A force measuring anchor rod

Abstract

The application provides a force measuring anchor rod which adopts a multi-section structure design, wherein a rod body of the anchor rod comprises a plurality of first pipe columns and a plurality of force measuring modules. The force measuring module comprises a protective shell, a liquid bag storing liquid and a liquid pipe. The protective shell is sleeved on one end of the first pipe column, the liquid bag is arranged in the protective shell, and the other end of the first pipe column is connected with a pressure plate. The pressure plate on one first pipe column is limited to move and is installed in the protective shell on another first pipe column to form a force measuring module. When the pressure plate moves, the liquid bag is pressed to change the pressure. One end of the liquid pipe is communicated with the liquid bag, the other end of the liquid pipe passes through the pressure plate and penetrates into the first pipe column, and the other end of the liquid pipe is connected with a pressure gauge. The force measuring anchor rod for monitoring anchoring force is used by utilizing the incompressibility of liquid, and the short circuit problem caused by water and moisture entering due to the use of a resistance strain gauge is effectively avoided.

Description

Technical Field

[0001] This invention belongs to the technical field of underground engineering protection equipment, and specifically relates to a force-measuring anchor rod. Background Technology

[0002] In underground engineering, reinforcing and supporting soil and rock masses is a common problem. Traditional soil and wall reinforcement methods have limitations in many cases, such as requiring large land areas, large amounts of filling materials, and long construction times. Especially when excavating or mining soil and rock masses in soft rock strata, the instability of the soft rock can lead to rock strata failure and collapse, causing engineering accidents and project delays. To overcome these limitations, anchor bolt support technology has emerged. Anchor bolt support transfers the load to more stable strata by fixing the support structure deep within the soil or rock layers, thus providing more reliable support and reinforcement for underground engineering construction. Therefore, continuous development and improvement of existing anchor bolt technology are essential to enhance the safety, reliability, and construction efficiency of underground engineering projects.

[0003] Typical force-measuring anchor bolts utilize the resistance strain gauge principle, widely applied in engineering testing. A resistance strain gauge is bonded to the anchor bolt body as the sensing element. When the anchor bolt deforms under stress, the resistance of the strain gauge changes accordingly. Therefore, by measuring the resistance change of the strain gauge, the strain value of the bolt body can be obtained, and the stress value can be calculated. However, moisture in the surrounding rock can slowly seep into the force-measuring anchor bolt, potentially causing a short circuit in the strain gauge and affecting normal operation. Summary of the Invention

[0004] The purpose of this invention is to provide a force-measuring anchor rod that utilizes the incompressibility of liquids to monitor anchoring force, effectively avoiding short-circuit problems caused by water ingress and moisture absorption due to the use of resistance strain gauges.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] Anchoring section, which is inserted into the rock and soil to fix the anchor rod;

[0007] A force measuring section, one end of which is connected to the anchoring section, is used to measure the anchoring force;

[0008] Its features are:

[0009] The force measuring section includes several first tubular columns and several force measuring modules. Each force measuring module includes a protective shell, a liquid bag containing liquid, a liquid tube, and a pressure plate. One end of each first tubular column is fitted with the protective shell, and the liquid bag is disposed within the protective shell. The other end of the first tubular column is connected to the pressure plate. A force measuring module is formed by restricting the movement of a pressure plate on one first tubular column and installing it within the protective shell on another first tubular column. When the pressure plate moves, it compresses the liquid bag, causing a pressure change. One end of the liquid tube communicates with the liquid bag, and the other end passes through the pressure plate and enters the interior of the first tubular column, exiting from the other end of the force measuring section away from the anchoring section. The other end of the liquid tube is connected to a pressure gauge.

[0010] Furthermore, one end of the protective shell is connected to the outer wall of the first tubular column, and a limiting ring is provided between the other end and the outer wall of the first tubular column to restrict the movement of the pressure plate and the liquid bag.

[0011] Preferably, the protective housing includes a first protective housing and a second protective housing. One end of the first protective housing is threaded to the outer wall of the first tubular column, and the other end of the first protective housing is connected to one end of the second protective housing. The other end of the second protective housing is provided with the limiting ring.

[0012] Preferably, the pressure plate is threaded to the outer wall of the first tubular column.

[0013] Furthermore, a second tubular column is detachably connected to the other end of the force measuring section away from the anchoring section.

[0014] Furthermore, a fixing plate and a nut for fixing the fixing plate are fitted onto the second tubular column.

