A method for rapid restoration of existing tunnel lining

Abstract

The present invention belongs to the technical field of tunnel construction, and particularly relates to a method for rapid restoration of existing tunnel linings. In order to achieve rapid restoration of existing tunnels, by zoning the operating sections and adopting the tunnel inverted arch double-trestle counter-logistics method, the simultaneous construction of the secondary lining area, the double inverted arch trestle area, and the expansion area is achieved, thereby improving the logistics efficiency of each construction area and solving the technical problem of material transportation in multiple working faces of the tunnel. Combined with the tunnel full-section waterproof board laying structure and the lining buffer layer laying structure, the construction speed of the waterproof board and the buffer layer is effectively improved; combined with the chute window-by-window layered pouring construction technology, the secondary lining arch wall concrete is quickly fed window by window, and the mechanical window-by-window layered pouring improves the pouring speed of the tunnel secondary lining concrete. In the later stage, maintenance is carried out by mobile fog cannons and moisturizing films to ensure the overall quality of the secondary lining concrete construction.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a method for quickly restoring an existing tunnel lining. Background Art

[0002] At present, the operating mileage of domestic highway and railway tunnels continues to grow. During the construction or operation of some tunnels, due to geological reasons, construction quality, repeated loads from operating vehicles, etc., serious cracking and inward extrusion of the lining, uplift of the roadbed and other geological disasters have been found in many places in the tunnel, which do not meet the requirements for safe tunnel operation; or during the construction stage, due to high ground stress or the tectonic action of active faults, some of the completed invert arches can no longer bear the load or are affected in use, and the diseased sections need to be completely replaced.

[0003] For the above-mentioned tunnel special geological disaster emergency rescue project, in order to achieve the expansion and resumption of operation of a single tunnel and a single line in a short period of time, it is necessary to carry out construction on multiple working surfaces simultaneously. Faced with the numerous lining restoration construction processes, there are problems such as mutual interference between the various processes, extremely difficult organization of logistics in the tunnel, and difficult construction organization and management. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for rapid restoration of existing tunnel linings in order to solve the technical problems of difficulty in transporting materials in multiple working faces of a tunnel and slow construction progress in the prior art.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for rapid restoration of existing tunnel lining, comprising the following steps:

[0007] Step 1: Divide the main tunnel operation section into sections and carry out tunnel invert construction;

[0008] The zoning includes four sections: along the length direction of the main tunnel operation section, there are the second lining section, the first trestle section, the second trestle section and the expansion section, with an interval of 20-50m between adjacent sections; the tunnel invert construction is carried out simultaneously in the first trestle section and the second trestle section;

[0009] Step 2: Lay waterproof panels on the entire tunnel section of the main tunnel operation section;

[0010] Step 3: After the waterproofing board is laid, the lining reinforcement is constructed; first, the positioning reinforcement is constructed, and the circumferential reinforcement and longitudinal distribution reinforcement are installed according to the positioning reinforcement, and finally the connecting reinforcement between the two layers of reinforcement is installed;

[0011] Step 4: construct the longitudinal annular waterstop, including overlapping the longitudinal annular waterstop;

[0012] Step 5: Lining casting and curing. The lining is constructed using a hydraulic steel mold integral lining trolley. The secondary lining is constructed using a large curved steel mold lining trolley. The arch wall is molded in one step.

[0013] Step 6. Repeat steps 1 to 5 to complete the restoration of all tunnel linings.

[0014] To achieve rapid restoration of existing tunnels, the technical solution of the present invention utilizes a tunnel inverted arch dual-trestle counter-logistics method, enabling simultaneous construction of four areas: the secondary lining area, the dual inverted arch trestles area, and the excavation area. This improves logistics efficiency in each construction area and addresses the technical challenges of material transportation within multiple working faces of the tunnel. The combination of a full-section waterproofing board installation and lining buffer layer installation effectively increases the construction speed of the waterproofing board and buffer layer. The combination of a window-by-window, layered pouring method using a chute allows for rapid window-by-window feeding of the secondary lining arch wall concrete. Mechanical window-by-window, layered pouring increases the pouring speed of the tunnel's secondary lining concrete. Later, mobile fog cannons and moisturizing membranes are used for maintenance to ensure the overall quality of the secondary lining concrete construction.

