Rock-soil body coupling performance testing device for non-uniform loading of soil body and method of rock-soil body coupling performance testing device

Abstract

The invention belongs to the technical field of rock-soil performance testing, and discloses a rock-soil body coupling performance testing device and method for soil body non-uniform loading, and the rock-soil body coupling performance testing device comprises a pressure control assembly, a sensing optical fiber, an optical fiber adjusting assembly and a gluing assembly, a pressure transmission pipeline is installed on the outer wall of the gluing assembly, a plurality of pressurizers are installed on the inner wall of the pressure transmission pipeline, a filling soil sample is placed in the pressure transmission pipeline, a sensing optical fiber is placed in the filling soil sample, and an optical fiber drawing assembly is placed on the outer side of the pressure transmission pipeline; the top of the optical fiber drawing assembly is provided with an optical fiber holder. According to the device, glue on the surface of the sensing optical fiber can be uniformly distributed by adopting a repeated and small-amount gluing mode, so that the situation that the optical fiber is bent due to non-uniform glue distribution is prevented, and the detection accuracy can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of rock and soil performance testing, and in particular relates to a rock and soil body coupling performance testing device and a method for testing rock and soil body coupling performance with non-uniform soil loading. Background Art

[0002] Rock-soil coupling refers to the fact that rock-soil in a natural underground environment is simultaneously affected by multiple physical fields such as groundwater, ground stress, and temperature. These physical fields interact and influence each other to form a complex coupling system. This coupling not only affects the physical and mechanical properties of rock-soil, but also has an important impact on its stability and safety. The study of rock-soil coupling is of great significance for understanding and predicting complex phenomena in geotechnical engineering. By deeply studying the behavior of rock-soil under the joint action of multiple physical fields, the mechanism of its deformation, destruction and other characteristics can be revealed, providing a scientific basis for engineering design and construction. At the same time, the study of rock-soil coupling is also helpful to improve the ability to predict and forecast geological disasters and prevent and reduce disasters, and protect people's lives and property. Sensing optical fiber has the advantages of long time series, full distribution, and anti-interference. It has been widely used in mining subsidence, foundation pit slope deformation, road settlement and other rock-soil deformation engineering monitoring. Commonly used sensing optical fiber construction methods mainly include laying inside and on the surface of rock-soil. Regardless of which method is used, the sensing optical fiber and rock-soil are regarded as a whole, and the deformation of the rock-soil is reflected by the observation value of the sensing optical fiber. During the monitoring process, the optical fiber observation hole is not only affected by the construction, but also easily affected by natural factors such as precipitation, drought and groundwater fluctuations. In addition, the deformation law and physical properties of the soil itself are complex, which leads to the relatively complex strain transfer relationship between the sensing optical fiber and the rock and soil. Therefore, ensuring the strain transfer efficiency between the sensing optical fiber and the rock and soil is the prerequisite for using the sensing optical fiber to carry out rock and soil deformation monitoring.

[0003] In the prior art, it is usually necessary to insert the sensing optical fiber into the rock and soil body and fix it to ensure the accuracy of the detection. When the sensing optical fiber is inserted, glue is generally applied to fix the optical fiber inside the rock and soil body. However, in the process of applying the glue, due to the influence of the application method and the gravity of the glue itself, the glue will be unevenly distributed in the sensing optical fiber, resulting in the glue causing the sensing optical fiber to bend inside the rock and soil body after solidification, thereby affecting the detection results and the accuracy of the detection. In addition, the strain transfer efficiency between the sensing optical fiber and the rock and soil body is related to their respective physical properties, mechanical properties and mechanical properties of the interface, among which the parameter with the greatest influence is the shear strength of the interface. Considering the accuracy and economy of the research, it is currently common to build an indoor similar material model and conduct a pull-out test method to explore the relationship between the type of sensing optical fiber, rock and soil body confining pressure, rock and soil body moisture content, density and strain transfer efficiency. However, the existing pull-out test equipment can only be used for the change of strain transfer efficiency under uniform load and fixed moisture content conditions, which is quite different from the actual working conditions. Summary of the invention

[0004] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a grouting assembly with multiple grouting ports and a grouting machine thereof, which solves the problem of uneven glue application in the prior art.

[0005] The object of the present invention can be achieved by the following technical scheme: a rock-soil coupling performance testing device with non-uniform soil loading, comprising a pressure control component, a sensing optical fiber, an optical fiber adjustment component and a glue coating component;

[0006] A glue coating component is installed on the back of the pressure control component, a pressure transmission pipeline is installed on the outer wall of the glue coating component, a plurality of pressurizers are installed on the inner wall of the pressure transmission pipeline, a filling soil sample is placed inside the pressure transmission pipeline, a sensing optical fiber is placed inside the filling soil sample, an optical fiber drawing component is placed on the outside of the pressure transmission pipeline, an optical fiber clamp is installed on the top of the optical fiber drawing component, an optical fiber adjustment component is placed on the outside of the optical fiber clamp, a data processing device is installed on the top of the optical fiber adjustment component, a total station is placed on the front of the pressure transmission pipeline, and a reflective marking is pasted on the outer wall of the pressure transmission pipeline;

[0007] The glue coating assembly includes a box body installed at one end of the pressure transmission pipeline, the inner wall of the box body is provided with a connecting pipe, the outer wall of the connecting pipe is provided with a plurality of grooves, a glue applicator is installed through the inner wall of the groove, an electric telescopic rod is installed on the inner wall of the glue applicator, an extrusion plate is installed at one end of the electric telescopic rod, an arc-shaped glue coating plate is installed at one end of the glue applicator, and the outer wall of the glue applicator is connected to a supplementary pipe.

