Detection system and detection method for tensile strength of directional drilling ground anchor

Abstract

The invention provides a directional drilling ground anchor tensile strength detection system and method, the detection system comprises a ground anchor box, a traction unit and a measurement unit, the ground anchor box is anchored underground, and the upper end of the ground anchor box is higher than the ground; one end of the traction unit is fixedly connected with the upper end of the ground anchor box, and the traction unit can apply horizontal tension to the ground anchor box; the measuring unit is connected with the traction unit, and the measuring unit can measure the horizontal tension value of the traction unit to the ground anchor box while the traction unit applies the horizontal tension to the ground anchor box. According to the method, the tensile strength of the ground anchor can be accurately detected before the ground anchor is officially put into use, and compared with experience judgment or theoretical model calculation, a conclusion whether the ground anchor is qualified or not can be more intuitively and accurately made. And construction interruption and risk increase caused by failure of the ground anchor in the construction process due to error judgment of experience, or waste caused by excessive material and cost consumption due to excessive conservative installation of the ground anchor and incapability of making the best use of materials are avoided.

Description

Technical Field

[0001] The present invention relates to the field of horizontal directional drilling equipment for oil and gas pipelines. Specifically, it relates to a detection system and a detection method for the tensile strength of directional drilling ground anchors. Background Art

[0002] As an important component during the installation of horizontal directional drilling rigs, ground anchors play a role in providing horizontal resistance during pipe dragging. High-quality ground anchors can maintain stable high-strength horizontal resistance output during pipe dragging, preventing the rig from slipping, and thus have received great attention from all parties involved in actual construction. Currently, the ground anchor systems of horizontal directional drilling rigs at home and abroad generally use self-made anchor boxes as the main anchors. For large-diameter and long-distance pipe dragging construction (requiring greater horizontal resistance output), auxiliary anchors will be added. However, regardless of the ground anchor installation form adopted, the top surface of the main ground anchor box is the actual direct stress point of the ground anchor system. The horizontal reaction force received during rig pipe dragging will directly act on the upper part of the anchor box, and the anchor box squeezes the soil to form passive earth pressure to prevent the rig from slipping forward.

[0003] Traditional construction workers are accustomed to estimating the size of ground anchors based on experience. However, under different geological conditions, ground anchors of the same size can provide different levels of horizontal resistance. Another approach is that theoretical scholars advocate using Rankine theory or Coulomb theory in soil mechanics to calculate the passive earth pressure on the contact surface between the anchor and the undisturbed soil. However, due to the limitation that the conditions for obtaining soil mechanical parameters are not available on site, and the stress conditions during pipe dragging are not exactly the same as the passive earth pressure theoretical model, there can sometimes be a large deviation between the calculated results and the actual situation.

[0004] Referring to the anchor pile reaction method and the loading method used to detect the compressive strength of foundation piles in pile foundation engineering, and combining with the pipe unclogging and pulling-back device in horizontal directional drilling emergency construction, by adding vibrating wire strain gauges, the present invention can be used to quantitatively detect the strength of ground anchors. Summary of the Invention

[0005] The purpose of the present invention is to solve at least one of the above deficiencies existing in the prior art. For example, one of the purposes of the present invention is to provide a detection system and a detection method for the tensile strength of directional drilling ground anchors to solve the technical problem of insufficient accuracy in detecting and calculating the strength of ground anchors in the prior art.

[0006] To achieve the above object, on the one hand, the present invention provides a detection system for the tensile strength of a directional drilling ground anchor. The detection system may include a ground anchor box, a traction unit, and a measurement unit. Among them, the ground anchor box is anchored underground, and the upper end of the ground anchor box is higher than the ground surface; one end of the traction unit is fixedly connected to the upper end of the ground anchor box, and the traction unit can apply a horizontal pulling force to the ground anchor box; the measurement unit is connected to the traction unit, and the measurement unit can measure the horizontal pulling force value of the traction unit on the ground anchor box while the traction unit applies a horizontal pulling force to the ground anchor box.

[0007] Optionally, the traction unit may include a movable pulley block. The movable pulley block includes a pulley stator and a plurality of movable pulleys. The plurality of movable pulleys are arranged side by side in the pulley stator and are rotatably connected to the pulley stator; one end of the pulley stator is fixedly connected to the upper end of the ground anchor box.

