Prestressed anchor cable dismantling method

Abstract

The invention relates to a pre-stressed anchor cable dismantling method which is applied to an anchor cable supporting structure and comprises the steps that one of multiple anchor cable assemblies on a steel belt ring is selected as a dismantling set, and other anchor cable assemblies on the steel belt ring serve as to-be-dismantled sets; the steel belt ring is cut until the disassembly set and the steel belt ring are in an independent state after being separated; after the disassembly set is in the independent state, the prestress of the disassembly set is released, and the disassembly set is disassembled until the disassembly set is in the relaxed state; after the disassembly group is disassembled, whether other to-be-disassembled groups exist on the steel belt ring or not is judged; and if yes, after one to-be-detached group is converted into a detached group, the step of cutting the steel belt ring till the detached group is in an independent state after being separated from the steel belt ring is executed. According to the method, the safety in the dismounting process of the pre-stressed anchor cable assembly can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of prestressed anchor cable assemblies, and in particular to a method for dismantling a prestressed anchor cable assembly. Background Art

[0002] With the development of tunnel excavation support construction, prestressed anchor cable assembly support technology has emerged. In some soft rock deformation tunnel sections and fault tunnel sections, settlement, deformation and other problems still occur at the tunnel arch after the initial support. Therefore, it is necessary to achieve joint support through the coordination of anchor cable support structure and initial support layer. In the tunnel section where local super-large deformation and disease occur in the initial support layer with steel support, prestressed anchor cable assembly and shotcrete as the main core, the removal of prestressed anchor cable assembly is an important link in the arch removal and replacement operation. At the same time, the removal of prestressed anchor cable assembly is a high-risk operation. According to the existing disassembly method, there are risks such as surrounding rock instability, structural damage, and personal injury caused by the unloading of prestressed anchor cable assembly during the disassembly process. Summary of the invention

[0003] Based on this, it is necessary to provide a method for dismantling a prestressed anchor cable assembly in order to solve the problem of safety in dismantling the anchor cable support structure.

[0004] A method for removing a prestressed anchor cable, applied to an anchor cable support structure, comprising:

[0005] Step S1, selecting one of the multiple groups of anchor cable assemblies on the steel belt ring as a disassembly group, and the other anchor cable assemblies on the steel belt ring as the to-be-disassembled group;

[0006] Step S2, cutting the steel belt ring until the disassembly group is separated from the steel belt ring and is in an independent state;

[0007] Step S3, after the disassembly group is in an independent state, releasing the prestress of the disassembly group until the disassembly group is in a relaxed state and then disassembling it;

[0008] Step S4: after the disassembly group is disassembled, determine whether there are other groups to be disassembled on the steel belt ring;

[0009] Step S5: If yes, after converting one of the to-be-disassembled groups into a disassembly group, proceed to step S2.

[0010] In one embodiment, step S3, after the disassembly group is in an independent state, the prestress of the disassembly group is released until the disassembly group is in a relaxed state and then disassembled.

[0011] The method comprises: excavating a unloading groove on the initial supporting layer corresponding to the disassembly group, the disassembly group is provided with a central axis in a direction perpendicular to the surface of the initial supporting layer, and the unloading groove is evenly opened relative to the central axis.

[0012] In one embodiment, a relief groove is excavated on the initial support layer corresponding to the disassembly group, the disassembly group is provided with a central axis in a direction perpendicular to the surface of the initial support layer, and the relief groove is evenly opened relative to the central axis.

[0013] The method comprises: the unloading groove is set as a trapezoidal groove, and the groove is gradually excavated from the central axis of the disassembly group toward the surrounding areas during the groove excavation process.

[0014] In one embodiment, step S1, one group of anchor cable assemblies on the steel belt ring is selected as a disassembly group, and other anchor cable assemblies on the steel belt ring are selected as a to-be-disassembled group.

[0015] The method comprises: selecting one of the anchor cable assemblies located at the top arch position of the initial supporting layer as a disassembly group.

[0016] In one embodiment, step S5: if yes, after converting one of the to-be-disassembled groups into a disassembly group, proceed to step S2.

[0017] The method comprises: selecting a to-be-disassembled group located at a top arch position of an initial supporting layer to be converted into a disassembly group; after the to-be-disassembled group at the top arch position of an initial supporting layer is disassembled, selecting a to-be-disassembled group located at a side wall position of the initial supporting layer to be converted into a disassembly group.

