the water flow tends to a steady state, so that the water flow has the same pressure when it enters the cracks, and the water inflow volumes are basically constant. Due to the loss of pressure during the flow of water through the cracks in the glass model 30 of the network of cracks, the water pressure decreases after the water flows out of the glass model 30 of the network of cracks, and the flowing water fills the hole of the model's outermost device 20 for collecting water and gas. Due to the buffering effect in the cavity inside the hole, the water flowing out through the water outlet 21 has a constant pressure. After the water flow is stable throughout the model, a differential pressure gauge is used to measure the hydrostatic pressure values of the water inlet 11 and the water outlet 21, respectively, at the water inlet hydrostatic test port 14 and the outlet hydrostatic test port 22. pipe for water.

[0034] The specific way of testing in this implementation scheme is as follows:

[0035] Step 1: Size of narrow overlay plates 50: Appropriately sized narrow overlay plates 50 are made in accordance with the desired amount and direction of shear displacement.

[0036] Step 2: Assemble the test device: Assemble the model outermost isobaric water injection device 10, the outermost isobaric water outlet device 20 and the glass fracture network model 30, and connect them by using wide patch plates 40 and narrow overlay plates 50. Further, the outermost isobaric device 10 for water injection in the model, the outermost isobaric device 20 for water outlet in the model, wide overlay plates 40 and narrow overlay plates 50 are treated to ensure water tightness (sealed with a sealant) at the edges connections.

[0037] Step 3: Prepare for testing: The glass model 30 of the crack network is moved in the x-axis or y-axis direction to achieve the required degree of opening and shear displacement; and injecting water through the water inlet 11 in the model isobaric water injection device 10 until the water flow exits from the water outlet 21 in the model isobaric water outlet 20 (water outlet through the outlet 21 indicates that that the water pressure inside the whole model is in a steady state).

[0038] Step 4. Measure the water pressure values at the water inlet and outlet pipes: After ensuring the stability of the entire water flow in step 3, use a differential pressure gauge to measure the hydrostatic pressure values of the water inlet 11 and the water outlet 21, respectively, on a hydrostatic test hole 14 on the water inlet; and a hydrostatic test hole 22 on the water outlet.

[0039] The model extreme isobaric water injection device 10 of the present invention provides equal water pressures in all cracks and fractures, and the model extreme isobaric water outlet 20 provides equal water pressures at the water outlet, so that the hydrostatic pressure of a steady flow is reached in the simulated area. The present invention implements a laboratory test with a physical model of shear leakage for a fracture network by moving one detachable half of the model in the direction of the x-axis or y-axis. The crack network in the glass model 30 of the crack network according to the present invention is obtained by machining a glass plate, providing ease of implementation and low cost. Moreover, due to the transparency of the glass plate, leakage can be easily observed during the test. For easier observation, the water source can be replaced with a colored dye solution, and the flow of the colored dye solution in different directions of fractures in the fracture network model can be observed through seepage.

[0040] Only preferred embodiments of the present invention have been described above. It should be noted that certain improvements and modifications can be made by one skilled in the art without departing from the spirit of the present invention, and these improvements and modifications should also be construed as falling within the protection scope of the present invention.

[0041] Those skilled in the art will appreciate that, unless otherwise specified, all terms (including technical and scientific terms) used herein have the same meaning as generally known to those of skill in the art, to to which the present invention relates. It is also to be understood that terms such as those defined in the general vocabulary are to be construed as having meanings consistent with those in the context of the prior art. Unless otherwise defined herein, these terms should not be interpreted in the most preferred or overly formal sense.

[0042] The meaning of "and/or" in this application refers to the fact that each element is provided separately or both elements at the same time.

[0043] "Connection" in this application can mean a direct connection between components or an indirect connection between components through another component.

[0044] After reading the above preferred embodiments of the present invention, based on the above content, competent specialists will be fully able to make a wide range of changes and modifications without deviating from the scope of the technical intent of the present invention. The technical scope of the present invention is not limited to the content of the description and should be determined in accordance with the scope of the claims.

