Pipe and cable combined type tension and compression mixed type anchoring system and construction method

Abstract

The invention relates to the technical field of anchoring, in particular to a pipe and cable combined type tension-compression mixed type anchoring system and a construction method. The pipe and cable combined type tension and compression mixed type anchoring system comprises an anchor cable, a hollow anchor rod is arranged on the outer side of the anchor cable in a sleeving mode, and the hollow anchor rod and the anchor cable are arranged at intervals. And the middle partition bearing structure is connected to the outer side of the hollow anchor rod in a sleeving manner. According to the pipe and cable combined type tension-compression mixed type anchoring system, the anchor cable and the hollow anchor rod can be cooperatively stressed and jointly provide uplift bearing capacity, the stress mode of the anchoring section is changed at the middle partition bearing structure, the anchoring section is stressed in a dispersed mode, the axial force of the hollow anchor rod and the anchor cable is reduced, and the tensile strength of the hollow anchor rod and the anchor cable is improved. The stress peak value of the contact surface of the grouting body and the hollow anchor rod and the stress peak value of the contact surface of the grouting body and the hole wall of the anchor hole are reduced, so that stress is more dispersed and uniform, the utilization rate of the bearing performance of the anchoring section of the grouting body is increased, and the ultimate bearing capacity of the pipe and cable combined type tension-compression mixed type anchoring system is improved.

Description

Technical Field

[0001] This invention relates to the field of anchoring technology, and in particular to a pipe-cable composite tension-compression hybrid anchoring system and its construction method. Background Technology

[0002] Load-concentrated anchoring systems are further divided into tension anchors and compression prestressed anchors based on the different stress forms.

[0003] Tension-type anchors have a simple structure and easy construction process, but stress concentration is prone to occur in the anchoring section, while the tensile strength of the grout is poor, and the rod body is easily affected by corrosive substances in the soil and rock, thus affecting its durability. Tension-type anchors mainly consist of three parts: the anchor rod, the grout body, and the anchor. There is no anchor at the end of the anchoring section, and its pull-out bearing capacity is mainly provided by the bonding effect between the two contact interfaces: the anchor rod body and the grout body, and the grout body and the soil and rock. The sliding force is transmitted to the grout body through the bonding interface, and then finally to the soil and rock through the grout-rock interface. Both the rod body and the grout body are subjected to tension, and the tensile stress tends to concentrate at the end of the anchoring section, that is, near the interface with the free section. The tensile strength of the grout body is low, and it is prone to tensile-shear failure under the pull-out action of the anchor rod.

[0004] Compared to tension anchors, pressure-type prestressed anchors have a more rational stress distribution. The grout mainly bears compressive stress, and the grout material typically has good compressive strength. The structure of pressure-type prestressed anchors differs from tension anchors in that a bearing plate is placed at the end of the anchorage section, and the anchor is anchored to the bearing plate. The sliding force is transmitted through the anchor to the bearing plate and the grout, and then to the rock mass through the bonding effect at the rock-grout interface. Although both transmit force indirectly through the grout, the anchor load is transmitted to the grout through the bearing plate, causing it to be compressed. Since the grout has better compressive strength, the pull-out bearing capacity of pressure-type prestressed anchors of the same specifications and under the same operating conditions is greater than that of tension anchors. The casing isolates the anchor from the grout to prevent bonding (or uses unbonded steel strands) and protects the anchor from corrosion by the external environment.

[0005] Both tension-type anchor bolts and compression-type prestressed anchor cables exhibit stress concentration and are unable to withstand large loads. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem that both tension-type anchor rods and compression-type prestressed anchor cables in the prior art suffer from stress concentration and cannot bear large loads, and to provide a pipe-cable composite tension-compression hybrid anchoring system and construction method.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A composite cable-tube tension-compression hybrid anchoring system includes: an anchor cable; a hollow anchor rod, sleeved on the outside of the anchor cable and spaced apart from the anchor cable; a load-bearing structure sleeved and connected to the outside of the hollow anchor rod; and a grouting body: the grouting body is sleeved on the outside of the hollow anchor rod, and at least a portion of the load-bearing structure is located within the grouting body; along the length direction of the hollow anchor rod, the portion of the grouting body located on one side of the load-bearing structure is in close contact with the outer wall of the hollow anchor rod, and the portion of the grouting body located on the other side of the load-bearing structure is spaced apart from the outer wall of the hollow anchor rod.

[0008] This application describes a composite tension-compression hybrid anchoring system using tubular cables. A hollow anchor rod is externally connected to a grouting body, and the hollow anchor rod is fitted onto the outside of the anchor cable. This allows the pull-out force acting on the structure to be distributed between the anchor cable and the hollow anchor rod, achieving a synergistic load-bearing effect. Furthermore, to make the stress distribution at the grouting body-soil interface more uniform, a connecting load-bearing structure is fitted onto the outside of the hollow anchor rod. This load-bearing structure divides the grouting body into two sections, changing the stress distribution of the section near the free section from tension to compression. This alters the stress system of the grouting body located on one side of the load-bearing structure, resulting in a more uniform stress distribution in the composite tension-compression hybrid anchoring system. Moreover, by controlling the position of the load-bearing structure within the anchoring section, a more rational load distribution of the grouting body can be achieved, enabling it to withstand greater loads.

[0009] Preferably, the intermediate support structure is provided with a flow hole extending along the length of the hollow anchor rod. During grouting, the flow hole allows grout to pass through the intermediate support structure, so that grout can be injected into both sides of the intermediate support structure along the length of the hollow anchor rod to form a grout body.

[0010] Preferably, the intermediate load-bearing structure is welded to the outside of the hollow anchor rod.

[0011] Preferably, one end of the hollow anchor rod is connected to an anchor rod anchorage for anchoring the hollow anchor rod; an anchor cable passes through the hollow anchor rod, and a bearing component is connected to the end of the anchor cable away from the anchor rod anchorage, while a first anchor cable anchorage for anchoring the anchor cable is connected to the end of the anchor cable near the anchor rod anchorage; both the bearing component and the first anchor cable anchorage are located outside the end of the hollow anchor rod, and the anchor rod anchorage is located inside the first anchor cable anchorage; along the length direction of the hollow anchor rod, the anchor rod anchorage and the first anchor cable anchorage do not interfere with each other, the bearing component is spaced apart from the hollow anchor rod, and the bearing component abuts against the grouting body; along the radial direction of the hollow anchor rod, the outer diameter of the bearing component is larger than the outer diameter of the hollow anchor rod. This application discloses a cable-and-tube composite tension-compression hybrid anchoring system. A hollow anchor rod is externally connected to a grouting body, and the hollow anchor rod is fitted over the anchor cable. This allows the pull-out force acting on the structure to be distributed between the anchor cable and the hollow anchor rod, achieving a synergistic load-bearing effect. Furthermore, to further distribute the stress at the grouting body-soil interface, a connecting load-bearing structure is fitted over the hollow anchor rod. This load-bearing structure divides the grouting body into two sections, causing the section near the free section to change from tension to compression. This forms a three-section load-bearing structure: the first section is a tension-compression hybrid type, and the second section is a compression type. This results in a more uniform stress distribution in the cable-and-tube composite tension-compression hybrid anchoring system. Moreover, by controlling the position of the load-bearing structure within the anchoring section, a more rational distribution of the grouting body's load can be achieved, enabling the system to withstand greater loads.

[0012] This application proposes a composite tension-compression hybrid anchoring system using tubular cables. A hollow anchor rod is sleeved on the outside of the anchor cable. The load-bearing component abuts against the grouting body, and the grouting body is closely connected to a portion of the outer wall of the hollow anchor rod. This allows the pull-out force acting on the composite tension-compression hybrid anchoring system to be distributed between the anchor cable and the hollow anchor rod, achieving a synergistic load-bearing effect. A load-bearing component (generally a plate) is installed at the end of the grouting body to anchor the anchor cable, but not the hollow anchor rod. Under the action of the sliding force, the anchor cable and the load-bearing component at the end of the anchoring section form a pressure-type prestressed anchor cable, while the hollow anchor rod and the grouting body separately form a tension-type anchoring system. To ensure a more uniform and even distribution of stress at the grout-soil interface, a central bearing structure is connected to the outside of the hollow anchor rod. This central bearing structure divides the grout into two sections, causing the section near the free section to change from tension to compression. This forms a three-section stress structure system: the first section of the grout (the part between the bearing component and the central bearing structure) is under a combined tension-compression stress, and the second section (the part between the central bearing structure and the anchor rod) is under a compression stress. This novel structure results in a more uniform stress distribution. Furthermore, the tubular cable composite tension-compression hybrid anchoring system described in this application, due to the presence of the central bearing structure, allows for a more rational distribution of the grout's load-bearing capacity by controlling its position within the grout, thus enabling it to withstand greater loads.

[0013] In the above scheme, due to the setting of the intermediate load-bearing structure, the grouting body is located in the part of the load-bearing component and the intermediate load-bearing structure. It bears both the extrusion force from the end of the load-bearing component and the tensile force of the corresponding part of the hollow anchor rod, thus forming a tensile-compressive composite force system.

[0014] In the above scheme, since the anchor cable passes through the hollow anchor rod, the anchor rod anchorage and the first anchor cable anchorage do not interfere with each other along the length direction of the hollow anchor rod, and the bearing component is spaced apart from the hollow anchor rod. Therefore, during anchoring, the hollow anchor rod and the anchor cable can be anchored separately without affecting each other, and the construction operation is simple. Under the action of sliding force, the component of the sliding force acting on the pipe-cable composite tension-compression hybrid anchoring system along the length direction of the hollow anchor rod is jointly borne by the hollow anchor rod and the anchor cable. The hollow anchor rod and the anchor cable cooperate in bearing the force, thereby effectively improving the overall ultimate bearing capacity of the anchoring system.

