A partially dismantled lining structure and lining construction method

Abstract

The present invention discloses a partially removable lining structure and a lining construction method, comprising an upper lining and a lower lining, wherein a connecting component is connected between the upper lining and the lower lining, wherein the connecting component comprises a connecting block, a first positioning plate and a second positioning plate, wherein the connecting block is in a cone shape, wherein the surface area of ​​the connecting block close to the surrounding rock is smaller than the surface area of ​​the side away from the surrounding rock, wherein the first positioning plate is fixedly arranged on the side of the connecting block close to the surrounding rock, wherein the upper lining, the lower lining and the side of the connecting block away from the surrounding rock are jointly formed with a receiving groove, wherein the second positioning plate is arranged in the receiving groove, wherein the first positioning plate, the second positioning plate and the upper lining are fixedly connected by a first fastener, wherein the first positioning plate, the second positioning plate and the connecting block are fixedly connected by a second fastener, and wherein the first positioning plate, the second positioning plate and the lower lining are fixedly connected by a third fastener. The present invention can safely and quickly perform maintenance and replacement of a local lining, and can reduce the time of road interruption.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel engineering construction, and in particular relates to a partially dismantled lining structure and a lining construction method. Background Art

[0002] Tunnel projects are located in complex geological environments. During long-term operation or use, they will be damaged by creep, groundwater, earthquakes or vehicle loads, such as structural cracks, steel corrosion, groundwater leakage, frost damage, etc. When the damage is serious, they will have to be dismantled and replaced. In my country, a large number of highway and railway tunnel structures need to be dismantled and replaced for maintenance.

[0003] At the current stage, for the replacement and maintenance of the lining, it is often necessary to partially or completely remove the lining, usually by blasting or mechanical chiseling. The current lining replacement methods usually have the following disadvantages: First, the blasting method will seriously affect the adjacent lining structure, while mechanical chiseling is extremely inefficient; second, after the removal, cast-in-place concrete is often used to rebuild the structure, and the construction of the in-tunnel formwork trolley and concrete maintenance is extremely difficult, and the quality control of the local replacement joints is extremely difficult; third, due to the low construction efficiency and long-term road interruption, very large additional economic losses are caused.

[0004] At present, the tunnel lining structure mainly adopts the cast-in-place concrete lining structure in the tunnel with a customized template trolley, while the subway and other projects are largely constructed by shield method, mainly using segment assembly lining. Both linings are not suitable for overall or partial replacement and maintenance. If the structure is damaged and must be replaced, it can only be removed by overall or partial destructive chiseling.

[0005] The Chinese utility model patent with the publication number CN210033452U discloses a graded anti-fracture mountain tunnel structure that crosses an active fault zone, including an outer lining layer, an outer waterproof layer, a deformation layer, a hollow corrugated steel pipe layer and an assembled second lining layer arranged in sequence from the outside to the inside, and the deformation layer is filled with foam concrete; the hollow corrugated steel pipe layer is formed by connecting the outer corrugated steel pipe and the inner corrugated steel pipe in a reverse docking manner; the assembled second lining layer is formed by prefabricated second lining segments spliced ​​along the circumferential and axial directions of the tunnel, wherein the axially adjacent segments are spliced ​​in a staggered manner, and the prefabricated second lining segments are provided with reserved bolt holes in the upper and lower and left and right directions, and the elbow bolts in the upper and lower reserved bolt holes are only arranged in the high-strength concrete layer to connect them into a high-strength concrete ring; the high-strength concrete ring is connected in series along the axial direction of the tunnel as a whole through the straight bolts in the left and right reserved bolt holes. However, after the second lining segments are connected to each other to form a high-strength concrete ring, the overall structure fits and is stable, and there is no large gap between adjacent second lining segments. When performing the replacement of the second lining segment, the second lining segment adjacent to the second lining segment to be replaced must be mechanically chiseled out or demolished by blasting before the second lining segment to be replaced can be removed. In addition, since the adjacent segments in the axial direction are spliced ​​in a staggered manner, cleaning and subsequent installation work are also very inconvenient, which greatly affects the efficiency of the tunnel replacement construction and prolongs the tunnel closure time. Summary of the invention

[0006] In order to solve the above problems in the prior art, the first object of the present invention is to provide a partially dismantled lining structure.

[0007] The second object of the present invention is to provide a lining construction method for the lining structure.