[0015] As a preferred solution of the present invention, in step 1, a first transverse channel is provided at the front end of the main tunnel operation section, and a second transverse channel is provided at the rear end of the main tunnel operation section. Logistics transportation in the first trestle area is carried out through the first transverse channel, and logistics transportation in the second trestle area is carried out through the second transverse channel. The first transverse channel and the second transverse channel are connected by a flat guide parallel to the main tunnel.

[0016] The first transverse passage is close to the second lining construction area, and the second transverse passage is close to the expansion excavation area.

[0017] Preferably, the inverted arch construction processes of the first trestle area and the second trestle area are carried out simultaneously, with opposite logistics directions, and the logistics transportation direction during the inverted arch construction process of the expansion area is the same as that of the first trestle area.

[0018] Preferably, the distance between the inverted arches corresponding to the first trestle area and the second trestle area is 20-24m.

[0019] As a preferred embodiment of the present invention, in step 1, the tunnel invert construction specifically includes:

[0020] Initial support and pouring of the inverted arch are carried out in the first trestle area and the second trestle area respectively.

[0021] As a preferred embodiment of the present invention, in step 2, the waterproof board laying and hanging step is:

[0022] a. First, install anchor steel bars on the side walls on both sides of the tunnel, with an anchor depth of 40cm;

[0023] b. Then, set a clamp point every 60cm along the longitudinal length of the waterproof board. The length of the waterproof board clamp is 3m, with a total of 4 clamp points. Then lay it from one side to the other.

[0024] c. Similarly, use the waterproof board clamp to clamp the other end of the waterproof board on the other side.

[0025] d. After the waterproof board fixture is adjusted into place, use a ladder to ultrasonically weld the waterproof board.

[0026] As a preferred solution of the present invention, after the waterproof board is installed, the inverted arch formwork is installed, and the inverted arch concrete is poured and maintained. After the inverted arch construction is completed, the trestle is dismantled.

[0027] Preferably, in step 4, the longitudinal annular waterstop overlap construction process is specifically as follows:

[0028] S1. First, cut off the rubber of the convex part of the steel edge rubber water stop;

[0029] S2. Then put the steel plate waterstop and the steel edge rubber waterstop together, and anchor them with at least two rivets on each side;

[0030] S3. After the rivets are anchored, the gap between the steel-edge rubber waterstop and the steel plate waterstop is tightly bonded with adhesive material.

[0031] Preferably, in step 5, the lining pouring construction process is specifically as follows: firstly, the concrete surface is roughened, then the buffer layer is constructed, and finally, the lining window is poured.

[0032] Preferably, before constructing the buffer layer, the bottom edge center line of the buffer layer, the center line of the annular hose and the center line of the drainage strip are marked on the initial support surface. The bottom edge line of the buffer layer is the rail top elevation, the annular hose and the annular drainage strip are arranged alternately, and the buffer layer is laid between adjacent annular hoses in the longitudinal and annular directions. Multiple dovetail clamps are provided between two adjacent buffer layers.

[0033] Preferably, the cushion layer is made of polyethylene.

[0034] Preferably, the lining is cast layer by layer using a chute and window by window, and a lining trolley is used for the lining casting. The lining trolley is provided with a graded diversion device, and the graded diversion device includes multi-stage diversion components from top to bottom, and each multi-stage diversion component includes a main hopper, a main trough, a three-way diversion trough, a diversion string tube and a window inlet trough.

[0035] Preferably, the lining is poured symmetrically in layers from bottom to top with layer-by-layer vibration, and a low-frequency vibrator and a high-frequency vibrator are used in combination during the concrete consolidation process.

[0036] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0037] 1. The technical solution of the present invention proposes a tunnel inverted arch double-trestle counter-logistics mode and an inverted arch dual-channel construction method, thereby realizing the simultaneous construction of four areas: the secondary lining area, the double inverted arch trestle area, and the expansion area. This greatly improves the logistics efficiency of each construction section and overcomes the problem of material transportation in multiple working faces of small-section and short-interval tunnels.