[0008] In some disclosures, a first motor is installed on the inner wall of the box, a chain is installed on the output end of the first motor through a sprocket, a rubber wheel is installed on the inner wall of the box, and the rubber wheel is connected to the first motor through a sprocket chain transmission.

[0009] In some disclosures, a buffer spring is installed on the inner wall of the connecting tube, an arc-shaped fixing plate is installed on one end of the buffer spring, the fixing plate, the inner wall of the connecting tube is staggered with drying plates, the inner wall of the drying plate is installed with heating wires, the outer wall of the connecting tube is installed with a motor, and the outer wall of the motor is installed with a driving gear.

[0010] In some disclosures, a turntable is installed on the outer wall of the connecting tube through a ball bearing, a gear groove is opened on the outer wall of the turntable on the side close to the motor, the gear groove is meshed with the driving gear, a circular fixing ring is installed on the outer wall of the other side of the turntable, a clamping rod is installed on the outer wall of the fixing ring, and a glue applicator is installed on the outer wall of the clamping rod.

[0011] In some disclosures, a storage cavity is installed on the inner wall of the box body, a delivery pump is installed on the outer wall of the storage cavity, the input end of the delivery pump extends into the interior of the storage cavity, a replenisher is installed on the output end of the delivery pump, a fixing groove is opened at the bottom of the replenisher, a moving rod is installed through the inner wall of the fixing groove, a return spring is installed around the outer wall of the moving rod, a plurality of guide wheels are installed on the inner wall of the replenisher, and the moving rod is connected to the output end of the delivery pump.

[0012] In some disclosures, the testing method of the testing device is as follows;

[0013] Step 1: First, determine the test sampling points according to the existing geological and hydrological data, and conduct drilling sampling at the designated locations. In order to obtain representative physical and mechanical properties of the soil, soil mechanics tests are carried out to obtain several key parameters of the soil, including: average water content, average density g / cm3, average initial porosity, average compression coefficient and average compression modulus, which are recorded as w, ρ, e, a, and E respectively. According to the collected soil parameter information, coarse sand with a particle size range of 0.5-2mm, medium sand with a particle size range of 0.25-0.5mm, fine sand with a particle size range of 0.075-0.25mm and clay with a particle size less than 0.005mm are selected to configure the test materials. Based on the configured test materials, they are made into geotechnical tests with diameters of 50mm and 100mm to verify whether their mechanical parameters are consistent with those of on-site sampling.

[0014] Step 2: Place the soil sample inside the pressurized water injection chamber, drill a hole at the axial position of the soil sample, and lay the distributed optical fiber inside the soil sample. After the laying is completed, inject a certain amount of glue into the drill hole. After a period of rest, fix the position of the optical fiber by fixing devices at both ends of the pressurized water injection chamber;

[0015] Step 3: Connect the optical fiber end to the clamping device and adjust the base height to ensure that the center axis of the soil sample is level with the clamping device.

[0016] In some publications, step 4, the coupling between the optical fiber and the soil is closely related to the confining pressure. For the convenience of analysis, the following assumptions are made:

[0017] The interfacial tension between the optical fiber and the soil satisfies the static equilibrium:

[0018] F t =F g

[0019] The interfacial friction between the optical fiber and the soil is evenly distributed on the optical fiber surface:

[0020] F t =πDLt

[0021] The horizontal stress of the optical fiber is equal to the circumferential gravity of the soil:

[0022] F h =K0γL

[0023] In the above formula, F t is the interface force between the optical fiber and the soil, F g is the axial tension on the optical fiber, F h is the vertical stress on the optical fiber, D is the outer diameter of the optical fiber, L is the length of the optical fiber buried in the soil, t is the shear strength of the optical fiber-soil interface, K0 is the static vertical pressure coefficient, and γ is the weight of the soil layer;

[0024] Where K0 is calculated by the following formula:

[0025] K0=λK a +(1-λ)K b

[0026] K a =1-sinσ

[0027]

[0028] In the above formula, K a represents the static vertical pressure coefficient of sand, K b represents the static vertical pressure coefficient of clay, σ represents the effective internal friction angle of sand, I represents the plasticity index of clay, and λ represents the proportion of sand in the soil layer;

[0029] In order to measure the coupling between the optical fiber and the soil during the pulling process, the optical fiber-soil coupling coefficient is defined as α;

[0030]

[0031] In the above formula, x represents the distance from the left end point on the central axis of the pressurized water injection chamber. Assuming that the length of the pressurized water injection chamber is L, 0≤x≤L. ε(x) represents the optical fiber observation value at the corresponding position, m0 is the deformation value of the clamping device segment, 0≤α≤1, and the closer α is to 1, the better the coupling between the optical fiber and the rock mass.