[0008] Optionally, the traction unit may further include a plurality of traction ropes. Each traction rope includes an anchoring end and a free end. The plurality of traction ropes correspond to the plurality of movable pulleys one by one. The plurality of traction ropes respectively bypass the plurality of movable pulleys. The anchoring ends of the plurality of traction ropes are respectively anchored underground, and a horizontal pulling force can be applied to the free ends of the plurality of traction ropes and transmitted to the ground anchor box through the movable pulley block.

[0009] Optionally, the traction unit may further include a traction machine. The traction machine is connected to the free ends of the plurality of traction ropes, and the traction machine can apply a horizontal pulling force to the ground anchor box through the plurality of traction ropes and the movable pulley block.

[0010] Optionally, the traction unit may further include a ground anchor plate. The ground anchor plate is anchored underground, and the anchoring ends of the plurality of traction ropes are fixedly connected to the ground anchor plate. The ground anchor plate can anchor the anchoring ends of the plurality of traction ropes underground.

[0011] Optionally, a plurality of lugs may be arranged side by side at the upper end of the ground anchor box. The pulley stator can be connected to the plurality of lugs to apply a horizontal pulling force to the ground anchor box through the lugs.

[0012] Optionally, the detection system may further include a traction plate. One end of the traction plate is hung on the plurality of lugs, and a connection hole is provided at the other end of the traction plate; a hook is provided at one end of the pulley stator, and the hook can be hung in the connection hole to connect the movable pulley block to the traction plate, so that the horizontal pulling force is applied to the ground anchor box through the traction plate and the lugs.

[0013] Optionally, the measurement unit may include a strain gauge. The strain gauge is installed on the traction rope between the anchoring end and the movable pulley, and the strain gauge can measure the strain value generated by the traction rope under the horizontal pulling force.

[0014] Optionally, the measuring unit may further include a data acquisition terminal, which is connected to the strain gauge, and the data acquisition terminal can obtain the strain parameters measured by the strain gauge.

[0015] On the other hand, the present invention provides a method for detecting the tensile strength of a directional drilling ground anchor. The detection method can adopt the detection system for the tensile strength of the directional drilling ground anchor as described above. The detection method may include excavating an anchor pit on the ground, placing the ground anchor box in the anchor pit and anchoring it, making the upper end of the ground anchor box higher than the ground as the stress point, connecting the traction unit to the upper end of the ground anchor box, connecting the measuring unit to the traction unit, applying a horizontal pulling force to the ground anchor box through the traction unit, and measuring the horizontal pulling force value applied by the traction unit to the ground anchor box through the measuring unit.

[0016] Compared with the prior art, the beneficial effects of the present invention include the following:

[0017] The present invention can accurately detect the tensile strength of the ground anchor before it is officially put into use. Compared with empirical judgment or theoretical model calculation, it can more intuitively and accurately make a conclusion on whether the ground anchor is qualified. It can avoid the failure of the ground anchor during the construction process due to incorrect empirical judgment, resulting in construction interruption and increased risk, or being too conservative when installing the ground anchor, consuming too much materials and costs, and not making the best use of things, causing waste. Description of the Drawings

[0018] Through the following description in conjunction with the drawings, the above and other objects and / or features of the present invention will become clearer, where:

[0019] Figure 1 Shows a schematic diagram of the detection system for the tensile strength of a directional drilling ground anchor according to Exemplary Embodiment 1 of the present invention.

[0020] Figure 2 Shows a front view of the assembly of the ground anchor box and the traction plate in the detection system for the tensile strength of a directional drilling ground anchor according to Exemplary Embodiment 1 of the present invention.

[0021] Figure 3 Shows a top view of the assembly of the ground anchor box and the traction plate in the detection system for the tensile strength of a directional drilling ground anchor according to Exemplary Embodiment 1 of the present invention.

[0022] Figure 4 Shows a process flow chart of the method for detecting the tensile strength of a directional drilling ground anchor according to Exemplary Embodiment 2 of the present invention.

[0023] Description of the Reference Numerals:

[0024] 1. Ground anchor box, 11. Pulling ear, 2. Traction unit, 21. Moving pulley block, 211. Pulley stator, 212. Moving pulley, 213. Hook, 22. Traction rope, 221. Anchoring end, 222. Free end, 23. Tractor, 24. Ground anchor plate, 3. Measuring unit, 31. Strain gauge, 32. Data acquisition terminal, 4. Pulling plate, 41. Connecting hole. Detailed implementation manners

[0025] In the following, the detection system and detection method for the tensile strength of the directional drilling ground anchor of the present invention will be described in detail in conjunction with exemplary embodiments.