[0018] In one embodiment, the to-be-disassembled group located at the top arch position of the initial supporting layer is selected to be converted into the disassembly group. After the to-be-disassembled group at the top arch position of the initial supporting layer is disassembled, the to-be-disassembled group located at the side wall position of the initial supporting layer is selected to be converted into the disassembly group.

[0019] The method comprises: selecting the to-be-disassembled groups in sequence along the direction from the top arch position to the side wall position and converting them into the disassembly groups.

[0020] In one embodiment, step S2, cutting the steel belt ring until the disassembly group is separated from the steel belt ring and is in an independent state,

[0021] The method comprises: cutting the corresponding position of the end of the anchor cable assembly on the steel belt ring until the anchor cable assembly is separated from the steel belt ring.

[0022] In one embodiment, step S3, after the disassembly group is in an independent state, the prestress of the disassembly group is released until the disassembly group is in a relaxed state and then disassembled.

[0023] The method includes: after the steel strands in the group to be disassembled are completely loosened, the anchor pad and anchor of the anchor cable assembly are first removed, and then the steel strands are cut off one by one.

[0024] In one embodiment, before the step S2, cutting the steel belt ring until the disassembly group is separated from the steel belt ring and in an independent state,

[0025] Also included: wrapping the anchor in the disassembly group with a protective cover.

[0026] In one embodiment, step S3, after the disassembly group is in an independent state, the prestress of the disassembly group is released until the disassembly group is in a relaxed state and then disassembled.

[0027] It includes: in the process of releasing the prestress of the disassembly group, the surrounding rock of the initial support layer where the steel belt ring is located is monitored, and the surrounding rock monitoring is used to synchronously monitor the sudden change of the initial support layer, and an alarm notification is issued if a sudden change occurs.

[0028] The above-mentioned method for removing prestressed anchor cable comprises: selecting one of the multiple groups of anchor cable assemblies on the steel belt ring as the disassembly group, and selecting the other anchor cable assemblies on the steel belt ring as the to-be-disassembled group; cutting the steel belt ring until the disassembly group is separated from the steel belt ring and is in an independent state; after the disassembly group is in an independent state, releasing the prestress of the disassembly group until the disassembly group is in a relaxed state and then disassembling it; after the disassembly group is disassembled, judging whether there are other to-be-disassembled groups on the steel belt ring; if so, after converting one of the to-be-disassembled groups into the disassembly group, entering the step of “cutting the steel belt ring until the disassembly group is separated from the steel belt ring and is in an independent state”. This method can improve the safety of the disassembly process of the prestressed anchor cable assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a flow chart of a specific implementation of a method for removing a prestressed anchor cable provided in an embodiment of the present application.

[0030] FIG. 2 is a schematic diagram of an anchor cable support structure using the method provided in an embodiment of the present application.

[0031] FIG3 is a side sectional view of the anchor cable support structure provided in an embodiment of the present application.

[0032] FIG. 4 is a cross-sectional view of an embodiment of the present application provided in a rock cave.

[0033] FIG5 is a flow chart of another specific implementation of the method for removing prestressed anchor cables provided in an embodiment of the present application.

[0034] Figure Number:

[0035] 1. Steel belt ring; 2. Anchor cable assembly; 3. Initial support layer; 4. Unloading groove; 5. Anchor plate; 6. Anchor; 7. Protective cover;

[0036] A. Disassembly group; B. Group to be disassembled; C. Center axis; D. Arch line. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0038] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0039] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0040] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0041] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0042] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If present, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0043] Referring to Figures 1 to 4, Figure 1 is a flow chart of a specific implementation method of the prestressed anchor cable removal method provided in an embodiment of the present application, Figure 2 is a schematic diagram of an anchor cable support structure to which the present method is applied provided in an embodiment of the present application, Figure 3 is a side sectional view of the anchor cable support structure provided in an embodiment of the present application, and Figure 4 is a cross-sectional view in a rock cave provided in an embodiment of the present application, showing a prestressed anchor cable removal method applied to an anchor cable support structure, wherein the anchor cable support structure refers to a conventional anchor cable support structure in the prior art, generally consisting of a steel belt ring 1 and an anchor cable assembly 2, the anchor cable assembly 2 may include an anchor pad 5, an anchor 6, and an anchor cable formed by applying prestress to a steel strand, and this article describes the anchor cable support structure and the initial support structure in a rock cave as an example. The specific structure and coordination method of the anchor cable support structure and the initial support structure may refer to the prior art settings, and this article does not make too many restrictions here.