[0015] Preferably, the intermediate bearing structure includes a pressure plate and an isolation pipe connected to each other. The isolation pipe is disposed on the side of the pressure plate near the anchor bolt. The isolation pipe is spaced out on the outside of the hollow anchor bolt. The portion of the grouting body located between the pressure plate and the anchor bolt is in close contact with the outer wall of the isolation pipe. Through the above scheme, the grouting body is divided into two sections by a pressure plate, and the portion of the grouting body located between the pressure plate and the anchor rod is bonded to the outer wall of the isolation pipe. This separates the portion of the grouting body between the pressure plate and the anchor rod from the hollow anchor rod. Only the portion of the grouting body between the bearing component and the pressure plate is bonded to a portion of the outer wall of the hollow anchor rod. This effectively changes the stress system of the grouting body near the free section from tension to compression, thereby altering the stress distribution of the portion of the grouting body located on one side of the intermediate bearing structure. This makes the stress distribution of the pipe-cable composite tension-compression hybrid anchoring system of this application more even and uniform. Furthermore, by controlling the position of the intermediate bearing structure in the anchoring section, a more reasonable load distribution of the grouting body can be achieved, enabling it to withstand greater loads.

[0016] Preferably, the pressure plate is threadedly connected to the hollow anchor rod, thereby enabling the position of the pressure plate on the hollow anchor rod to be adjusted as needed; thus making the tubular cable composite tension-compression hybrid anchoring system described in this application more widely applicable.

[0017] Preferably, the pressure plate and the isolation pipe are threaded together, which facilitates installation and disassembly, and allows for the selection of isolation pipes of different lengths based on the position of the pressure plate on the hollow anchor rod, resulting in lower costs.

[0018] Preferably, the pipe-cable composite tension-compression hybrid anchoring system described in this application further includes a rock and soil mass with anchor holes formed on the rock and soil mass, and the grouting body is located in the anchor holes.

[0019] This application also discloses a construction method for the pipe-cable composite tension-compression hybrid anchoring system described in this application, comprising the following steps: A1. Opening anchor holes in the rock and soil; A2. Placing at least a portion of the pipe-cable composite tension-compression hybrid anchoring system into the anchor holes; A3. Injecting grout into the anchor holes to form the grout body; A4. Applying prestress to the anchor cable.

[0020] The construction method described in this application is used to construct a composite tension-compression anchoring system of pipe and cable. Prestress is applied to the anchor cable, and the hollow anchor rod and anchor cable deform in coordination to jointly provide pull-out bearing capacity. This transforms the single-stress state of the load-concentrated anchoring structure into a composite tension-compression stress mode, improving the utilization rate of the grouting body's bearing capacity, thereby increasing the ultimate bearing capacity of the composite tension-compression anchoring system of pipe and cable.

[0021] Preferably, the construction method for the pipe-cable composite tension-compression hybrid anchoring system of this application further includes a design method for the stress distribution uniformity of the pipe-cable composite tension-compression hybrid anchoring system, comprising the following steps: S1. Determining the basic dimensions of the pipe-cable composite tension-compression hybrid anchoring system; S2. Obtaining the standard deviation parameter and mean parameter of the shear stress at the grout-soil interface of the pipe-cable composite tension-compression hybrid anchoring system; S3. Obtaining the coefficient of variation of the shear stress at the grout-soil interface based on the standard deviation parameter and the mean parameter, and comparing the coefficient of variation with the critical coefficient of variation. If the coefficient of variation is greater than the critical coefficient of variation, the position of the intermediate bearing structure of the pipe-cable composite tension-compression hybrid anchoring system in the grout in step S1 is adjusted, and steps S2 and S3 are repeated until the coefficient of variation is less than or equal to the critical coefficient of variation, thereby obtaining the final dimensions of the pipe-cable composite tension-compression hybrid anchoring system. The construction method for the cable-tube composite tension-compression hybrid anchoring system described in this application establishes a reasonable standard for the dimensional design of the cable-tube composite tension-compression hybrid anchoring system by setting a coefficient of variation, thereby effectively guiding the design of a more optimized structural dimension of the cable-tube composite tension-compression hybrid anchoring system.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: The tubular cable composite tension-compression hybrid anchoring system of the present invention has a hollow anchor rod with a grouting body externally formed and connected. The hollow anchor rod is sleeved on the outside of the anchor cable, which can distribute the pull-out force acting on the structure to both the anchor cable and the hollow anchor rod, achieving a synergistic bearing effect. In addition, in order to make the stress at the grouting body-soil interface more evenly distributed, a connecting load-bearing structure is sleeved on the outside of the hollow anchor rod. The load-bearing structure divides the grouting body into two sections, so that the section of the grouting body near the free section changes from tension to compression, thereby changing the stress system of the part of the grouting body located on one side of the load-bearing structure, making the stress of the tubular cable composite tension-compression hybrid anchoring system more even. Moreover, by controlling the position of the load-bearing structure in the anchoring section, a more reasonable load distribution of the grouting body can be achieved, enabling it to withstand greater loads. Attached Figure Description

[0023] Figure 1 This is a longitudinal cross-sectional schematic diagram of a tube-cable composite tension-compression hybrid anchoring system according to the present invention.

[0024] Figure 2 This is a schematic diagram of the pressure plate of the present invention.

[0025] Figure 3 This is a schematic longitudinal section of the central support structure of the present invention.

[0026] Figure 4 A schematic diagram of a flexible spacer structure between the load-bearing component and the hollow anchor rod of the present invention.

[0027] Figure 5 This is a schematic diagram showing the relative positions between the first anchor cable anchor and the anchor rod anchor of the present invention.

[0028] Figure 6 This is a three-dimensional schematic diagram of the clip structure of the present invention.

[0029] Figure 7 This is a three-dimensional 1 / 4 cross-sectional view of the tensioning end of the cable-tube composite tension-compression hybrid anchoring system of the present invention.

[0030] Figure 8 This is a three-dimensional structural schematic diagram of the anchor plate of the present invention; Figure 8 a is a three-dimensional structural schematic diagram of the anchor plate of the present invention (annular sidewall). Figure 8 b is a three-dimensional structural schematic diagram of the anchor plate of the present invention (with legs arranged in a ring).

[0031] Figure 9 This is a three-dimensional schematic diagram of the tubular cable composite tension-compression hybrid anchoring system of the present invention; Figure 9 a is a three-dimensional schematic diagram (one direction) of the tubular cable composite tension-compression hybrid anchoring system of the present invention. Figure 9 b is a three-dimensional schematic diagram (from another direction) of the tubular cable composite tension-compression hybrid anchoring system of the present invention.

[0032] Figure 10 This is a longitudinal sectional view of the anchor plate structure of the present invention.

[0033] Figure 11 This is a schematic diagram of the sleeve position according to the present invention.

[0034] Figure 12 This is a longitudinal cross-sectional schematic diagram of the cable-tube composite tension-compression hybrid anchoring system of the present invention in conjunction with the reinforced surface structure and the support structure.

[0035] Figure 13 This is a schematic diagram of the combination of the multiple tube-cable composite tension-compression hybrid anchoring system of the present invention with the reinforced surface structure.

[0036] Figure 14 Here are simplified diagrams of the three anchoring system structures of the present invention; Figure 14 a is a simplified diagram of a tension-type anchorage system; Figure 14 b is a simplified diagram of a pressure-type anchorage system; Figure 14 c is a simplified structural diagram of the pipe-cable composite tension-compression hybrid anchoring system of the present invention.

[0037] Figure 15 Dimensions of a tension-type anchoring system model (T-7 m).

[0038] Figure 16 The model dimensions of the cable-tube composite tension-compression hybrid anchoring system of the present invention are shown in the table (CTC-7 m).

[0039] Figure 17 Dimensions of the pressure-type anchoring system model (C-7 m).

[0040] Figure 18 This is a table of material parameters for each component in the numerical model of this invention.

[0041] Figure 19 This is a parameter table for the contact model of the two interfaces of the present invention.

[0042] Figure 20 This is a comparison diagram of the shear stress distribution law at the grout-soil interface of the present invention; Figure 20 a is a comparison diagram of the shear stress distribution at the grout-soil interface between the CTC21-7m model and the T-7m model; Figure 20 b is a comparison diagram of the shear stress distribution at the grout-soil interface between the CTC21-7 m model and the C-7 m model; Figure 20 c is a comparison diagram of the shear stress distribution at the grout-soil interface between the CTC31-7 m model and the T-7 m model; Figure 20 d is a comparison diagram of the shear stress distribution at the grout-soil interface between the CTC31-7m model and the C-7m model.

[0043] Figure 21 This is a comparison diagram showing the uniformity of shear stress distribution at the grout-soil interface of the present invention.

[0044] Figure 22 This is a table of characteristic values ​​of shear stress distribution at the grout-soil interface for each model in this invention.

[0045] Figure 23 These are comparative diagrams of the axial stress of the hollow anchor rod of the present invention; Figure 23 a represents the axial stress of the hollow anchor rod in the CTC21-7 m model of this invention; Figure 23 b represents the axial stress of the hollow anchor rod in the CTC31-7m model of this invention.

[0046] Figure 24 This is a comparison diagram of the shear stress distribution at the interface between the grouting body and the hollow anchor bolt of the present invention; Figure 24 a is a diagram showing the shear stress distribution at the grout-hollow anchor interface in the CTC21-7 m model of this invention; Figure 24 b is a diagram showing the shear stress distribution at the grout-hollow anchor interface in the CTC31-7m model of this invention.

