Sectional type anchor cable, sectional type supporting structure and construction method

Abstract

The invention belongs to the technical field of tunnel engineering, and particularly relates to a sectional type anchor cable, a sectional type supporting structure and a construction method.The sectional type anchor cable comprises a first anchor cable body and a second anchor cable body, the first anchor cable body and the second anchor cable body are connected through an anchor cable body connecting assembly, and a tensioning structure is arranged in the anchor cable body connecting assembly; one end of the tensioning structure is connected with one end of the first anchor cable body, the other end of the tensioning structure is connected with one end of the second anchor cable body, and the other end of the second anchor cable body is connected with a damping base plate. The first anchor cable body and the second anchor cable body are both fixed to the anchor cable hole, the anchor cable body connecting assembly is located at a tunnel extension boundary, and the damping base plate is located in a built tunnel. The invention further discloses a construction method of the sectional type anchor cable and a sectional type supporting structure composed of a plurality of sectional type anchor cables. Segmented reinforcing can be achieved, the permanent supporting structure and the pre-reinforcing structure easy to dismantle are adopted, the pre-reinforcing requirement is met, and follow-up expanding excavation dismantling operation is not hindered.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel engineering, and in particular relates to a segmented anchor cable, a segmented support structure and a construction method. Background Art

[0002] During long-term tunnel operation, tunnel structures may experience various structural defects and significant degradation of lining quality. Furthermore, the capacity of some existing tunnels is insufficient to meet growing transportation demands, leading to significant traffic congestion. Therefore, to improve the capacity of existing tunnels and address existing tunnel defects, some older tunnels require in-situ expansion.

[0003] The inadequate lining capacity of existing tunnels and the loosening of surrounding rock caused by initial excavation disturbances increase the risk of collapse and instability during in-situ tunnel expansion. Therefore, pre-reinforcement treatment is required in areas prone to collapse. Currently, while traditional pre-reinforcement methods such as anchor bolts or cables can improve the stability of existing tunnels to a certain extent, they also bring inconvenience to the subsequent excavation of new tunnels. Furthermore, after demolition by blasting, the pre-reinforced structures remaining outside the expanded tunnel cannot be reused, resulting in a waste of resources.

[0004] Therefore, a pre-reinforcement support structure and a construction method thereof are needed that can achieve pre-reinforcement of existing tunnels without affecting subsequent excavation. Summary of the Invention

[0005] The purpose of the present invention is to provide a segmented anchor cable, a segmented support structure and a construction method to solve the above problems.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A segmented anchor cable comprising:

[0008] a first anchor cable body and a second anchor cable body, wherein the first anchor cable body and the second anchor cable body are connected by an anchor cable body connecting assembly, wherein a tensioning structure is provided in the anchor cable body connecting assembly, wherein one end of the tensioning structure is connected to one end of the first anchor cable body, and the other end of the tensioning structure is connected to one end of the second anchor cable body, and the other end of the second anchor cable body is connected to a shock-absorbing pad;

[0009] The first anchor cable body and the second anchor cable body are both fixed to the anchor cable holes, the anchor cable body connection assembly is located at the tunnel expansion boundary line, and the shock-absorbing pad is located in the built tunnel.

[0010] Optionally, the anchor cable connection assembly further includes:

[0011] A first sleeve and a second sleeve fixed together, wherein the first sleeve and the second sleeve together form a chamber for accommodating the tensioning structure;

[0012] The first anchor body and the second anchor body are arranged through the cavity.

[0013] Optionally, the tensioning structure includes:

[0014] A connecting plate is movably arranged in the chamber; the top of the connecting plate is fixed to the bottom end of the first anchor body, and the bottom of the connecting plate is fixed to the top end of the second anchor body;

[0015] A one-way lock is provided to limit the position of the first anchor cable body. The one-way lock is fixedly provided on the first sleeve, and the first anchor cable body passes through the one-way lock.

[0016] Optionally, the one-way lock is limited by a limiting portion, and the limiting portion is used to prevent the one-way lock from separating from the first sleeve.

[0017] Optionally, the limiting portion includes:

[0018] A push plate is slidably disposed in the first sleeve, and the push plate is limitedly engaged with the one-way lock;

[0019] The limiting block is fixedly arranged in the first sleeve, and the limiting block is matched with the push plate in a limiting manner.

[0020] Optionally, the push plate is transmission-connected to the connecting disk, and the push plate and the connecting disk have opposite displacement directions.