[0044] The above-mentioned prestressed anchor cable removal method comprises:

[0045] Step S1, selecting one of the multiple groups of anchor cable assemblies 2 on the steel belt ring 1 as a disassembly group A, and the other anchor cable assemblies 2 on the steel belt ring 1 as a to-be-disassembled group B;

[0046] Specifically: Several steel belt rings 1 are opened in the rock cave, and several steel belt rings 1 are sequentially set along the opening direction of the rock cave, and all steel belt rings 1 are set on the initial support structure. When it is necessary to dismantle and replace the anchor cable support structure, first select a group of anchor cable components 2 on one of the steel belt rings 1, and after all the anchor cable components 2 on the same steel belt ring 1 are completely dismantled, the steel belt ring 1 currently being dismantled will also be removed from the inner wall of the rock cave, and after one steel belt ring 1 is dismantled, the next steel belt ring 1 will be dismantled.

[0047] Step S2, cutting the steel belt ring 1 until the disassembly group A is separated from the steel belt ring 1 and is in an independent state;

[0048] Specifically: disassembly group A is installed on a section of steel belt ring 1. Similarly, each group B to be disassembled also has a corresponding steel belt section. The steel belt section of the currently selected disassembly group A is cut, and the disassembly group A is separated from the entire steel belt ring 1 after cutting. Until the disassembly group A is in an independent state, where the independent state means that the disassembly group A is completely separated from the rest of the steel belt ring 1, and there is no longer any force association between the separated disassembly group A and the steel belt ring 1. Ensure that when the above disassembly group A is subsequently disassembled, the force it generates will not affect other parts of the steel belt ring 1, and ensure that the disassembly of the anchor cable is changed from the disassembly of the ring-type component to the disassembly of the point-type structure, making the entire disassembly process more stable.

[0049] Step S3, after the disassembly group A is in an independent state, releasing the prestress of the disassembly group A until the disassembly group A is in a relaxed state and then disassembling it;

[0050] Specifically: when the above-mentioned disassembly group A is cut to an independent state, the prestress of the disassembly group A is released. Specifically, the prestress of the steel strands inside the currently selected anchor cable assembly 2 is released until the steel strands of the disassembly group A are completely loose, that is, the disassembly group A reaches a relaxed state. After the prestress is completely released, separating the anchor cable assembly 2 from the initial support structure can ensure that the anchor cable will not have the risk of popping out due to the tight prestress.

[0051] Step S4: after the disassembly of the disassembly group A is completed, determine whether there is another group B to be disassembled on the steel belt ring 1:

[0052] Specifically: determine whether there is an anchor cable that has not been removed on the same steel belt ring 1,

[0053] Step S5: If yes, after converting one of the to-be-disassembled groups B into the disassembly group A, proceed to step S2.

[0054] Specifically: after entering step S2, the new disassembly group A can be disassembled according to the same process to form a cyclic disassembly plan. When the next disassembly group B does not appear, the disassembly of the current steel belt ring 1 is completed.

[0055] Step S6: If not, stop the disassembly operation, or switch to disassembly of other steel belt rings 1.

[0056] Specifically: if there is no other group B to be disassembled on the same steel belt ring 1, it means that the current steel belt ring 1 has been disassembled, and the disassembly can be stopped, or the disassembly can be switched to other steel belt rings 1 in the cave.

[0057] In one embodiment, a steel belt ring 1 in a rock cave is first selected, and an anchor cable assembly 2 is selected on the steel belt ring 1 as a disassembly group A, and other anchor cable assemblies 2 on the same steel belt ring 1 are selected as a to-be-disassembled group B. As shown in FIG. 4 , only one anchor cable assembly 2 is selected as the disassembly group A for disassembly at the same time, but there may be multiple to-be-disassembled groups B at the same time.