[0047] The diagram is labeled as follows: 1-Hollow anchor bolt, 2-Anchor cable, 3-First anchor cable anchorage, 30-Anchor plate, 31-Groove, 32-Anchor cable anchoring structure, 33-Anchor hole, 34-Wedge, 35-Groove bottom, 36-Side wall, 37-Through hole, 38-Conical hole, 4-Anchor bolt anchorage, 5-Bearing component, 51-Bearing structure, 52-Second anchor cable anchorage, 53-Through hole, 6-Flexible structure, 7-Grouting body, 8-Anchor hole, 9-Reinforced surface structure, 10-Soil and rock mass, 11-Support structure, 12-Sleeve, 13-Pipe-cable composite tension-compression hybrid anchoring system, 14-Anchorage; 15-Intermediate bearing structure; 151-Pressure plate; 152-Isolation pipe; 16-Flow hole. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0049] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of this invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on this invention. Furthermore, the use of terms such as "horizontal," "vertical," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have deviations. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention. Furthermore, the use of terms such as "first," "second," "third," etc., in the terminology is merely for distinguishing descriptions of identical or similar components and should not be construed as emphasizing or implying the relative importance of a specific component. Additionally, in the description of the embodiments of the present invention, "several," "multiple," or "several" represent at least two. It can be any number of two, three, four, five, six, seven, eight, nine, or even more than nine. Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0050] Example like Figure 1As shown, this embodiment of a pipe-cable composite tension-compression hybrid anchoring system includes an anchor cable 2, a hollow anchor rod 1, and a central load-bearing structure 15, wherein: the hollow anchor rod 1 is sleeved on the outside of the anchor cable 2 and is spaced apart from the anchor cable 2; the central load-bearing structure 15 is sleeved and connected to the outside of the hollow anchor rod 1.

[0051] Furthermore, it also includes a grouting body 7, with at least a portion of the intermediate bearing structure 15 located within the grouting body 7; along the length of the hollow anchor rod 1, the portion of the grouting body 7 located on one side of the intermediate bearing structure 15 is bonded to the outer wall of the hollow anchor rod 1, while the portion of the grouting body 7 located on the other side of the intermediate bearing structure 15 is spaced apart from the outer wall of the hollow anchor rod 1. In the above scheme, along the length of the hollow anchor rod 1, the intermediate bearing structure 15 divides the grouting body 7 into two segments, one segment of the grouting body 7 near the root being bonded to the outer wall of the hollow anchor rod 1, and the other segment of the grouting body 7 being spaced apart from the outer wall of the hollow anchor rod 1.

[0052] This embodiment of a pipe-cable composite tension-compression hybrid anchoring system allows the anchor cable 2 and the hollow anchor rod 1 to work together to provide pull-out bearing capacity. The stress pattern of the anchoring section changes at the intermediate bearing structure 15, distributing the force across the anchoring section. This not only reduces the axial force on the hollow anchor rod 1 and the anchor cable 2, but also reduces the peak stress at the contact surfaces between the grout and the hollow anchor rod 1, and between the grout and the anchor hole wall. This improves the utilization rate of the bearing capacity of the grout anchoring section, thereby increasing the ultimate bearing capacity of the pipe-cable composite tension-compression hybrid anchoring system of this application. Furthermore, this embodiment of the pipe-cable composite tension-compression hybrid anchoring system also includes an independently anchorable anchor rod system and an anchor cable system. The anchor rod system includes the hollow anchor rod 1, and the anchor cable system includes the anchor cable 2. The hollow anchor rod 1 and the anchor cable 2 are independently anchored.

[0053] like Figure 5 As shown, in a preferred embodiment, one end of the hollow anchor rod 1 is connected to an anchor rod anchorage 4 for anchoring the hollow anchor rod 1; the anchor cable 2 passes through the hollow anchor rod 1, and the end of the anchor cable 2 away from the anchor rod anchorage 4 is connected to a bearing component 5, while the end of the anchor cable 2 near the anchor rod anchorage 4 is connected to a first anchor cable anchorage 3 for anchoring the anchor cable 2; the bearing component 5 is located at one end of the hollow anchor rod 1, and the first anchor cable anchorage 3 is located at the other end of the hollow anchor rod 1.

[0054] This embodiment presents a composite tension-compression hybrid anchoring system using tubular cables. The anchor bolt anchoring system and the anchor cable anchoring system are relatively independent, meaning they can be independently anchored during installation. A further preferred embodiment: the anchor bolt anchoring system and the anchor cable anchoring system are relatively independent in spatial position, and also relatively independent in spatial position during installation and anchoring.

[0055] This application discloses a composite tension-compression hybrid anchoring system, comprising a hollow anchor rod 1, an anchor cable 2, a first anchor cable anchor 3, and an anchor rod anchor 4. The anchor cable 2 passes through the interior of the hollow anchor rod 1. A bearing component 5 is located at one end of the hollow anchor rod 1, and the first anchor cable anchor 3 is located at the other end of the hollow anchor rod 1. Since the anchor rod anchoring system and the anchor cable anchoring system can be anchored independently during installation, the anchor rod anchor 4 and the first anchor cable anchor 3 are installed at the ends to separate and anchor the hollow anchor rod 1 and the anchor cable 2, without affecting each other. The component of the downward force acting on the composite tension-compression hybrid anchoring system along the length of the hollow anchor rod 1 is jointly borne by the hollow anchor rod 1 and the anchor cable 2. Because this composite tension-compression hybrid anchoring system includes an anchor rod anchoring system and an anchor cable anchoring system that can be anchored independently, the anchor rod anchoring system and the anchor cable anchoring system can be anchored independently during construction, while cooperating in resisting the downward force. Furthermore, in certain situations, the cable-tube composite tension-compression hybrid anchoring system of this application, under the action of sliding force, forms a pressure-type prestressed anchoring system with the anchor cable 2, the bearing component 5, and the first anchor cable anchor 3, while the hollow anchor rod 1 and the anchor rod anchor 4 separately form a tension-type anchoring system. This results in the grouting body 7 on the outer side of the hollow anchor rod 1 being compressed at the end and stretched at the end, achieving the effect of dispersing the force on the anchoring section and fully utilizing the interfacial bonding force. Moreover, under the action of sliding force, the hollow anchor rod 1 and the anchor cable 2 deform in coordination, jointly providing pull-out bearing capacity. Compared to tension-type or compression-type anchoring systems, this method transforms the single-force mode of the load-concentrated anchoring structure into a combined tension-compression force mode in the anchoring section. This disperses the force in the anchoring section, reducing not only the axial force of the hollow anchor rod 1 and the anchor cable 2, but also, in particular, the stress peak values ​​at the contact surfaces between the grouting body 7 and the hollow anchor rod 1, and between the grouting body 7 and the wall of the anchor hole 8. This improves the utilization rate of the bearing capacity of the grouting body anchoring section, thereby increasing the ultimate bearing capacity of the pipe-cable combined tension-compression hybrid anchoring system of this application.

[0056] In certain construction conditions, the hollow anchor rod 1 is first anchored by the anchor rod anchor 4, and then the anchor cable 2 is anchored by the first anchor cable anchor 3, with prestress applied to the anchor cable 2. In this case, two situations may occur: Situation 1: In certain construction conditions, after applying prestress to the anchor cable 2, the anchor rod anchor 4 remains in a state of mutual stress with the soil or reinforced surface structure 9. In this case, during later use, the soil or reinforced surface structure 9 exerts a sliding force on the anchor rod anchor 4 and the first anchor cable anchor 3. Under the action of this sliding force, the hollow anchor rod 1 and the anchor cable 2 jointly provide pull-out bearing capacity, transforming the pipe-cable composite tension-compression hybrid anchoring system of this application from a single-stress state of a load-concentrated anchoring structure to a tension-compression composite stress mode, improving the utilization rate of the grouting body's bearing capacity, thereby improving the ultimate bearing capacity of the pipe-cable composite tension-compression hybrid anchoring system; Situation 2: In In certain construction conditions, after prestressing is applied to the anchor cable 2, the anchor rod and anchor 4 need to undergo a certain displacement or deformation before they can be in a mutually stressed state. During later use, the rock and soil or reinforced surface structure 9 first applies a sliding force to the first anchor cable and anchor 3. Under the pull-out load, the anchor cable 2 first acts as the main load-bearing component. After the first anchor cable and anchor 3 undergoes a certain displacement or deformation, the rock and soil or reinforced surface structure 9 applies a sliding force to the anchor rod and anchor 4 and the first anchor cable and anchor 3. Under the action of the sliding force, the hollow anchor rod 1 and the anchor cable 2 jointly provide pull-out bearing capacity, so that the pipe-cable composite tension-compression hybrid anchoring system changes from a single force state of a load-concentrated anchoring structure to a tension-compression composite force mode, which improves the utilization rate of the bearing capacity of the grouting body, thereby improving the ultimate bearing capacity of the pipe-cable composite tension-compression hybrid anchoring system.

[0057] In a preferred embodiment, the anchor bolt 4 is located inside the first anchor cable 3 along the length of the hollow anchor bolt 1.

[0058] like Figure 3 As shown, in a preferred embodiment, the intermediate load-bearing structure 15 includes a pressure plate 151 and an isolation pipe 152 connected to each other. The isolation pipe 152 is disposed on the side of the pressure plate 151 near the anchor bolt 4. The isolation pipe 152 is spaced out on the outside of the hollow anchor bolt 1. The portion of the grouting body 7 located between the pressure plate 151 and the anchor bolt 4 is in close contact with the outer wall of the isolation pipe 152.

[0059] Through the above scheme, the grouting body 7 is divided into two sections by the bearing plate 151, and the part of the grouting body 7 located between the bearing plate 151 and the anchor bolt 4 is attached to the outer wall of the isolation pipe 152. This separates the part of the grouting body 7 located between the bearing plate 151 and the anchor bolt 4 from the hollow anchor bolt 1. Only the part of the grouting body 7 located between the bearing component 5 and the bearing plate 151 is attached to a part of the outer wall of the hollow anchor bolt 1. This effectively changes the tension of the section of the grouting body 7 near the free section from tension to compression, thereby changing the force system of the part of the grouting body 7 located on one side of the intermediate bearing structure 15. This makes the force distribution of the pipe-cable composite tension-compression hybrid anchoring system of this application more even. Moreover, by controlling the position of the intermediate bearing structure 15 in the anchoring section, a more reasonable distribution of the grouting body load can be achieved, enabling it to withstand greater loads.

[0060] like Figure 2 As shown, in a preferred embodiment, the pressure plate 151 is provided with a flow hole 16 extending through the hollow anchor rod 1 along its length.

[0061] In a preferred embodiment, the pressure plate 151 is a plate structure. More preferably, the pressure plate 151 is threadedly connected to the hollow anchor rod 1, thereby allowing the position of the pressure plate 151 on the hollow anchor rod 1 to be adjusted as needed; thus broadening the applicability of the tubular cable composite tension-compression hybrid anchoring system of this application.