[0032] In some disclosures, step 5, after a period of rest, the hydraulic device is started, and the initial confining pressure F0 is applied in sequence, and the axial force value F of the optical fiber of the clamping device segment is calculated. z Verify the validity of the device results, taking F0 as the independent variable, F z Linear regression analysis was performed for the dependent variable. If the R2 of the regression equation was greater than 0.95, the observation results at this time were considered valid;

[0033] F z =EAε

[0034] In the above formula, E represents the average elastic modulus of the optical fiber, A is the cross-sectional area of ​​the optical fiber, and ε represents the strain of the optical fiber in the clamping device section;

[0035] Step 6: Determine the pressure of different depths of the soil layer at different positions of the pressurized water injection chamber according to the depth of the target layer as F(x) h , start the intelligent pressurizing device, and assume that the force applied above the pressurized water filling chamber is F(x) 上 , the force applied below the pressurized water chamber is F(x) 下 , where x is the distance from the left end point on the central axis of the pressurized water injection chamber. Assuming that the length of the pressurized water injection chamber is L, then 0≤x≤L;

[0036] At this time, F(x) h -F0=F(x) 上 +F(x) 下

[0037] After applying pressure, the axial force F of the optical fiber in the clamping device is calculated z and coupling coefficient α, verify the validity of the experimental results, and explore the changes in the coupling between optical fiber and rock and soil at different depths.

[0038] In some disclosures, in step 7, since the rock formation may move horizontally during the mining process, and the sensing optical fiber has poor sensitivity to horizontal movement, during the loading process in step 7, F(x) c It will inevitably be distributed in a curve, and the pressurized water-filled chamber will move along the vertical axis. Therefore, the vertical displacement of the pressurized water-filled chamber is observed by the total station and the total station reflector. For the convenience of analysis, it is assumed that a point (x i y i), and it is assumed that the material of the optical fiber is uniform, continuous, and linearly elastic; the interface geometry will not be deformed by force; the two ends of the microelement are simply supported, and the force on the optical fiber here is shown in the figure. The calculation formula is:

[0039]

[0040] In the above formula represents the deflection of the soil, represents the optical fiber observation value, R represents the outer radius of the pressurized water injection chamber, a and b are integration coefficients, which are determined by the observation values ​​at both ends of the pressurized water injection chamber in this experiment.

[0041] In some disclosures, in step eight, during the loading process of step seven, the lateral displacement of the pressurized water injection chamber is observed by a total station, assuming that point (x i y i ) has a deflection value of Y q , assuming Y q is the independent variable, Linear regression analysis is performed for the dependent variable. If the R2 of the regression equation is greater than 0.95, it is considered that the optical fiber-soil coupling is high at this time.

[0042] The nouns, conjunctions or adjectives involved in the above technical solution are explained as follows:

[0043] A fixed connection is one where the parts or components are fixed without any relative movement;

[0044] A rotational connection is a connection between parts that allows the parts to rotate relative to each other;

[0045] Threaded connection is a detachable fixed connection with the advantages of simple structure, reliable connection, and convenient assembly and disassembly. It is widely used in the fields of mechanical engineering and connection structures.

[0046] A sliding connection is a connection between parts that allows the parts to slide against each other.

[0047] Beneficial effects of the present invention:

[0048] 1. The present invention can ensure that the glue on the surface of the sensing optical fiber can be evenly distributed by adopting a glue coating method of multiple small amounts, thereby preventing the optical fiber from bending due to uneven glue distribution. The device can effectively improve the accuracy of detection.

[0049] 2. The present invention can be applied to a variety of mining conditions. The device can realize the lateral pressure at different positions of the control device, which is convenient for studying the changing law of the mechanical properties of the fiber-soil interface under different geological conditions, different depths, and different mining progress conditions, and exploring the changing law of the coupling between the two. The present invention uses distributed optical fiber stress measurement to achieve full-section measurement of the soil, with low cost and strong resistance to external interference. The structure of the present invention has high measurement accuracy and is easy to operate. It has good application prospects in the fields of safe mining and rock and soil movement monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

[0052] Figure 2 is a schematic diagram of a total station and a reflective marking structure according to an embodiment of the present invention;

[0053] Figure 3 is a schematic diagram of the structure of a turntable portion of an embodiment of the present invention;

[0054] Figure 4 is a schematic diagram of a side cross-sectional structure of a box body according to an embodiment of the present invention;

[0055] Figure 5 is a schematic diagram of the structure of the replenisher part of an embodiment of the present invention;

[0056] Figure 6 It is a schematic diagram of the structure of the connecting pipe part of an embodiment of the present invention.