[0058] Cut the position of the steel belt ring 1 corresponding to the selected disassembly group A so that the disassembly group A is disconnected from the steel belt ring 1. After the disassembly group A is in an independent state, the prestress of the disassembly group A is released. At this time, the prestress release is performed on the single point of the disassembly group A, and the same steel belt ring 1 will not be affected during the process. When the single disassembly group A releases the prestress to a relaxed state, it can be disassembled, and then it is determined whether there are other groups B to be disassembled on the same steel belt ring 1, so as to determine whether the anchor cable of the current steel belt ring 1 has been disassembled. Assuming that there are other groups B to be disassembled, a group B to be disassembled is selected and regarded as a new disassembly group A, and then it is disassembled according to the above disassembly method for the disassembly group A, until the current anchor cable of the steel belt ring 1 is completely disassembled. After the current steel belt ring 1 is completely disassembled, you can choose to stop the disassembly operation or continue to disassemble the next steel belt ring 1 in the cave.

[0059] In addition, in the cave, each time a ring of steel belt rings 1 where the prestressed anchor cable is located is removed, one arch frame in the initial support layer 3 is gradually replaced; one ring here refers to a general term for a ring of steel belt rings 1 with an anchor cable assembly 2. When performing the demolition operation: each time a ring of prestressed anchor cable and steel belt ring 1 is removed, an arch frame is gradually replaced. The demolition process is carried out in a top-down order, and the specific steps are: first chisel out the shotcrete, then cut the arch frame, then remove the arch frame, then trim the rock surface, install the mesh, and then assemble the arch frame for the second time. After the assembly is completed, the arch frame is locked, and finally the second shotcrete is carried out. In order to ensure construction safety, prevent rock collapse and ensure rock stability, the number of arch frames replaced each time should not exceed one. And only when the strength of the second shotcrete reaches 15Mpa, the next ring of prestressed anchor cable can be removed. To ensure the safety of personnel and mechanical equipment, to prevent safety risks and economic costs caused by subsequent deformation.

[0060] In one embodiment of the present application, with respect to step S3, after the disassembly group A is in an independent state, the prestress of the disassembly group A is released until the disassembly group A is in a relaxed state and then disassembled.

[0061] It includes: step S31, excavating a unloading groove 4 on the initial supporting layer 3 installed corresponding to the disassembly group A, the disassembly group A is provided with a central axis C along a direction perpendicular to the surface of the initial supporting layer 3, and the unloading groove 4 is evenly opened relative to the central axis C.

[0062] Specifically: a groove is dug near the central axis C of the corresponding anchor cable to unload. The anchor cable will slowly shrink in the space of the unloading groove 4 due to the prestress, thereby achieving the effect of releasing the prestress. Until the steel strand of the anchor cable is completely in a relaxed state. Among them, the method of excavating the unloading groove 4 can be selected and is not limited to the use of manual handheld pneumatic picks for excavation, and this article does not make too many restrictions.

[0063] In one embodiment of the present application, with respect to step S31, a unloading groove 4 is excavated on the initial support layer 3 installed corresponding to the disassembly group A, and the disassembly group A is provided with a central axis C along a direction perpendicular to the surface of the initial support layer 3, and the unloading groove 4 is evenly opened relative to the central axis C.

[0064] The method comprises: step S32, the unloading groove 4 is set as a trapezoidal groove, and the groove is gradually excavated from the central axis C of the disassembly group A toward the surrounding areas during the groove excavation process.

[0065] Specifically: the unloading groove 4 is opened with the central axis C of the disassembly group A as the center and expands in all directions. The unloading groove 4 has a depth L relative to the installation surface of the anchor cable. When pre-disassembling anchor cable assemblies 2 of different specifications, the depth L is preset according to the specific data of the anchor cable assemblies 2, and the prestress release effect of the anchor cable can be met until the groove reaches the depth L.

[0066] In one embodiment, the anchor cable assembly 2 is composed of an anchor cable, a resin anchor, a "W"-shaped steel belt, an anchor pad 5 and an anchor 6. The specific specifications of the above-mentioned anchor cable are: 19 strands, a diameter of 21.80 mm, a tensile strength of 1860 MPa and a material of 82B steel. The above-mentioned resin anchor is of MSZ2850 type. The above-mentioned steel belt ring 1 is of "W"-shaped steel belt, with specific specifications of 130 cm in length, 28 cm in width and 2.8 mm in thickness. The specific specifications of the above-mentioned anchor pad 5 are that the length and width are both 25 cm and are square in shape. The thickness is 20 mm. The length of the above-mentioned prestressed anchor cable is 8m, with 18 bundles in a single ring, and the arrangement range is within 180° of the top arch. The anchoring length is 1m, and the tension force of the anchor cable is not less than 250KN.