[0008] In order to achieve the above-mentioned first purpose, the partially dismantled lining structure provided by the present invention includes an upper lining and a lower lining, and the upper lining and the lower lining are detachably connected with a connecting component, and the connecting component includes a connecting block, a first positioning plate and a second positioning plate. The connecting block is cone-shaped, and the area of ​​the surface of the connecting block close to the surrounding rock is smaller than the area of ​​the surface on the side away from the surrounding rock. The connecting block and the upper lining and the lower lining form a ring as a whole. The first positioning plate is fixedly arranged on the side of the connecting block close to the surrounding rock, and the upper lining, the lower lining and the side of the connecting block away from the surrounding rock jointly form a receiving groove, and the second positioning plate is arranged in the receiving groove. The first positioning plate, the second positioning plate and the upper lining are correspondingly provided with one or more first connecting holes, and the first positioning plate and the second positioning plate are provided with one or more first connecting holes. One or more second connecting holes are correspondingly arranged on the first positioning plate, the second positioning plate and the connecting block, and one or more third connecting holes are correspondingly arranged on the first positioning plate, the second positioning plate and the lower lining. The first positioning plate, the second positioning plate and the upper lining are fixedly connected by passing through a first connecting hole using a detachable first fastener, the first positioning plate, the second positioning plate and the connecting block are fixedly connected by passing through a second connecting hole using a detachable second fastener, the first positioning plate, the second positioning plate and the lower lining are fixedly connected by passing through a third connecting hole using a detachable third fastener, and the number of the first fasteners, the second fasteners and the third fasteners respectively corresponds to the number of the first connecting hole, the second connecting hole and the third connecting hole.

[0009] As can be seen from the above, the upper lining and the lower lining are fixedly connected as a whole into a ring by means of the setting of the connecting block, the first positioning plate, and the second positioning plate. The first positioning plate, the second positioning plate, the connecting block, the upper lining, and the lower lining are all detachably connected. The surface area of ​​the connecting block close to the surrounding rock is smaller than the surface area of ​​the side away from the surrounding rock. After the connecting block is removed, there is a corresponding space between the upper lining and the lower lining, which is convenient for the removal and replacement of the upper lining or the lower lining. In this way, there is no need to remove or replace the upper lining or the lower lining by blasting or mechanical chiseling, and the blasting method is prevented from affecting the adjacent lining structure. The lining structure that needs to be replaced can be removed without destroying the entire or adjacent lining structure, and the adjacent lining structure will not be affected during the removal and installation process, which greatly improves the efficiency and safety of the construction.

[0010] A further solution is that the first fastener includes a first stud, the first stud is abutted against a first outer nut on a side of the first positioning plate close to the surrounding rock, and the first stud is abutted against a first inner nut on a side of the second positioning plate away from the surrounding rock; the second fastener includes a second stud, the second stud is abutted against a second outer nut on a side of the first positioning plate close to the surrounding rock, and the second stud is abutted against a second inner nut on a side of the second positioning plate away from the surrounding rock; the third fastener includes a third stud, the third stud is abutted against a third outer nut on a side of the first positioning plate close to the surrounding rock, and the third stud is abutted against a third inner nut on a side of the second positioning plate away from the surrounding rock.

[0011] As can be seen from the above, by using stud nuts to fix the first positioning plate and the second positioning plate to the upper lining, the lower lining and the connecting block respectively, the connecting parts of the upper lining, the lower lining and the connecting block are fixed, which plays a role in stabilizing the connecting parts.

[0012] A further solution is that a positioning groove is provided on one side of the connecting block close to the surrounding rock, the second stud is movably inserted into the positioning groove, and an auxiliary nut is further provided on the second stud, and the auxiliary nut is located in the positioning groove.

[0013] In a further embodiment, the connecting block is made of steel or concrete.

[0014] As can be seen from the above, by providing an auxiliary nut on the connecting block, the second stud on the connecting block is screwed out a preset distance when the connecting block is removed, and the connecting block can be removed more conveniently through the cooperation of the second stud and the auxiliary nut.

[0015] A further solution is that both the upper lining and the lower lining include more than three prefabricated concrete segments that are circumferentially fixed and spliced ​​together; or, the upper lining includes more than three prefabricated concrete segments that are circumferentially fixed and spliced ​​together, and the lower lining is formed in one piece.

