A method for recovering a recoverable anchor system

Abstract

The present invention relates to a recoverable anchor rod system, which includes an anchor cable bundle for anchoring; a recovery unit, including a shell sleeved on the anchor cable bundle, and the shell encapsulates a hot-melt component; an excitation unit, which is used to activate the hot-melt component in the form of electric energy so that the hot-melt component generates chemical reaction heat that can melt the anchor cable bundle; and a monitoring unit installed on the anchor cable bundle, the monitoring unit at least includes a strain sensor for monitoring stress changes of the anchor cable bundle, and the sampling period of the strain sensor can be set according to a preset strain amplitude corresponding to the stress change of the anchor cable bundle, wherein, in the process of recovering the anchor cable bundle, the time-related stress change information of the anchor cable bundle is recorded and transmitted via the strain sensor with the preset strain amplitude of the anchor cable bundle as the starting event.

Description

[0001] Description of the case

[0002] The original basis of this divisional application is a patent application with application number 202210364067.8, application date April 7, 2022, and invention name “A recyclable intelligent anchoring device and its recycling method”. Technical Field

[0003] The invention relates to the technical field of geotechnical engineering, and in particular to a recovery method of a recoverable anchor rod system. Background Art

[0004] Traditional anchor rods serve as temporary support structures. After their functions fail, they are usually buried underground together with the constructed structures. This will occupy a large amount of underground space, form underground garbage, and cause underground environmental pollution. The remaining anchor rods will also become underground obstacles for subsequent projects. At the same time, steel is wasted because the anchor rods cannot be effectively recycled.

[0005] To solve this problem, people have developed recyclable anchor cable technology. After the anchor cable completes its task, it will be recycled. This can not only avoid the problem of the anchor cable exceeding the building red line, but also reduce construction costs. At present, a variety of recyclable anchor cable technologies have been developed. Recyclable anchor cables are safe, fast and easy to recycle. The recycled steel strands can be reused, which makes up for the shortcomings of early anchor cable technology.

[0006] Hot-melt recovery anchor is a common anchor form in the technology of recoverable anchor. Its principle is mainly to remove the core by electrifying the hot-melt anchor. After the hot-melt anchor is electrified for a certain period of time, the steel strand is pulled out and recovered. For example, an article entitled "Application and Research of New Hot-melt Removable Core Anchor" in the journal "Engineering Investigation" provides a hot-melt anchor. The hot-melt device in the anchor mainly includes a metal anchor ring and a metal clip of the anchor hole. Among them, the outer wall of the metal anchor ring wraps the electric heating ring and the connected external wire, which is the dominant part of the hot-melt device; the metal clip is a truncated cone with a threaded through hole in the middle for embedding the anchor. When the anchor is inserted into the metal clip, the thread on the inner surface of the through hole is interference fit with the truncated cone through hole, which increases the ultimate pull-out resistance and stabilizes the anchor. The inner wall of the anchor hole is filled with a bushing made of hot-melt material and is close to the metal clip. When the anchor cable in the anchoring project is used, the conductor is energized through the ground device, and the electric heating ring generates heat to heat the metal anchor ring to melt the bushing, thereby releasing the anchor cable bundle and allowing the free section of the anchor cable bundle to be taken out.

[0007] However, this type of hot-melt anchor needs to be powered on to allow the hot-melt ring to reach a certain temperature before the anchor bundle can be melted and recovered, so its recovery efficiency is low; secondly, the design structure of this type of hot-melt anchor usually only takes into account the recovery of the free segment anchor, and during the recovery process, as the anchor bundle moves, it is very likely to affect the anchoring force of the original anchor, and this type of hot-melt anchor cannot effectively monitor the real-time changes in the anchoring force during the recovery of the anchor bundle, and cannot maintain or increase the anchoring force of the anchor through corresponding means when the anchoring force weakens. Therefore, the application effect of this type of hot-melt anchor is poor.

[0008] In addition, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making the present invention, but due to space limitations, not all details and contents are listed in detail. However, this does not mean that the present invention does not have the characteristics of these prior arts. On the contrary, the present invention already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art to the background technology. Summary of the invention

[0009] In view of the deficiencies of the prior art, the present invention provides a recyclable anchor system, aiming to solve at least one or more technical problems existing in the prior art.