[0057] In the figure: 1. pressure control component; 2. pressure transmission pipeline; 3. pressurizer; 4. filling soil sample; 5. sensing optical fiber; 6. optical fiber pulling component; 7. optical fiber clamp; 8. optical fiber adjustment component; 9. data processing device; 10. total station; 11. reflective marking; 12. glue coating component; 120. box; 13. connecting pipe; 14. first motor; 15. chain; 16. rubber wheel; 17. storage chamber; 18. delivery pump; 19. replenisher; 20. fixing groove; 21. moving rod; 22. reset spring; 23. guide wheel; 25. buffer spring; 26. fixing plate; 27. drying plate; 28. heating wire; 29. ​​motor; 30. driving gear; 31. turntable; 32. fixing ring; 33. clamping rod; 34. glue coating device; 35. electric telescopic rod; 36. extrusion plate; 37. glue coating plate; 38. replenishing pipe. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] See also Figure 1 , Figure 3 and Figure 6 A soil coupling performance testing device for non-uniformly loaded rock and soil, comprising a pressure control component 1, a sensing optical fiber 5, an optical fiber adjustment component 8 and a glue coating component 12, wherein the back of the pressure control component 1 is installed with the glue coating component 12, the outer wall of the glue coating component 12 is installed with a pressure transmission pipeline 2, the inner wall of the pressure transmission pipeline 2 is installed with a plurality of pressurizers 3, a filling soil sample 4 is placed inside the pressure transmission pipeline 2, a sensing optical fiber 5 is placed inside the filling soil sample 4, an optical fiber drawing component 6 is placed outside the pressure transmission pipeline 2, an optical fiber clamp 7 is installed on the top of the optical fiber drawing component 6, and an optical fiber adjustment component 8 is placed outside the optical fiber clamp 7. Part 8, a data processing device 9 is installed on the top of the optical fiber adjustment component 8, a total station 10 is placed on the front of the pressure transmission pipeline 2, and a reflective mark 11 is pasted on the outer wall of the pressure transmission pipeline 2. The glue coating component 12 includes a box body 120 installed at one end of the pressure transmission pipeline 2, and the inner wall of the box body 120 is provided with a connecting pipe 13, and the outer wall of the connecting pipe 13 is provided with a plurality of grooves. A glue applicator 34 is installed through the inner wall of the groove, and an electric telescopic rod 35 is installed on the inner wall of the glue applicator 34. An extrusion plate 36 is installed at one end of the electric telescopic rod 35, and an arc-shaped glue coating plate 37 is installed at one end of the glue applicator 34. The outer wall of the glue applicator 34 is connected to a supplementary tube 38.

[0060] Specifically, when applying glue, the glue enters the interior of the glue applicator 34 through the replenishing tube 38, and then the electric telescopic rod 35 extends to drive the extrusion plate 36 to move. The extrusion plate 36 squeezes the glue so that the glue is discharged through the glue applying plate 37. The glue applying plate 37 applies the glue on the outer surface of the sensing optical fiber 5 to achieve the gluing function.

[0061] See also Figure 6 A first motor 14 is installed on the inner wall of the box body 120 , and a chain 15 is installed on the output end of the first motor 14 through a sprocket. A rubber wheel 16 is installed on the inner wall of the box body 120 , and the rubber wheel 16 is connected to the first motor 14 through the sprocket chain 15 .

[0062] Specifically, the sensing optical fiber 5 is fed into the interior of the box 120, and then the first motor 14 rotates to drive the chain 15 to rotate, and then drives the rubber wheel 16 to rotate. The rubber wheel 16 drives the sensing optical fiber 5 forward by rotating, thereby transporting the sensing optical fiber 5 to the interior of the filled soil sample 4.

[0063] See also Figure 5 and Figure 6 A buffer spring 25 is installed on the inner wall of the connecting tube 13, and an arc-shaped fixing plate 26 is installed on one end of the buffer spring 25. The fixing plate 26 and the inner wall of the connecting tube 13 are staggeredly installed with drying plates 27, and the inner wall of the drying plate 27 is installed with a heating wire 28. A motor 29 is installed on the outer wall of the connecting tube 13, and a driving gear 30 is installed on the outer wall of the motor 29.

[0064] Specifically, when the sensing optical fiber 5 moves to the fixing plate 26, the fixing plate 26 scrapes off the excess glue on the sensing optical fiber 5, so that the glue applied on the surface of the sensing optical fiber 5 can be evenly applied. After the glue is applied, the heating wire 28 works to dissipate heat, and the glue is preliminarily dried and shaped by the drying plate 27, so that the outermost layer of glue solidifies into a thin film state, thereby preventing the sensing optical fiber 5 from being scraped off during the movement of the filling soil sample 4, resulting in uneven application.

[0065] See also Figure 3 , Figure 4 and Figure 5 A turntable 31 is installed on the outer wall of the connecting tube 13 through a ball bearing. A gear groove is provided on the outer wall of the turntable 31 on one side close to the motor 29, and the gear groove is meshed with the driving gear 30. A circular fixing ring 32 is installed on the outer wall of the other side of the turntable 31, and a clamping rod 33 is installed on the outer wall of the fixing ring 32, and a glue applicator 34 is installed on the outer wall of the clamping rod 33.