[0062] More preferably, the pressure plate 151 and the isolation pipe 152 are threaded together, facilitating installation and disassembly. Furthermore, the length of the isolation pipe 152 can be selected based on the position of the pressure plate 151 on the hollow anchor rod 1, resulting in lower costs. Preferably, the pressure plate 151 is welded or threaded to the outside of the hollow anchor rod 1. The isolation pipe 152 is spaced apart from the hollow anchor rod 1. Preferably, the pressure plate 151 is made of steel, and the isolation pipe 152 is preferably made of PVC, PP, or PE material. Preferably, the distance between one side of the pressure plate 151 and the anchor hole 8 is 1cm-2cm. Pressure grouting is preferred during grouting, where the grout rises from the depth until it overflows.

[0063] In a preferred embodiment, there is a gap between the first anchor cable anchor and the anchor rod anchor, thereby achieving the goal of ensuring that the anchor rod anchor 4 and the first anchor cable anchor 3 do not interfere with or affect each other along the length direction of the hollow anchor rod 1. More preferably, the gap A1+A2 between the first anchor cable anchor 3 and the anchor rod anchor 4 along the length direction of the hollow anchor rod 1 is ≥ 5cm.

[0064] This embodiment of a tube-cable composite tension-compression hybrid anchoring system includes a hollow anchor rod 1 and an anchor cable 2. The anchor cable 2 passes through the hollow anchor rod 1. Along the length of the hollow anchor rod 1, the hollow anchor rod 1 and the anchor cable 2 can be anchored separately without interfering with each other.

[0065] One end of the anchor cable 2 is connected to the bearing component 5, and the other end of the anchor cable 2 is connected to the first anchor cable anchor 3. The first anchor cable anchor 3 is used to anchor the anchor cable 2. The hollow anchor rod 1 is connected to the anchor rod anchor 4 at the end near the first anchor cable anchor 3. The anchor rod anchor 4 is used to anchor the hollow anchor rod 1. The first anchor cable anchor 3 and the anchor rod anchor 4 do not interfere with each other along the length direction of the hollow anchor rod 1.

[0066] The tubular cable composite tension-compression hybrid anchoring system of this embodiment includes a hollow anchor rod 1, an anchor cable 2, a first anchor cable anchorage 3, and an anchor rod anchorage 4. The anchor cable 2 passes inside the hollow anchor rod 1, and the anchor rod anchorage 4 and the first anchor cable anchorage 3 are set at the anchorage 14 to anchor the hollow anchor rod 1 and the anchor cable 2 separately. The pull-out force acting on the tubular cable composite tension-compression hybrid anchoring system is distributed to the hollow anchor rod 1 and the anchor cable 2 to be borne by both, achieving the effect of synchronous force on both but without interference. Moreover, a bearing component 5 is set at the end of the grouting body 7 to anchor the anchor cable 2, but not the hollow anchor rod 1. In use, the hollow anchor rod 1 is grouted to form a grout body 7 on the outside. The bearing component 5 pushes against (extrudes) the grout body 7. Under the action of the sliding force, the anchor cable 2, the bearing component 5 and the grout body 7 form a pressure-type prestressed anchor cable. The hollow anchor rod 1 and the grout body 7 also form a tension-type anchoring system, so that the end of the grout body 7 is compressed and the end is tensile, which achieves the effect of dispersing the force of the anchoring section and giving full play to the interface bonding force.

[0067] The first anchor cable anchor 3 and the anchor rod anchor 4 do not interfere with each other along the length of the hollow anchor rod 1, meaning that the first anchor cable anchor 3 and the anchor rod anchor 4 can move freely relative to each other along the length of the anchor cable 2. The first anchor cable anchor 3 is located at the tension end of the anchor cable 2, and the bearing component 5 is located at the fixed end of the anchor cable 2. The anchor cable 2 passes through the hollow anchor rod 1, meaning that the hollow anchor rod 1 is fitted onto the outside of the anchor cable 2.

[0068] In a preferred embodiment, a gap exists between the first anchor cable anchor 3 and the anchor rod anchor 4. Further, the first anchor cable anchor 3 and the anchor rod anchor 4 are spaced apart. More preferably, the first anchor cable anchor 3 is provided with a groove 31, and at least a portion of the anchor rod anchor 4 is located within the groove 31. Further, the entire anchor rod anchor 4 is located within the groove 31.

[0069] like Figure 5 and 7 As shown, a preferred embodiment of the first anchor cable anchor 3 is as follows: the first anchor cable anchor 3 includes an anchor plate 30 and an anchor cable anchoring structure 32. A groove 31 is provided on the anchor plate 30, and an anchoring hole 33 is provided at the bottom 35 of the groove 31. The end of the anchor cable 2 passes through the anchoring hole 33 and can be anchored by the anchor cable anchoring structure 32.

[0070] In a specific preferred embodiment, the end of the anchor cable 2 passes through the anchoring hole 33 and is anchored by the anchor cable anchoring structure 32, including at least the following two specific cases: Method 1: The end of the anchor cable 2 passes through the anchoring hole 33 and is anchored by the anchor cable anchoring structure 32. In this case, the anchor cable anchoring structure 32 is preferably a wedge-type anchor. Method 2: As... Figure 6 and 7 As shown, the end of the anchor cable 2 passes through the anchor hole 33. The anchor cable 2 is anchored together by the anchor cable anchoring structure 32 and the anchor plate 30. At this time, the anchor cable anchoring structure 32 preferably includes at least two clamps 34. All clamps 34 are arranged circumferentially and clamp the anchor cable 2 together. The clamps 34 and the anchor hole 33 can be matched and limited along the axial direction of the anchor hole 33. The clamps 34 can be selected from the clamps 34 used in the existing clamp type anchors. The anchoring form at this position is the same as that of the existing clamp type anchors.

[0071] In a preferred embodiment, the outer surface of the anchor cable anchoring structure 32 is tapered, and at least one section of the anchoring hole 33 is a tapered hole 38, for example... Figure 10 As shown, the anchoring hole 33 includes a through hole 37 and a conical hole 38 that are connected. The through hole 37 is located between the groove 31 and the conical hole 38. The large end of the conical hole 38 faces away from the through hole 37. The conical hole 38 and the outer side of the anchor cable anchoring structure 32 are matched to limit each other, so as to achieve the purpose of limiting the wedge 34 and the anchoring hole 33 along the axial direction of the anchoring hole 33.

[0072] like Figure 8 As shown in Figure a, the sidewall 36 of the groove 31 can be a continuous annular shape. Alternatively, it can be as follows: Figure 8 As shown in b, the sidewall 36 includes at least two circumferentially arranged legs, all of which form a groove 31.

[0073] In a preferred embodiment, the bottom of the groove 31 is provided with at least two anchoring holes 33, and all anchoring holes 33 are provided with anchor cables 2 for at least two anchor cables 2 to pass through the anchor plate 30.

[0074] The following is a detailed introduction to load-bearing component 5: (e.g.) Figure 1 As shown, in a specific preferred embodiment, the outer diameter D1 of the bearing component 5 along the radial direction of the hollow anchor rod 1 is greater than the outer diameter D3 of the hollow anchor rod 1, so that the outer side of the hollow anchor rod 1 is grouted to form a grouting body 7. In use, the bearing component 5 can push against the grouting body 7, and the bearing component 5 and the end of the grouting body 7 can be mutually stressed.

[0075] like Figure 4As shown, in a preferred embodiment, the bearing component 5 includes a bearing structure 51 and a second anchor 52. The second anchor 52 is located on the side of the bearing structure 51 away from the first anchor 3, and the second anchor 52 can compress the bearing structure 51 along the length of the hollow anchor rod 1. The bearing structure 51 is provided with a through hole 53, and the end of the anchor cable 2 away from the first anchor 3 passes through the through hole 53 and is anchored through the second anchor 52. The second anchor 52 is preferably a compression anchor or a wedge anchor. When the second anchor cable anchor 52 is preferably a compression anchor [end anchor]: the compression anchor includes a compression anchor ring and a compression spring installed in its cavity, for example, models YMP15-N and YMP13-N, where 15: represents the steel strand specification of 15.24 mm nominal diameter steel strand according to national standards; 13: represents the steel strand specification of 12.70 mm nominal diameter steel strand; N: refers to the number of steel strands to be threaded; Y: circular; M: anchor; P: because the compression anchor is also called a p-type anchor.

[0076] The load-bearing structure 51 is preferably a plate structure or a frame structure.

[0077] The connection between the anchor bolt 4 and the hollow anchor bolt 1 is preferably made in one of the following two ways. Method 1: The hollow anchor bolt 1 and the anchor bolt 4 are connected by threads. The anchor bolt 4 preferably includes a nut, and the connection between the hollow anchor bolt 1 and the nut is threaded. Method 2: The anchor bolt 4 includes at least two arc-shaped clamps that together hold the hollow anchor bolt 1. At least two steps are preferably provided on the outer wall of the hollow anchor bolt 1 along its length (the steps are very thin and do not affect the stress on the hollow anchor bolt 1). Along the length of the hollow anchor bolt 1, the steps abut against the anchor bolt 4. In this case, external tools are needed to apply a certain prestress to the hollow anchor bolt 1, and then the appropriate steps are selected by the anchor bolt 4 to abut against it.

[0078] like Figure 12 As shown, the cable-tube composite tension-compression hybrid anchoring system of this embodiment further includes a support structure 11, with the first anchor cable anchor 3 and the anchor rod anchor 4 both abutting against the support structure 11, and the support structure 11 can provide support reaction force for the anchor rod anchor 4; furthermore, the first anchor cable anchor 3 and the anchor rod anchor 4 both abut against the support structure 11, and the support structure 11 can provide support reaction force for the anchor rod anchor 4 and the first anchor cable anchor 3.