[0010] To achieve the above object, the present invention provides a retrievable anchor system, comprising at least:

[0011] Anchor cables for anchoring;

[0012] A monitoring unit is installed on the anchor bundle, the monitoring unit includes at least a strain sensor for monitoring the stress change of the anchor bundle, the sampling period of the strain sensor can be set according to a preset strain amplitude corresponding to the stress change of the anchor bundle, wherein, during the process of recovering the anchor bundle, the time-related stress change information of the anchor bundle is recorded and transmitted via the strain sensor with the preset strain amplitude of the anchor bundle as the starting event.

[0013] Preferably, the retrievable anchor system of the present invention further comprises:

[0014] A recovery unit, which at least comprises a housing sleeved to the anchor cable bundle, and the housing encapsulates a hot-melt component;

[0015] An activation unit is used to activate the hot-melt component in the form of electrical energy.

[0016] Preferably, the hot melt component includes an activation agent and a hot melt agent, which are activated in sequence by energy supplied by an excitation unit and produce a chemical reaction to release chemical reaction heat, and when the hot melt agent is discharged through the shell and contacts the anchor bundle, the anchor bundle can be melted due to the heat of the chemical reaction. In the present invention, the melting of the anchor bundle is mainly achieved by the high amount of chemical reaction heat released by the hot melt reagent. Compared with continuously heating the anchor bundle by the wire to melt it, the hot melt reagent can release a large amount of heat instantly through the redox reaction, so the anchor bundle can be melted in a very short time to be recovered, unlike the prior art that uses the energized wire to continuously heat the anchor bundle, which takes a lot of time to melt the anchor bundle, making the efficiency of anchor recovery extremely low. In addition, since the operating state of the energized wire in the deep underground space is also relatively complicated, it is also impossible to effectively ensure that the energized wire can continuously and stably heat the anchor bundle. In the present invention, the energized wire only needs to provide an initial heat energy sufficient to ignite the hot melt reagent, and the subsequent anchor melting can be assisted by the molten hot melt reagent. The hot melt reagent can instantly provide high amount of heat, so there is no need to consume too much energy from the energized wire. The entire melting process takes a very short time, the efficiency and stability of anchor recovery are significantly improved, and the reaction products of the hot melt reagent usually do not cause serious damage to the anchor bundle and the underground space structure.

[0017] Preferably, the excitation unit comprises at least a control unit and a wire electrically connected to each other, wherein the wire is coupled to the hot-melt component so that the wire can activate the hot-melt component to release chemical reaction heat under the drive of the control unit.

[0018] Preferably, at least the wire of the excitation unit is in physical contact with the activation reagent, and the activation reagent can be activated through the wire and ignite the hot melt reagent in a heat transfer manner, so that the hot melt reagent releases chemical reaction heat through a chemical reaction.

[0019] Preferably, the activation reagent comprises a glycerine bottle and potassium permanganate, and the hot melt reagent comprises an igniter and thermite.

[0020] Preferably, when the excitation unit provides electrical energy to the glycerol bottle, the glycerol bottle is punctured to react the glycerol therein with potassium permanganate and activate the igniter, and the igniter ignites the thermite to form a molten state through a chemical reaction. In the present invention, the hot melt component includes an activation agent and a hot melt agent, wherein the activation agent can be composed of glycerol and potassium permanganate, the activation agent can be activated to burn via a small input current provided by an energized wire, and can release heat to the hot melt agent through an oxidation-reduction reaction, and the hot melt agent can include an igniter and thermite, wherein the igniter is used to assist combustion, and the thermite is used as the main component for melting the anchor cable bundle, when the heat released by the activation agent is transferred to the igniter, the igniter burns to generate higher heat to ignite the thermite, the thermite undergoes a strong oxidation-reduction reaction and forms a molten metal with an ultra-high temperature, with the help of the ultra-high heat of the molten metal, the anchor cable bundle in contact with it will be melted or the tensile strength will be greatly reduced, thereby achieving the purpose of separation and recovery. In particular, once the activation reagent is ignited, it can continue to burn and release heat to ignite the ignition agent and thermite in turn, thereby prompting the thermite to undergo a redox reaction and release a large amount of heat to melt the anchor bundle. That is, once the combustion or redox reaction of the activation reagent and the hot melt reagent begins, it is highly self-sustaining and will hardly be interrupted by formation environmental factors. No additional manual assistance is required during the entire reaction and melting process, and no other unexpected chemical reactions will occur during the entire reaction process, and the process is controllable.