[0026] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present application.

[0027] The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0028] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] In the related art, the estimation method of the ground anchor strength mainly depends on the experience of construction workers on the one hand, and on the other hand, theoretical scholars advocate using the Rankine theory or Coulomb theory in soil mechanics to calculate the passive earth pressure on the contact surface between the anchor and the undisturbed soil. However, due to the limitation that the conditions for obtaining the soil mechanical parameters are not available on site, and the stress conditions during pipe jacking are not exactly the same as the passive earth pressure theoretical model, the calculated results sometimes deviate greatly from the actual situation.

[0030] Based on this, the present invention provides a detection system and a detection method for the tensile strength of a directional drilling ground anchor. The detection system includes an anchor box, a traction unit, and a measurement unit. The anchor box is anchored underground, and the upper end of the anchor box is higher than the ground. One end of the traction unit is fixedly connected to the upper end of the anchor box, and the traction unit can apply a horizontal pulling force to the anchor box. The measurement unit is connected to the traction unit and can measure the horizontal pulling force value of the traction unit on the anchor box while the traction unit applies a horizontal pulling force to the anchor box.

[0031] The present invention can accurately detect the tensile strength of the ground anchor before it is officially put into use. Compared with empirical judgment or theoretical model calculation, it can more intuitively and accurately draw a conclusion on whether the ground anchor is qualified. This can avoid the failure of the ground anchor during the construction process due to incorrect empirical judgment, resulting in construction interruption and increased risk, or being overly conservative when installing the ground anchor, consuming too much material and cost, and not making the best use of the materials, causing waste.

[0032] Exemplary Embodiment 1

[0033] This exemplary embodiment provides a detection system for the tensile strength of a directional drilling ground anchor.

[0034] Figure 1 FIG. shows a schematic diagram of the detection system for the tensile strength of a directional drilling ground anchor according to Exemplary Embodiment 1 of the present invention; Figure 2 FIG. shows a front view of the assembly of the anchor box and the traction plate in the detection system for the tensile strength of a directional drilling ground anchor according to Exemplary Embodiment 1 of the present invention; Figure 3 FIG. shows a top view of the assembly of the anchor box and the traction plate in the detection system for the tensile strength of a directional drilling ground anchor according to Exemplary Embodiment 1 of the present invention.

[0035] As Figures 1 to 3 shown in, the detection system for the tensile strength of the directional drilling ground anchor described in this exemplary embodiment may include an anchor box 1, a traction unit 2, and a measurement unit 3. Among them, the anchor box 1 can be anchored underground, and the upper end of the anchor box 1 is higher than the ground. The upper end of the anchor box 1 can be used as the stress point for the horizontal pulling force. Here, the anchor box 1 can be a cubic solid anchor block with sufficient mass for horizontal positioning of the directional drilling rig. One end of the traction unit 2 can be fixedly connected to the upper end of the anchor box 1, and the traction unit 2 can apply a horizontal pulling force to the anchor box to test the tensile strength of the anchor box.

[0036] The measurement unit 3 can be connected to the traction unit 2. When the traction unit 2 applies a horizontal pulling force to the anchor box 1, the measurement unit 3 can measure the horizontal pulling force value applied to the anchor box 1. However, the present invention is not limited thereto. The specific shape, structure, and mass of the anchor box 1 can be arbitrarily selected according to actual test requirements, and the present invention does not make specific limitations thereon.

[0037] Specifically, for the anchoring method of the ground anchor box 1, the ground anchor box (including the auxiliary anchor) can be placed into the excavated anchor pit, and the gap between the ground anchor box and the surrounding soil can be filled with concrete. The size of the anchor pit is determined according to the size of the ground anchor box 1, and the width of the gap between the ground anchor box 1 and the surrounding soil is about 1.0 m. Here, the specific anchoring method of the ground anchor box 1 is only one feasible implementation mode included in the present invention, and the anchoring method can also be arbitrarily adjusted according to actual test requirements. The present invention does not make specific limitations thereto.

