An acceptance method for the invert of a tunnel

Abstract

A method for accepting a tunnel invert includes the following steps. Step 1, designing an acceptance tool. Step 2, measuring and setting out. Step 3, installing and positioning the invert acceptance tool. Step 4, after the invert acceptance tool is positioned, it is slowly moved forward and backward, and a sensor is used to collect the invert profile data; Step 5, the data collected from the invert profile is processed to obtain relevant invert profile parameters, and the invert profile parameters are compared with the design requirements, and the deviation values are recorded; Step 6, for the part of the invert profile parameters that does not meet the design requirements, the construction personnel adjust the invert according to the deviation report; Step 7, after the invert profile is corrected, the invert acceptance tool is used to perform a profile check again to ensure that all deviations are within the allowable range, and the construction is completed. The present invention solves the technical problems that the acceptance of traditional tunnel inverts mostly relies on manual measurement and manual recording, and there are large measurement errors, low efficiency, strong subjectivity and inaccurate detection results.

Description

Technical Field

[0001] The present invention belongs to the technical field of civil engineering construction, and particularly relates to an acceptance method for a tunnel invert. Background Art

[0002] There are mainly five tunnels in a certain project, with lengths of 5652m, 8924m, 9343m, 2395m, and 267.9m respectively. The main lithology in the tunnel site area is phyllitic slate, with grade III surrounding rock accounting for 10% of the whole tunnel; grade IV surrounding rock accounting for 75% of the whole tunnel; grade V surrounding rock accounting for 25% of the whole tunnel; the tunnel excavation adopts manual drill and blast excavation. The invert construction is carried out with the cooperation of a 36m long fully hydraulic self-propelled mobile trestle. During the tunnel construction process, the invert, as an important structure to support the tunnel top, its quality is directly related to the overall stability and safety of the tunnel project. At present, after the tunnel construction is completed, the acceptance of the tunnel invert mostly relies on manual measurement and manual recording, which has problems such as large measurement errors, low efficiency, strong subjectivity, and inaccurate detection results, thus it is difficult to meet the requirements of modern tunnel construction quality control. Therefore, it is of great significance to develop an accurate, efficient, and automated acceptance method for tunnel invert. Summary of the Invention

[0003] The purpose of the present invention is to provide an acceptance method for a tunnel invert, and solve the technical problems that the traditional acceptance of tunnel invert mostly relies on manual measurement and manual recording, with large measurement errors, low efficiency, strong subjectivity, and inaccurate detection results.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions.

[0005] An acceptance method for a tunnel invert includes the following steps.

[0006] Step 1, design an acceptance tooling: According to the design drawings and the requirements of the tunnel invert structure, design an invert acceptance tooling;

[0007] The invert acceptance tooling includes an invert acceptance plate, a chute, and a sensor; the cross-section of the invert acceptance plate is adapted to the cross-section shape of the designed invert; the invert acceptance plate is installed at the invert at the bottom of the tunnel, and the center line of the invert acceptance plate corresponds to the tunnel center line; on the inner side of the invert acceptance plate, sizing bars are installed at intervals along the longitudinal direction; the shape of the sizing bar is adapted to the cross-section shape of the invert acceptance plate, and both ends of the sizing bar extend beyond the two side top edges of the invert acceptance plate; at the top positions at both ends of the invert acceptance plate, limiting plates are respectively arranged along the longitudinal direction on the side walls on both sides of the tunnel; on the surface of the limiting plate, a chute is arranged along the longitudinal direction; both ends of the sizing bar are respectively provided with sliding ends; the sliding ends are inserted into the chute and slide along the chute; a rolling support device is arranged at the bottom of the invert acceptance plate; the sensors are arranged at intervals on the invert acceptance plate for real-time measurement of the geometric shape of the tunnel invert;

[0008] Step 2: Survey and set out: First, lay out the tunnel centerline, and lay out elevation control lines on the side walls on both sides of the tunnel and at the upper ends of the corresponding invert acceptance plates on both sides;