[0016] A further solution is that a first positioning piece is provided at one end of a concrete precast pipe segment adjacent to each other, and a second positioning piece is provided at one end of another concrete precast pipe segment close to the first positioning piece, and the first positioning piece and the second positioning piece cooperate to position and splice the adjacent concrete precast pipe segments.

[0017] A further solution is that adjacent prefabricated concrete segments are fixedly connected by bent bolt joints.

[0018] It can be seen from the above that the cooperation between the first positioning member and the second positioning member between two adjacent precast concrete segments reduces the difficulty of assembly construction and improves the construction efficiency of assembled lining. In addition, the adjacent precast concrete segments are fixedly connected by bent bolt joints, which greatly improves the stability and safety of the tunnel lining structure.

[0019] In order to achieve the above second object, the present invention provides a lining construction method of the above partially removable lining structure, the method comprising an installation construction step and a removal construction step, the installation construction step comprising:

[0020] Step 1: splice three or more prefabricated concrete segments to form a lower lining and install them at a preset position, fix adjacent prefabricated concrete segments with a first bent bolt joint passing through a first stud hole, and fix a first positioning plate, a first stud, a second stud, a third stud, and a first outer nut, a second outer nut, and a third outer nut at the preset position;

[0021] Step 2: Use a lifting device to splice three or more prefabricated concrete segments to form an upper lining, fix adjacent prefabricated concrete segments with a second bent bolt joint passing through the second stud hole, and lift and install the upper lining to the designed position;

[0022] Step 3: Install a connection block between the upper lining and the lower lining, install a second positioning plate in the receiving groove, and install a first inner nut, a second inner nut and a third inner nut for fixing;

[0023] The steps of dismantling and replacing include:

[0024] Step a: first determine the prefabricated concrete segment to be replaced, remove the first inner nut, the second inner nut, the third inner nut and the second positioning plate, and remove the first stud, the second stud, the third stud and the connecting block;

[0025] Step b: removing the first bent bolt joint or the second bent bolt joint between the precast concrete pipe segment to be replaced and the precast concrete pipe segment connected thereto, removing the corresponding precast concrete pipe segment and replacing it with a new precast concrete pipe segment;

[0026] Step c1: when carrying out the upper lining construction, repeat the steps 2 and 3 in the installation construction steps;

[0027] Step c2: When carrying out the lower lining construction, repeat steps 1 and 3 in the installation construction steps.

[0028] Another solution is that the method includes an installation construction step and a removal construction step, and the installation construction step includes:

[0029] Step 1: First, cast concrete of a preset size at a preset position to form a lower lining, and fix the first positioning plate and the first stud, the second stud, the third stud, and the first outer nut, the second outer nut, and the third outer nut at the preset position;

[0030] Step 2: Use a lifting device to splice three or more precast concrete segments to form an upper lining. Use bent bolt joints to pass through the stud holes to fix adjacent precast concrete segments, and lift and install the upper lining to the designed position.

[0031] Step 3: Install a connection block between the upper lining and the lower lining, install a second positioning plate in the receiving groove, and install a first inner nut, a second inner nut and a third inner nut for fixing;

[0032] The steps of dismantling and replacing include:

[0033] Step a: first determine the prefabricated concrete segment to be replaced, remove the first inner nut, the second inner nut, the third inner nut and the second positioning plate of the connecting component, and remove the first stud, the second stud, the third stud and the connecting block;

[0034] Step b: removing the bent bolt joint between the precast concrete pipe segment to be replaced and the precast concrete pipe segment connected thereto, removing the precast concrete pipe segment to be replaced and replacing it with a new precast concrete pipe segment;

[0035] Step c1: when carrying out the upper lining construction, repeat the steps 2 and 3 in the installation construction steps;

[0036] Step c2: When carrying out the lower lining construction, repeat steps 1 and 3 in the installation construction steps.

[0037] It can be seen from the above that the lining construction method of the above-mentioned partially dismantled lining structure is not only simple to operate, but also can conveniently dismantle and replace the prefabricated concrete segments that need to be replaced locally by dismantling the connecting structure between the upper lining and the lower lining, without the need for blasting and mechanical chiseling, thereby ensuring the stability and safety of the lining structure, greatly reducing the working time in the tunnel, realizing rapid repair of the tunnel lining structure, and reducing the road interruption time.