[0066] Specifically, the motor 29 rotates to drive the driving gear 30, and the driving gear 30 drives the turntable 31 to rotate. When the turntable 31 rotates, it drives the clamping rod 33 to rotate, and the clamping rod 33 drives the glue applicator 34 to rotate. At this time, the glue applicator 34 drives the glue plate 37 to rotate around the outer wall of the sensing optical fiber 5, and the glue is applied to the surface of the sensing optical fiber 5 while rotating.

[0067] It should be noted that multiple glue applicators 34 can be placed, and each time the glue is applied, a small amount is applied multiple times to prevent excessive glue from dripping and uneven glue on the sensing optical fiber 5. After each glue application, the drying plate 27 is used to slightly dry and shape the glue to further ensure the uniformity of the glue. By applying the glue in the above manner, when the sensing optical fiber 5 enters the filling soil sample 4, the glue content on the surface of the optical fiber is the same, thereby preventing the optical fiber from bending due to uneven glue application.

[0068] See also Figure 3and Figure 6 A storage chamber 17 is installed on the inner wall of the box body 120, and a delivery pump 18 is installed on the outer wall of the storage chamber 17. The input end of the delivery pump 18 extends into the interior of the storage chamber 17, and a replenisher 19 is installed on the output end of the delivery pump 18. A fixing groove 20 is opened at the bottom of the replenisher 19, and a moving rod 21 is installed through the inner wall of the fixing groove 20. A return spring 22 is installed around the outer wall of the moving rod 21. A plurality of guide wheels 23 are installed on the inner wall of the replenisher 19, and the moving rod 21 is connected to the output end of the delivery pump 18.

[0069] Specifically, the delivery pump 18 extracts the glue in the storage chamber 17. At this time, the replenishing tube 38 is located in the replenisher 19. The replenishing tube 38 squeezes the moving rod 21. The contraction of the moving rod 21 drives the return spring 22 to extend. At this time, the cable passes through the guide wheel 23 to pull the output end of the delivery pump 18 down, so that the output end of the delivery pump 18 is connected to the replenishing tube 38. The delivery pump 18 works to transport the glue to the inside of the glue applicator 34 through the pipeline, thereby realizing the function of replenishing glue.

[0070] See also Figure 1 and Figure 2 , the testing method of the testing device is as follows;

[0071] Step 1: First, determine the test sampling points according to the existing geological and hydrological data, and conduct drilling sampling at the designated locations. In order to obtain representative physical and mechanical properties of the soil, soil mechanics tests are carried out to obtain several key parameters of the soil, including: average water content, average density g / cm3, average initial porosity, average compression coefficient and average compression modulus, which are recorded as w, ρ, e, a, and E respectively. According to the collected soil parameter information, coarse sand with a particle size range of 0.5-2mm, medium sand with a particle size range of 0.25-0.5mm, fine sand with a particle size range of 0.075-0.25mm and clay with a particle size less than 0.005mm are selected to configure the test materials. Based on the configured test materials, they are made into geotechnical tests with diameters of 50mm and 100mm to verify whether their mechanical parameters are consistent with those of on-site sampling.

[0072] Step 2: Place the soil sample inside the pressurized water injection chamber, drill a hole at the axial position of the soil sample, and lay the distributed optical fiber inside the soil sample. After the laying is completed, inject a certain amount of glue into the drill hole. After a period of rest, fix the position of the optical fiber by fixing devices at both ends of the pressurized water injection chamber;

[0073] Step 3: Connect the optical fiber end to the clamping device and adjust the base height to ensure that the center axis of the soil sample is level with the clamping device.

[0074] In some publications, step 4, the coupling between the optical fiber and the soil is closely related to the confining pressure. For the convenience of analysis, the following assumptions are made:

[0075] The interfacial tension between the optical fiber and the soil satisfies the static equilibrium:

[0076] F t =F g

[0077] The interfacial friction between the optical fiber and the soil is evenly distributed on the optical fiber surface:

[0078] F t =πDLt

[0079] The horizontal stress of the optical fiber is equal to the circumferential gravity of the soil:

[0080] F h =K0γL

[0081] In the above formula, F t is the interface force between the optical fiber and the soil, F g is the axial tension on the optical fiber, F h is the vertical stress on the optical fiber, D is the outer diameter of the optical fiber, L is the length of the optical fiber buried in the soil, t is the shear strength of the optical fiber-soil interface, K0 is the static vertical pressure coefficient, and γ is the weight of the soil layer;

[0082] Where K0 is calculated by the following formula:

[0083] K0=λK a +(1-λ)K b

[0084] K a =1-sinσ

[0085]

[0086] In the above formula, K a represents the static vertical pressure coefficient of sand, K b represents the static vertical pressure coefficient of clay, σ represents the effective internal friction angle of sand, I represents the plasticity index of clay, and λ represents the proportion of sand in the soil layer;

[0087] In order to measure the coupling between the optical fiber and the soil during the pulling process, the optical fiber-soil coupling coefficient is defined as α;

[0088]

[0089] In the above formula, x represents the distance from the left end point on the central axis of the pressurized water injection chamber. Assuming that the length of the pressurized water injection chamber is L, 0≤x≤L, ε(x) represents the optical fiber observation value at the corresponding position, m0 is the deformation value of the clamping device segment, 0≤α≤1, and the closer α is to 1, the better the coupling between the optical fiber and the rock mass.