Claims (14)

1. An apparatus for conducting a shear leakage test, comprising: the isobaric device (10) for water injection, which is the last in the model, the isobaric device (20) for water outlet and the glass model (30) of the network of cracks, and the isobaric device (10) for water injection that is the last in the model has a c-shaped section and the hole of the extreme isobaric device (10) for water injection in the model faces the test environment; The outermost isobaric device (20) for water outlet in the model has a c-shaped section and the hole of the outermost isobaric device (20) for outlet of water in the model faces the test environment; and the opening of the extreme isobaric device (20) in the model for discharging water and the opening of the extreme isobaric device (10) in the model for injecting water are oriented opposite each other; the glass model (30) of the network of cracks is formed by two separable halves of the model, and the side of one of the two separable halves of the model, which is facing away from the test environment, is installed in the hole of the isobaric device (10) for water injection, which is extreme in the model, and the side of the other detachable half of the model, which is facing away from the test environment, is installed in the hole of the isobaric device (20) for the release of water, which is extreme in the model; and using the direction of the length of the glass model (30) of the crack network as the x-axis and the direction of its width as the y-axis, a coordinate system is set; in this case, the two detachable halves of the model can be moved in the direction of the x-axis or the y-axis, and the offset in the direction of the x-axis must be greater than 0. 2. The device according to claim. 1, characterized in that it additionally contains wide overlay plates (40) and narrow overhead plates (50), and narrow overhead plates (50) are placed, respectively, in the upper and lower parts of the place of tight connection of two detachable halves of the model, and wide overlay plates (40) are tightly attached to narrow overlay plates (50) and are placed in the upper and lower parts of the two detachable halves of the model in the direction from the test environment. 3. Device according to claim 2, characterized in that it further comprises a water inlet (11), a lower water inlet damper (12), an upper water inlet damper (13), and a hydrostatic test hole (14). on the water inlet pipe, wherein the water inlet pipe (11) and the hydrostatic test hole (14) on the water inlet pipe are made in a row on the upper part of the isobaric water injection device (10) extreme in the model; the lower damper (12) of the water inlet and the upper damper (13) of the water inlet are located inside the hole of the isobaric device (10) for water injection; the bottom flap (13) of the water inlet is located under the water inlet (11) and the hydrostatic test port (14) on the water inlet; and the upper damper (14) of the water inlet is located on the upper part of the contact point between the extreme isobaric device (10) for water injection in the model and the glass model (30) of the crack network. 4. The device according to claim 3, characterized in that it further comprises a water outlet (21), a hydrostatic test hole (22) on the water outlet and an upper damper (23) of the water outlet, wherein the outlet ( 21) for water and a hole (22) for hydrostatic testing on the outlet pipe for water is made on the upper part of the extreme isobaric device (20) for water outlet in the model; and the upper damper (23) of the water outlet pipe is located inside the hole of the isobaric device (20) for water outlet, which is extreme in the model, and on the upper part of the contact point between the isobaric device (20), which is extreme in the model, for water outlet and the glass model (30) of the network of cracks . 5. The device according to claim 4, characterized in that the isobaric device (10) extreme in the model for injecting water, the isobaric device (20) extreme in the model for discharging water, wide overlay plates (40) and narrow overhead plates (50) are subjected to sealing treatment at the edges of the connection. 6. A method for conducting a shear leakage test for a fracture network based on the apparatus of claim 5, comprising the steps of: step 1: determine the size of the narrow overlay plates: make narrow overlay plates (50) of the appropriate size in accordance with the required amount and direction of the shear displacement; step 2: assemble the device for testing: assemble the outermost isobaric device (10) for water injection, the outermost isobaric device (20) for discharging water and the glass model (30) of the crack network and connect them by using wide overlays plates (40) and narrow overlay plates (50); stage 3: prepare for the test: start the water source and inject water through the inlet pipe (11) for water in the extreme isobaric device (10) for water injection in the model until the water flow exits from the outlet pipe (21) for water in the outermost model isobaric device (20) for water outlet; and step 4: measure the water pressure values at the water inlet and outlet pipes: after ensuring the stability of the entire water flow in step 3, use a differential pressure gauge to measure the hydrostatic pressure values of the water inlet (11) and water outlet (21), respectively, on the hydrostatic test port (14) on the water inlet and on the hydrostatic test port (22) on the water outlet.

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