[0021] Optionally, a support rod is fixedly connected in the first sleeve, and the support rod is provided with a plurality of reverse thrust parts, one end of the reverse thrust part is fixedly connected to the push plate, and the other end of the reverse thrust part is fixedly connected to the connecting disk;

[0022] The reverse thrust portion includes two symmetrically arranged sliding sleeves, the sliding sleeves slidingly cooperate with the support rod, and connecting sleeves are hingedly connected to both sides of the two sliding sleeves through connecting rods, one end of the connecting rod is hingedly connected to the sliding sleeve, and the other end of the connecting rod is hingedly connected to the connecting sleeve;

[0023] The connecting sleeve is fixedly connected to one end of a connecting rod, wherein the other end of one of the connecting rods is fixed to the push plate, and the other end of the other connecting rod is fixed to the connecting disk.

[0024] Optionally, the shock-absorbing pad includes two steel plates, one of which is fixed to the bottom end of the second anchor cable body, and a plurality of energy-absorbing components and a plurality of shock-absorbing components are provided between the two steel plates;

[0025] The energy absorbing component comprises:

[0026] a sliding rod, fixed between the two steel plates;

[0027] a sliding sleeve, slidably connected to the sliding rod;

[0028] a first spring, one end of which is fixed to one of the steel plates, the other end of which is fixed to the sliding sleeve, and the first spring is sleeved on the sliding rod;

[0029] a second spring, one end of which is fixed to the other steel plate, the other end of which is fixed to the sliding sleeve, and the second spring is sleeved on the sliding rod;

[0030] The second spring has a harderness than the first spring;

[0031] a first limiting ring, cooperating with the sliding sleeve to limit position, the first limiting ring being coaxially fixed to the outside of the sliding rod and located on one side of the first spring;

[0032] The shock absorbing assembly comprises:

[0033] A moving piston rod and a cylinder sleeve, wherein the moving piston rod and the cylinder sleeve are in sliding engagement, one end of the moving piston rod is fixed to one of the steel plates, and the cylinder sleeve is fixed to the other steel plate;

[0034] The moving piston rod is provided with a piston, which is slidably arranged in the cylinder sleeve, and the cylinder sleeve is filled with damping fluid. The piston is provided with a plurality of variable-section through-holes at equal intervals in the circumferential direction, and the variable-section through-holes have a large-diameter end and a small-diameter end, and two adjacent variable-section through-holes are arranged oppositely;

[0035] The piston is slidably arranged on the moving piston rod, and the piston is respectively limited and matched with a first gasket and a second gasket at the upper and lower parts, and the first gasket and the second gasket are slidably matched with the moving piston rod;

[0036] Two second limiting rings are coaxially fixed to the moving piston rod, the first gasket, the second gasket and the piston are located between the two second limiting rings, and the first gasket and the second gasket are both limitedly matched with the second limiting rings on the corresponding side.

[0037] A construction method for a segmented anchor cable, used for installing the above-mentioned segmented anchor cable, comprises:

[0038] Drill anchor holes in the tunnel according to geological survey conditions;

[0039] Inserting the segmented anchor cable into the anchor cable hole so that the anchor cable body connection assembly is located at the tunnel expansion boundary line;

[0040] Extending the grouting pipe to the top of the anchor cable connection assembly and injecting a grouting separation material with expansion and rapid solidification properties, and forming a grouting separation section after the grouting separation material solidifies;

[0041] Passing a grouting pipe through the grouting stop partition section and injecting grout at the first anchor cable body, and forming a first reinforcement section after the grout solidifies;

[0042] tensioning the first anchor cable body to generate prestress;

[0043] Grouting is performed at the second anchor cable body through a grouting pipe, and a second reinforcement section is formed after the grouting solidifies;

[0044] The second anchor cable body is tensioned to generate prestress, and the shock-absorbing pad is connected to the end of the second anchor cable body;

[0045] The first reinforcement section and the grouting separation section are preserved in the rock mass as permanent support structures, and the second reinforcement section is used as a pre-reinforcement area. When the tunnel is expanded to the pre-reinforcement area, the shock-absorbing pad and the second anchor body are removed.

[0046] A segmented support structure is composed of a plurality of segmented anchor cables mentioned above.