[0015] Furthermore, a liquid valve is also provided on the pipe body that extends out of the force measuring section.

[0016] Furthermore, the anchoring section includes an end enlargement module, which includes an anchoring block connected to the first pipe column. The anchoring block is provided with a plurality of friction-increasing teeth that can extend and retract.

[0017] Furthermore, one end of the friction-enhancing tooth is rotatably connected to the anchor block, and the middle part is connected to the anchor block spring.

[0018] Preferably, the liquid bag is made of rubber material, and the liquid tube is made of high-density polyethylene material.

[0019] Beneficial effects of this invention:

[0020] The force-measuring anchor rod of the present invention utilizes the incompressibility of liquid to monitor the anchoring force on the anchor rod; when the anchor rod is subjected to tension, the pressure plate moves within the protective shell to compress the liquid bag, thereby generating a pressure change and measuring the anchoring force; the present invention does not use resistance strain gauges or external wires, and there is no circuit in the anchor rod, so the measurement will not be inaccurate due to water ingress or moisture. Compared with the prior art, the present invention can be used in more complex geological environments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the main structure of the force-measuring anchor rod in this application;

[0022] Figure 2 This is the left view of the force-measuring anchor rod in this application;

[0023] Figure 3 This is a schematic diagram of the external structure of the pressure measuring module in the force measuring anchor rod of this application;

[0024] Figure 4 This is a schematic cross-sectional view of the first protective shell in the force-measuring anchor rod of this application;

[0025] Figure 5 This is a top view of the first protective casing of the force-measuring anchor rod in this application;

[0026] Figure 6 This is a schematic cross-sectional view of the second protective shell in the force-measuring anchor rod of this application;

[0027] Figure 7 This is a top view of the first protective casing of the force-measuring anchor rod in this application;

[0028] Figure 8 This is a schematic cross-sectional view of the protective housing assembly in the force-measuring anchor rod of this application;

[0029] Figure 9 This is a cross-sectional view of the pressure measuring module in the force measuring anchor bolt of this application after removing the first protective shell;

[0030] Figure 10 This is a top view of the pressure plate in the force-measuring anchor rod of this application;

[0031] Figure 11 This is a schematic diagram of the main structure of the enlarged end module of the force-measuring anchor rod in this application;

[0032] Figure 12 This is a partial structural diagram of the end enlargement module in the force-measuring anchor rod of this application;

[0033] Figure 13 This application presents a curve showing the stress in the force-measuring anchor rod versus the depth of the anchor rod embedded in the soil and rock under normal stress conditions.

[0034] Figure 14The curve of stress in the force-measuring anchor rod versus the depth of anchor rod embedded in the soil and rock under conditions of large deformation of the soil and rock mass is presented in this application.

[0035] In the diagram: 101 First tubing string, 102 Second tubing string;

[0036] 200 Force measuring module, 201 First outer protective shell, 202 Second protective shell, 2021 Limiting ring, 203 Liquid bag, 204 Pressure plate, 2041 Second perforation, 205 Liquid pipe, 206 Assembly gap;

[0037] 300 End-capping module, 301 Anchor block, 302 Friction-increasing teeth, 303 Rotating shaft, 304 Spring;

[0038] 1. Pressure gauge, 2. Fixed plate, 3. Nut, 4. Liquid valve. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0040] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Furthermore, directional terms mentioned in the following embodiments, such as "upper," "lower," "left," and "right," are merely directions with reference to the accompanying drawings; therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0041] Reference Figure 1 , 3 9. This application provides a force-measuring anchor rod, including,

[0042] Anchoring section, which is inserted into the rock and soil to fix the anchor rod;

[0043] A force measuring section, one end of which is connected to the anchoring section, is used to measure the anchoring force;

[0044] The force measuring section includes several first tubular columns 101, on which a force measuring module 200 is installed. The force measuring module 200 includes a protective shell, a liquid bag 203, a liquid tube 205, and a pressure plate 204. One end of the first tubular column 101 is fitted with the protective shell, and the liquid bag 203 is disposed in the protective shell. The other end of the first tubular column 101 is connected to the pressure plate 204. The pressure plate 204 on one first tubular column 101 restricts movement and is installed in the protective shell on another first tubular column 101 to form a force measuring module 300. When the pressure plate 204 moves, it compresses the liquid bag 203, thereby causing a pressure change. One end of the liquid tube 205 is connected to the liquid bag 203, and the other end passes through the pressure plate 204 and enters the interior of the first tubular column 101, and exits from the other end of the force measuring section away from the anchoring section. The other end of the liquid tube 205 is connected to a pressure gauge 1.