[0067] Taking the above anchor cable support structure as an example, the unloading groove 4 at this time corresponds to a trench with a length of 50 cm, a width of 20 cm, and a depth of 40 cm. When the trench reaches 40 cm, the tightness is judged by observation and pulling and pushing. If the anchor cable is still in a tight state, the trench depth should be further deepened until the anchor cable is in a relaxed state.

[0068] In one embodiment of the present application, with respect to step S1, one of the multiple groups of anchor cable assemblies 2 on the steel belt ring 1 is selected as the disassembly group A, and the other anchor cable assemblies 2 on the steel belt ring 1 are selected as the to-be-disassembled group B.

[0069] The method comprises: step S11, selecting one of the anchor cable assemblies 2 located at the top arch position of the initial supporting layer 3 as the disassembly group A.

[0070] Specifically: an arch line D is set in the rock cave parallel to the horizontal plane, the rock cave and the initial support layer 2 above the arch line D are both within the top arch range, and the rock cave and the initial support layer 3 below the arch line D are both within the side wall range. The anchor cable assembly 2 set within the top arch range is preferentially selected as the first disassembly group A in a steel belt ring 1, and the anchor cables are subsequently disassembled one by one from the top arch range to the side walls on both sides.

[0071] In one embodiment of the present application, in step S5, if yes, after converting one of the to-be-disassembled groups B into the disassembly group A, proceed to step S2,

[0072] It includes: step S51, selecting the to-be-disassembled group B located at the top arch position of the initial supporting layer 3 to be converted into the disassembly group A; after the to-be-disassembled group B at the top arch position of the initial supporting layer 3 is disassembled, selecting the to-be-disassembled group B located at the side wall position of the initial supporting layer 3 to be converted into the disassembly group A.

[0073] In one embodiment of the present application, in step S51, the to-be-disassembled group B located at the top arch position of the initial supporting layer 3 is selected to be converted into the disassembly group A. After the to-be-disassembled group B at the top arch position of the initial supporting layer 3 is disassembled, the to-be-disassembled group B located at the side wall position of the initial supporting layer 3 is selected to be converted into the disassembly group A.

[0074] The method comprises: step S52, sequentially selecting the to-be-disassembled group B to be converted into the disassembly group A along the direction from the top arch position to the side wall position.

[0075] Specific:

[0076] First, select the anchor cable assembly 2 at the top arch position as the first disassembly group A. After the first disassembly group A is disassembled, the to-be-disassembled group B at the top arch position is preferentially selected to be converted to disassembly group A, and the anchor cables are disassembled in sequence from the top arch to the side walls on both sides. The principle of disassembly is to disassemble the top arch position first, and then disassemble the anchor cables at the side wall position after the anchor cables at the top arch position are removed.

[0077] Such disassembly can gradually release stress: the top arch is a key part of the structure with complex stress. Disassembling the top arch anchor cable first can gradually release the stress in the structure and avoid the sudden concentration of stress on the side wall, which will cause the structure to become unstable. In this way, the deformation and stress changes of the structure during the removal of the anchor cable can be better controlled. To a certain extent, the side wall can rely on its own stability and interaction with the surrounding rock and soil to gradually adapt to the new stress state after the top arch anchor cable is removed.

[0078] At the same time, it can protect the side wall structure: if the side wall anchor cables are removed first, the load of the top arch may be transferred to the side wall, increasing the stress on the side wall, which may easily cause cracks, deformation and other damage to the side wall. However, removing the top arch anchor cables first can reduce the burden on the side wall to a certain extent and protect the integrity of the side wall structure.

[0079] In one embodiment of the present application, with respect to step S2, the steel belt ring 1 is cut until the disassembly group A is separated from the steel belt ring 1 and is in an independent state.

[0080] The method comprises: step S21, cutting the corresponding position of the end of the anchor cable assembly 2 on the steel belt ring 1, until the anchor cable assembly 2 is separated from the steel belt ring 1.