[0021] Preferably, a sealing plate for encapsulating the hot-melt component is provided on one side of the shell close to the anchor bundle. When the activation reagent is activated by the excitation unit and the hot-melt reagent is ignited to convert the hot-melt reagent into a molten state, the hot-melt reagent can melt the sealing plate and flow out of the shell to contact and fuse with the anchor bundle. In the present invention, the shell of the recovery unit is formed by docking two independent annular or semi-cylindrical shells. Therefore, compared with the one-piece shell structure, the recovery unit of the present invention has certain cost and efficiency advantages in combined installation and maintenance and replacement. Based on the shell structure of the present invention, it is very easy to adjust the fixed position of the recovery unit in the circumferential direction of the anchor bundle. Therefore, the fixed position of the recovery unit can be determined according to the recovery requirements, so as to obtain anchor bundles of different lengths or diameters.

[0022] Preferably, the shell is provided with a reagent channel, the hot melt component is filled into the shell via the reagent channel, and the reagent channel is sealed by a sealing plug, and the wire passes through the sealing plug to be connected to the glycerol bottle.

[0023] Preferably, the recyclable anchor system of the present invention further comprises a grouting unit, which comprises a grouting device and a grouting channel, wherein the grouting channel is arranged in the anchor cable bundle, and the grouting channel is connected to the grouting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a recyclable intelligent anchoring device according to a preferred embodiment of the present invention;

[0025] Figure 2 This is one of the structural schematic diagrams of a recovery unit according to a preferred embodiment of the present invention;

[0026] Figure 3 This is the second structural schematic diagram of a recovery unit of a preferred embodiment provided by the present invention.

[0027] Reference numerals list

[0028] 101: anchor cable bundle; 102: recovery unit; 103: anchoring section; 104: grouting channel; 105: control unit; 106: grouting device; 107: drilling hole; 108: strain sensor; 109: wire; 110: communication cable; 111: heating wire; 112: excitation reagent; 113: igniter; 114: thermite; 115: sealing plate; 116: shell; 117: reagent channel; 118: sealing plug; 119: glycerol bottle; 120: potassium permanganate. DETAILED DESCRIPTION

[0029] The following is a detailed description with reference to the accompanying drawings.

[0030] The present invention provides a recyclable intelligent anchoring device, such as Figure 1 As shown, it may include one of the following components:

[0031] Anchor cable bundle 101, which is used to reinforce the soil layer to be anchored;

[0032] A recovery unit 102, which is sleeved on the free section of the anchor cable bundle 101, so as to recover the anchor cable bundle 101;

[0033] A monitoring unit, which at least includes a strain sensor 108 installed on the free section of the anchor cable bundle 101, and is used to monitor the stress change of the anchor cable bundle 101 in real time;

[0034] The grouting unit at least comprises a grouting channel 104 installed inside the anchor cable bundle 101 and is used for performing secondary grouting on the anchor cable bundle 101 .

[0035] According to a preferred embodiment, the recovery unit 102 , the monitoring unit and the grouting unit are each independently mechanically and / or electrically connected to the anchor bundle 101 so as to be used in conjunction with the anchor bundle 101 .

[0036] According to a preferred embodiment, Figure 1As shown, in addition to the strain sensor 108 for monitoring the real-time stress change of the anchor cable bundle 101, the monitoring unit also includes a control unit 105 located outside the borehole. Further, the strain sensor 108 and the control unit 105 are connected by a communication cable 110 signal, and the strain sensor 108 can transmit the monitoring data collected by it about the stress change of the anchor cable bundle 101 to the control unit 105 through the communication cable 110. The control unit 105 can judge the anchoring force change of the anchor cable bundle 101 based on the real-time stress change data of the anchor cable bundle 101, so as to provide data support for the anchoring engineering quality assessment, and can take corresponding anchoring measures according to the real-time anchoring force change of the anchor cable bundle 101.

[0037] Preferably, the signal transmission mode between the strain sensor 108 and the control unit 105 can be not only wired, but also wireless according to different anchoring scenarios. For example, for some strata with shallow anchoring depths, wireless communication can be used to avoid lengthy line layout, thereby increasing the flexibility and portability of the recyclable anchoring device, and wireless communication is more convenient to install and maintain.

[0038] According to a preferred embodiment, Figure 1 As shown, in addition to the grouting channel 104 pre-packaged in the anchor cable bundle 101, the grouting unit also includes a grouting device 106 disposed outside the borehole 107 and connected to the grouting channel 104. Further, in the process of recovering the anchor cable bundle 101, if the control unit 105 determines that the anchoring force of the anchor cable bundle 101 is lower than the design threshold according to the stress monitoring data of the strain sensor 108, secondary grouting can be performed to the anchor cable bundle 101 through the grouting device 106 and the grouting channel 104 to improve the anchor cable, especially the anchoring force of the anchor section 103 of the anchor cable.