[0038] In this embodiment, the traction unit 2 may include a movable pulley block 21. The movable pulley block 21 may include a pulley stator 211 and a plurality of movable pulleys 212. Here, the movable pulley block 21 may adopt a 500t pulley block or a 1000t pulley block commonly used in trenchless operations. The number of the movable pulleys 212 may be 4. The 4 movable pulleys 212 can all be installed in the pulley stator 211 and rotatably connected to the pulley stator 211. That is to say, the 4 movable pulleys 212 can all rotate freely in the pulley stator 211, and the 4 movable pulleys 212 can be arranged side by side in the pulley stator 211. One end of the pulley stator 211 may be fixedly connected to the upper end of the ground anchor box 1. Specifically, the connection end of the pulley stator 211 connected to the ground anchor box 1 may be located at the other end relative to the movable pulleys 212. That is to say, the ground anchor box 1 can be connected to one end of the pulley stator 211, and the movable pulleys 212 can be installed at the other end of the pulley stator 211. However, the present invention is not limited thereto. The load parameters selected for the movable pulley block 21 can be adjusted according to requirements, and the number of the movable pulleys 212 installed in the pulley stator 211 can be arbitrarily selected according to actual test requirements. The present invention does not make specific limitations thereto.

[0039] In this embodiment, the traction unit 2 may further include a plurality of traction ropes 22. Here, the traction ropes 22 may specifically be steel wires, which can ensure sufficient strength to withstand the horizontal tension, and the number of the traction ropes 22 may also be 4. Both ends of each traction rope 22 may be an anchoring end 221 and a free end 222 respectively. The 4 traction ropes 22 may correspond to the 4 movable pulleys 212 one by one. Each traction rope 22 may bypass its corresponding movable pulley 212. The anchoring end of each traction rope 22 can be anchored underground, and a horizontal tension can be applied to the free end of each traction rope 22, so that the tension can be transmitted to the ground anchor box 1 through the traction ropes 22 and the movable pulley block 21, thereby realizing the test of the tensile strength of the ground anchor box 1. However, the present invention is not limited thereto. The number of the traction ropes 22 can be arbitrarily selected according to actual test requirements, as long as it is consistent with the number of the movable pulleys 212 and corresponds to each other. The present invention does not make specific limitations thereto.

[0040] In this embodiment, the traction unit 2 may further include a tractor 23. The tractor 23 may be connected to the free ends 222 of the four traction ropes 22. The tractor 23 may apply a horizontal pulling force to the four traction ropes 22, and this pulling force may be transmitted to the anchor box 1 along the traction ropes 22 and the movable pulley block 21. The magnitude of the horizontal pulling force may also be adjusted by the tractor 23 to meet the actual test requirements of the tensile strength of the anchor box 1. Here, the tractor 23 may specifically be an excavator. It is preferably an excavator with a tonnage of more than 320t to generate a greater frictional force with the ground for traction. It may also be other equipment capable of providing sufficient horizontal pulling force outside the excavator, which can be arbitrarily selected according to the actual test requirements, and the present invention does not make specific limitations thereon.

[0041] In this embodiment, the traction unit 2 may further include an anchor plate 24. The anchor plate 24 may be anchored underground, buried underground and kept fixed. The anchoring ends 221 of the four traction ropes 22 may be fixedly connected to the anchor plate 24, so that the anchoring ends 221 of the traction ropes 22 are anchored underground. Specifically, the anchor plate 24 may be a thick steel plate with a thickness of 20 mm or 30 mm. Two anchoring holes (not shown in the figure) may be spaced apart on the anchor plate 24. The anchoring ends 221 of the four traction ropes 22 may be passed through the two anchoring holes on the anchor plate 24 and the anchoring ends 221 may be fixed to the anchor plate 24. Here, parameters such as the shape, size, opening position and size of the anchoring holes of the anchor plate 24 may be arbitrarily selected according to the actual test requirements, and the present invention does not make specific limitations thereon.

[0042] Optionally, a plurality of lugs 11 may be installed at the upper end of the anchor box 1. Here, the number of lugs 11 may specifically be four. The four lugs 11 may be arranged side by side and spaced apart. The lugs 11 may be fixedly connected to the anchor box 1 by welding. The shape of each lug 11 may be hook-shaped. The pulley stator 211 may be connected to the lug 11, so that the anchor box 1 is fixedly connected to the movable pulley block 21. The movable pulley block 21 may transmit the horizontal pulling force applied by the tractor 23 to the anchor box 1 through the lugs 11, thereby realizing the test of the tensile strength of the anchor box 1. However, the present invention is not limited thereto. The number of lugs 11 installed at the upper end of the anchor box 1 may be arbitrarily selected according to the actual test requirements. The connection manner between the lugs 11 and the anchor box 1 may also be other fixed connection manners, such as integral molding, etc., and the present invention does not make specific limitations thereon.