[0009] Step 3, installation and positioning of the inverted arch acceptance tooling: the designed inverted arch acceptance plate is set at the inverted arch at the bottom of the tunnel, and the limit plates are installed on the side walls on both sides of the tunnel; then the two ends of the inverted arch acceptance plate are respectively inserted into the slide grooves of the limit plates to ensure the stability and accuracy of the inverted arch acceptance tooling during the installation process;

[0010] Step 4: Inverted arch profile measurement: After the inverted arch acceptance tool is positioned, it is slowly moved forward and backward, and sensors are used to collect inverted arch profile data; the moving process accurately controls the centerline position of the inverted arch acceptance plate and the elevations at both ends;

[0011] Step 5, deviation detection and analysis: Process the data collected from the invert profile to obtain relevant invert profile parameters, compare the invert profile parameters with the design requirements, and record the deviation values;

[0012] Step 6, deviation correction and adjustment: For the part of the inverted arch profile parameters that do not meet the design requirements, the construction personnel will adjust the inverted arch according to the deviation report to ensure that the inverted arch profile meets the design standards;

[0013] Step seven: After the invert arch profile has been corrected, use the invert arch acceptance tool to check the profile again to ensure that all deviations are within the allowable range. This completes the construction.

[0014] Preferably, the inverted arch acceptance plate is connected to the shaping rod by bolts; an oblique brace is also provided on the inner side of the inverted arch acceptance plate; the oblique brace is connected between the bottom plate and the side wall of the inverted arch acceptance plate.

[0015] Preferably, the rolling support device includes a connecting plate and a rolling sleeve; the connecting plate is arranged at the bottom of the inverted arch acceptance plate and is located on both sides of the tunnel centerline, and the connecting plates on both sides of the central axis are arranged laterally correspondingly; a positioning shaft is detachably connected between the laterally corresponding connecting plates; the rolling sleeve is sleeved on the positioning shaft and can roll on the positioning shaft.

[0016] Preferably, the cross-section of the slide groove is a horizontal U-shape, and clamping edges are respectively provided at the two side ends of the slide groove; the vertical section of the sliding end is arc-shaped, the lower end of the sliding end is connected to the top of the forming rod, and the upper end of the sliding end is provided with an enlarged end, and the enlarged end is clamped in the slide groove.

[0017] Preferably, when setting the tunnel center line in step two, first set the center line points, with the longitudinal distance between adjacent center line points not greater than 3m. After the setting is completed, connect the front and rear center line points, and use self-spray paint to draw the tunnel center line; then set the elevation control points on the side walls on both sides respectively, with the longitudinal distance between adjacent elevation control points not greater than 3m, and connect the elevation control points on the side walls on both sides with self-spray paint lines.

[0018] Preferably, in step three, after the installation of the invert acceptance tooling is completed, use measuring tools to position and calibrate the invert acceptance plate to ensure that the position and size of the invert acceptance plate are consistent with the geometric position and size of the design drawings.

[0019] Preferably, in step four, the sensor collects the vertical distances between the invert and the invert acceptance plate at different positions, so as to obtain the three-dimensional coordinate information of the corresponding points of the invert, and calculates the invert profile parameters through multiple measurement points; the invert profile parameters in step five include the width, curvature and height of the corresponding cross-section of the invert.

[0020] Preferably, in step six, the process of correcting the invert profile is specifically as follows:

[0021] If under-excavation occurs locally in the invert profile, it shall be treated by additional blasting or chiseling with a breaker.

[0022] If over-excavation occurs locally in the invert profile, it shall be filled with primary support concrete, and it is strictly prohibited to backfill with tunnel muck.

[0023] Preferably, after the acceptance in step seven is completed, an acceptance report is generated according to the acceptance process. The acceptance report includes measurement data, deviation analysis, corrective measures and final acceptance conclusions, and the acceptance report serves as an important basis for quality control and project management.