[0039] According to a preferred embodiment, Figure 1 As shown, the recovery unit 102 is sleeved on the free section of the anchor cable bundle 101, and the recovery unit 102 is composed of a shell 116, and the shell 116 is the frame body of the entire recovery structure. Figure 2 and Figure 3 As shown, the shell 116 is composed of at least two semi-cylindrical shells, and the middle of the combined shell 116 has a hollow channel, which is composed of two semi-cylindrical shells in a partially concave manner, and the anchor cable bundle 101 can pass through the hollow channel. Further, the semi-cylindrical shells constituting the shell 116 are hollow shells, and the cavity inside them is filled with a hot melt agent for fusing the anchor cable bundle 101. In particular, the shell 116 can be a ceramic shell, which has good high temperature resistance, and the material price of the ceramic shell is low, and the manufacturing process is also very simple.

[0040] According to a preferred embodiment, in the present invention, when the anchor cable bundle 101 is recovered by using the recovery unit 102, the control unit 105 is used to pass current to the wire 109 to activate the hot melt reagent encapsulated in the housing 116, and the anchor cable bundle 101 is melted by the large amount of chemical reaction heat released by the hot melt reagent to achieve recovery. In particular, in the present invention, the chemical reaction heat released by the hot melt reagent is mainly produced by thermite reaction, and the heat released by thermite reaction can raise the ambient temperature to 2000℃~3000℃.

[0041] According to a preferred embodiment, in the present invention, a large amount of heat generated by the thermite reaction of the hot-melt reagent can melt the sealing material used for sealing the shell 116, so that the hot-melt reagent with ultra-high temperature sealed in the shell 116 can flow out, and the hot-melt reagent in a molten state can melt the anchor bundle 101 after contacting the anchor bundle 101, or can greatly reduce the yield strength of the anchor bundle 101, thereby facilitating the pulling and recovery of the anchor bundle 101.

[0042] According to a preferred embodiment, Figure 2 As shown, the shell 116 is connected to a heating wire 111, the heating wire 111 signal is connected to the wire 109, the wire 109 circuit is connected to the control unit 105 outside the borehole 107, and the heating wire 111 can be controlled to work by the control unit 105. Specifically, after the wire 109 is energized by the control unit 105, the heating wire 111 works and continues to heat up, and the heat generated by the heating wire 111 can be transferred to the excitation reagent 112 sealed in the shell 116 and in contact with the heating wire 111, thereby igniting it, the excitation reagent 112 burns to release energy and further transfers heat to the igniter 113 to ignite it, and the igniter 113 contacts the thermite 114 in the shell 116 and transfers heat to the thermite 114 to activate it. Particularly preferably, the excitation reagent 112 can be a magnesium bar.

[0043] According to a preferred embodiment, after the thermite 114 is activated by the high temperature generated by the combustion of the igniter 113, a strong redox reaction, i.e., a thermite reaction, will occur, thereby releasing a large amount of heat to form a molten metal with a temperature of up to 2000°C. The molten metal formed by the reaction of the thermite 114 will melt the sealing plate 115 on the side of the shell 116 after contacting the sealing plate 115 and flowing out of the shell 116 to contact the anchor bundle 101. After the ultra-high temperature molten thermite 114 contacts the anchor bundle 101, it can melt the anchor bundle 101. At this time, the anchor bundle 101 can be pulled out of the anchoring stratum by cooperating with the tensioning equipment outside the borehole 7 to provide a certain pulling force, so as to realize the recovery of the anchor bundle 101.

[0044] According to a preferred embodiment, Figure 2As shown, a reagent channel 117 is provided on the surface of the housing 116, and the hot melt reagent for melting the anchor cable bundle 101 can be pre-filled and sealed in the housing 116 through the reagent channel 117 reserved on the housing 116. Further, after the hot melt reagent is filled, the reagent channel 117 is blocked with a sealing plug 118, and the heating wire 111 is inserted into the housing 116 through the sealing plug 118 and directly contacts with the excitation reagent 112.