[0079] The supporting structure 11 is preferably a plate or frame structure, or a combination of plate and frame structures. The pad is set on the side of the frame structure near the anchor bolt and anchorage 4. In this application, when the anchor cable 2 is tensioned, the anchor plate 30 abuts against the supporting structure 11. The anchor plate 30 transfers the external force it receives to the supporting structure 11 or the reinforced surface structure 9, so that the external force is not transferred to the hollow anchor bolt 1 or the anchor bolt and anchorage 4. This ensures that when prestress is applied to the anchor cable 2 outside the anchor plate 30, it does not affect the hollow anchor bolt 1 and the anchor bolt and anchorage 4, making the structural stress of this application more reasonable and the prestress application safer and more convenient.

[0080] Anchor cable 2 can be prestressed, or both anchor cable 2 and hollow anchor rod 1 can be prestressed.

[0081] Prestress is applied to the hollow anchor rod 1. During the later deformation, the hollow anchor rod 1 and the anchor cable 2 deform synchronously and in coordination. If prestress is not applied to the hollow anchor rod 1, the anchor cable 2 will be stressed first, the hollow anchor rod 1 will be stressed later, and then they will be stressed together.

[0082] When anchor cable 2 is prestressed, under certain conditions, anchor cable 2 works independently under pull-out loads. Once hollow anchor rod 1 begins to work, the deformation of hollow anchor rod 1 and anchor cable 2 coordinates, jointly providing pull-out bearing capacity. This transforms the single-stress state of the load-concentrated anchoring structure into a combined tension-compression stress mode, improving the utilization rate of the bearing capacity of the grouting body 7, thereby increasing the ultimate bearing capacity of the pipe-cable combined tension-compression hybrid anchoring system. Hollow anchor rod 1 is preferably made of threaded steel pipe or round steel pipe. When using round steel pipe, threads need to be machined at the connection point with the anchor rod and anchorage 4. The recommended prestress range for hollow anchor rod 1 is 10-20KN for easy manual application of prestress; when the supporting structure 11 shifts, better contact between the anchor rod and anchorage 4 and the supporting structure 11 is desired; the anchorage section + free section is recommended to be 6-16m long, and the free end is recommended to not exceed 5m. The preferred prestress range for anchor cable 2 is 50KN-400KN, and the preferred bearing capacity range for anchor cable 2 is 200KN-1000KN.

[0083] The following is a force comparison analysis of the proposed cable-tube composite tension-compression hybrid anchoring system with existing tension-type anchoring systems: 1. The working mechanism of three different anchoring structures: such as Figure 14As shown in Figure a, the tension-type anchoring system mainly consists of three parts: the anchor rod, the grouting body, and the anchor head. Its pull-out bearing capacity is mainly provided by the bond between the two contact interfaces: the anchor rod-grouting body and the grouting body-soil mass. The sliding force is transmitted to the anchor rod through the bearing plate at the end of the free section, and then from the anchor rod to the soil mass in the anchored section through the grouting body. Both the anchor rod and the grouting body are subjected to tensile forces, and the stress tends to concentrate at the end of the anchored section, near the interface with the free section. The bond strength of the grouting body-soil mass contact interface is limited, and the stress concentration point is prone to reaching its bond strength, resulting in slippage. This reduces the length of the anchored section and makes it unsuitable for projects with excessively large loads or requiring long-term service.

[0084] like Figure 14 As shown in Figure b, in a pressure-type anchoring system, a bearing plate is placed at the end of the anchoring section, and the anchor cable is bound to the bearing plate. The sliding force is transmitted to the anchor cable through the bearing plate at the free end, and then from the anchor cable to the bearing plate at the end of the anchoring section. The bearing plate at the end of the anchoring section then transmits the force to the grout-soil interface through the grouting material. The anchor rod is under tension, and the grouting material is under pressure. Although the grouting material has better compressive performance than tensile performance, stress concentration is more likely to occur at the grouting material in contact with the bearing plate at the end of the anchoring section. This stress concentration also causes the shear stress at the grout-soil interface to easily reach its bond strength, leading to slippage. This results in a reduction in the length of the anchoring section and a decrease in the load-bearing capacity.

[0085] like Figure 14 As shown in Figure c, to address the aforementioned problem and achieve peak reduction, this application proposes a composite tension-compression hybrid anchoring system, comprising a hollow anchor rod 1, an anchor cable 2, and an anchor head. The hollow anchor rod 1 has a grouting body 7 on its exterior, and the anchor cable 2 passes through the hollow anchor rod 1. An anchoring component at the anchor head distributes the pull-out force acting on the structure to both the anchor cable 2 and the hollow anchor rod 1, achieving a synergistic load-bearing effect. Furthermore, a load-bearing component 5 (generally a plate) is installed at the end of the anchoring section to anchor the anchor cable 2, but not the hollow anchor rod 1. Under the action of the sliding force, the anchor cable 2 and the load-bearing component 5 at the end of the anchoring section form a pressure-type prestressed anchor cable, while the hollow anchor rod 1 and the grouting body separately form a tension-type anchoring system. To achieve a more uniform and even distribution of stress at the grout-soil interface, a central bearing structure 15 is also attached to the hollow anchor rod 1. This central bearing structure 15 is located inside the grout body and divides it into two sections. The second section, closer to the free section, changes from tension to compression, forming a three-section load-bearing structure where the first section is a tension-compression composite type and the second section is a compression type. This new structure results in a more uniform stress distribution. Furthermore, by controlling the position of the central bearing plate in the anchoring section, a more rational load distribution of the grout body can be achieved, enabling it to withstand greater loads.

[0086] 2. Numerical Model Establishment: Based on engineering simulation finite element analysis software, the proposed cable-tube composite tension-compression hybrid anchoring system of this application is analyzed against existing tension-type anchoring systems. The working mechanism of the cable-tube integrated tension-compression composite anchoring system is explored, and its stress and deformation characteristics are compared and analyzed with tension-type and compression-type anchoring systems. For example, ABAQUS engineering simulation finite element analysis software is used for numerical simulation analysis. ABAQUS has various types of material models and contact models, which can simulate arbitrary geometries. Among them, the bond-slip model can better simulate the stress and deformation characteristics of the bond interface of the anchoring structure.

[0087] 2.1 Geometric Parameters of the Model: To more clearly observe the stress distribution law of the anchorage structure, especially the shear stress distribution law of the grout-soil interface that affects the anchorage performance, this embodiment establishes numerical models of three different anchorage structures. The anchorage section length is consistently 7 m, and the borehole wall size (outer diameter of the grout body) is consistently 0.15 m. This ensures that the contact area of ​​the grout-soil interface is the same, and the same external load is applied to clearly compare the advantages of the bearing mechanism of the pipe-cable composite tension-compression hybrid anchorage system of this application compared with the traditional tension anchorage system and the tension anchorage system. For ease of description, this embodiment names the tension anchorage system T-7 m, the compression anchorage system C-7 m, and the pipe-cable composite tension-compression hybrid anchorage system of this application CTC-7 m. The model dimensions are shown in the table below. Figures 15-17 As shown.

[0088] 2.2 Material Constitutive Model and Parameters: In numerical calculations, the Mohr-Coulomb model is mainly used for soil and rock masses. This model is suitable for materials that yield under shear stress, but where the shear stress depends only on the maximum and minimum principal stresses, and the second principal stress does not affect the yield. Examples include loose or cemented granular materials such as soil, rock, and concrete. The yield function expression is as follows:

[0089] In the formula, , f Let be the yield function. These are the first invariant of the stress tensor, the second invariant of the stress deviator, and the third invariant of the stress deviator, respectively.

[0090] Parameter selection is crucial in finite element analysis for evaluating load transfer in anchoring systems, as it is primarily related to the material's inherent properties. This invention references, for example... Figure 18The material parameters of the soil and rock mass, anchor bolts, and anchor cables are shown. In order to study the working mechanism of the pipe-cable composite tension-compression hybrid anchoring system, except for the soil and rock mass which adopts the Mohr-Coulomb plastic model, the other components (excluding the bearing plate) are simulated using the linear elastic model. The bearing plate at different locations is set as a rigid body, which only transmits loads and does not participate in deformation.

[0091] 2.3 Contact Model and Parameters: To address the diverse contact interfaces between different materials, based on finite element software, the mechanical behavior of the anchor-grout and grout-soil interfaces is modeled using viscous and damage-related contact properties. This contact property is also known as the bond-slip model, which has two main configuration methods: thickness-free contact pairs and cohesive elements. In this embodiment, thickness-free contact pairs are used to configure the interface contact. The cohesive model shows that the interface contact stress undergoes an elastic stage, a damage evolution stage, and finally complete failure. The elastic constitutive equation is as follows, where the elastic deformation stage is determined by the stiffness coefficient. K nn , K ss and K tt Control, where the subscript n represents the normal direction, and s and t represent the two tangential directions.

[0092]

[0093] In the above formula, t s Normal shear stress t n、 t t Let represent the shear stress in two tangential directions; t represents the interfacial shear stress; and [K] is the stiffness matrix. K This is the stiffness coefficient. This represents the relative displacement of the interface. These represent the relative displacements in the normal and two tangential directions, respectively.

[0094] The damage evolution stage consists of two parts: the damage initiation criterion and the damage evolution law. Damage initiation refers to the entry into the damage evolution stage when the contact stress and contact displacement at the contact point meet the specified damage initiation criteria. Since this simulation focuses on the interfacial bond-slip behavior during anchor pull-out, and the load mainly acts as a mechanical behavior along the longitudinal direction of the anchor, grout, and borehole wall, the maximum nominal stress criterion in the damage initiation criteria is selected as the basis for judging the start of damage. Damage is assumed to begin when the maximum contact stress ratio reaches 1. This criterion can be expressed as:

[0095] Where <> is Macaulay brackets, indicating that only tension is considered, otherwise it is 0; ts Normal shear stress t n、 t t These are the shear stresses in two tangential directions; t on , t os and t ot These represent the peak contact stresses when the separation is completely perpendicular to the interface, or completely perpendicular to the first or second shear direction, respectively.