[0090] In some disclosures, step 5, after a period of rest, the hydraulic device is started, and the initial confining pressure F0 is applied in sequence, and the axial force value F of the optical fiber of the clamping device segment is calculated. z Verify the validity of the device results, taking F0 as the independent variable, F z Linear regression analysis was performed for the dependent variable. If the R2 of the regression equation was greater than 0.95, the observation results at this time were considered valid;

[0091] F z =EAε

[0092] In the above formula, E represents the average elastic modulus of the optical fiber, A is the cross-sectional area of ​​the optical fiber, and ε represents the strain of the optical fiber in the clamping device section;

[0093] Step 6: Determine the pressure of different depths of the soil layer at different positions of the pressurized water injection chamber according to the depth of the target layer as F(x) h , start the intelligent pressurizing device, and assume that the force applied above the pressurized water filling chamber is F(x) 上 , the force applied below the pressurized water chamber is F(x) 下 , where x is the distance from the left end point on the central axis of the pressurized water injection chamber. Assuming that the length of the pressurized water injection chamber is L, then 0≤x≤L;

[0094] At this time, F(x) h -F0=F(x) 上 +F(x) 下

[0095] After applying pressure, the axial force F of the optical fiber in the clamping device is calculated z and coupling coefficient α, verify the validity of the experimental results, and explore the changes in the coupling between optical fiber and rock and soil at different depths.

[0096] In some disclosures, in step 7, since the rock formation may move horizontally during the mining process, and the sensing optical fiber has poor sensitivity to horizontal movement, during the loading process in step 7, F(x) c It will inevitably be distributed in a curve, and the pressurized water-filled chamber will move along the vertical axis. Therefore, the vertical displacement of the pressurized water-filled chamber is observed by the total station and the total station reflector. For the convenience of analysis, it is assumed that a point (x i y i ), and it is assumed that the material of the optical fiber is uniform, continuous, and linearly elastic; the interface geometry will not be deformed by force; the two ends of the microelement are simply supported, and the force on the optical fiber here is shown in the figure. The calculation formula is:

[0097]

[0098] In the above formula represents the deflection of the soil, represents the optical fiber observation value, R represents the outer radius of the pressurized water injection chamber, a and b are integration coefficients, which are determined by the observation values ​​at both ends of the pressurized water injection chamber in this experiment.

[0099] In some disclosures, in step eight, during the loading process of step seven, the lateral displacement of the pressurized water injection chamber is observed by a total station, assuming that point (x i y i ) has a deflection value of Y q , assuming Y q is the independent variable, Linear regression analysis is performed for the dependent variable. If the R2 of the regression equation is greater than 0.95, it is considered that the optical fiber-soil coupling is high at this time.

[0100] Working principle: The pressurizer in this device mainly includes an intelligent pressurized water injection module, a device main body module, an optical fiber drawing module, an optical fiber demodulation module, and an auxiliary observation module. The intelligent pressurized water injection module of the device includes an intelligent pressurizing device, a hydraulic device, a pressurizing line, a pressurizing probe, and a water injection pipeline. The pressurizing control device consists of a hydraulic pump, a water injection pump, and a control device. The hydraulic pump is used to pressurize the device body, the water injection pump is used to inject water into the device body, and the control device is used to regulate the hydraulic pump and the water injection pump to apply different degrees of pressure and inject different amounts of water at different positions of the device body; the hydraulic device is used to provide a uniform and stable initial pressure to simulate the undisturbed rock formation confining pressure.

[0101] The main module of the device includes a pressurized water-filled chamber and an optical fiber fixing device. The pressurized water-filled chamber is used to place the optical fiber and fill the soil sample; the optical fiber fixing device is used to fix the optical fiber at the axial position of the pressurized water-filled chamber.

[0102] The optical fiber drawing module is composed of an optical fiber clamping device and a drawing device. The optical fiber clamping device is used to connect the optical fiber to the drawing device; the drawing device is used to apply a certain degree of tension to the sensing optical fiber.

[0103] The optical fiber demodulation module consists of an optical fiber demodulation device and an optical fiber data processing device, wherein the optical fiber demodulation device is used to demodulate the frequency data of the sensing optical fiber into strain data, and the optical fiber data processing device is used to clean, reduce noise, calculate, and store the demodulated optical fiber data.