[0047] Compared with the prior art, the present invention has the following advantages and technical effects:

[0048] Traditional anchor cable pre-reinforcement methods anchor the existing tunnel lining, the area to be excavated, and the surrounding rock fragmentation zone as a whole. This makes construction difficult when the tunnel is excavated to the pre-reinforcement zone, and the remaining anchorage structure loses its support capacity, posing safety hazards and causing material waste. The present invention enables segmented reinforcement of the existing tunnel's surrounding rock fragmentation zone. The outer portion of the expanded tunnel's outline can be converted into a permanent support structure for the expanded tunnel, while the inner portion of the expanded tunnel outline utilizes easily removable anchor cables. This not only meets the pre-reinforcement requirements of the existing tunnel's deteriorated lining structure, but also does not hinder subsequent excavation and demolition operations, thereby improving the stability of the existing tunnel during excavation construction and reducing the difficulty of subsequent construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work.

[0050] Figure 1 Schematic diagram of the overall structure of the support structure of the present invention;

[0051] Figure 2Schematic diagram of the segmented anchor cable pre-reinforcement support structure of the present invention;

[0052] Figure 3 A schematic structural diagram of the anchor cable connection assembly of the present invention;

[0053] Figure 4 Schematic diagram of the structure of the shock-absorbing pad of the present invention;

[0054] Figure 5 A schematic structural diagram of the energy absorbing assembly of the present invention;

[0055] Figure 6 A schematic structural diagram of the shock absorbing assembly of the present invention;

[0056] Figure 7 A schematic structural diagram of the first and second gaskets of the shock absorbing assembly of the present invention;

[0057] Figure 8 A top view of the structure of the first gasket of the shock absorbing assembly of the present invention;

[0058] Among them, 1. the first anchor body; 2. the second anchor body; 3. the anchor body connecting assembly; 4. the shock-absorbing pad; 5. the anchor hole; 6. the first reinforcement section; 7. the grouting separation section; 8. the second reinforcement section; 9. the first sleeve; 10. the second sleeve; 11. the connecting plate; 12. the support rod; 13. the connecting rod; 14. the sliding sleeve; 15. the bolt; 16. the one-way lock; 17. the fixed lock; 18. the limit block; 19. the push plate; 20. the energy absorption assembly; 21. the shock-absorbing assembly; 22. the steel plate; 23. the first spring; 24. the second spring; 25. the first limit ring; 26. the damping fluid; 27. the moving piston rod; 28. the first gasket; 29. ​​the second gasket; 30. the variable-section through hole; 31. the second limit ring. DETAILED DESCRIPTION

[0059] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0060] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] Reference Figures 1 to 8 The present invention discloses a segmented anchor cable, comprising:

[0062] A first anchor cable body 1 and a second anchor cable body 2 are connected by an anchor cable body connecting assembly 3. A tensioning structure is provided in the anchor cable body connecting assembly 3. One end of the tensioning structure is connected to one end of the first anchor cable body 1, and the other end of the tensioning structure is connected to one end of the second anchor cable body 2. The other end of the second anchor cable body 2 is connected to a shock-absorbing pad 4.

[0063] The first anchor cable body 1 and the second anchor cable body 2 are both fixed to the anchor cable hole 5, the anchor cable body connection assembly 3 is located at the tunnel expansion boundary line, and the shock-absorbing pad 4 is located in the existing tunnel.

[0064] The present invention includes a first anchor body 1, a second anchor body 2, an anchor body connecting assembly 3 and a shock-absorbing pad 4. The first anchor body 1 and the second anchor body 2 are connected by the anchor body connecting assembly 3. The anchor body connecting assembly 3 is set at the outline of the expanded tunnel, see S1 in the figure.

[0065] Traditional anchor cable pre-reinforcement methods anchor the existing tunnel lining, the area to be excavated, and the surrounding rock fragmentation zone as a whole. This makes construction difficult when the tunnel is excavated to the pre-reinforcement zone, and the remaining anchorage structure loses its support capacity, posing safety hazards and causing material waste. The present invention enables segmented reinforcement of the existing tunnel's surrounding rock fragmentation zone. The outer portion of the expanded tunnel's outline can be converted into a permanent support structure for the expanded tunnel, while the inner portion of the expanded tunnel outline utilizes easily removable anchor cables. This not only meets the pre-reinforcement requirements of the existing tunnel's deteriorated lining structure, but also does not hinder subsequent excavation and demolition operations, thereby improving the stability of the existing tunnel during excavation construction and reducing the difficulty of subsequent construction.