[0038] A further solution is that a positioning groove is provided on one side of the connecting block close to the surrounding rock, and an auxiliary nut is installed in the positioning groove; step a also includes: unscrewing the second stud provided on the connecting block a preset distance along the direction close to the tunnel surrounding rock toward the direction away from the tunnel surrounding rock, and removing the connecting block using the auxiliary nut in the positioning groove and the second stud provided on the connecting block.

[0039] As can be seen from the above, by screwing the second stud out by a preset distance, the connecting block can be conveniently removed through the cooperation between the second stud and the connecting block.

[0040] In summary, when the above-mentioned partially removable lining structure is being dismantled and replaced, the connection blocks can be removed to facilitate the dismantling and replacement of the local lining structure, thereby avoiding the risk of seriously affecting the stability of adjacent lining structures and greatly improving the efficiency of installation and replacement construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a structural diagram of the partially dismantled lining structure of the present invention.

[0042] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0043] Figure 3 for Figure 1 Enlarged view of point B in the middle. DETAILED DESCRIPTION

[0044] See also Figure 1 and Figure 2The partially removable lining structure of this embodiment includes an upper lining 1, a connecting component 3 and a lower lining 2. The connecting component 3 includes a connecting block 5, a first positioning plate 6 and a second positioning plate 4. The connecting block 5 is cone-shaped and made of steel or high-strength concrete. The high-strength concrete of this embodiment is concrete with a grade of C60 or above. The surface area of ​​the connecting block 5 close to the surrounding rock is smaller than the surface area of ​​the side away from the surrounding rock. The connecting block 5 forms a ring with the upper lining 1 and the lower lining 2 as a whole. The first positioning plate 6 is fixedly installed on the side of the connecting block 5 close to the surrounding rock. The upper lining 1, the lower lining 2 and the side of the connecting block 5 away from the surrounding rock form a receiving groove 7. The second positioning plate 4 is installed in the receiving groove 7. The first positioning plate 6, the second positioning plate 4 and the upper lining 1 are correspondingly provided with a first connecting hole 8. The first positioning plate 6, the second positioning plate 4 and the connecting block 5 are correspondingly provided with a second connecting hole 9. The first positioning plate 6, the second positioning plate 4 and the lower lining 2 are correspondingly provided with a third connecting hole 10. The first stud 11 passes through the first connecting hole 8. The first stud 11 has first connecting holes 8 and first connecting holes 9 and 10 respectively arranged at both ends. The outer nut 14 and the first inner nut 17, the first outer nut 14 abuts against the side of the first positioning plate 6 close to the surrounding rock, and the first inner nut 17 abuts against the side of the second positioning plate 4 away from the surrounding rock; the second stud 12 passes through the second connecting hole 9, and the second outer nut 15 and the second inner nut 18 are respectively provided at both ends of the second stud 12, the second outer nut 15 abuts against the side of the first positioning plate 6 close to the surrounding rock, and the second inner nut 18 abuts against the side of the second positioning plate 4 away from the surrounding rock; the third stud 13 passes through the third connecting hole 10, and the third outer nut 16 and the third inner nut 19 are respectively provided at both ends of the third stud 13, the third outer nut 16 abuts against the side of the first positioning plate 6 close to the surrounding rock, and the third inner nut 19 abuts against the side of the second positioning plate 4 away from the surrounding rock. The upper lining 1, the lower lining 2, the first positioning plate 6, the second positioning plate 4 and the connecting block 5 are detachably fixedly connected through the cooperation among the first stud 11, the first outer nut 14, the first inner nut 17, the second stud 12, the second outer nut 15, the second inner nut 18, the third stud 13, the third outer nut 16 and the third inner nut 19, so as to achieve the purpose of partial replacement of the upper lining 1 and the lower lining 2. Optionally, the upper lining 1, the lower lining 2, the first positioning plate 6, the second positioning plate 4 and the connecting block 5 are fixedly connected by using existing fasteners, which will not be described in detail here.

[0045] Preferably, the number of the first connecting hole 8, the second connecting hole 9 and the third connecting hole 10 is more than one, the first stud 11, the first outer nut 14, the first inner nut 17 correspond to the number of the first connecting holes 8, the second stud 12, the second outer nut 15, the second inner nut 18 correspond to the number of the second connecting holes 9, and the number of the third stud 13, the third outer nut 16, the third inner nut 19 corresponds to the number of the third connecting holes 10.