[0038] 2. The technical solution of this invention, based on simultaneous multi-section construction, also incorporates the installation of waterproofing panels across the entire tunnel section. This lining buffer layer installation effectively enhances the waterproofing effectiveness of the waterproofing panels' overlaps. During the secondary lining pouring process, a secondary lining trolley is integrated with a graded diversion device, enabling rapid window-by-window material feeding across the entire tunnel section and accelerating the secondary lining's recovery. After the secondary lining is poured, high- and low-frequency vibration, mobile fog cannons, and a moisturizing film are further incorporated for maintenance, ensuring the final quality of the secondary lining. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a construction flow chart of the present invention;

[0040] Figure 2 It is a schematic diagram of the partition of the main tunnel operation section of the present invention;

[0041] Figure 3 It is a logistics transportation route map during the tunnel invert construction process of the present invention;

[0042] Figure 4 This is a schematic diagram of the waterproof board laying and hanging structure of the present invention;

[0043] Figure 5 It is a schematic diagram of the hanging structure of the present invention;

[0044] Figure 6 This is a schematic diagram of the clamp structure of the waterproof board laying and hanging structure of the present invention;

[0045] Figure 7 This is a schematic diagram of the overlap of the longitudinal annular waterstop of the present invention;

[0046] Figure 8 Schematic diagram of the cushion structure of the present invention;

[0047] Figure 9 It is a schematic structural diagram of the dovetail clamp of the present invention;

[0048] Figure 10 Schematic diagram of the grading and diversion device of the present invention;

[0049] Icons: 1-first transverse channel; 2-second transverse channel; 3-second lining area; 4-first trestle area; 5-second trestle area; 6-expansion area; 7-steel pipe; 8-clamp; 9-waterproof board; 10-adjusting bolt; 11-anchor bolt; 12-steel plate waterstop; 13-steel edge rubber waterstop; 14-longitudinal construction joint; 15-drainage board strip; 16-circumferential hose; 17-buffer cushion; 18-dovetail clamp;

[0050] 19- Main hopper; 20- Main flow chute; 21- Three-way diversion chute; 22 Diversion string tube; 23- Window flow chute. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0052] Example 1

[0053] This embodiment is explained with reference to a specific case. The method of this embodiment has been successfully applied to a special geological disaster emergency rescue project in a certain mountain and a certain tunnel.

[0054] Project Overview

[0055] The entrance to a tunnel on the Wanji Railway is located in Pu County, and its exit is at the junction of Yaodu District, Linfen City, and Hongdong County. Designed as a twin-hole, single-track tunnel, the upline is 23,468.5 meters long, and the downline is 23,441 meters long. Since the tunnel opened, severe lining cracking, inward extrusion, and roadbed heave have repeatedly been observed. Monitoring and observation have shown that the damage continues to progress and the number of sections is increasing. An expert meeting determined that the tunnel disaster was primarily caused by special geological hazards such as complex geological structures, groundwater fluctuations, and gypsum-salt rock. The affected sections require complete replacement, with specific sections and measures dynamically adjusted during construction based on monitoring results.

[0056] A method for rapid restoration of existing tunnel lining, combining the overall construction process Figure 1 It is understood that the primary support section is inspected and reviewed before construction, and the tunnel centerline, level, section dimensions and clearance size all meet the design requirements to ensure that the lining does not intrude into the tunnel construction limits.

[0057] The specific steps include:

[0058] Step 1: Divide the main tunnel working section into sections and carry out tunnel invert construction; the main tunnel working section is located between two transverse passages, and the sections include four sections: along the length direction of the main tunnel working section, there are the second lining section 3, the first trestle section 4, the second trestle section 5 and the expansion section 6, wherein the first transverse passage 1 is provided near the second lining section 3, and the second transverse passage 2 is provided near the expansion section 6. Figure 2 The figure shows the zoning diagram of the main tunnel operation section, in which the first transverse channel 1 and the second transverse channel 2 are connected by a horizontal guide parallel to the main tunnel.