[0066] The first anchor body 1 is made of ordinary steel strand material, and its arrangement range extends from the bottom of the anchor hole 5 to the contour line S1 of the expanded tunnel. The first reinforcement section 6 formed by the first anchor body 1 can serve as a permanent reinforcement structure and remain outside the contour line S1 of the expanded tunnel to provide long-term support for the expanded tunnel.

[0067] The second anchor cable body 2 is made of glass fiber anchor cable, and its layout range starts from the anchor cable body connection component 3 at the expanded tunnel outline S1 and extends to the existing tunnel lining S2. The tensile strength of the second anchor cable body 2 is equivalent to that of ordinary steel strands, ensuring the feasibility of tensioning the first anchor cable body 1 through the anchor cable body connection component 3. In addition, its excavability can not only achieve pre-reinforcement of the existing tunnel lining S2, but also does not affect subsequent construction operations, reducing interference with the construction progress.

[0068] As an optional embodiment, the anchor body connection assembly 3 further includes:

[0069] A first sleeve 9 and a second sleeve 10 are fixed together, and the first sleeve 9 and the second sleeve 10 together form a chamber for accommodating the tensioning structure;

[0070] The first anchor body 1 and the second anchor body 2 are arranged through the cavity.

[0071] As an optional embodiment, the tension structure includes:

[0072] The connecting plate 11 is movably arranged in the chamber; the top of the connecting plate 11 is fixed to the bottom end of the first anchor body 1, and the bottom of the connecting plate 11 is fixed to the top of the second anchor body 2;

[0073] The one-way lock 16 is set to limit the first anchor cable body 1. The one-way lock 16 is fixedly set on the first sleeve 9, and the first anchor cable body 1 is set through the one-way lock 16.

[0074] The anchor body connection assembly 3 includes a first sleeve 9, a second sleeve 10, a connecting plate 11, a support rod 12, a connecting rod 13, a sliding sleeve 14, a bolt 15, a one-way lock 16, a fixed lock 17, a limit block 18 and a push plate 19, which can fix the first anchor body 1 and the second anchor body 2. During the construction process, the anchor body connection assembly 3 can independently apply prestress to the first anchor body 1 and the second anchor body 2, thereby realizing segmented pre-reinforcement of the broken zone of the tunnel surrounding rock and optimizing the pre-reinforcement effect of the anchor body.

[0075] The first sleeve 9 and the second sleeve 10 are fixed together by bolts 15 .

[0076] Through holes are provided on the first sleeve 9, the push plate 19, the connecting plate 11 and the second sleeve 10. The number of the through holes is determined according to the number of the anchor cable bodies and the grouting pipes.

[0077] The first anchor cable body 1 , the second anchor cable body 2 and the connecting plate 11 are fixed by a fixing lock 17 .

[0078] As an optional embodiment, the one-way lock 16 is limited and matched with a limiting portion, and the limiting portion is used to prevent the one-way lock 16 from separating from the first sleeve 9.

[0079] As an optional implementation, the limiting portion includes:

[0080] The push plate 19 is slidably disposed in the first sleeve 9, and the push plate 19 is limitedly engaged with the one-way lock 16;

[0081] The limiting block 18 is fixedly disposed in the first sleeve 9 , and the limiting block 18 is matched with the push plate 19 for limiting purpose.

[0082] A limit block 18 is provided inside the first sleeve to control the distance between the push plate 19 and the one-way lock 16 to prevent the one-way lock 16 from being pulled out due to the movement of the first anchor body 1 during the prestressing process of the first anchor body 1.

[0083] As an optional embodiment, the push plate 19 is transmission-connected to the connecting disk 11 , and the push plate 19 and the connecting disk 11 have opposite displacement directions.

[0084] As an optional embodiment, a support rod 12 is fixedly connected to the first sleeve 9, and the support rod 12 is provided with a plurality of reverse thrust parts, one end of the reverse thrust part is fixedly connected to the push plate 19, and the other end of the reverse thrust part is fixedly connected to the connecting disk 11;

[0085] The reverse thrust part includes two symmetrically arranged sliding sleeves 14, which are slidably matched with the support rod 12. The two sides of the two sliding sleeves 14 are respectively hinged with connecting sleeves through connecting rods, one end of the connecting rod is hinged to the sliding sleeve 14, and the other end of the connecting rod is hinged to the connecting sleeve;

[0086] One end of the connecting rod 13 is fixed to the connecting sleeve, the other end of one connecting rod 13 is fixed to the push plate 19 , and the other end of the other connecting rod 13 is fixed to the connecting disk 11 .