[0043] In this embodiment, the detection system for the tensile strength of the directional drilling ground anchor described in this exemplary embodiment may further include a traction plate 4. One end of the traction plate 4 can be hung on 4 lugs 11, and a connection hole 41 can be formed at the other end of the traction plate 4. The connection hole 41 can penetrate through the upper and lower sides of the traction plate 4. A hook 213 can be installed at one end of the pulley stator 211. The hook 213 can be fixedly connected to one end of the pulley stator 211 by welding. The hook 213 can be hung in the connection hole 41 to connect the movable pulley group 21 with the traction plate 4. Then, the movable pulley group 21 can be connected to the lug 11 and the ground anchor box 1 through the traction plate 4. The horizontal pulling force applied by the tractor 23 can be transmitted to the ground anchor box 1 through the traction rope 22, the movable pulley group 21, the traction plate 4, and the lug 11, so as to realize the test of the tensile strength of the ground anchor box 1. However, the present invention is not limited thereto. Other types of connectors can also be selected between the ground anchor box 1 and the movable pulley group 21 according to actual test requirements, and the present invention does not make specific limitations on this.

[0044] In this embodiment, the measuring unit 3 may include a strain gauge 31. The strain gauge 31 can be installed on the traction rope 22 and located between the anchoring end 221 and the movable pulley 212. The strain gauge 31 can measure the strain value generated on the traction rope 22 under the state of being subjected to a horizontal pulling force, and then further convert the pulling force value received by the ground anchor box 1. Specifically, the strain gauge 31 can be a vibrating wire strain gauge. The vibrating wire strain gauge (surface type) can be installed at the dead-end of the wire rope connected to the ground anchor plate. When a micro-strain occurs at the dead-end of the wire rope, the mounting supports at the left and right ends of the vibrating wire strain gauge generate relative displacement and transmit it to the vibrating wire, causing the vibrating wire to be stressed and change. The measuring instrument outputs a pulse signal, exciting the vibrating wire through a coil and detecting the frequency of the signal induced by the coil, and obtaining the strain of the measured structure through conversion. However, the present invention is not limited thereto. The installation position of the strain gauge 31 on the traction rope 22 can be arbitrarily selected according to actual test requirements, and the present invention does not make specific limitations on this.

[0045] In this embodiment, the measuring unit 3 may further include a data acquisition terminal 32. The data acquisition terminal 32 can be connected to the strain gauge 31 through a cable. The data acquisition terminal 32 can collect the strain parameters measured by the strain gauge 31 and enable testers to obtain and analyze them. Here, the data acquisition terminal 32 can be specifically a data acquisition box. At the start of the test, the strain gauge 31 needs to be installed on the traction rope 22 between the anchoring end 221 and the movable pulley 212 (i.e., the dead-end of the wire rope), and the data acquisition terminal 32 is connected to the strain gauge 31 through a cable, and the initial value is debugged and ready for testing. However, the present invention is not limited thereto. The data acquisition terminal 32 can also be other devices other than the data acquisition box, which can be arbitrarily selected according to actual test requirements, and the present invention does not make specific limitations on this.

[0046] The testing process of the detection system for the tensile strength of the directional drilling ground anchor described in this exemplary embodiment is described in detail as follows:

[0047] Place the ground anchor box 1 (including the auxiliary anchor) into the excavated anchor pit, and use concrete to fill the gap between the ground anchor box 1 and the surrounding soil. The size of the anchor pit is determined according to the size of the ground anchor box 1. The width of the gap between the ground anchor box 1 and the surrounding soil is about 1.0 m.

[0048] Weld a plurality of lugs 11 on the top surface of the ground anchor box 1. The lugs 11 are the direct stress points of the tensile force of the ground anchor box 1 (the shape and number of the lugs 11 in the attached drawings can be designed according to the actual project and equipment).

[0049] Excavate the anchor plate pit. The ground anchor plate 24 is about 5 - 8 m long, 2.5 - 3.5 m wide, and 2 cm - 3 cm thick. Two symmetric anchor holes are opened in the middle for passing the towing rope 22. The work of passing the towing rope 22 is completed on the ground. The size of the anchor plate pit should be such that it can accommodate the ground anchor plate 24 and enable workers to enter for operation.