[0096] Damage evolution refers to the process by which micro-defects within a material or interface initiate, propagate, and ultimately fail under load. This embodiment describes this process through stiffness softening of interfacial adhesion behavior. In the Cohesive model, the damage evolution stages are represented by damage variables. D The change from 0 to 1 quantitatively describes this irreversible degradation process. With the change in damage variables... D As the material strength increases, the effective stiffness (or modulus) of the interface gradually decreases, either linearly or nonlinearly. In practice, some material parameters are difficult to measure. Therefore, finite element software provides two damage evolution modes to characterize stiffness damage in interfacial bonding behavior: one based on energy and the other based on displacement. Energy evolution only requires setting the material's fracture energy G. TC Data shows that once the energy reaches this set value, the unit will fail and be deleted. Displacement evolution only requires setting the fracture displacement at which material failure occurs. This embodiment uses a displacement-based linear softening law, which can be expressed as follows:

[0097] in, D The loss variable represents the stage of damage evolution, varying from 0 to 1. This represents the relative displacement of the interface; This represents the interface displacement at the onset of damage. This refers to the fracture displacement, i.e., the displacement when interfacial bonding fails. This represents the maximum shear stress at the interface. K This represents the stiffness coefficient. The contact model parameters for the two interfaces are as follows: Figure 19 As shown.

[0098] 2.4 Application of Prestress and External Load: An external load of 500 kN was applied to the T-7 m model, C-7 m model, and CTC-7 m model respectively, and a prestress of 200 kN was applied to the anchor cable of the CTC-7 m model to improve its bearing capacity. The prestress was applied by the cooling method, which utilizes the thermal expansion and contraction property of the anchor cable material to deform it. The temperature decrease causes the anchor cable to shrink, and the anchor cable itself is constrained at both ends. This effect inhibits the generation of temperature deformation, resulting in internal force in the material. Its basic principle is shown in Equation (6), where The linear expansion coefficient of the prestressed anchor cable is taken as 1×10⁻⁶. -5 ; E P The elastic modulus of the prestressed tendon; A Δ is the cross-sectional area of ​​the prestressed anchor cable; L Δ represents the deformation of the prestressed anchor cable. T To reduce the temperature difference, F Design the prestress magnitude for the anchor cable. L This refers to the length of the anchor cable.

[0099]

[0100] 3. Model Calculation Results: Considering that the position of the plate in the grouting body of the CTC-7 m model may also affect the stress distribution law, two models with plates at different positions were established and compared with the results of the T-7 m model and the C-7 m model. The plates at the two different positions were set at 2 / 3 and 3 / 4 of the distance from the end of the anchoring section, respectively, that is, the grouting body is divided into two parts: a composite tension-compression section and a compression section. The length ratio of the two parts of the grouting body is 2:1 and 3:1, respectively. Therefore, they are named CTC21-7 m and CTC31-7 m.

[0101] Figure 20 This is a comparison of the shear stress distribution at the grout-soil interface between the CTC21-7 m and CTC31-7 m models and the T-7 m and C-7 m models, respectively. It can be seen that compared to the traditional T-7 m and C-7 m models, the new composite anchoring structure has a lower peak stress and a more uniform stress distribution along the entire anchoring section. Under the same load, the lower peak stress of the new structure makes it less likely to reach the bond strength at the contact surface, and the more uniform stress distribution of the new structure allows it to withstand a larger load. Figure 20 a and Figure 20As shown in b, the peak stress of the CTC21-7 m model is at the end of the anchorage section, with a maximum stress of 226,640 Pa; the peak stress of the T-7 m model is at the end of the free section, with a maximum stress of 254,223 Pa; and the peak stress of the C-7 m model is at the end of the anchorage section, with a maximum stress of 338,713 Pa. The peak stress of the CTC21-7 m model is reduced by 10.8% compared to the T-7 m model and by 33.1% compared to the C-7 m model. Figure 20 c and Figure 20 As shown in Figure d, the peak stress of the CTC31-7 m model is at the end of the anchorage section, with a maximum stress of 214,861 Pa; the peak stress of the T-7 m model is at the end of the free section, with a maximum stress of 254,223 Pa; and the peak stress of the C-7 m model is at the end of the anchorage section, with a maximum stress of 338,713 Pa. The peak stress of the CTC21-7 m model is reduced by 15.5% compared to the T-7 m model and by 36.6% compared to the C-7 m model. Figure 20 In the diagram, CTC21 and CTC31 represent different positions, and their influence patterns are as follows: Figure 21 As can be seen, CTC31 has better uniformity than CTC21. To more clearly describe and compare the uniformity of stress distribution in the four models, this embodiment introduces the coefficient of variation (CPV). The CPV measures the relative fluctuation of data around the mean; it is a percentage of the mean after standard deviation is normalized. A smaller CPV indicates a more uniform data distribution. Equation (7) is its expression. Figure 20 The results calculated by substituting the data from each model into equation (7) are shown in Table 5. The coefficients of variation of the shear stress at the grout-soil interface in the T-7 m model, C-7 m model, CTC21-7 m model, and CTC31-7 m model are 35.19%, 79.95%, 17.58%, and 13.87%, respectively. In comparison, the stress distribution in the CTC21-7 m model and the CTC31-7 m model is much more uniform than that in the T-7 m model and the C-7 m model. In the following equation: Xi represents the values ​​of each sample. This is the sample average.

[0102]

[0103] The characteristic values ​​of shear stress distribution at the interface between the grouting body and the soil in each model are shown in the table below. Figure 22 As shown. Figure 23 As shown, Figure 23 'a' represents the axial stress of the hollow anchor rod in the CTC21-7 m model. Figure 23b represents the axial stress of the hollow anchor rod in the CTC31-7 m model. It can be seen that the axial stress of the anchor rod is negative near the end of the anchoring section, showing a trend of first increasing and then decreasing. When it decreases to 0, it begins to turn positive and gradually increases, remaining constant after reaching a certain value of 153.7 MPa and 156.0 MPa, corresponding to z values ​​of 4.5 m and 5.25 m, respectively, which is exactly the location of the intermediate bearing plate. The first section of grouting material in front of the plate is in direct contact with the anchor rod, and the two interact; the second section of grouting material behind the plate is separated from the anchor rod and is only subjected to the pressure transmitted by the anchor rod through the intermediate bearing plate. There is no shearing action between them, so the axial stress of the anchor rod behind the plate will also remain unchanged. This is demonstrated by... Figure 24 a and Figure 24 As can be seen from b, the shear stress at the anchor bolt-grout interface remains constant at 0 after the intermediate bearing plate. In summary, the interaction between the second section of grout and the anchor bolt behind the plate is relatively simple; the second section structure is a single pressure-type anchoring system. The interaction between the first section of grout and the anchor bolt in front of the plate is more complex; the first section structure is a tension-compression composite anchoring system. This is because the first section of grout is subjected not only to the direct tension of the anchor bolt but also to the pressure transmitted by the anchor cable through the bearing plate at the end of the anchoring section. Therefore, the grout near the end of the anchoring section, after being compressed, will continue to transmit the pressure to the anchor bolt, causing negative axial stress in the anchor bolt. As the position gradually moves away from the end of the anchoring section and closer to the free end where the load is applied, the pressure effect on the anchor bolt weakens, while the tension effect strengthens. The axial stress of the anchor bolt gradually changes from negative to positive and gradually increases, and the shear stress at the anchor bolt-grout interface also gradually changes from negative to positive and gradually increases.

[0104] The slight difference in maximum axial stress between the CTC21-7 m and CTC31-7 m models is because the intermediate bearing plate at two different positions affects the load distribution between the first and second sections of the anchor bolt, and also slightly influences the load distribution of the anchor bolt and anchor cable. This indicates that we can control the load ratio between the front and rear sections of the anchor bolt by controlling the position of the intermediate bearing plate, making it more adaptable to complex reinforcement projects. This paper mainly explains that the new composite anchoring system has a more uniform stress distribution than traditional tension-type and compression-type anchoring systems, and the interfacial shear stress is less likely to reach its interfacial bond strength.

[0105] The following describes some preferred structural details of a cable-tube composite tension-compression hybrid anchoring system according to this embodiment: A gap is left between the bearing component 5 and the hollow anchor rod 1 to avoid applying a large force to the hollow anchor rod 1 while the bearing component 5 is under pressure to compress the grouting body 7, which would lead to serious mutual interference between the hollow anchor rod 1 and the anchor cable 2, thus affecting the effect of the pipe-cable composite tension-compression hybrid anchoring system of this application in distributing the force on the anchoring section.

[0106] like Figure 4 As shown, the distance between the bearing component 5 and the end of the hollow anchor rod 1 is A, where 0 < A ≤ 1 cm, to prevent excessive grout from entering between the bearing component 5 and the hollow anchor rod 1 and the anchor cable 2 when grouting is performed on the outside of the hollow anchor rod 1 to form the grout body 7, thereby affecting the effect of dispersing the force on the anchoring section in the pipe-cable composite tension-compression hybrid anchoring system of this embodiment.

[0107] like Figure 4 As shown, in a preferred embodiment, a flexible structure 6 is provided between the load-bearing component 5 and the hollow anchor rod 1. The flexible structure 6 is preferably a ring structure and is sleeved on the outside of the anchor cable 2. The flexible structure 6 is preferably a component made of plastic, rubber, or silicone. The flexible structure 6 can be connected to the load-bearing component 5 or the hollow anchor rod 1; it can be connected to both the load-bearing component 5 and the hollow anchor rod 1 simultaneously, or it can be not connected to either the load-bearing component 5 or the hollow anchor rod 1.

[0108] like Figure 11 As shown, in a preferred embodiment, a sleeve 12 is further provided between the hollow anchor rod 1 and the anchor cable 2. The sleeve 12 separates the hollow anchor rod 1 and the anchor cable 2 to prevent grout from contaminating the anchor cable 2. The sleeve 12 is not a load-bearing component under the action of sliding force, which is the essential difference between the sleeve 12 and the hollow anchor rod 1. The sleeve 12 is preferably a PVC pipe. More preferably, the sleeve 12 is connected to the load-bearing component 5, and the end of the sleeve 12 can also extend into the through hole 53.

[0109] In a preferred embodiment, a pipe-cable composite tension-compression hybrid anchoring system further includes a grouting body 7, which is connected to the outside of the hollow anchor rod 1, and the bearing component 5 abuts against the end of the grouting body 7 away from the first anchor cable anchor 3.