[0087] A sliding sleeve 14 is provided inside the first sleeve 9 , and its sliding along the support rod 12 will drive the connecting rod 13 on the upper part of the support rod 12 to move upward, thereby pushing the push plate 19 to move upward, thereby enhancing the pressing effect on the one-way lock 16 .

[0088] The first anchor cable body 1 passes through the first sleeve 9, the push plate 19 and the connecting plate 11 in sequence, and is fixedly connected to the connecting plate 11 through the fixing lock 17. It can cooperate with the one-way lock 16 along the through hole on the first sleeve 9 to realize unidirectional movement of the first anchor cable body 1.

[0089] The first anchor cable body 1 and the second anchor cable body 2 are connected via a connecting plate 11 , and the first anchor cable body 1 and the second anchor cable body 2 are fixed to the connecting plate 11 using a fixing lock 17 .

[0090] The second sleeve 10 is provided with a through hole to facilitate the free movement of the second anchor body 2 or the grouting pipe. After the first anchor body 1 and the second anchor body 2 are fixedly connected, the first sleeve 9 and the second sleeve 10 are fixedly connected by bolts 15.

[0091] As an optional embodiment, the shock-absorbing pad 4 includes two steel plates 22, one of which is fixed to the bottom end of the second anchor body 2, and a plurality of energy-absorbing components 20 and a plurality of shock-absorbing components 21 are provided between the two steel plates 22;

[0092] The energy absorbing assembly 20 includes:

[0093] A slide bar, fixed between two steel plates 22;

[0094] A sliding sleeve, slidably connected to the sliding rod;

[0095] A first spring 23, one end of which is fixed to one of the steel plates 22, and the other end of which is fixed to the sliding sleeve. The first spring 23 is sleeved on the sliding rod;

[0096] A second spring 24, one end of which is fixed to the other steel plate 22, and the other end of which is fixed to the sliding sleeve. The second spring 24 is sleeved on the sliding rod;

[0097] The second spring 24 has a harderness than the first spring 23;

[0098] A first limiting ring 25 cooperates with the sliding sleeve to limit the position. The first limiting ring 25 is coaxially fixed to the outside of the sliding rod and is located on one side of the first spring 23;

[0099] The shock absorbing assembly 21 includes:

[0100] The moving piston rod 27 and the cylinder sleeve are in sliding cooperation with each other. One end of the moving piston rod 27 is fixed to one of the steel plates 22, and the cylinder sleeve is fixed to the other steel plate 22.

[0101] A piston is provided on the moving piston rod 27, and the piston is slidably arranged in a cylinder sleeve filled with a damping fluid 26. A plurality of variable cross-section through-holes 30 are equidistantly provided on the circumference of the piston. The variable cross-section through-holes 30 have a large diameter end and a small diameter end, and two adjacent variable cross-section through-holes 30 are arranged opposite to each other.

[0102] The piston is slidably arranged on the moving piston rod 27. The upper and lower limits of the piston are respectively matched with the first gasket 28 and the second gasket 29. The first gasket 28 and the second gasket 29 are slidably matched with the moving piston rod 27.

[0103] Two second limiting rings 31 are coaxially fixed to the moving piston rod 27. The first gasket 28, the second gasket 29 and the piston are located between the two second limiting rings 31. The first gasket 28 and the second gasket 29 are both limitedly engaged with the second limiting rings 31 on the corresponding side.

[0104] The shock-absorbing pad 4 consists of an energy-absorbing component 20, a shock-absorbing component 21 and two steel plates 22. The energy-absorbing component 20 and the shock-absorbing component 21 are fixedly connected between the steel plates 22, effectively absorbing and reducing the vibration caused by the blasting construction process, and protecting the anchor cable prestress from damage.

[0105] The energy absorption component 20 includes a first spring 23 and a second spring 24, wherein the first spring 23 is a soft spring with a lower hardness so that it can respond quickly and absorb most of the impact energy at the initial stage of vibration. A first limit ring 25 is provided to prevent the soft spring from failing under strong vibration. The second spring 24 is a hard spring with a higher hardness and is used to further absorb the remaining vibration energy after the soft spring. The two cooperate to achieve progressive energy absorption, thereby effectively reducing the impact of vibration on the structure.