[0050] Select a towing rope 22 passing through the movable pulley block 21 with a strength not less than twice the maximum on-site tensile force.

[0051] Connect the anchored end 221 (dead rope end) of the towing rope 22 to the ground anchor plate 24, and the free end 222 to the towing machine 23. The hook 213 of the movable pulley block 21 is connected through the towing plate 4 on the ground anchor box 1.

[0052] After the connection is completed, start the towing machine 23 to make the entire towing rope 22 in a taut state.

[0053] Install a strain gauge 31 between the anchored end 221 of the towing rope 22 and the movable pulley block 21, connect the data acquisition terminal 32 to the strain gauge 31 through a cable, and debug the initial value.

[0054] Start the towing machine 23 to start towing. Since when the ground anchor box 1 is in a stable state, the towing machine 23 is in a "strong pull" state and cannot move, the towing rope 22 will undergo a slight deformation. Use the strain gauge 31 to collect the slight deformation of the anchored end 221, and combine it with the elastic modulus of the towing rope 22 to calculate the horizontal tensile force on both sides of the movable pulley block. Then, through the number of movable pulleys, the traction force of its hook 213 can be calculated. When this traction force meets the maximum tensile force borne by the ground anchor during construction, the test stops.

[0055] Exemplary Embodiment 2

[0056] This exemplary embodiment provides a method for detecting the tensile strength of a directional drilling ground anchor.

[0057] The detection method for the tensile strength of the directional drilling ground anchor described in this exemplary embodiment can adopt the detection system for the tensile strength of the directional drilling ground anchor as described in Exemplary Embodiment 1.

[0058] Figure 4 The process flow chart of the detection method for the tensile strength of the directional drilling ground anchor according to Exemplary Embodiment 2 of the present invention is shown.

[0059] As Figures 1 to 4 shown, the detection method for the tensile strength of the directional drilling ground anchor described in this exemplary embodiment may include the following steps:

[0060] S1: Preparation

[0061] Put the ground anchor box 1 (including the auxiliary anchor) into the excavated anchor pit, and use concrete to fill the gap between the ground anchor box 1 and the surrounding soil. The size of the anchor pit is determined according to the size of the ground anchor box 1. The width of the gap between the ground anchor box 1 and the surrounding soil is about 1.0 m.

[0062] Weld a plurality of lugs 11 on the top surface of the ground anchor box 1. The lugs 11 are the direct stress-bearing points of the ground anchor box 1 (the shape and number of the lugs 11 in the drawings can be designed according to the actual project and equipment).

[0063] S2: Installation of the ground anchor plate

[0064] Excavate the anchor plate pit. The ground anchor plate 24 is about 5 - 8 m long, 2.5 - 3.5 m wide, and 2 cm - 3 cm thick. Two symmetric anchor holes are opened in the middle for passing the towing rope 22. The work of passing the towing rope 22 is completed on the ground. The size of the anchor plate pit should be such that the ground anchor plate 24 can be placed and workers can enter for operation.

[0065] The strength of the towing rope 22 passing through the movable pulley block 21 is selected to be of a model not less than 2 times the maximum on-site tensile force.

[0066] S3: Connect the towing rope (steel wire rope)

[0067] Connect the anchor end 221 (dead rope end) of the towing rope 22 to the ground anchor plate 24, and the free end 222 to the towing machine 23. The hook 213 of the movable pulley block 21 is connected through the towing plate 4 on the ground anchor box 1.

[0068] After the connection is completed, start the towing machine 23 to make the towing rope 22 in an overall straight state.

[0069] S4: Stress test

[0070] Install a strain gauge 31 between the anchor end 221 of the towing rope 22 and the movable pulley block 21, connect the data acquisition terminal 32 to the strain gauge 31 through a cable, and debug the initial value.

[0071] Start the tractor 23 to start traction. Since the tractor 23 is in a "strong pull" state and cannot move when the local anchor box 1 is in a stable state, the traction rope 22 will undergo a slight deformation. The slight deformation of the anchoring end 221 is collected by the strain gauge 31, and combined with the elastic modulus of the traction rope 22, the horizontal tensile forces on both sides of the movable pulley block can be calculated. Then, through the number of movable pulleys, the traction force of its hook 213 can be calculated. When the traction force meets the maximum tensile force borne by the ground anchor during construction, the test stops.