[0059] The interval between adjacent sections is 20-50m; the inverted arch is supported for 14m (support 3m / cycle), poured for 12m, and the distance between the two inverted arches is 24m.

[0060] In this embodiment, by using the flat guide as the main transportation channel, adding a cross channel to connect the flat guide and the expansion line, giving priority to constructing a parallel auxiliary guide pit through the main tunnel, and after completion, constructing the main tunnel through the parallel auxiliary guide pit, multiple short construction sections are set up, and the working sections are constructed in both directions to increase the construction working surface and speed up the construction progress through clustered short-distance working surface rapid construction.

[0061] like Figure 3 The figure shows the logistics route during tunnel invert construction. During this process, the first and second trestle areas 4 and 5 operated simultaneously, with logistics moving in opposite directions. The excavation area 6 and the first trestle area 4 operated in the same logistics direction. Concrete and steel frames were transported from the first transverse passage 1 to the various construction sections.

[0062] The inverted arch reinforcement setting and mucking of the first trestle area 4 are carried out through the first transverse passage 1 after passing through the second lining area 3;

[0063] The inverted arch reinforcement setting and mucking of the second trestle area 5 are carried out through the second transverse passage 2 after passing through the expansion area 6;

[0064] The excavated slag from the expansion excavation area 6 is sequentially transported through the second trestle area 5, the first trestle area 4, and the second lining construction area, and then transported through the first transverse passage 1; the excavation excavation excavation is preceded by drilling and blasting and the site is leveled, and the excavation excavation drilling and blasting are carried out simultaneously without considering the time consumption of the excavation excavation drilling and blasting. Figure 3 shown.

[0065] The rapid demolition of the existing tunnel lining concrete is carried out in the expansion area 6.

[0066] In this embodiment, the primary branch of the tunnel adopts anti-seepage and sulfate-resistant shotcrete and wet shotcrete.

[0067] During the logistics organization of the inverted double trestle, we need to pay attention to the following:

[0068] a. Excavation and ballast removal of the secondary lining must begin after the invert trestle is returned to its original position;

[0069] b. When the invert is excavated and slag is removed, mucking and shotcrete operations cannot be carried out in the excavation area 6.

[0070] c. The excavator is parked in a close-range cross passage area;

[0071] d. The steel frame, steel mesh, anchor rods, locking anchor pipes and other materials for expanding the excavation working surface arrive near the working area before the invert is mucking out.

[0072] Step 2: Lay the waterproof board 9 on the whole section of the tunnel in the main tunnel operation section; specifically, the waterproof board 9 is laid with reference to Figure 4 As shown, the waterproof board 9 laying process is specifically as follows:

[0073] ① First, install Φ22 anchor steel bars on the side wall, anchoring 40cm. The specific hanging structure is as follows: Figure 5 As shown,

[0074] ② Then set a clamp 8 point every 60cm along the waterproof board 9. The length of the clamp 8 of the waterproof board 9 is 3m, and a total of 4 clamp points are set. Then lay it from one side to the other. The form of the clamp 8 of the waterproof board 9 is as follows Figure 6 As shown;

[0075] ③ Similarly, use the waterproof board 9 clamp 8 on the other side to clamp the other end of the waterproof board 9;

[0076] ④ After the waterproof board 9 fixture 8 is adjusted into place, the waterproof board 9 is welded using a ladder ultrasonic method.

[0077] Step 3: After the waterproof board 9 is laid, the lining steel bar construction is carried out;

[0078] After the waterproofing sheet 9 is laid, the steel bars are tied. The steel bars used in this project are all processed and formed in a centralized factory and then transported to the site for use. First, the positioning steel bars are installed. The circumferential and longitudinal distribution steel bars are installed according to the positioning steel bars. Finally, the connecting bars between the two layers of steel bars are installed.

[0079] After waterproof board 9 is laid, also comprise that inverted arch template is installed, and carry out inverted arch concrete pouring, maintenance.After inverted arch construction is completed, remove trestle.