[0045] According to a preferred embodiment, Figure 3 Another preferred structural diagram of the recovery unit 102 of the present invention is shown. Specifically, Figure 3 As shown, the housing 116 may be filled with a glycerin bottle 119, potassium permanganate 120, an igniter 113, and a thermite 114. Furthermore, the glycerin bottle 119, potassium permanganate 120, and other chemical reaction reagents for melting the anchor cable bundle 101 may be pre-filled and sealed in the housing 116 through a reagent channel 117 reserved on the housing 116, and the reagent channel 117 may be sealed with a sealing plug 118, and the wire 109 may be inserted into the housing 116 through the sealing plug 118 and connected to the glycerin bottle 119.

[0046] According to a preferred embodiment, when using Figure 3 When the recovery unit 102 shown recovers the anchor cable bundle 101, the control unit 105 outside the borehole 107 is used to energize the wire 109. After the wire 109 is energized, the glycerin bottle 119 can be broken down, so that the glycerin encapsulated in the glycerin bottle 119 flows out and contacts the potassium permanganate 120 in the shell 116 to react chemically, thereby releasing heat. The chemical reaction heat released by the glycerin and the potassium permanganate 120 can activate or ignite the igniter 113. After the igniter 113 is ignited, it will further activate or ignite the thermite 114, causing the thermite 114 to undergo a strong thermite reaction to form a molten metal with an ultra-high temperature, which finally contacts the anchor cable bundle 101 and melts it, so as to realize the recovery of the anchor cable bundle 101. In particular, the sealing plate 115 of the shell 116 close to the anchor cable bundle 101 can be made of a thin iron plate, or replaced by other materials with higher strength but not resistant to high temperatures, such as PPS material.

[0047] According to a preferred embodiment, the existing hot melt anchor is usually powered on to remove the core, and after the power is turned on for a certain period of time, the hot melt anchor is de-cored and the steel strand is pulled out and recovered. However, the existing hot-melt anchors need to rely on the wire 109 to generate a large amount of heat to heat, for example, the metal anchor ring in order to melt the anchor bundle 101. Therefore, before the steel strand reaches the corresponding melting temperature or meets the corresponding recoverable yield strength, the wire 109 needs to be used for a long time to continuously heat the anchor bundle 101. Therefore, the recovery process of the anchor bundle 101 will take a lot of time, especially a lot of preheating preparation time; on the other hand, the anchor bundle 101 is buried in the deep underground space, and the heat transfer effect of the underground soil is poor. Therefore, in the process of using the wire 109 to continuously heat the anchor bundle 101 for a long time, it may be necessary to continuously output a large current. However, due to the large number of uncertain environmental factors in the underground space and the long heat transfer line of the wire 109, in the process of using the wire 109 to continuously heat the anchor bundle 101, it is very likely that the heat of the wire 109 cannot be effectively transferred to the anchor bundle 101. In particular, the wire 109 in the underground space is very prone to failure and damage, and it is also difficult to maintain current output for a long time.

[0048] According to a preferred embodiment, in the present invention, the conductor 109 is only used to provide initial heat to activate the corresponding hot-melt agent, and the melting of the anchor bundle 101 is mainly achieved by the high amount of heat released by the hot-melt agent through chemical reaction. Specifically, when it is necessary to melt the anchor bundle 101 to recover it, the control unit 105 can be used to energize the conductor 109 to make the heating wire 111 work. Compared with directly using the heating wire 111 to continuously transfer physical heat to melt the anchor bundle 101, the heating wire 111 only needs to provide a greatly reduced amount of heat energy to ignite the hot-melt reagent. The subsequent melting of the anchor bundle 101 depends entirely on the chemical reaction heat generated by the chemical reaction of the hot-melt reagent, and there is no need to continuously provide a large amount of heat energy through the heating wire 111. Therefore, energy consumption and waste can be greatly reduced. When the hot-melt reagent forms an ultra-high temperature molten metal through an oxidation-reduction reaction, the molten metal contacts the anchor bundle 101 and melts it. At the same time, the tensioning equipment outside the drilling hole 107 is used to pull out the melted anchor bundle 101 to complete the recovery.

[0049] Preferably, the reaction process of the thermite reaction is very rapid and violent, and a large amount of heat can be released instantly. Compared with the continuous heating of the anchor bundle 101 by the heating wire 111, the heat released by the thermite reaction can instantly raise the ambient temperature to thousands of degrees Celsius, so that the entire process from energizing the heating wire 111 to releasing a large amount of heat by thermite reaction can be completed in a very short time, so the efficiency of the entire anchor recovery can be significantly improved; secondly, the main products of the thermite reaction are various metal oxides. After the anchor bundle 101 is melted by the thermite reaction, the residual reaction products will not cause secondary damage to the anchor bundle 101, and will not affect the use of the recovered steel strands. Moreover, even if the metal oxides produced by the thermite reaction remain in the underground space, they will not cause serious damage to the underground space structure.