[0072] In summary, the present invention can accurately detect the tensile strength of the ground anchor when it is officially put into use. Compared with empirical judgment or theoretical model calculation, it can more intuitively and accurately draw a conclusion on whether the ground anchor is qualified. It can avoid the failure of the ground anchor during the construction process due to incorrect empirical judgment, resulting in construction interruption and increased risks, or being too conservative when installing the ground anchor, consuming too much materials and costs, and not making the best use of things, causing waste.

[0073] Although the present invention has been described above in conjunction with exemplary embodiments and the accompanying drawings, those of ordinary skill in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A detection system for the tensile strength of a directional drilling ground anchor, characterized in that, The detection system includes an anchor box, a traction unit, and a measurement unit. Among them, the anchor box is anchored underground, and the upper end of the anchor box is higher than the ground surface; one end of the traction unit is fixedly connected to the upper end of the anchor box, and the traction unit can apply a horizontal pulling force to the anchor box. The measurement unit is connected to the traction unit, and the measurement unit can measure the horizontal pulling force value of the traction unit on the anchor box while the traction unit applies a horizontal pulling force to the anchor box.

2. The detection system for the tensile strength of a directional drilling ground anchor according to claim 1, characterized in that, The traction unit includes a movable pulley block. The movable pulley block includes a pulley stator and a plurality of movable pulleys. The plurality of movable pulleys are arranged side by side in the pulley stator and are rotatably connected to the pulley stator; one end of the pulley stator is fixedly connected to the upper end of the anchor box.

3. The detection system for the tensile strength of a directional drilling ground anchor according to claim 2, characterized in that, The traction unit further includes a plurality of traction ropes. Each traction rope includes an anchoring end and a free end. The plurality of traction ropes correspond to the plurality of movable pulleys one by one. The plurality of traction ropes respectively bypass the plurality of movable pulleys. The anchoring ends of the plurality of traction ropes are respectively anchored underground, and a horizontal pulling force can be applied to the free ends of the plurality of traction ropes and transmitted to the anchor box through the movable pulley block.

4. The detection system for the tensile strength of a directional drilling ground anchor according to claim 3, characterized in that, The traction unit further includes a traction machine. The traction machine is connected to the free ends of the plurality of traction ropes. The traction machine can apply a horizontal pulling force to the anchor box through the plurality of traction ropes and the movable pulley block.

5. The detection system for the tensile strength of a directional drilling ground anchor according to claim 3, characterized in that, The traction unit further includes an anchor plate. The anchor plate is anchored underground, and the anchoring ends of the plurality of traction ropes are fixedly connected to the anchor plate. The anchor plate can anchor the anchoring ends of the plurality of traction ropes underground.

6. The detection system for the tensile strength of a directional drilling ground anchor according to claim 2, characterized in that, A plurality of lugs are arranged side by side at the upper end of the anchor box. The pulley stator can be connected to the plurality of lugs to apply a horizontal pulling force to the anchor box through the lugs.

7. The detection system for the tensile strength of a directional drilling ground anchor according to claim 6, characterized in that, The detection system further includes a traction plate. One end of the traction plate is hung on the plurality of lugs, and a connection hole is opened at the other end of the traction plate; a hook is provided at one end of the pulley stator. The hook can be hung in the connection hole to connect the movable pulley block to the traction plate, so that the horizontal pulling force is applied to the anchor box through the traction plate and the lugs.

8. The detection system for the tensile strength of a directional drilling ground anchor according to claim 3, characterized in that, The measurement unit includes a strain gauge. The strain gauge is installed on the traction rope between the anchoring end and the movable pulley. The strain gauge can measure the strain value generated by the traction rope under the horizontal pulling force.

9. The detection system for the tensile strength of a directional drilling ground anchor according to claim 8, characterized in that, The measurement unit further includes a data acquisition terminal. The data acquisition terminal is connected to the strain gauge, and the data acquisition terminal can obtain the strain parameters measured by the strain gauge.

10. A detection method for the tensile strength of a directional drilling ground anchor, characterized in that, The detection method uses the detection system for the tensile strength of the directional drilling anchor as described in any one of claims 1 to 9; The detection method includes excavating an anchor pit on the ground, placing the anchor box in the anchor pit and anchoring it, making the upper end of the anchor box higher than the ground surface as the stress point, connecting the traction unit to the upper end of the anchor box, connecting the measurement unit to the traction unit, applying a horizontal pulling force to the anchor box through the traction unit, and measuring the horizontal pulling force value of the traction unit on the anchor box through the measurement unit.

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