[0080] Step 4: Carry out the construction of longitudinal annular waterstop;

[0081] Since the rubber part of the steel edge rubber water stop 13 is raised, the groove of the steel plate water stop 12 faces the primary support surface, and the longitudinal construction joint 14 steel plate water stop 12 and the annular steel edge rubber water stop 13 are not tightly attached when they are overlapped. There is a large gap in the middle, which is a weak link in waterproofing. It is necessary to strengthen the overlapping construction of the annular longitudinal water stop. For specific settings, see Figure 7As shown, the lap joint construction sequence is as follows:

[0082] ① First, cut off the rubber of the overlapping raised part of the steel edge rubber water stop 13;

[0083] ② Then put the steel plate waterstop 12 and the steel edge rubber waterstop 13 together, and anchor them with 3 rivets on each side.

[0084] ③ After the rivets are anchored, the gap between the steel edge rubber water stop 13 and the steel plate water stop 12 is bonded tightly with adhesive material.

[0085] Step 5: Secondary lining pouring and curing; the lining is constructed using a hydraulic steel mold integral lining trolley, and the secondary lining is constructed using a large curved steel mold lining stand, and the arch wall is molded in one step;

[0086] Before constructing the buffer layer 17, mark the bottom edge center line of the buffer layer 17, the center line of the annular hose 16 and the center line of the drainage strip 15 on the initial support surface. The bottom edge line of the buffer layer 17 is the rail top elevation. The annular hose 16 and the annular drainage strip 15 are arranged alternately. The buffer layer is laid between adjacent annular hoses 16 in the longitudinal and annular directions. Multiple dovetail clamps are set between two adjacent buffer layers 17.

[0087] Specifically, the following steps are included:

[0088] 1. Roughening the concrete surface: Specific construction process: pouring concrete → spraying retarder (slurry extraction is completed) → roughening (washing with high-pressure water gun) → cleaning the interface (removing accumulated water and waste residue);

[0089] Pour concrete according to the concrete construction process. Spray retarder and treat the interface between the secondary lining and the inverted arch. Spray the end formwork with retarder before closing the formwork. Spray the top surface of the small sidewall with retarder immediately after concrete slurrying is completed (spraying the retarder should be completed within 20 minutes). Rinse: After the concrete has initially set or 6-8 hours after pouring, use a high-pressure water gun to high-pressure wash the concrete interface. Clean the interface and remove any accumulated water and waste residue.

[0090] 2. Construction of polyethylene cushion layer 17 (5cm thick);

[0091] The buffer layer is made of polyethylene foam board with a thickness of 50mm. It is installed on the side walls and arches. The polyethylene buffer layer is processed in blocks with a processing size of 1.5m*1.5m and a thickness of 50mm. It is fixed with dovetail clamps.

[0092] like Figure 8-9 As shown;

[0093] ① Alignment: Use red paint to mark the bottom edge of the cushion layer 17 and the center lines of the annular hose 16 and drainage strip 15 on the primary support surface. The bottom edge of the cushion layer should be at the rail top elevation. The annular hose 16 and annular drainage strip 15 should be arranged in a staggered pattern with a centerline spacing of 1.6m.

[0094] ②Install the bottom dovetail clamps: the size of the buffer layer material is 0.75m*1.5m, and the dovetail clamp spacing is 81cm*78cm (longitudinal direction of the ring).

[0095] A buffer layer is laid between adjacent annular hoses 16 at a net distance of 3m. The size of the buffer layer 17 is 0.75m high × (1.5+1.5)m wide, with 39-40cm reserved at both ends. The spacing between dovetail clips 18 is 77cm, with four on each side.

[0096] ③Install the polyethylene buffer layer. Install one dovetail clip and one buffer layer in sequence from bottom to top.

[0097] ④ Buffer layer laying: The bottom two layers are laid using a ladder before the inverted arch waterproofing board 9 is laid, and the upper part is constructed using a stand after the inverted arch and the inverted arch filling are poured.