[0110] This application discloses a cable-tube composite tension-compression hybrid anchoring system. The load is transferred to the grouting body 7 through the bearing components and the anchor bolt bonding contact surface, resulting in the load being mainly distributed at both ends of the grouting body 7, thereby effectively improving stress concentration in the anchoring section. Compared with traditional load-distributed anchoring structures, this system simplifies the construction process and reduces production and construction costs.

[0111] This application discloses a composite tension-compression hybrid anchoring system using tubular cables. Because it includes one of the tubular cable composite tension-compression hybrid anchoring systems 13 as described in Embodiments 1, 2, or 3, the anchor bolt anchoring system and the anchor cable anchoring system can be independently anchored during construction and installation. The anchor cable 2 passes through the interior of the hollow anchor bolt 1, the bearing component 5 is located at one end of the hollow anchor bolt 1, and the first anchor cable anchor 3 is located at the other end of the hollow anchor bolt 1. Since the anchor bolt anchoring system and the anchor cable anchoring system can be independently anchored during installation, during anchoring, the anchor bolt anchor 4 and the first anchor cable anchor 3 are provided at the end. The three anchors and cable anchors separately anchor the hollow anchor rod 1 and the anchor cable 2, without affecting each other. The component of the downward force acting on the pipe-cable composite tension-compression hybrid anchoring system along the length of the hollow anchor rod 1 is jointly borne by the hollow anchor rod 1 and the anchor cable 2. Since the pipe-cable composite tension-compression hybrid anchoring system of this application includes an anchor rod anchoring system and an anchor cable anchoring system that can be anchored independently, the anchor rod anchoring system and the anchor cable anchoring system can be anchored independently during construction, while cooperating to bear the force when resisting the downward force.

[0112] Moreover, in certain situations, under the action of sliding force, anchor cable 2, bearing component 5 and first anchor cable anchor 3 form a pressure-type prestressed anchor cable anchoring system, while hollow anchor rod 1 and anchor rod anchor 4 separately form a tension-type anchoring system. This results in the grouting body 7 on the outer side of hollow anchor rod 1 being compressed at the end and tensile at the end, achieving the effect of dispersing the force on the anchoring section and fully utilizing the interfacial bonding force. Furthermore, under the action of sliding force, hollow anchor rod 1 and anchor cable 2 deform in coordination, jointly providing pull-out bearing capacity. Compared to tension-type or compression-type anchoring systems, this method transforms the single-force mode of a load-concentrated anchoring structure into a combined tension-compression force mode in the anchoring section. This disperses the force in the anchoring section, reducing not only the axial force of the hollow anchor rod 1 and the anchor cable 2, but also, in particular, the stress peak values ​​at the contact surfaces between the grouting body 7 and the hollow anchor rod 1, and between the grouting body 7 and the wall of the anchor hole 8. This improves the utilization rate of the bearing capacity of the grouting body anchoring section, thereby increasing the ultimate bearing capacity of the pipe-cable composite tension-compression hybrid anchoring system of this application.

[0113] In certain construction conditions, the hollow anchor rod 1 is first anchored by the anchor rod anchor 4, and then the anchor cable 2 is anchored by the first anchor cable anchor 3, with prestress applied to the anchor cable 2. In this case, two situations may occur: Situation 1: In certain construction conditions, after applying prestress to the anchor cable 2, the anchor rod anchor 4 remains in a state of mutual stress with the soil or reinforced surface structure 9. In this case, during later use, the soil or reinforced surface structure 9 exerts a sliding force on the anchor rod anchor 4 and the first anchor cable anchor 3. Under the action of this sliding force, the hollow anchor rod 1 and the anchor cable 2 jointly provide pull-out bearing capacity, transforming the pipe-cable composite tension-compression hybrid anchoring system of this application from a single-stress state of a load-concentrated anchoring structure to a tension-compression composite stress mode, improving the utilization rate of the grouting body's bearing capacity, thereby improving the ultimate bearing capacity of the pipe-cable composite tension-compression hybrid anchoring system; Situation 2: Under certain working conditions, after applying prestress to the anchor cable 2, the anchor rod 4 and the soil or reinforced surface structure 9 need to undergo a certain displacement or deformation before they can be in a mutually stressed state. In this case, during later use, the soil or reinforced surface structure 9 first applies a sliding force to the first anchor cable 3. Under the pull-out load, the anchor cable 2 first acts as the main load-bearing component. After the first anchor cable 3 undergoes a certain displacement or deformation, the soil or reinforced surface structure 9 applies a sliding force to the anchor rod 4 and the first anchor cable 3. Under the action of the sliding force, the hollow anchor rod 1 and the anchor cable 2 jointly provide pull-out bearing capacity, so that the pipe-cable composite tension-compression hybrid anchoring system of this application changes from the single force state of the load-concentrated anchoring structure to the tension-compression composite force mode, which improves the utilization rate of the bearing capacity of the grouting body, thereby improving the ultimate bearing capacity of the pipe-cable composite tension-compression hybrid anchoring system.

[0114] The pipe-cable composite tension-compression hybrid anchoring system of this embodiment also includes a soil-rock mass 10 with anchor holes 8, a grouting body 7 located inside the anchor holes 8, and a bearing component 5 with an outer diameter D1 along the radial direction of the hollow anchor rod 1 that is smaller than the diameter D2 of the anchor hole 8. This arrangement allows the grout to flow through the gap between the bearing component 5 and the soil-rock mass 10 to the back of the bearing component 5, thereby enabling the grout to provide corrosion protection for the bearing component 5. Simultaneously, it integrates the grouting body 7 with the bearing component 5, achieving a better anchoring effect.

[0115] like Figure 12 and 13 As shown, a reinforced surface structure 9 is provided on the outside of the soil and rock mass 10. The reinforced surface structure 9 is preferably laid on the slope outside the soil and rock mass 10. The pipe-cable composite tension-compression hybrid anchoring system passes through the reinforced surface structure 9. The reinforced surface structure 9 provides the first anchor cable anchor 3 and the anchor rod anchor 4 with reaction force support toward the direction away from the bearing component 5.

[0116] The solid surface structure 9 preferably has a plate or a frame beam, or it can be a combination of a plate and a frame beam. The plate is set on the side of the frame beam near the anchor bolt 4. The frame beam is also called a transverse and longitudinal frame beam.

[0117] like Figure 13 As shown, at least two tube-cable composite tension-compression hybrid anchoring systems 13 are installed on the reinforced surface structure 9. In a preferred embodiment, the reinforced surface structure 9 has at least two through holes, and the end of the tube-cable composite tension-compression hybrid anchoring system near the bearing component 5 passes through the through holes and enters the anchor hole 8 on the soil mass 10.

[0118] The pipe-cable composite tension-compression hybrid anchoring system preferably has multiple components near the bearing component 5, arranged in an array on the soil mass 10.

[0119] like Figure 1 As shown, the outer diameter of the support structure 11 is preferably larger than the diameter D2 of the anchor hole 8. During construction, when the support structure 11 shifts, the anchor bolt 4 should have better contact with the support structure 11; the anchorage section plus the free section is recommended to be 6-16m long, and the free end is recommended to not exceed 5m. The preferred prestress range for the anchor cable 2 is 50KN-400KN. The preferred load-bearing range for the anchor cable 2 is 200KN-1000KN.

[0120] This embodiment of a pipe-cable composite tension-compression hybrid anchoring system includes a hollow anchor rod 1, an anchor cable 2, a first anchor cable anchorage 3, an anchor rod anchorage 4, and a grouting body 7. The anchor cable 2 is inserted inside the hollow anchor rod 1, and the anchor rod anchorage 4 and the first anchor cable anchorage 3 are set at the anchorage 14 to anchor the hollow anchor rod 1 and the anchor cable 2 separately. The pull-out force acting on the pipe-cable composite tension-compression hybrid anchoring system is distributed to the hollow anchor rod 1 and the anchor cable 2 to be borne by both, so as to achieve the effect of synchronous force on both but without interference.

[0121] Furthermore, a bearing component 5 is installed at the end of the grouting body 7 to anchor the anchor cable 2. The bearing component 5 pushes against (compresses) the grouting body 7, but does not anchor the hollow anchor rod 1. Under the action of the sliding force, the anchor 14 forms a pressure-type prestressed anchor cable with the anchor cable 2, the bearing component 5, and the grouting body 7, while the hollow anchor rod 1 and the grouting body 7 separately form a tension-type anchoring system. This results in the grouting body 7 being compressed at the end and tensile at the end, achieving the effect of dispersing the force on the anchoring section and fully utilizing the interfacial bonding force.

[0122] The working mechanism of the pipe-cable composite tension-compression hybrid anchoring system is as follows: when the anchor cable 2 is prestressed, under the action of pull-out load, the anchor cable 2 works independently first. After the hollow anchor rod 1 starts to work, the hollow anchor rod 1 and the anchor cable 2 deform in coordination, jointly providing pull-out bearing capacity. This transforms the single force state of the load-concentrated anchoring structure into a tension-compression composite force mode, improving the load-bearing capacity utilization rate of the grouting body 7, thereby improving the ultimate bearing capacity of the pipe-cable composite tension-compression hybrid anchoring system. The grouting body 7 is formed by grouting. In this embodiment, along the length direction of the anchor cable 2, the section where the grouting body 7 is located in the pipe-cable composite tension-compression hybrid anchoring system is the anchoring section.

[0123] The working mechanism of the pipe-cable composite tension-compression hybrid anchoring system in this embodiment is that the anchor bolts and anchor cables deform in a coordinated manner, jointly providing pull-out bearing capacity. This transforms the single-stress state of the load-concentrated anchoring structure into a tension-compression composite stress mode, improving the utilization rate of the bearing capacity of the grouting body 7, thereby increasing the ultimate bearing capacity of the structure.