[0104] The auxiliary observation module consists of a total station and a total station reflection display. The total station reflection sheet is pasted on the outer surface of the pressurized water injection chamber to assist the total station monitoring. The total station is used to measure the horizontal and vertical displacements on the axis of the outer surface of the pressurized water injection chamber.

[0105] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0106] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A rock-soil coupling performance testing device with non-uniform soil loading, characterized in that: It comprises a pressure control component (1), a sensing optical fiber (5), an optical fiber adjustment component (8) and a glue coating component (12); A glue coating component (12) is installed on the back of the pressure control component (1), a pressure transmission pipeline (2) is installed on the outer wall of the glue coating component (12), a plurality of pressurizers (3) are installed on the inner wall of the pressure transmission pipeline (2), a filling soil sample (4) is placed inside the pressure transmission pipeline (2), a sensing optical fiber (5) is placed inside the filling soil sample (4), an optical fiber drawing component (6) is placed on the outside of the pressure transmission pipeline (2), an optical fiber clamp (7) is installed on the top of the optical fiber drawing component (6), an optical fiber adjustment component (8) is placed on the outside of the optical fiber clamp (7), a data processing device (9) is installed on the top of the optical fiber adjustment component (8), a total station (10) is placed on the front of the pressure transmission pipeline (2), and a reflective marking (11) is pasted on the outer wall of the pressure transmission pipeline (2); The glue coating assembly (12) comprises a box body (120) installed at one end of the pressure transmission pipeline (2), the inner wall of the box body (120) is provided with a connecting pipe (13), the outer wall of the connecting pipe (13) is provided with a plurality of grooves, a glue coating device (34) is installed through the inner wall of the groove, an electric telescopic rod (35) is installed on the inner wall of the glue coating device (34), an extrusion plate (36) is installed at one end of the electric telescopic rod (35), an arc-shaped glue coating plate (37) is installed at one end of the glue coating device (34), and a replenishing pipe (38) is connected to the outer wall of the glue coating device (34).

2. The rock-soil coupling performance testing device with non-uniform soil loading according to claim 1 is characterized in that: A first motor (14) is installed on the inner wall of the box body (120), a chain (15) is installed on the output end of the first motor (14) via a sprocket, a rubber wheel (16) is installed on the inner wall of the box body (120), and the rubber wheel (16) is connected to the first motor (14) via the sprocket chain (15).

3. The rock-soil coupling performance testing device for non-uniform soil loading according to claim 1, characterized in that: The inner wall of the connecting tube (13) is provided with a buffer spring (25), one end of the buffer spring (25) is provided with an arc-shaped fixing plate (26), the fixing plate (26), the inner wall of the connecting tube (13) is provided with drying plates (27) staggeredly installed, the inner wall of the drying plates (27) is provided with a heating wire (28), the outer wall of the connecting tube (13) is provided with a motor (29), and the outer wall of the motor (29) is provided with a driving gear (30).

4. The rock-soil coupling performance testing device for non-uniform soil loading according to claim 1, characterized in that: A rotating disk (31) is mounted on the outer wall of the connecting tube (13) via a ball bearing, a gear groove is provided on the outer wall of the rotating disk (31) on one side close to the motor (29), the gear groove is meshed with the driving gear (30), a circular fixing ring (32) is mounted on the outer wall of the other side of the rotating disk (31), a clamping rod (33) is mounted on the outer wall of the fixing ring (32), and a glue applicator (34) is mounted on the outer wall of the clamping rod (33).

5. The rock-soil coupling performance testing device with non-uniform soil loading according to claim 1 is characterized in that: The inner wall of the box body (120) is installed with a storage chamber (17), the outer wall of the storage chamber (17) is installed with a delivery pump (18), the input end of the delivery pump (18) extends into the interior of the storage chamber (17), the output end of the delivery pump (18) is installed with a replenisher (19), a fixing groove (20) is provided at the bottom of the replenisher (19), a moving rod (21) is installed through the inner wall of the fixing groove (20), a return spring (22) is installed around the outer wall of the moving rod (21), a plurality of guide wheels (23) are installed on the inner wall of the replenisher (19), and the moving rod (21) is connected to the output end of the delivery pump (18).

6. The testing method of a rock-soil coupling performance testing device with non-uniform soil loading according to claim 1 is characterized in that: The testing method of the rock-soil coupling performance testing device is as follows: Step 1: First, determine the test sampling points according to the existing geological and hydrological data, and conduct drilling sampling at the designated locations. In order to obtain representative physical and mechanical properties of the soil, soil mechanics tests are carried out to obtain several key parameters of the soil, including: average water content, average density g / cm3, average initial porosity, average compression coefficient and average compression modulus, which are recorded as w, ρ, e, a, and E respectively. According to the collected soil parameter information, coarse sand with a particle size range of 0.5-2mm, medium sand with a particle size range of 0.25-0.5mm, fine sand with a particle size range of 0.075-0.25mm and clay with a particle size less than 0.005mm are selected to configure the test materials. Based on the configured test materials, they are made into geotechnical tests with diameters of 50mm and 100mm to verify whether their mechanical parameters are consistent with those of on-site sampling. Step 2: Place the soil sample inside the pressurized water injection chamber, drill a hole at the axial position of the soil sample, and lay the distributed optical fiber inside the soil sample. After the laying is completed, inject a certain amount of glue into the drill hole. After a period of rest, fix the position of the optical fiber by fixing devices at both ends of the pressurized water injection chamber; Step 3: Connect the optical fiber end to the clamping device and adjust the base height to ensure that the center axis of the soil sample is level with the clamping device.