[0098] 3. Cast the lining in windows; the lining is cast layer by layer using a chute, window by window, and a lining trolley is used for the casting. The lining trolley is provided with a graded diversion device, which includes multi-stage diversion components from top to bottom. Each multi-stage diversion component includes a main hopper, a main trough, a three-way diversion trough, a diversion string tube and a window inlet trough.

[0099] Lining casting adopts chute to cast layer by layer:

[0100] The lining is cast in layers by window using a chute, and a lining trolley is used for the lining casting. The lining trolley is provided with a graded diversion device, which includes a multi-stage diversion component from top to bottom. Each multi-stage diversion component includes a main hopper 19, a main trough 20, a three-way diversion trough 21, a diversion string tube 22 and a window inlet trough 23.

[0101] By combining the hopper, main chute, "three-way" diverter trough, diverter string tube and window chute, and setting valves on the plug plates at each level, the concrete can flow to each working window, realizing the window-by-window feeding of the secondary lining arch wall concrete. Two main diverter hoppers are set at the center line of the top platform of the 12m trolley, and two first-level diverter chutes are set on the left and right sides of each main diverter funnel. The first and second level diverter troughs are composed of arc chutes and first level funnels. Eight diverter chutes are set on the left and right sides of the first level funnel to lead to the corresponding working windows of the first and second level platforms. The third level diverter trough is composed of a string tube, a second level funnel and an arc chute. The string tube is used to connect the first level funnel and the second level funnel. Four diverter chutes are set on the left and right sides of the second level funnel to the corresponding working windows of the third level platform.

[0102] Specifically, the lining window casting setting method is:

[0103] When the concrete mixer truck arrives at the site, it is pumped into the main hopper of the top platform by a concrete pump. Concrete is poured horizontally and symmetrically in layers, controlling the pouring speed and height on one side. The difference in pouring height between the two sides should not exceed 0.5m. The vertical distance from the delivery hose nozzle to the pouring surface should not exceed 2m, and the vertical distance should not exceed 1m to prevent concrete segregation. Concrete should be poured continuously, with the time interval between pouring two adjacent layers controlled to within 2 hours.

[0104] 4. Vibration with high and low frequency attached vibrators;

[0105] The vibration time of traditional attached vibrators is difficult to control, which can easily cause over-vibration and external defects such as "sand flipping"; traditional inserted vibrators are due to the large spacing between the concrete windows of the lining trolley, and the vibrator cannot fully cover them, which can easily cause missed vibrations. The side walls are prone to honeycombing, missing reinforcement and other quality defects, the vault is prone to voids, and the concrete strength is difficult to meet the design requirements.

[0106] In order to overcome the above-mentioned defects, in this embodiment, a vibrating rod is used in combination with high and low frequency attached vibrators to tamp the concrete. One trolley is equipped with 8 low-frequency vibrators (arranged on the side formwork and 8 high-frequency vibrators (arranged on the top formwork), totaling 16 units.

[0107] ① During the actual pouring process, the slump of concrete is controlled at 180mm, and symmetrical pouring and layered vibration are adopted.

[0108] ② The windows on the first, second, and third floors were poured using a chute. When the concrete reached a height approximately 1 meter above the vibrator, the vibrators on that floor were activated simultaneously for 10 seconds. The attached vibrators on the second, third, and vault floors were vibrated simultaneously for 10 seconds. After demolding 12 hours later, the concrete surface throughout the warehouse was smooth and even, and its 28-day strength exceeded the design value.

[0109] 5. Secondary lining maintenance

[0110] After demolding, a mobile mist cannon is used to spray-cure the lining concrete. The cannon can be mounted on a sprinkler truck to spray-cure concrete in various sections of the tunnel or to remove dust from the tunnel. The concrete surface must be kept continuously moist during curing, and the curing water temperature must be roughly the same as the ambient temperature. Watering is prohibited when the temperature is below 5°C.

[0111] When curing concrete with moisturizing film, if the concrete temperature is high before demolding, use water spraying at a temperature not lower than 20°C to cool the formwork down. After demolding, a moisturizing film should be hung to cure the concrete surface.