[0045] In some embodiments, the first tubular column 101 has a first perforation corresponding to the liquid bag 203, and the pressure plate 204 has a first perforation as shown in the figure. Figure 10 The diagram shows a second perforation 204. One end of the liquid tube 205 is connected to the liquid bag 203, and the other end passes through the second perforation 2041 and the first perforation in sequence, enters the interior of the first tube column 101, and exits from the other end of the force measuring section away from the anchoring section.

[0046] The principle utilized in this invention's anchor bolt device is that liquids are generally considered to be approximately incompressible fluids, especially water, the most common fluid in daily life (Zhai Yunfang. Seepage Mechanics [M]. Petroleum Industry Press, 2009.). In this invention, water is preferred as the liquid stored in the liquid bag 203. Although the volume of water may change slightly in extreme cases, within the range of forces applied to the anchor bolt, we can approximately consider water as an incompressible fluid. In other words, when water is subjected to pressure, its volume change is negligible and will not affect the monitoring results of this invention. It should be noted that those skilled in the art can select other suitable liquids as the storage liquid.

[0047] In some embodiments, according to the design requirements of the anchor bolt length, multiple first pipe columns 101 and force measuring modules 200 can be combined to extend the anchor bolt, thereby enabling monitoring of the anchor bolt stress within the anchor bolt length range. Secondly, at the end of the anchor bolt inserted into the soil or rock mass, the first pipe column 101 needs to be connected to the anchoring section to increase the anchoring force of the anchor bolt, preventing it from being pulled out.

[0048] In some embodiments, one end of the protective housing is connected to the outer wall of the first tubing 101, and the other end is provided with a limiting ring 2021 at a certain distance from the outer wall of the first tubing to restrict the movement of the pressure plate 204 and the liquid bag 203. The distance between the inner wall of the limiting ring 2021 and the outer wall of the first tubing 101 should be as small as possible, so as not to restrict the movement of the pressure plate 204 and not to cause the liquid bag 203 to detach from the protective housing.

[0049] In some embodiments, refer to Figure 3 The protective housing includes a first protective housing 201 and a second protective housing 202; wherein the first protective housing 201 is positioned as follows: Figure 4 and 5 The structure shown has a smaller opening at the top and a larger opening at the bottom. The smaller opening at the top has an internal thread for threaded connection with the first tube column 10, while the outer wall of the first tube column 10 has a corresponding external thread. The larger opening at the bottom also has an internal thread. The second protective housing 202 is as follows... Figure 6 and 7 As shown, it has an open-end design. The outer wall of the upper opening has an external thread corresponding to the internal thread at the lower large opening of the first protective shell 201. A limiting ring 2021 is provided inside the lower opening to restrict the pressure plate 204 and the liquid bag 203. (Refer to...) Figure 8 The first protective shell 201 and the second protective shell 202 are assembled together by threads, wherein a certain assembly gap 206 is left between the first protective shell 201 and the second protective shell 202 for placing the liquid tube 205.

[0050] In some embodiments, the pressure plate 204 is threadedly connected to the outer wall of the first tubular column 101. It should be noted that those skilled in the art can utilize existing technologies to connect the first tubular column 101 and the pressure plate 204, such as welding or snap-fitting. In this invention, the force measuring module 200 and the first tubular column 101 are assembled using a detachable structure, allowing for the addition or reduction of the number of the first tubular column 101 and the force measuring module 200 according to actual monitoring needs, thereby controlling the length of the force measuring anchor and consequently controlling the measurement range.

[0051] In some embodiments, the end of the force-measuring section away from the anchoring section is detachably connected to a second tubing 102, and the liquid pipe 205 passes through the first tubing 101 and finally exits from the second tubing 102. It should be noted that the force-measuring section is detachably connected to the second tubing 102 via a first section of the first tubing 101 at the end of the force-measuring section. This detachable connection is preferably a threaded connection. The detachable connection structure allows for the replacement of second tubing 102 of different lengths, thereby enabling further control of the force-measuring anchor length while meeting monitoring requirements.

[0052] In some embodiments, a fixing disc 2 and a nut 3 for fixing the fixing disc 2 are fitted onto the second pipe column 102. When the anchoring section and the force-measuring section of the force-measuring anchor are inserted into the soil, the fixing disc 2 and the nut 3 installed on the second pipe column 102 can cooperate with the anchoring section to firmly install the force-measuring anchor in the soil.