[0106] The shock absorber assembly 21 includes a damping fluid 26, a moving piston rod 27, a first gasket 28, and a second gasket 29. The moving piston is provided with a variable-section through-hole 30. The first gasket 28 and the second gasket 29 are respectively positioned above and below the moving piston rod 27. Both gaskets are provided with a second limiting ring 31 to limit the distance between them and the moving piston rod 27. As the piston moves up and down, the damping fluid 26 flows in the variable-section through-hole 30, generating resistance that dissipates the vibration energy caused by the explosion and further enhances the shock absorption effect.

[0107] A construction method for a segmented anchor cable, used for installing the above-mentioned segmented anchor cable, comprises:

[0108] Drill anchor holes 5 in the tunnel according to geological survey conditions;

[0109] Insert the segmented anchor cable into the anchor cable hole 5 so that the anchor cable body connection assembly 3 is located at the tunnel expansion boundary line;

[0110] Extend the grouting pipe to the top of the anchor cable connection assembly 3 and inject a grouting separation material with expansion and rapid solidification properties, and form a grouting separation section 7 after the grouting separation material solidifies;

[0111] Make the grouting pipe pass through the grouting stop partition section 7 and inject grout at the first anchor cable body 1, and form the first reinforcement section 6 after the grout solidifies;

[0112] The first anchor cable body 1 is tensioned to generate prestress;

[0113] Grouting is performed at the second anchor cable body 2 through a grouting pipe, and a second reinforcement section 8 is formed after the grouting solidifies;

[0114] The second anchor cable body 2 is tensioned to generate prestress, and a shock-absorbing pad 4 is connected to the end of the second anchor cable body 2;

[0115] The first reinforcement section 6 and the grouting separation section 7 are preserved in the rock mass as permanent support structures, and the second reinforcement section 8 is used as a pre-reinforcement area. When the tunnel is expanded to the pre-reinforcement area, the shock-absorbing pad 4 and the second anchor cable body 2 are removed.

[0116] The anchor hole 5 is divided into a first reinforcement section 6, a grouting separation section 7 and a second reinforcement section 8; the first reinforcement section 6 is from the tail of the first anchor body 1 to the top of the anchor body connecting assembly 3, the grouting separation section 7 is from the top to the tail of the anchor body connecting assembly 3, and the second reinforcement section 8 is from the tail of the anchor body connecting assembly 3 to the existing tunnel lining, see S2 in the figure.

[0117] Determine the location of the existing tunnel's surrounding rock fracture zone through geological exploration, and use a drilling rig to drill into the existing tunnel toward the surrounding rock fracture zone to form anchor holes;

[0118] The first anchor body 1 and the second anchor body 2 are fixedly connected through the anchor body connecting assembly 3, and the connected first anchor body 1 and the second anchor body 2 are arranged into the anchor hole 5 by a drilling rig, ensuring that the anchor body connecting assembly 3 is located near the contour line S1 of the expanded tunnel.

[0119] The length of the anchor cable is determined by the location of the surrounding rock fracture zone and the expanded tunnel outline S1. The first anchor cable 1, constructed from ordinary steel strands, extends from the bottom of the anchor hole 5 to the expanded tunnel outline S1, ensuring that the first reinforcement section 6 serves as a permanent support structure for the expanded tunnel. The second anchor cable 2, constructed from fiberglass, extends from the anchor cable connection assembly 3 at the expanded tunnel outline S1 to the existing tunnel lining S2, pre-reinforcing the existing tunnel lining S2 while ensuring its excavation capability during subsequent excavation.

[0120] The grouting pipe is extended to the top of the anchor body connection assembly 3, and a grouting separation material with expansion and rapid solidification properties is injected to form a grouting separation section 7 to prevent the slurry from flowing out during the subsequent grouting of the first reinforcement section 6.

[0121] The solid body strength of the grouting partition section 7 is low and the thickness is thin. The grouting partition section 7 can be drilled through by a drilling rig to ensure that the grouting pipe can smoothly enter the first reinforcement section 6 for grouting, or anti-stick coating can be sprayed on the grouting pipe. After the grouting partition material is injected, the grouting pipe is moved forward and backward to ensure that there is no adhesion between the grouting pipe and the newly formed grouting partition section 7, thereby keeping the grouting channel unobstructed.

[0122] Move the grouting pipe to the top of the first anchor body 1 to perform grouting of the first reinforcement section 6. Use cement mortar as the anchoring material, control the grouting pressure and injection speed according to the construction requirements, and complete the grouting reinforcement of the first reinforcement section 6.