[0050] According to a preferred embodiment, the reaction process of thermite reaction is usually known. Compared with directly using the wire 109 to continuously heat the anchor bundle 101 and maintaining a continuous and stable output of the wire 109, once the thermite reaction begins, it will hardly be affected by the surrounding environment. The wire 109 in a complex formation space is more likely to become unstable due to many uncertain factors, which will add unexpected difficulties and costs to the recovery of the anchor bundle 101. The anchor bundle 101 can be melted instantly by the thermite reaction, which not only improves the efficiency of anchor recovery, but also greatly reduces the possibility of uncertain factors, making the stability of anchor recovery better.

[0051] According to a preferred embodiment, when the strain sensor 108 is used to monitor the stress change of the anchor bundle 101 in the prior art, the monitoring and transmission frequencies of the strain sensor 108 are usually known and fixed. When the anchoring force of the anchor bundle 101 is abnormally attenuated, the anchoring effect of the anchor bundle 101 will be greatly reduced or even disappear. The strain sensor 108 usually sends corresponding monitoring data only at a preset sampling node, and the control unit 105 can only judge the anchoring force of the anchor bundle 101 when receiving the corresponding monitoring data. Therefore, when the anchoring force of the anchor bundle 101 changes abnormally, the conventional monitoring and judgment method has a certain hysteresis, and this hysteresis The delay is extremely disadvantageous for reinforcing the stratum with anchor cables, especially when the delayed sending and receiving effect continues to accumulate. The error between the actual change in the anchoring force of the anchor cable bundle and the expected change may be as high as several times. The change in the anchoring force of the anchor cable bundle, especially when the anchor cable bundle 101 is recovered, the attenuation of the anchoring force of the anchor cable bundle also affects the timing of secondary grouting of the anchor cable through the grouting part, thereby affecting the anchoring quality. In particular, when the anchoring force of the anchor cable bundle 101 is significantly lower than a certain range of the set threshold, if the secondary grouting is not carried out in time, even if grouting is carried out later, the anchoring force of the anchor cable bundle 101 may not be restored to its original level due to missing the best grouting opportunity.

[0052] According to a preferred embodiment, in the present invention, the sampling period of the strain sensor 108 can be set according to the preset strain amplitude corresponding to the stress change of the anchor cable bundle 101. In other words, in the process of recovering the anchor cable bundle 101, the time-related stress change information of the anchor cable bundle 101 is recorded and transmitted via the strain sensor 108 with the preset strain amplitude of the anchor cable bundle 101 as the starting event. Specifically, the preset strain amplitude can be set by the engineering design personnel according to the engineering experience value or the measured value based on the engineering simulation experiment. For example, for the anchoring soil layer with a known geological environment, the attenuation change of the anchor cable bundle 101 when recovering the anchor cable from the stratum can be simulated by software, and the corresponding anchoring force and time-related change curve can be formed, thereby setting the preset strain amplitude according to the theoretical change trend of the anchoring force of the anchor cable bundle.

[0053] Preferably, the time consumed by the anchor bundle 101 for each single preset strain amplitude or each reduction of the anchoring force of the anchor bundle 101 by a single preset strain amplitude is the sampling period of the strain sensor 108. When the stress change of the anchor bundle 101 is accelerated or slowed down, the time consumed by the anchor bundle 101 for each single preset strain amplitude will also change. In particular, the ratio of the sampling period of the strain sensor 108 to the preset strain amplitude can be used to characterize the stress change rate of the anchor bundle 101, so that the anchoring force attenuation rate of the anchor bundle 101 can be known. The larger the ratio, the slower the anchoring force attenuation rate of the anchor bundle 101, that is, the longer the time consumed by the anchor bundle 101 for each single preset strain amplitude or each reduction of the anchoring force by a single preset strain amplitude. On the contrary, the smaller the ratio, the faster the anchoring force attenuation rate of the anchor bundle 101, that is, the shorter the time consumed by the anchor bundle 101 for each single preset strain amplitude or each reduction of the anchoring force by a single preset strain amplitude.

[0054] According to a preferred embodiment, when the attenuation rate of the anchoring force of the anchor bundle 101 slows down, the strain sensor 108 can reduce the frequency and amount of monitoring data transmitted to the control unit 105, so as to reduce the delay generated in the data transmission interaction process on the basis of reducing the amount of data interaction, so that the control unit 105 can analyze and calculate the anchoring force of the anchor rod more timely and smoothly, especially can respond to the changes in the anchoring force of the anchor rod in a timely manner, so that the anchoring force of the anchor bundle 101 can be enhanced in time through the grouting part.