[0053] In some embodiments, the liquid tube 205 extending out of the force measuring section is further provided with, as shown in the following... Figure 1 The liquid valve 4 is shown. The liquid valve 4 prevents the water in the liquid bag 203 from draining when monitoring stress in the anchor rod. When a large tensile stress in the anchor rod exceeds the ultimate bearing capacity of the rod, the liquid valve 4 can be actively opened to drain the water from the liquid bag 203, increasing the displacement in the anchor rod and preventing it from breaking.

[0054] In some embodiments, referring to the anchoring section, an end enlargement module 300 is included. The end enlargement module 300 includes an anchoring block 301 connected to the first pipe 101 post. The anchoring block 301 is provided with a plurality of extendable and retractable friction-enhancing teeth 302. Preferably, the anchoring block 301 has a circular cross-section. Preferably, the anchoring block 301 has a circular cross-section. Figure 11 As shown, the friction-enhancing teeth 302 are evenly arranged on the side wall of the end enlargement module 300, wherein, Figure 11 The friction-enhancing teeth 302 described herein are in a retracted state. When the friction-enhancing teeth 302 are extended, they can be inserted into the soil or rock mass, thereby achieving an anchoring effect. It should be noted that the anchoring block 301 is detachably connected to the last section of the first pipe column 101 at the other end of the force measuring section. The detachable connection is preferably a threaded connection, and the detachable connection structure facilitates the assembly and replacement of components.

[0055] In some embodiments, one end of the friction-enhancing tooth 302 is rotatably connected to the anchor block 301, and the middle part is connected to the anchor block 301 via a spring 304. Before using the force-measuring anchor rod, pre-drilling anchor holes are performed on the soil and rock mass. After the pre-drilling is completed, the force-measuring anchor rod is inserted into the anchor hole. To ensure smooth insertion of the force-measuring anchor rod into the anchor hole, the anchor block 301 is... Figure 11 The surface of the device has a slot, and the friction-enhancing teeth 302 are connected to the slot via a rotating shaft 303 and a spring 304. When the force-measuring anchor rod is inserted... Figure 12 The lower part of the anchor block 301 shown is the insertion section. When inserted, the friction-increasing teeth 302 are restricted by the side wall of the anchor hole and retract into the slot. After being fully inserted, the friction-increasing teeth 302 flip and extend out of the slot under the action of the spring 304. At this time, when the fixing plate and nut 3 are connected to the force-measuring anchor rod, the force-measuring anchor rod can be pulled out of the anchor hole, thereby causing the friction-increasing teeth 302 to further flip and insert into the rock and soil, forming an anchoring effect.

[0056] In some embodiments, the liquid bag 203 in the force measuring module 200 is subjected to significant pressure, so a high-strength, pressure-resistant material should be selected as the manufacturing material for the liquid bag 203, such as pressure-resistant rubber or other polymer materials. Meanwhile, to ensure the durability of the liquid tube 205, the liquid tube 205 is made of high-density polyethylene.

[0057] In some embodiments, the present invention also includes a method of using the force-measuring anchor rod:

[0058] ① Assemble the force measuring modules 200, each containing a liquid bag 203 filled with water, and connect the liquid pipe 205 and liquid valve 4 for sealing. Assume the anchor rod body contains... There are one force measuring module 200, so the water pressure in the liquid bag 203 in each force measuring module 200 can be measured by pressure gauge 1. ;

[0059] ② Connect the anchor rod and place it into the soil or rock to be reinforced. Preferably, this invention uses a hollow steel pipe column as the anchor rod body. A grouting conduit can be inserted into the pipe column, and grouting can begin from the bottom end of the anchor rod until grouting is complete.

[0060] ③ After the grout has basically solidified, the anchor bolts will exert their anchoring force. At this time, pressure gauge 1 is used to measure the water pressure in the liquid bag 203 of each force measuring module 200. Then, the tensile stress on the anchor rod at 200 points in each force measuring module can be obtained. ;