[0046] See also Figure 1 and Figure 3 The upper lining 1 is formed by five precast concrete segments 21 fixedly spliced ​​in an annular direction, and the lower lining 2 is formed by three precast concrete segments 21 fixedly spliced ​​in an annular direction. The first positioning members 23 are arranged at both ends of the precast concrete segments 21 of the arch, and the second positioning members 22 are arranged at the ends of the precast concrete segments 21 of the two adjacent sides connected to the precast concrete segments 21 of the arch. The second positioning members 22 are arranged at both ends of the precast concrete segments 21 of the arch bottom, and the first positioning members 23 are arranged at the ends of the precast concrete segments 21 of the two adjacent sides connected to the precast concrete segments 21 of the arch bottom. The surface of the end of the precast concrete segments 21 connected to the connecting block 5 corresponds to the surface of the connecting block 5. The first positioning member 23 is a wedge-shaped block, and the second positioning member 22 is a concave groove. The wedge-shaped block cooperates with the concave groove to facilitate the construction personnel to splice. The optional first positioning member and the second positioning member can be matched and connected using the existing structure, which will not be repeated here. Adjacent prefabricated concrete segments 21 are fastened by bent bolt joints 20. Modularizing the lining structure helps save the cost of replacement and construction while facilitating construction. Optionally, the lower lining is cast in one piece.

[0047] Preferably, the upper lining and the lower lining are both formed by splicing three or more prefabricated concrete segments 21 .

[0048] See also Figure 2 A positioning groove 24 is provided on the side of the connection block 5 close to the surrounding rock, and an auxiliary nut 25 is provided on the inner side of the second stud 12 close to the first positioning plate 6, and the auxiliary nut 25 is installed in the positioning groove 24. The second stud 12 is rotated away from the second outer nut 15 to the position of the auxiliary nut 25, and the connection block 5 can be easily removed through the cooperation between the auxiliary nut 25 and the positioning groove 24 and the cooperation between the auxiliary nut 25 and the second stud 12.

[0049] The present invention also provides a lining construction method for the above-mentioned partially removable lining structure, including an installation construction step and a removal construction step, wherein the installation construction step includes:

[0050] Step 1: Splice more than three prefabricated concrete segments 21 to form a lower lining 2 and install them at a preset position. Adjacent prefabricated concrete segments 21 are fixed with a first bent bolt joint 26. Then, a first positioning plate 6, a first stud 11, a second stud 12, a third stud 13, and a first external nut 14, a second external nut 15, and a third external nut 16 are fixedly installed at the preset position.

[0051] Step 2: Use a lifting device to splice three or more prefabricated concrete segments 21 to form an upper lining 1, fix adjacent prefabricated concrete segments 21 with second bent bolt joints 20, and lift and install the upper lining 1 to the designed position.

[0052] Step three: Install the connecting block 5 between the upper lining 1 and the lower lining 2, then install the second positioning plate 4 in the receiving groove 7, and install the first inner nut 17, the second inner nut 18 and the third inner nut 19 for fixing.

[0053] The steps of dismantling and replacing include:

[0054] Step a: First determine the prefabricated concrete segment 21 to be replaced, remove the first inner nut 17, the second inner nut 18, the third inner nut 19 and the second positioning plate 4 of the connecting component 3, and then remove the first stud 11, the second stud 12, the third stud 13 and the connecting block 5.

[0055] Step b: remove the first bent bolt joint 26 or the second bent bolt joint 20 between the precast concrete segment 21 to be replaced and the precast concrete segment 21 connected thereto, remove the precast concrete segment 21 to be replaced and replace it with a new precast concrete segment 21.

[0056] Step c1: When constructing the upper lining 1, repeat steps 2 and 3 in the installation construction steps.

[0057] Step c2: When constructing the lower lining 2, repeat steps 1 and 3 in the installation construction steps.

[0058] Optionally, when the lower lining is integrally formed, the installation construction steps may also be:

[0059] Step 1: First, cast concrete of a preset size at a preset position to form a lower lining 2, and fix the first positioning plate 6 and the first stud 11, the second stud 12, the third stud 13 and the first outer nut 14, the second outer nut 15, and the third outer nut 16 at the preset position.

[0060] Step 2: Use a lifting device to splice three or more prefabricated concrete segments 21 to form an upper lining 1, fix adjacent prefabricated concrete segments 21 with bent bolt joints 20, and lift and install the upper lining 1 to the designed position.

[0061] Step three: Install the connecting block 5 between the upper lining 1 and the lower lining 2, install the second positioning plate 4 in the receiving groove 7, and install the first inner nut 17, the second inner nut 18 and the third inner nut 19 for fixing.