[0081] Specifically: The steel belt can be cut by, but is not limited to, a grinding machine to ensure that the load on the steel belt is evenly released and to prevent the cut steel belt from bouncing up due to stress. The cutting position is set at the corresponding position of the anchor cable end on the steel belt ring 1. The stress of the steel belt at this position is relatively small, and it is not easy to cause the problem of stress concentration affecting the overall stability of the steel belt ring 1. The corresponding disassembly of a disassembly group A is performed once, and the single steel belt ring 1 is cut into sections one by one. The cutting order is determined according to the disassembly order of the cutting group A. Preferably, the steel belt at the top arch position is cut first, and then the steel belt at the side wall position is cut.

[0082] In one embodiment of the present application, with respect to step S3, after the disassembly group A is in an independent state, the prestress of the disassembly group A is released until the disassembly group A is in a relaxed state and then disassembled.

[0083] The method comprises: step S33, after the steel strands are completely loosened, firstly removing the anchor pad 5 and the anchor 6 of the anchor cable assembly 2, and then cutting off the steel strands one by one.

[0084] Specifically: After the prestressing of the anchor cable is released stably and the steel strand is completely relaxed, first remove the loose concrete of the initial support, then use a manual handheld grinder to cut and destroy the anchor 6 of each bundle of anchor cables, then remove the anchor pad 5, cut off the exposed steel strands, and cut off each bundle of anchor cable steel wires one by one during the cutting process.

[0085] During the anchor cable cutting process, the operator should stand on the side of the anchor cable end and should not cut directly at the anchor cable. Before cutting the anchor cable, check whether the anchor cable strand is in a tight state. It is strictly forbidden to cut the anchor cable when the strand is in a tight state. Wait until the anchor cable stress is released and relaxed before cutting and removing.

[0086] In one embodiment of the present application, in step S2, the steel belt segment corresponding to the load-bearing disassembly group A on the steel belt ring 1 is determined, and the steel belt segment is cut off from the steel belt ring 1 until the steel belt segment is in an independent state.

[0087] It also includes: step S20, wrapping the anchor 6 in the disassembly group A with the protective cover 7. Specifically: In one embodiment, the protective cover 7 is set as a geotextile, and the anchor cable and the anchor 6 in each disassembly group A are completely wrapped with the geotextile, and the sealing position of the package is tied with lead wire to prevent the anchor clip from ejecting and injuring people during the unloading of the prestressed anchor cable. It is foreseeable that the protective cover 7 is not limited to being set as a geotextile. In order to achieve the protective effect of the anchor cable prestress during the release process, various protective parts on the outside of the anchor cable can be used, which will not be expanded in this article.

[0088] During the demolition process, it is possible to avoid the anchor 6, clips, and steel strands being broken and ejected to injure people, and to avoid the rebound of the primary concrete around the anchor cable after the prestress of the anchor cable is suddenly released. At the same time, it is possible to avoid the primary concrete reinforced by the anchor cable from falling off, thereby increasing the safety of the demolition process.

[0089] In one embodiment of the present application, referring to FIG5 of the specification, FIG5 is a flowchart of another specific implementation of the prestressed anchor cable removal method provided in the embodiment of the present application, with respect to step S3, after the disassembly group A is in an independent state, the prestress of the disassembly group A is released until the disassembly group A is in a relaxed state and then disassembled.

[0090] It includes: step S34, in the process of releasing the prestress of the disassembly group A, the surrounding rock monitoring is performed on the initial support layer 3 where the steel belt ring 1 is located, and the surrounding rock monitoring is used to synchronously monitor the sudden change of the initial support layer 3, and an alarm notification is issued if a sudden change occurs.

[0091] Specifically: During the entire process of steel strip cutting and anchor cable prestress release, necessary surrounding rock monitoring is carried out towards the surrounding rock of the corresponding demolition section. By increasing the monitoring measurement frequency and scanning and analyzing the deformation of the primary support section, the monitoring frequency of surrounding rock monitoring is carried out in a random manner to monitor whether there is a sudden change in the primary support structure of the surrounding rock in the deformation section. If a sudden change occurs, an alarm notification feedback is given in time to ensure personnel safety.