7. The testing method of the rock-soil coupling performance testing device with non-uniform soil loading according to claim 6 is characterized in that: Step 4: The coupling between the optical fiber and the soil is closely related to the confining pressure. For the convenience of analysis, the following assumptions are made: The interfacial tension between the optical fiber and the soil satisfies the static equilibrium: F t =F g The interfacial friction between the optical fiber and the soil is evenly distributed on the optical fiber surface: F t =πDLt The horizontal stress of the optical fiber is equal to the circumferential gravity of the soil: F h =K0γL In the above formula, F t is the interface force between the optical fiber and the soil, F g is the axial tension on the optical fiber, F h is the vertical stress on the optical fiber, D is the outer diameter of the optical fiber, L is the length of the optical fiber buried in the soil, t is the shear strength of the optical fiber-soil interface, K0 is the static vertical pressure coefficient, and γ is the weight of the soil layer; Where K0 is calculated by the following formula: K0=λK a +(1-λ)K b K a =1-sinσ In the above formula, K a represents the static vertical pressure coefficient of sand, K b represents the static vertical pressure coefficient of clay, σ represents the effective internal friction angle of sand, I represents the plasticity index of clay, and λ represents the proportion of sand in the soil layer; In order to measure the coupling between the optical fiber and the soil during the pulling process, the optical fiber-soil coupling coefficient is defined as α; In the above formula, x represents the distance from the left end point on the central axis of the pressurized water injection chamber. Assuming that the length of the pressurized water injection chamber is L, 0≤x≤L, ε(x) represents the optical fiber observation value at the corresponding position, m0 is the deformation value of the clamping device segment, 0≤α≤1, and the closer α is to 1, the better the coupling between the optical fiber and the rock mass.

8. The testing method of the rock-soil coupling performance testing device with non-uniform soil loading according to claim 6 is characterized in that: Step 5: After a period of rest, start the hydraulic device and apply the initial confining pressure F0 in turn. By calculating the axial force value F of the optical fiber in the clamping device z Verify the validity of the device results, taking F0 as the independent variable, F z Linear regression analysis was performed for the dependent variable. If the R2 of the regression equation was greater than 0.95, the observation results at this time were considered valid; F z =EAε In the above formula, E represents the average elastic modulus of the optical fiber, A is the cross-sectional area of ​​the optical fiber, and ε represents the strain of the optical fiber in the clamping device section; Step 6: Determine the pressure of different depths of the soil layer at different positions of the pressurized water injection chamber according to the depth of the target layer, which is F(x) h , start the intelligent pressurizing device, and assume that the force applied above the pressurized water filling chamber is F(x) 上 , the force applied below the pressurized water chamber is F(x) 下 , where x is the distance from the left end point on the central axis of the pressurized water injection chamber. Assuming that the length of the pressurized water injection chamber is L, then 0≤x≤L; At this time, F(x) h -F0=F(x) 上 +F(x) 下 After applying pressure, the axial force F of the optical fiber in the clamping device is calculated z and coupling coefficient α, verify the validity of the experimental results, and explore the changes in the coupling between optical fiber and rock and soil at different depths.

9. The testing method of the rock-soil coupling performance testing device with non-uniform soil loading according to claim 6 is characterized in that: Step 7: During the mining process, the rock layer will move horizontally, and the sensing fiber has poor sensitivity to horizontal movement. During the loading process in step 7, F(x) c It will inevitably be distributed in a curve, and the pressurized water-filled chamber will move along the vertical axis. Therefore, the vertical displacement of the pressurized water-filled chamber is observed by the total station and the total station reflector. For the convenience of analysis, it is assumed that a point (x i y i ), and it is assumed that the material of the optical fiber is uniform, continuous, and linearly elastic; the interface geometry will not be deformed by force; and the two ends of the microelement are simply supported. The optical fiber force calculation formula here is: In the above formula represents the deflection of the soil, represents the optical fiber observation value, R represents the outer radius of the pressurized water injection chamber, a and b are integration coefficients, which are determined by the observation values ​​at both ends of the pressurized water injection chamber in this experiment.

10. The testing method of a rock-soil coupling performance testing device with non-uniform soil loading according to claim 6, characterized in that: Step 8: During the loading process in step 7, the lateral displacement of the pressurized water injection chamber is observed by the total station. Assume that point (x i y i ) has a deflection value of Yq, assuming that Y q is the independent variable, Linear regression analysis is performed for the dependent variable. If the R2 of the regression equation is greater than 0.95, it is considered that the optical fiber-soil coupling is high at this time.

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