[0123] After the anchor strength of the first reinforcement section 6 reaches the design requirements, the prestressing of the first anchor body 1 is started. The tensioning device is set at the existing tunnel lining S2. The tensioning stress is transmitted to the first anchor body 1 through the second anchor body 2 and the anchor body connecting assembly 3. The one-way lock 16 on the first sleeve 9 in the anchor body connecting assembly 3 is used to ensure the application of prestress and prevent the loss of prestress of the first anchor body 1.

[0124] After the strength of the first reinforcement section 6 and the first anchor body 1 is stabilized, the grouting pipe is moved to the tail of the anchor body connection assembly 3 to grout the second reinforcement section 8. After the anchor body strength of the second reinforcement section 8 reaches the design strength, the tensioning device set at the existing tunnel lining S2 is used to apply prestress to the second anchor body 2.

[0125] In order to reduce the influence of vibration caused by tunnel expansion construction on the prestress of the anchor cable, a shock-absorbing pad 4 is installed between the lock of the second anchor cable body 2 and the existing tunnel lining S2.

[0126] When the tunnel is excavated to the pre-reinforced area, the shock-absorbing pad 4 is removed to release the prestress applied by the second anchor 2. The second anchor 2 is made of fiberglass anchor cable, making it easy to remove. The first anchor 1 and the anchor connection assembly 3 serve as the permanent support structure for the expanded tunnel. After excavation, the first anchor 1 can be tensioned again through the anchor connection assembly 3.

[0127] A segmented support structure is composed of a plurality of segmented anchor cables mentioned above.

[0128] By opening a plurality of anchor holes 5 on the inner wall of the tunnel, inserting a plurality of segmented anchor cables into each anchor hole 5, and fixing each segmented anchor cable according to the construction method of the segmented anchor cable, the segmented anchor cables form a segmented support structure.

[0129] Furthermore, several segmented anchor cables are evenly distributed in the tunnel in a matrix.

[0130] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0131] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A segmented anchor cable, characterized in that: include: A first anchor cable body (1) and a second anchor cable body (2), wherein the first anchor cable body (1) and the second anchor cable body (2) are connected via an anchor cable body connecting assembly (3), wherein a tensioning structure is provided in the anchor cable body connecting assembly (3), wherein one end of the tensioning structure is connected to one end of the first anchor cable body (1), and the other end of the tensioning structure is connected to one end of the second anchor cable body (2), and the other end of the second anchor cable body (2) is connected to a shock-absorbing pad (4); The first anchor cable body (1) and the second anchor cable body (2) are both fixed to the anchor cable hole (5); the anchor cable body connection assembly (3) is located at the tunnel expansion boundary line; and the shock-absorbing pad (4) is located in the existing tunnel.

2. A segmented anchor cable according to claim 1, characterized in that: The anchor cable connecting assembly (3) further comprises: A first sleeve (9) and a second sleeve (10) fixed together, wherein the first sleeve (9) and the second sleeve (10) together form a chamber for accommodating the tensioning structure; The first anchor cable body (1) and the second anchor cable body (2) are arranged through the chamber.

3. A segmented anchor cable according to claim 2, characterized in that: The tensioning structure comprises: A connecting plate (11) is movably arranged in the chamber; the top of the connecting plate (11) is fixed to the bottom end of the first anchor cable body (1), and the bottom of the connecting plate (11) is fixed to the top end of the second anchor cable body (2); A one-way lock (16) is arranged to limit the first anchor cable body (1); the one-way lock (16) is fixedly arranged on the first sleeve (9); and the first anchor cable body (1) is arranged to pass through the one-way lock (16).

4. A segmented anchor cable according to claim 3, characterized in that: The one-way lock (16) is limited and matched with a limiting portion, and the limiting portion is used to prevent the one-way lock (16) from separating from the first sleeve (9).

5. A segmented anchor cable according to claim 4, characterized in that: The limiting portion includes: A push plate (19) is slidably disposed in the first sleeve (9), and the push plate (19) is limitedly matched with the one-way lock (16); A limit block (18) is fixedly arranged in the first sleeve (9), and the limit block (18) is matched with the push plate (19) for limiting.

6. The segmented anchor cable according to claim 5, characterized in that: The push plate (19) is in transmission connection with the connecting disk (11), and the push plate (19) and the connecting disk (11) have opposite displacement directions.