[0055] According to a preferred embodiment, as the anchoring force of the anchor cable bundle 101 continues to decay, the risks corresponding to different anchoring force change intervals are different, and the corresponding grouting amounts are also different. Preferably, for different anchoring force change intervals, the sampling period of the strain sensor 108 is different, and the corresponding preset strain amplitude is also different. Specifically, the engineering design personnel can set different anchoring force change intervals for the anchor cable bundle 101 according to the requirements of the anchoring project, and set different preset strain amplitudes for each anchoring force change interval, so as to timely adjust the monitoring frequency of the strain sensor 108 on the anchor cable bundle 101 as the anchoring force changes, thereby improving the timeliness of the anchoring force monitoring of the anchor cable bundle 101.

[0056] In particular, as the anchoring force of the anchor cable bundle continues to decay, the possibility of anchor failure becomes greater. Therefore, as the anchoring force of the anchor cable bundle continues to decrease, the preset strain amplitude of the anchor cable bundle 101 can be linearly / nonlinearly reduced to shorten the corresponding sampling period, so that the strain sensor 108 can monitor the anchoring force of the anchor cable bundle 101 more frequently, so that the change of the anchoring force of the anchor cable bundle can be timely known. In particular, in the process of continuous decrease of the anchoring force, the grouting part can be timely started according to the change of the anchoring force to perform secondary grouting on the anchor cable, so as to timely respond to the decay of the anchoring force and maintain the corresponding anchoring effect through timely grouting. On the contrary, when the anchoring force of the anchor cable bundle is increased or restored after grouting, the preset strain amplitude of the anchor cable bundle 101 can be linearly / nonlinearly increased with the increase of the anchoring force. In this way, when the anchoring force of the anchor cable bundle continues to decrease, During the process, by shortening the sampling period of the strain sensor 108, the control unit 105 can make the analysis and judgment frequency of the anchoring force of the anchor bundle more intensive and frequent, so as to be able to timely know the attenuation state of the anchoring force of the anchor bundle, and timely start the grouting part for secondary grouting. On the other hand, the monitoring frequency of the anchoring force of the anchor bundle by the strain sensor 108 can be adjusted in time according to the change of the anchoring force of the anchor bundle, so that the monitoring frequency of the anchoring force of the anchor bundle is more reasonable and accurate. In particular, for example, when the attenuation degree of the anchoring force of the anchor bundle is weak, frequent monitoring may be unnecessary, because this will increase the amount of data interaction, occupy computing resources and cause delays. At the same time, too much data output will also generate a certain amount of pseudo data, which will affect the analysis and judgment of the anchoring force of the anchor bundle by the control unit 105, thereby affecting the optimal grouting time. Specifically, for example, when the first anchoring force change interval related to the stress change of the anchor bundle 101 is greater than the second anchoring force change interval, the preset strain amplitude corresponding to the strain sensor 108 in the first anchoring force change interval is greater than the preset strain amplitude corresponding to the strain sensor 108 in the second anchoring force change interval, that is, as the real-time anchoring force of the anchor bundle 101 continues to decrease, the monitoring frequency of the anchoring force of the anchor bundle by the strain sensor 108 also increases accordingly.

[0057] In the present invention, the recyclability of the anchor cable or anchor rod is achieved through a controllable hot-melt device, which can reduce material consumption and reduce engineering costs. The controllable hot-melt device of the present invention has a simple structure, does not require high-precision processing, has a low production cost, is easy to use and maintain, and has a high recycling efficiency. Secondly, the present invention reflects the size of the anchoring force of the anchor cable or anchor rod by real-time monitoring of the stress changes of the free section anchor cable, so as to be able to judge the expected anchoring effect. In particular, when the anchoring project does not achieve the expected effect, secondary grouting can be implemented through the grouting unit to promptly compensate for the lack of anchoring force. The main components of the anchor cable adopt a modular and mechanized design, which is easy to process and manufacture, reduces production costs, and the modular design is simple to disassemble and assemble, and maintenance and replacement are faster.

[0058] It should be noted that the above-mentioned specific embodiments are exemplary, and those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention. Those skilled in the art should understand that the present invention specification and its drawings are illustrative and do not constitute a limitation on the claims. The scope of protection of the present invention is defined by the claims and their equivalents. The present invention specification contains multiple inventive concepts, such as "preferably", "according to a preferred embodiment" or "optionally", all of which indicate that the corresponding paragraph discloses an independent concept, and the applicant reserves the right to file a divisional application based on each inventive concept.