[0061] ④ Since the liquid bag 203 is filled with water, and water is incompressible, the liquid bag 203 will hardly undergo any compression deformation. Furthermore, according to Newton's third law, the pressure in the liquid bag 203 is equal to the tensile force on the anchor rod. Therefore, the stress in the anchor rod can be calculated from the measured water pressure. Specifically, knowing the force-bearing area A1 of the liquid bag 203 along the length of the anchor rod and the force-bearing area A2 of the first pipe column 101, the stress in the anchor rod can be determined as follows: Furthermore, since the force measuring module 200 is distributed throughout the entire anchor bolt, the distribution of anchoring force along the length of the anchor bolt can be determined based on the measured water pressure, and a curve showing the relationship between the stress in the anchor bolt body and the depth of the anchor bolt embedded in the soil can be plotted, such as... Figure 13 As shown;

[0062] ⑤ If the curve of tensile stress in the anchor rod body and the depth of anchor rod embedded in the rock and soil are basically consistent with the curve during the use of the anchor rod, it indicates that the anchor rod is under good stress; conversely, if the curve changes, it indicates that the rock and soil have undergone large deformation. The location of large deformation of the rock and soil can be determined according to the position of the curve change, and reasonable reinforcement measures can be taken to reinforce the rock and soil.

[0063] ⑥ For example Figure 14 As shown, when a large deformation occurs in the soil and rock mass surrounding the anchor rod at a certain moment, it will cause a sudden change in the curve of the relationship between the stress of the anchor rod and the depth of the anchor rod embedded in the soil and rock mass, resulting in an increase in the anchoring force in the anchor rod. Based on the position of the curve change, the location of the large deformation of the soil and rock mass can be determined, and then corresponding reinforcement measures can be implemented at the corresponding location.

[0064] When the large deformation of the rock and soil causes the anchoring force in the anchor rod to reach the design bearing capacity of the anchor rod, the water in the liquid bag 203 can be actively discharged by opening the liquid valve 4, causing the anchor rod to shift, thereby reducing the anchoring force in the anchor rod, preventing the anchor rod from being pulled apart, and allowing the anchor rod to continue to play its anchoring role.

[0065] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A force-measuring anchor rod, comprising: Anchoring section, which is inserted into the rock and soil to fix the anchor rod; A force measuring section, one end of which is connected to the anchoring section, is used to measure the anchoring force; Its features are: The force measuring section includes several first tubular columns and several force measuring modules. Each force measuring module includes a protective shell, a liquid bag containing liquid, a liquid tube, and a pressure plate. One end of each first tubular column is fitted with the protective shell, and the liquid bag is disposed within the protective shell. The other end of the first tubular column is connected to the pressure plate. A force measuring module is formed by restricting the movement of a pressure plate on one first tubular column and installing it within the protective shell on another first tubular column. When the pressure plate moves, it compresses the liquid bag, causing a pressure change. One end of the liquid tube communicates with the liquid bag, and the other end passes through the pressure plate and enters the interior of the first tubular column, exiting from the other end of the force measuring section away from the anchoring section. The other end of the liquid tube is connected to a pressure gauge.

2. The force-measuring anchor bolt according to claim 1, characterized in that: One end of the protective shell is connected to the outer wall of the first tubular column, and a limiting ring is provided between the other end and the outer wall of the first tubular column to limit the movement of the pressure plate and the liquid bag.

3. A force-measuring anchor rod according to claim 2, characterized in that: The protective housing includes a first protective housing and a second protective housing. One end of the first protective housing is threaded to the outer wall of the first tubular column, and the other end of the first protective housing is connected to one end of the second protective housing. The other end of the second protective housing is provided with the limiting ring.

4. A force-measuring anchor rod according to any one of claims 1-3, characterized in that: The pressure plate is threadedly connected to the outer wall of the first tubular column.

5. A force-measuring anchor rod according to claim 1, characterized in that: The force measuring section is detachably connected to a second pipe column at the other end away from the anchoring section.

6. A force-measuring anchor rod according to claim 5, characterized in that: The second tubular column is fitted with a fixing plate and a nut for fixing the fixing plate.

7. A force-measuring anchor rod according to claim 1, characterized in that: A liquid valve is also installed on the pipe body that extends out of the force measuring section.

8. A force-measuring anchor rod according to claim 1, characterized in that: The anchoring section includes an end enlargement module, which includes an anchoring block connected to the first pipe column. The anchoring block is provided with a plurality of friction-increasing teeth that can extend and retract.

9. A force-measuring anchor rod according to claim 8, characterized in that: One end of the friction-enhancing tooth is rotatably connected to the anchor block, and the middle part is connected to the anchor block spring.

10. A force-measuring anchor rod according to claim 1, characterized in that: The liquid bag is made of rubber, and the liquid tube is made of high-density polyethylene.

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