7. The segmented anchor cable according to claim 6, characterized in that: A support rod (12) is fixedly connected inside the first sleeve (9), and the support rod (12) is provided with a plurality of reverse thrust parts, one end of the reverse thrust part is fixedly connected to the push plate (19), and the other end of the reverse thrust part is fixedly connected to the connecting disk (11); The reverse thrust portion comprises two symmetrically arranged sliding sleeves (14), the sliding sleeves (14) slidingly cooperate with the support rod (12), and both sides of the two sliding sleeves (14) are respectively hinged with connecting sleeves through connecting rods, one end of the connecting rod is hinged to the sliding sleeve (14), and the other end of the connecting rod is hinged to the connecting sleeve; The connecting sleeve is fixedly connected to one end of a connecting rod (13), the other end of one connecting rod (13) is fixed to the push plate (19), and the other end of the other connecting rod (13) is fixed to the connecting disk (11).

8. The segmented anchor cable according to claim 1, characterized in that: The shock-absorbing pad (4) comprises two steel plates (22), one of which is fixed to the bottom end of the second anchor cable body (2), and a plurality of energy-absorbing components (20) and a plurality of shock-absorbing components (21) are provided between the two steel plates (22); The energy absorbing component (20) comprises: A sliding rod fixed between the two steel plates (22); a sliding sleeve, slidably connected to the sliding rod; A first spring (23), one end of which is fixed to one of the steel plates (22), the other end of which is fixed to the sliding sleeve, and the first spring (23) is sleeved on the sliding rod; A second spring (24), one end of which is fixed to the other steel plate (22), the other end of which is fixed to the sliding sleeve, and the second spring (24) is sleeved on the sliding rod; The second spring (24) has a harderness than the first spring (23); A first limiting ring (25) is engaged with the sliding sleeve in limiting position, and the first limiting ring (25) is coaxially fixed to the outside of the sliding rod and is located on one side of the first spring (23); The shock absorbing assembly (21) comprises: A moving piston rod (27) and a cylinder sleeve, wherein the moving piston rod (27) and the cylinder sleeve are in sliding cooperation, one end of the moving piston rod (27) is fixed to one of the steel plates (22), and the cylinder sleeve is fixed to the other steel plate (22); The moving piston rod (27) is provided with a piston, and the piston is slidably arranged in the cylinder sleeve, and the cylinder sleeve is filled with a damping fluid (26). The piston is circumferentially and evenly spaced with a plurality of variable-section through-holes (30), and the variable-section through-holes (30) have a large-diameter end and a small-diameter end, and two adjacent variable-section through-holes (30) are arranged oppositely. The piston is slidably arranged on the moving piston rod (27), and the piston is respectively limited and matched with a first gasket (28) and a second gasket (29) at the upper and lower parts, and the first gasket (28) and the second gasket (29) are slidably matched with the moving piston rod (27); Two second limiting rings (31) are coaxially fixedly connected to the moving piston rod (27); the first gasket (28), the second gasket (29) and the piston are located between the two second limiting rings (31); the first gasket (28) and the second gasket (29) are both limitedly matched with the second limiting rings (31) on the corresponding side.

9. A construction method for a segmented anchor cable, used for installing a segmented anchor cable according to any one of claims 1 to 8, characterized in that: include: Drilling anchor holes (5) in the tunnel according to geological survey conditions; Inserting the segmented anchor cable into the anchor cable hole (5) so that the anchor cable body connection assembly (3) is located at the tunnel expansion boundary line; Extending the grouting pipe to the top of the anchor cable connecting assembly (3) and injecting a grouting separation material with expansion and rapid solidification properties, and forming a grouting separation section (7) after the grouting separation material solidifies; Passing a grouting pipe through the grouting stop partition section (7) and injecting grout at the first anchor cable body (1), and forming a first reinforcement section (6) after the grout solidifies; tensioning the first anchor cable body (1) to generate prestress; Grouting is performed at the second anchor cable body (2) through a grouting pipe, and a second reinforcement section (8) is formed after the grouting solidifies; The second anchor cable body (2) is tensioned to generate prestress, and the shock-absorbing pad (4) is connected to the end of the second anchor cable body (2); The first reinforcement section (6) and the grouting-stopping partition section (7) are preserved in the rock mass as permanent support structures, and the second reinforcement section (8) serves as a pre-reinforcement area. When the tunnel is expanded to the pre-reinforcement area, the shock-absorbing pad (4) and the second anchor cable body (2) are removed.

10. A segmented support structure, characterized in that: The invention is composed of a segmented anchor cable as described in any one of claims 1 to 8.

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