[0092] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for removing a prestressed anchor cable, applied to an anchor cable support structure, characterized in that: include: Step S1, selecting one of the multiple groups of anchor cable assemblies on the steel belt ring as a disassembly group, and the other anchor cable assemblies on the steel belt ring as a to-be-disassembled group; Step S2, cutting the steel belt ring until the disassembly group is separated from the steel belt ring and is in an independent state; Step S3, after the disassembly group is in an independent state, releasing the prestress of the disassembly group until the disassembly group is in a relaxed state and then disassembling it; Step S4, after the disassembly group is disassembled, determining whether there are other groups to be disassembled on the steel belt ring; Step S5: If yes, after converting one of the to-be-disassembled groups into the disassembly group, proceed to step S2.

2. The method for removing the prestressed anchor cable according to claim 1, characterized in that: Step S3, after the disassembly group is in an independent state, releasing the prestress of the disassembly group until the disassembly group is in a relaxed state and then disassembling it. The method comprises: excavating a unloading groove on the initial supporting layer corresponding to the disassembly group, the disassembly group is provided with a central axis in a direction perpendicular to the surface of the initial supporting layer, and the unloading groove is evenly opened relative to the central axis.

3. The method for removing the prestressed anchor cable according to claim 2, characterized in that: A unloading groove is excavated on the initial support layer corresponding to the disassembly group, the disassembly group is provided with a central axis in a direction perpendicular to the surface of the initial support layer, and the unloading groove is evenly opened relative to the central axis. It includes: the unloading groove is set as a trapezoidal groove, and during the groove digging process, the groove is gradually dug from the edge of the unloading groove toward the central axis direction of the disassembly group.

4. The method for removing the prestressed anchor cable according to claim 2, characterized in that: Step S1, selecting one of the multiple groups of anchor cable assemblies on the steel belt ring as a disassembly group, and selecting the other anchor cable assemblies on the steel belt ring as a to-be-disassembled group, The method comprises: selecting one group of the anchor cable assemblies located at the top arch position of the initial supporting layer as the disassembly group.

5. The method for removing the prestressed anchor cable according to claim 4, characterized in that: Step S5: If yes, after converting one of the to-be-disassembled groups into the disassembly group, proceed to step S2. The method comprises: selecting the to-be-disassembled group located at the top arch position of the initial supporting layer to be converted into the disassembly group; after the to-be-disassembled group located at the top arch position of the initial supporting layer is disassembled, selecting the to-be-disassembled group located at the side wall position of the initial supporting layer to be converted into the disassembly group.

6. The method for removing the prestressed anchor cable according to claim 5, characterized in that: The to-be-disassembled group located at the top arch position of the initial supporting layer is selected to be converted into the disassembly group. After the to-be-disassembled group located at the top arch position of the initial supporting layer is disassembled, the to-be-disassembled group located at the side wall position of the initial supporting layer is selected to be converted into the disassembly group. The method comprises: sequentially selecting the to-be-disassembled group and converting it into the disassembly group along the direction from the top arch position to the side wall position.

7. The method for removing the prestressed anchor cable according to claim 1, characterized in that: Step S2, cutting the steel belt ring until the disassembly group is separated from the steel belt ring and is in an independent state, The method comprises: cutting the corresponding position of the end of the anchor cable assembly on the steel belt ring until the anchor cable assembly is separated from the steel belt ring.

8. The method for removing the prestressed anchor cable according to claim 1, characterized in that: Step S3, after the disassembly group is in an independent state, releasing the prestress of the disassembly group until the disassembly group is in a relaxed state and then disassembling it. The method comprises: after the steel strands in the disassembly group are completely loosened, firstly removing the anchor pad and the anchor of the anchor cable assembly, and then cutting off the steel strands one by one.

9. The method for removing the prestressed anchor cable according to claim 1, characterized in that: Step S2: before cutting the steel belt ring until the disassembly group is separated from the steel belt ring and is in an independent state, The method also includes: wrapping the anchors in the disassembly group with a protective cover.

10. The method for removing the prestressed anchor cable according to claim 1, characterized in that: Step S3, after the disassembly group is in an independent state, releasing the prestress of the disassembly group until the disassembly group is in a relaxed state and then disassembling it. It includes: in the process of releasing the prestress of the disassembly group, the surrounding rock monitoring of the initial support layer where the steel belt ring is located is performed, and the surrounding rock monitoring is used to synchronously monitor the sudden change of the initial support layer, and an alarm notification is issued if the sudden change occurs.

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