Claims

1. A method for recovering a recoverable anchor system, characterized in that: The retrievable anchor system comprises: An anchor cable bundle (101) for anchoring; A recovery unit (102), comprising at least a shell (116) sleeved onto the anchor cable bundle (101), wherein the shell (116) is encapsulated with a hot-melt component; an excitation unit, which is used to activate the hot melt component in the form of electrical energy, wherein the hot melt component comprises an activation agent and a hot melt agent, the activation agent and the hot melt agent are activated in sequence by the energy supplied by the excitation unit and produce a chemical reaction to release chemical reaction heat, and when the hot melt agent is discharged through the housing (116) and contacts the anchor cable bundle (101), the anchor cable bundle (101) can be melted due to the chemical reaction heat; A grouting unit, the grouting unit comprising a grouting device (106) and a grouting channel (104), wherein the grouting channel (104) is arranged in the anchor cable bundle (101), and the grouting channel (104) is connected to the grouting device (106); A monitoring unit installed on the anchor cable bundle (101), the monitoring unit comprising at least a strain sensor (108) communicatively connected to a control unit (105) for monitoring stress changes of the anchor cable bundle (101), wherein a sampling period of the strain sensor (108) can be set according to a preset strain amplitude corresponding to the stress change of the anchor cable bundle (101), wherein: During the process of recovering the anchor cable bundle (101), the time-dependent stress change information of the anchor cable bundle (101) is recorded and transmitted via the strain sensor (108) using the preset strain amplitude of the anchor cable bundle (101) as a starting event. The time consumed by the anchor cable bundle (101) for each generation of a single preset strain amplitude or the anchoring force of the anchor cable bundle (101) for each reduction of a single preset strain amplitude is the sampling period of the strain sensor (108). When the stress change of the anchor cable bundle (101) is accelerated or slowed down, the time consumed by the anchor cable bundle (101) for a single preset strain amplitude to occur will change. The excitation unit comprises at least a control unit (105) and a wire (109) electrically connected to each other, wherein the wire (109) is connected to the hot-melt component so that the wire (109) can activate the hot-melt component under the drive of the control unit (105) to cause it to release the chemical reaction heat. The control unit (105) monitors and determines changes in the anchoring force of the anchor bundle (101) based on the stress monitoring data of the monitoring unit, and when the anchoring force of the anchor bundle (101) is lower than a set threshold, secondary grouting is performed on the anchor bundle (101) through the grouting unit. As the anchoring force of the anchor cable bundle (101) continues to decay, the preset strain amplitude of the anchor cable bundle (101) is reduced to shorten the corresponding sampling period.

2. The method for recovering a recoverable anchor system according to claim 1, characterized in that: At least the wire (109) of the excitation unit is in physical contact with the activation reagent, and the activation reagent can be activated through the wire (109) and ignite the hot melt reagent in a heat transfer manner, so that the hot melt reagent releases chemical reaction heat through a chemical reaction.

3. The method for recovering a recoverable anchor system according to claim 1, characterized in that: The activation reagent includes a glycerin bottle (119) and potassium permanganate (120), and the hot melt reagent includes an igniter (113) and thermite (114).

4. The method for recovering a recoverable anchor system according to claim 3, characterized in that: When the excitation unit provides electrical energy to the glycerol bottle (119), the glycerol bottle (119) is punctured so that the glycerol therein reacts with potassium permanganate (120) and activates the igniter (113), and the igniter (113) ignites the thermite (114) to form a molten state through a chemical reaction.

5. The method for recovering a recoverable anchor system according to claim 1, characterized in that: A sealing plate (115) for encapsulating the hot-melt component is provided on one side of the shell (116) close to the anchor bundle (101); when the activation agent is activated by an excitation unit and the hot-melt agent is ignited to convert the hot-melt agent into a molten state, the hot-melt agent can melt the sealing plate (115) and flow out of the shell (116) to contact and fuse with the anchor bundle (101).

6. The method for recovering a recoverable anchor system according to claim 4, characterized in that: The shell (116) is provided with a reagent channel (117), and the hot melt component is filled into the shell (116) via the reagent channel (117). The reagent channel (117) is sealed by a sealing plug (118), and the wire (109) passes through the sealing plug (118) to be connected to the glycerol bottle (119).

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