[0062] The steps of dismantling and replacing include:

[0063] Step a: First determine the prefabricated concrete segment 21 that needs to be replaced, remove the first inner nut 17, the second inner nut 18, the third inner nut 19 and the second positioning plate 4 of the connecting component 3, and then remove the first stud 11, the second stud 12, the third stud 13 and the connecting block 5.

[0064] Step b: dismantle the bent bolt joint 20 between the precast concrete segment 21 to be replaced and the precast concrete segment 21 connected thereto, remove the corresponding precast concrete segment 21 and replace it with a new precast concrete segment 21 .

[0065] Step c1: When constructing the upper lining 1, repeat steps 2 and 3 in the installation construction steps.

[0066] Step c2: When constructing the lower lining 2, repeat steps 1 and 3 in the installation construction steps.

[0067] Preferably, a positioning groove 24 is provided on a side of the connecting block 5 close to the surrounding rock in this embodiment, and an auxiliary nut 25 is installed in the positioning groove 24;

[0068] Step a also includes: unscrewing the second stud 12 provided on the connecting block 5 by a preset distance along the direction close to the tunnel surrounding rock toward the direction away from the tunnel surrounding rock, and removing the connecting block 5 using the auxiliary nut 25 in the positioning groove 24 and the second stud 12 provided on the connecting block 5.

[0069] In summary, the partially removable lining structure of the present invention can effectively avoid serious impact on adjacent lining structures when replacing the local lining structure. The installation and construction operation is simple, and the subsequent replacement construction does not require mechanical removal of adjacent lining structures, which greatly reduces the operation time in the tunnel, improves construction efficiency, enables rapid repairs and reduces road interruption time, and has certain economic benefits.

[0070] It should be noted that the above are only preferred embodiments of the present invention, but the design concept of the invention is not limited thereto, and any non-substantial modifications made to the present invention using this concept also fall within the protection scope of the present invention.

Claims

1. A partially removable lining structure, comprising an upper lining and a lower lining; Features: The upper lining and the lower lining are detachably connected with a connecting component, the connecting component comprising a connecting block, a first positioning plate and a second positioning plate, the connecting block is cone-shaped, the surface area of ​​the connecting block close to the surrounding rock is smaller than the surface area of ​​the side away from the surrounding rock, the connecting block and the upper lining and the lower lining are integrally ringed, the first positioning plate is fixedly arranged on the side of the connecting block close to the surrounding rock, the upper lining, the lower lining and the side of the connecting block away from the surrounding rock jointly form a receiving groove, the second positioning plate is arranged in the receiving groove, and one or more first connecting holes are correspondingly arranged on the first positioning plate, the second positioning plate and the upper lining, and the first positioning plate, the second positioning plate and the connecting block are connected to the connecting block. One or more second connecting holes are correspondingly provided, and one or more third connecting holes are correspondingly provided on the first positioning plate, the second positioning plate and the lower lining. The first positioning plate, the second positioning plate and the upper lining are fixedly connected by a detachable first fastener passing through one of the first connecting holes, the first positioning plate, the second positioning plate and the connecting block are fixedly connected by a detachable second fastener passing through one of the second connecting holes, and the first positioning plate, the second positioning plate and the lower lining are fixedly connected by a detachable third fastener passing through one of the third connecting holes, and the number of the first fasteners, the second fasteners and the third fasteners respectively corresponds to the number of the first connecting holes, the second connecting holes and the third connecting holes.

2. A partially removable lining structure according to claim 1, characterized in that: The first fastener comprises a first stud, the first stud abuts against a first outer nut on a side of the first positioning plate close to the surrounding rock, and the first stud abuts against a first inner nut on a side of the second positioning plate away from the surrounding rock; The second fastener comprises a second stud, the second stud abuts against a second outer nut on a side of the first positioning plate close to the surrounding rock, and the second stud abuts against a second inner nut on a side of the second positioning plate away from the surrounding rock; The third fastener comprises a third stud, which is abutted against a third outer nut on a side of the first positioning plate close to the surrounding rock, and is abutted against a third inner nut on a side of the second positioning plate away from the surrounding rock.

3. A partially removable lining structure according to claim 2, characterized in that: A positioning groove is arranged on one side of the connection block close to the surrounding rock, and the second stud is movably inserted into the positioning groove. An auxiliary nut is also arranged on the second stud, and the auxiliary nut is located in the positioning groove.