[0124] This embodiment also discloses a construction method for a pipe-cable composite tension-compression hybrid anchoring system, including the following steps: A1. Opening anchor holes 8 in the soil mass 10; A2. Placing at least a portion of the pipe-cable composite tension-compression hybrid anchoring system into the anchor holes 8; A3. Injecting grout into the anchor holes 8 to form a grout body 7; A4. Applying prestress to the hollow anchor rod 1; A5. Applying prestress to the anchor cable 2.

[0125] This embodiment presents a construction method for constructing the pipe-cable composite tension-compression hybrid anchoring system. When the anchor cable 2 is prestressed, under certain conditions, the anchor cable 2 initially works independently under pull-out loads. Once the hollow anchor rod 1 begins operation, the deformation of the hollow anchor rod 1 and the anchor cable 2 coordinates, jointly providing pull-out bearing capacity. This transforms the single-stress state of the load-concentrated anchoring structure into a tension-compression composite stress mode, improving the utilization rate of the grouting body 7's bearing capacity, thereby increasing the ultimate bearing capacity of the pipe-cable composite tension-compression hybrid anchoring system.

[0126] In step A2, the hollow anchor rod 1 is fitted onto the outside of the anchor cable 2; one end of the anchor cable 2 is connected to the bearing component 5; the hollow anchor rod 1 is used to push the bearing component 5, so that the bearing component 5, a part of the anchor cable 2, and at least a part of the hollow anchor rod 1 enter the anchor hole 8, to facilitate the installation of the bearing component 5. The prestress applied to the anchor cable 2 is preferably 50KN-400KN.

[0127] The pipe-cable composite tension-compression hybrid anchoring system of this embodiment has a relatively simple construction method. The differences from the load-concentrated anchoring system are explained below from three aspects: the fabrication and installation of hollow anchor rod 1 and anchor cable 2, grouting of the anchoring section, and tensioning of anchor cable 2.

[0128] The fabrication and installation of the hollow anchor rod 1 are the same as those of the tension anchoring system, while the fabrication and installation of the anchor cable 2 are the same as those of the compression prestressed anchor cable. There are two main differences: first, the anchor cable 2 needs to be inserted inside the hollow anchor rod 1; second, a first anchor cable anchorage 3 and an anchor rod anchorage 4 need to be fabricated at the anchor head to achieve separate anchoring of the hollow anchor rod 1 and the anchor cable 2. The structure is as follows: Figure 1 As shown. Furthermore, in a preferred embodiment, only the anchored section of the anchor bolt is anchored, while the free section should be fitted with a debonded sleeve or an unbonded anchor bolt should be used.

[0129] Grouting of the anchorage section forms the grout body, which is the main source of pull-out bearing capacity in the cable-tube composite tension-compression hybrid anchorage system, making its grouting quality particularly important. In actual engineering, the preferred method for grouting prestressed anchor cables is usually a one-time grouting method, where the grout in the anchorage section and the free section are grouted at the same time. Although this simplifies the construction process, it makes it difficult to guarantee the quality of the grout in the anchorage section.

[0130] The preferred method for secondary grouting involves installing a grout stopper at the junction of the anchorage and free sections. Grouting is first performed on the anchorage section, and once the grout has reached a certain strength, the anchor cable is tensioned and locked. Then, additional grouting is performed on the free section. This method is particularly suitable for composite cable-tube tension-compression anchoring systems, as it allows for verification of the grout's load-bearing capacity during tensioning and locking, resulting in higher safety and applicability to structures with high load-bearing requirements.

[0131] Anchor cable tensioning is a crucial step in prestressed anchor construction, typically performed after the grout has reached 80% of its design strength. Tensioning of preferred load-distributed anchoring structures involves complex processes such as staged tensioning, unit-to-whole tensioning, differential load tensioning, and overall compensation tensioning. However, the tensioning method for pipe-cable composite tension-compression hybrid anchoring systems is the same as for ordinary pressure-type prestressed anchors, requiring only one tensioning operation. It is noteworthy that analysis of the impact of anchor cable prestress on the stress distribution of the anchoring system reveals that the magnitude of the prestress directly affects the deformation coordination process of the anchor rod and anchor cable. The prestress should not be excessive, especially on weaker bearing surfaces, where secondary tensioning of the anchor cable will result in greater shrinkage deformation, leading to extremely uneven load distribution in the early and mid-stages of the pipe-cable composite tension-compression hybrid anchoring system.

[0132] In a preferred embodiment, the construction method of this application further includes a design method for the stress distribution uniformity of a pipe-cable composite tension-compression hybrid anchoring system. This design method comprises the following steps: S1. Determining the basic dimensions of the pipe-cable composite tension-compression hybrid anchoring system; S2. Obtaining the standard deviation and mean values ​​of the shear stress at the grout-soil interface of the pipe-cable composite tension-compression hybrid anchoring system; S3. Obtaining the coefficient of variation of the shear stress at the grout-soil interface based on the standard deviation and mean values, and comparing the coefficient of variation with the critical coefficient of variation. If the coefficient of variation > the critical coefficient of variation, the position of the intermediate bearing structure 15 in the grout 7 in step S1 is adjusted, and steps S2 and S3 are repeated until the coefficient of variation ≤ the critical coefficient of variation, thus obtaining the final dimensions of the pipe-cable composite tension-compression hybrid anchoring system. The construction method of this application, by setting the coefficient of variation, establishes a reasonable standard for the dimensional design of the pipe-cable composite tension-compression hybrid anchoring system, thereby effectively guiding the design of more optimized structural dimensions for the pipe-cable composite tension-compression hybrid anchoring system. The critical coefficient of variation is preferably 20%. For details on the calculation of the coefficient of variation, please refer to the coefficient of variation calculation section in this embodiment.

[0133] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite tension-compression anchoring system using tubular cables, characterized in that, include: Anchor cable (2); Hollow anchor rod (1) is sleeved on the outside of the anchor cable (2) and spaced apart from the anchor cable (2); The intermediate load-bearing structure (15) is sleeved and connected to the outside of the hollow anchor rod (1); Grouting body (7): The grouting body (7) is sleeved on the outside of the hollow anchor rod (1); Along the length of the hollow anchor rod (1), the intermediate bearing structure (15) divides the grouting body (7) into two sections, one of which is close to the root and is attached to the outer wall of the hollow anchor rod (1), and the other section of the grouting body (7) is spaced apart from the outer wall of the hollow anchor rod (1).

2. The tubular cable composite tension-compression hybrid anchoring system according to claim 1, characterized in that, The intermediate load-bearing structure (15) is provided with a flow hole (16) through the hollow anchor rod (1) along its length direction.

3. The tubular cable composite tension-compression hybrid anchoring system according to claim 1, characterized in that, The central load-bearing structure (15) is welded to the outside of the hollow anchor rod (1).

4. The cable-tube composite tension-compression hybrid anchoring system according to claim 1, characterized in that: One end of the hollow anchor rod (1) is connected to an anchor rod anchor (4) for anchoring the hollow anchor rod (1). The anchor cable (2) passes through the hollow anchor rod (1), and the end of the anchor cable (2) away from the anchor rod anchor (4) is connected to a bearing component (5). The end of the anchor cable (2) near the anchor rod anchor (4) is connected to a first anchor cable anchor (3) for anchoring the anchor cable (2). The bearing component (5) and the first anchor cable anchor (3) are both located outside the end of the hollow anchor rod (1), and the anchor rod anchor (4) is located inside the first anchor cable anchor (3). Along the length of the hollow anchor rod (1), the anchor rod anchor (4) and the first anchor cable anchor (3) do not interfere with each other, the bearing component (5) is spaced apart from the hollow anchor rod (1), and the bearing component (5) abuts against the grouting body (7); Along the radial direction of the hollow anchor rod (1), the outer diameter of the bearing component (5) is larger than the outer diameter of the hollow anchor rod (1).

5. The cable-tube composite tension-compression hybrid anchoring system according to claim 4, characterized in that: The intermediate bearing structure (15) includes a pressure plate (151) and an isolation pipe (152) connected to each other. The isolation pipe (152) is located on the side of the pressure plate (151) near the anchor bolt (4). The isolation pipe (152) is spaced out on the outside of the hollow anchor bolt (1). The part of the grouting body (7) located between the pressure plate (151) and the anchor bolt (4) is in close contact with the outer wall of the isolation pipe (152).

6. The cable-tube composite tension-compression hybrid anchoring system according to claim 5, characterized in that: The pressure plate (151) is threadedly connected to the hollow anchor rod (1).

7. The cable-tube composite tension-compression hybrid anchoring system according to claim 6, characterized in that: The pressure plate (151) and the isolation pipe (152) are threaded together.

8. A composite tension-compression anchoring system for tubular cables according to any one of claims 1-7, characterized in that: It also includes a rock and soil body (10), on which anchor holes (8) are provided, and the grouting body (7) is located in the anchor holes (8).

9. A construction method for the pipe-cable composite tension-compression hybrid anchoring system as described in claim 8, characterized in that, Includes the following steps: A1. Anchor holes (8) are made in the rock and soil mass (10); A2. Place at least a portion of the tubular cable composite tension-compression hybrid anchoring system into the anchor hole (8); A3. Grouting is injected into the anchor hole (8) to form the grout body (7); A4. Apply prestress to the anchor cable (2).

10. A construction method for a composite tension-compression anchoring system using tubular cables according to claim 9, characterized in that, It also includes a design method for stress distribution uniformity in a composite tension-compression anchoring system using tubular cables, which comprises the following steps: S1. Determine the basic dimensions of the composite tension-compression anchoring system using tubular cables; S2. Obtain the standard deviation and mean values ​​of the shear stress at the grout-soil interface of the cable-tube composite tension-compression hybrid anchoring system; S3. Based on the standard deviation parameter and mean parameter, obtain the coefficient of variation of the shear stress at the grout-soil interface, and compare the coefficient of variation with the critical coefficient of variation. If the coefficient of variation is greater than the critical coefficient of variation, adjust the position of the intermediate bearing structure (15) of the pipe-cable composite tension-compression hybrid anchoring system in step S1 in the grout (7), and repeat steps S2 and S3 until the coefficient of variation is less than or equal to the critical coefficient of variation, and then obtain the final dimensions of the pipe-cable composite tension-compression hybrid anchoring system.

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