[0024] Compared with the prior art, the present invention has the following characteristics and beneficial effects.

[0025] 1. The present invention adopts a specially designed invert acceptance tooling, including devices such as an invert acceptance plate, a chute, a shaping rod, a sensor, etc., which can accurately reflect the geometric shape of the tunnel invert and ensure precision control during the acceptance process. Through the accurate measurement of the invert profile by the sensor, the collected data can be further used to calculate parameters such as the cross-section width, curvature, and height of the invert, so as to achieve high-precision acceptance and detection. In addition, the structural designs such as the bolt connection between the invert acceptance plate and the shaping rod, the rolling support device and the chute enable the acceptance tooling to be positioned and moved stably and accurately, thus ensuring the efficiency and precision of the measurement process.

[0026] 2. The inverted arch acceptance tooling adopted by the present invention facilitates real-time data collection and analysis. The spaced arrangement of the sensors enables the real-time collection of geometric data of the inverted arch at different positions. By obtaining the vertical distance between the inverted arch and the acceptance plate and calculating the three-dimensional coordinate information of the corresponding points on the inverted arch, relevant parameters of the inverted arch profile can be obtained quickly and effectively. These real-time collected data can be processed and analyzed rapidly, any existing deviations can be detected, and compared with the design requirements, so as to provide an accurate deviation report quickly. Deviation analysis and correction can be efficiently fed back to the construction personnel, further improving the quality control of the acceptance. The method of the present invention proceeds step by step from the design of the acceptance tooling, measurement layout to deviation correction, and the implementation details are strictly specified for each step. The standardization of the process ensures that each link has strict technical support, greatly reducing errors and avoiding problems caused by manual measurement and inaccurate positioning in the traditional acceptance process. At the same time, the use of automated sensors for measurement and real-time data collection greatly reduces the workload and time cost of manual measurement. The sensors can quickly and accurately collect geometric data at different positions, saving a lot of time compared with the traditional manual measurement method and reducing errors caused by manual operation.

[0027] 3. After the acceptance is completed, the acceptance report generated by the present invention includes detailed measurement data, deviation analysis, correction measures and final conclusions, which can provide a clear basis for the quality control of the project. These data can be used as important references for project management and later maintenance, helping to improve the transparency of the project and ensure the implementation of quality standards. And through the acceptance report, relevant parties of the project can clearly understand each link in the construction process and take timely measures to solve possible problems, thus enhancing the controllability of project management and the basis for decision-making.

[0028] 4. The present invention uses customized acceptance tooling for the acceptance of the inverted arch profile, which can provide more accurate measurement results and avoid errors in traditional manual measurement. The acceptance tooling makes the whole acceptance process more standardized and systematic, reduces the time for repeated measurement and correction, and improves the acceptance efficiency. This set of tunnel inverted arch acceptance method of the present invention enables each construction link to be strictly quality-controlled, and has significant advantages in improving acceptance accuracy, data collection efficiency, construction quality control, saving time and labor costs, enhancing project controllability and transparency. At the same time, through a strict deviation detection and correction mechanism, it ensures that the final structure of the tunnel inverted arch meets the design standards, reduces potential safety hazards, and improves the quality and reliability of the tunnel project. These beneficial effects make this method have strong promotion value and practical application significance in tunnel engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The following further describes the present invention in detail with reference to the drawings.

[0030] Figure 1 It is a schematic diagram of the connection structure between the shaping rod and the inverted arch acceptance plate in the present invention.

[0031] Figure 2 It is a schematic diagram of the connection structure between the sliding end and the sliding groove in the present invention.

[0032] Figure 3 It is a schematic diagram of the structure where the enlarged end is clamped in the sliding groove in the present invention.