[0112] Use a secondary lining trolley to lay the moisturizing membrane. Curing should be carried out in sections from top to bottom to prevent leaks. When curing concrete with plastic sheeting, all exposed surfaces should be tightly covered.

[0113] The above description is only a preferred embodiment of the present invention and is 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 in the scope of protection of the present invention.

Claims

1. A method for rapid restoration of existing tunnel lining, characterized in that: The steps include: Step 1: Divide the main tunnel operation section into four sections: a secondary lining construction section, a first trestle section, a second trestle section, and an expansion section along the length of the main tunnel operation section, with an interval of 20-50 m between adjacent sections; and simultaneously carry out tunnel invert construction in the first trestle section and the second trestle section. Step 2: Lay waterproof panels on the entire tunnel section of the main tunnel operation section; Step 3: After the waterproofing board is laid, the secondary lining reinforcement is constructed; first, the positioning reinforcement is constructed, and the circumferential reinforcement and longitudinal distribution reinforcement are installed according to the positioning reinforcement, and finally, the connecting reinforcement between the two layers of reinforcement is installed; Step 4: Carry out longitudinal annular waterstop construction: including longitudinal annular waterstop overlap; Step 5: Secondary lining pouring and curing; the lining is constructed using a hydraulic steel mold integral lining trolley, and the secondary lining is constructed using a large curved steel mold lining stand, and the arch wall is molded in one step; Step 6: Repeat steps 1 to 5 to complete the restoration of all tunnel linings; In step 5, the lining pouring construction process is as follows: first, roughen the concrete surface, then construct the buffer layer, and finally pour the lining window; Before constructing the buffer layer, mark the bottom edge center line of the buffer layer, the center line of the annular hose and the center line of the drainage strip on the primary support surface. The bottom edge line of the buffer layer is the rail top elevation. The annular hose and the annular drainage strip are arranged in a staggered manner. The buffer layer is laid between adjacent annular hoses in the longitudinal and annular directions. Multiple dovetail clamps are set between adjacent buffer layers. The lining is cast in layers by window using a chute, and a lining trolley is used for the lining casting. The lining trolley is provided with a graded diversion device, which includes multi-stage diversion components from top to bottom. Each multi-stage diversion component includes a main hopper, a main trough, a three-way diversion trough, a diversion string tube and a window inlet trough.

2. The method for rapid restoration of existing tunnel lining according to claim 1 is characterized in that: In step 1, a first transverse channel is provided at the front end of the main tunnel operation section, and a second transverse channel is provided at the rear end of the main tunnel operation section. The logistics transportation of the first trestle area is carried out through the first transverse channel, and the logistics transportation of the second trestle area is carried out through the second transverse channel.

3. The method for rapid restoration of existing tunnel lining according to claim 2 is characterized in that: The inverted arch construction processes of the first trestle area and the second trestle area are carried out simultaneously, with opposite logistics directions. The logistics transportation direction during the inverted arch construction process of the expansion area is the same as that of the first trestle area.

4. The method for rapid restoration of existing tunnel lining according to claim 1 is characterized in that: After the waterproof board is installed, the inverted arch formwork is installed, and the inverted arch concrete is poured and maintained. After the inverted arch construction is completed, the trestle is dismantled.

5. The method for rapid restoration of existing tunnel lining according to claim 1 is characterized in that: In step 4, the specific construction process of overlapping the longitudinal annular waterstop is as follows: S1. First, cut off the rubber of the convex part of the steel edge rubber water stop; S2. Then put the steel plate waterstop and the steel edge rubber waterstop together, and anchor them with at least two rivets on each side; S3. After the rivets are anchored, the gap between the steel-edge rubber waterstop and the steel plate waterstop is tightly bonded with adhesive material.

6. The method for rapid restoration of existing tunnel lining according to claim 1, characterized in that: The cushion layer is made of polyethylene.

7. The method for rapid restoration of existing tunnel lining according to claim 1 is characterized in that: The secondary lining casting is performed by symmetrically casting in layers from bottom to top in combination with layer-by-layer vibration, and a low-frequency vibrator and a high-frequency vibrator are used in combination during the concrete consolidation process.

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