4. A partially removable lining structure according to claim 2 or 3, characterized in that: The connecting block is made of steel or high-strength concrete.

5. A partially removable lining structure according to claim 2 or 3, characterized in that: The upper lining and the lower lining are both composed of three or more prefabricated concrete segments fixedly spliced ​​in an annular direction; or, The upper lining includes more than three prefabricated concrete segments which are circumferentially fixed and spliced ​​together, and the lower lining is formed in one piece.

6. A partially dismantled lining structure according to claim 5, characterized in that: A first positioning piece is provided at one end of one of the adjacent precast concrete segments, and a second positioning piece is provided at one end of another precast concrete segment close to the first positioning piece. The first positioning piece and the second positioning piece cooperate to position and splice the adjacent precast concrete segments.

7. A partially dismantled lining structure according to claim 6, characterized in that: Adjacent prefabricated concrete segments are fixedly connected via bent bolt joints.

8. A method for lining construction of a partially dismantled lining structure according to any one of claims 2 to 7, characterized in that: The method comprises an installation construction step and a removal construction step, wherein the installation construction step comprises: Step 1: splicing three or more prefabricated concrete segments to form the lower lining and installing them at a preset position, fixing adjacent prefabricated concrete segments with a first bent bolt joint, and fixing the first positioning plate, the first stud, the second stud, the third stud, and the first outer nut, the second outer nut, and the third outer nut at the preset position; Step 2: Use a lifting device to splice three or more prefabricated concrete segments to form the upper lining, fix adjacent prefabricated concrete segments with second bent bolt joints, and lift and install the upper lining to the designed position; Step three: installing the connection block between the upper lining and the lower lining, installing the second positioning plate in the receiving groove, installing the first inner nut, the second inner nut and the third inner nut and fixing them; The dismantling and replacement construction steps include: Step a: first determine the prefabricated concrete segment to be replaced, remove the first inner nut, the second inner nut, the third inner nut and the second positioning plate, and remove the first stud, the second stud, the third stud and the connecting block; Step b: removing the first bent bolt joint or the second bent bolt joint between the precast concrete segment to be replaced and the precast concrete segment connected thereto, removing the precast concrete segment to be replaced and replacing it with a new precast concrete segment; Step c1: when the upper lining construction is being carried out, repeating the steps 2 and 3 in the installation construction steps; Step c2: When carrying out the lower lining construction, repeat the steps 1 and 3 in the installation construction steps.

9. A lining construction method according to claim 8, characterized in that: A positioning groove is provided on one side of the connection block close to the surrounding rock, and an auxiliary nut is installed in the positioning groove; The step a also includes: unscrewing the second stud arranged on the connecting block by a preset distance along the direction close to the tunnel surrounding rock toward the direction away from the tunnel surrounding rock, and removing the connecting block using the auxiliary nut in the positioning groove and the second stud arranged on the connecting block.

10. A method for lining construction of a partially dismantled lining structure according to any one of claims 2 to 7, characterized in that: The method comprises an installation construction step and a removal construction step, wherein the installation construction step comprises: Step 1: First, cast concrete of a preset size at a preset position to form the lower lining, and fix the first positioning plate and the first stud, the second stud, the third stud, and the first outer nut, the second outer nut, and the third outer nut at the preset position; Step 2: Use a lifting device to splice three or more prefabricated concrete segments to form the upper lining, fix adjacent prefabricated concrete segments with bent bolt joints, and lift and install the upper lining to the designed position; Step three: installing the connection block between the upper lining and the lower lining, installing the second positioning plate in the receiving groove, installing the first inner nut, the second inner nut and the third inner nut and fixing them; The dismantling and replacement construction steps include: Step a: first determine the prefabricated concrete segment to be replaced, remove the first inner nut, the second inner nut, the third inner nut and the second positioning plate, and remove the first stud, the second stud, the third stud and the connecting block; Step b: removing the bent bolt joint between the precast concrete pipe segment to be replaced and the precast concrete pipe segment connected thereto, removing the precast concrete pipe segment to be replaced and replacing it with a new precast concrete pipe segment; Step c1: when the upper lining construction is being carried out, repeating the steps 2 and 3 in the installation construction steps; Step c2: When carrying out the lower lining construction, repeat the steps 1 and 3 in the installation construction steps.

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