[0033] Reference numerals: 1 - inverted arch acceptance plate, 2 - sliding groove, 3 - sensor, 4 - shaping rod, 5 - limiting plate, 6 - sliding end, 7 - connecting plate, 8 - rolling sleeve, 9 - positioning shaft, 10 - clamping edge. Specific embodiments

[0034] As Figures 1 - 3 shown, this acceptance method for the tunnel inverted arch includes the following steps.

[0035] Step 1, design the acceptance tooling: According to the design drawings and the requirements of the inverted arch structure of the tunnel, design the inverted arch acceptance tooling; the inverted arch acceptance tooling includes an inverted arch acceptance plate 1, a sliding groove 2 and a sensor 3; the cross-section of the inverted arch acceptance plate 1 is adapted to the cross-sectional shape of the designed inverted arch and is an arc-shaped plate; the bottom of the inverted arch acceptance plate 1 is arranged substantially parallel to the bottom surface of the tunnel, and both ends of the inverted arch acceptance plate 1 bend upward and extend towards the side walls of the tunnel; this inverted arch acceptance plate 1 is installed at the inverted arch at the bottom of the tunnel, and the midline of the inverted arch acceptance plate 1 corresponds to the midline of the tunnel; on the inner side of the inverted arch acceptance plate 1, shaping rods 4 are installed at intervals along the longitudinal direction; the shape of the shaping rod 4 is adapted to the cross-sectional shape of the inverted arch acceptance plate 1, and both ends of the shaping rod 4 respectively extend beyond the top edges on both sides of the inverted arch acceptance plate 1; at the top positions at both ends of the inverted arch acceptance plate 1, limiting plates 5 are arranged along the longitudinal direction on the side walls on both sides of the tunnel; on the surface of the limiting plate 5, a sliding groove 2 is arranged along the longitudinal direction; both ends of the shaping rod 4 are respectively provided with a sliding end 6; the sliding end 6 is inserted into the sliding groove 2 and slides along the sliding groove 2; a rolling support device is arranged at the bottom of the inverted arch acceptance plate 1; the sensors 3 are arranged at intervals on the inverted arch acceptance plate 1 for real-time measurement of the geometric shape of the tunnel inverted arch.

[0036] Step 2, measurement and lofting: First, release the tunnel midline, and release the elevation control lines on the side walls of the tunnel corresponding to the upper ends on both sides of the inverted arch acceptance plate 1.

[0037] Step 3, installation and positioning of the inverted arch acceptance tooling: Set the designed inverted arch acceptance plate 1 at the inverted arch at the bottom of the tunnel, and at the same time install the limiting plates 5 on the side walls on both sides of the tunnel; then insert both ends of the inverted arch acceptance plate 1 into the sliding grooves of the limiting plates 5 respectively to ensure the stability and accuracy of the inverted arch acceptance tooling during the installation process, and use measuring tools to position and calibrate the inverted arch acceptance plate to ensure the accuracy during the acceptance process.

[0038] Step 4, inverted arch contour measurement: After the inverted arch acceptance tooling is positioned, three auxiliary workers slowly move it back and forth through the rolling support device, and use the sensor 3 to collect the inverted arch contour data; the moving process accurately controls the centerline position of the inverted arch acceptance plate 1 and the elevations at both ends; the centerline position of the inverted arch acceptance plate is accurately controlled to avoid the influence of human deviation.

[0039] Step 5: Deviation detection and analysis: Process the data collected from the invert profile to obtain relevant invert profile parameters, compare the invert profile parameters with the design requirements, record the deviation value, and further analyze the cause of the deviation.

[0040] Step 6, deviation correction and adjustment: For the parts of the invert profile parameters that do not meet the design requirements, the construction personnel adjusted the invert according to the deviation report to ensure that the invert profile meets the design standards. For local defects or parts that do not meet the design requirements, reasonable correction measures such as additional blasting, hammer chiseling, and initial support concrete filling are taken to ensure that the final geometric shape of the invert meets the design standards and enhance the stability and safety of the project. In particular, when correcting the deviation, it is strictly stipulated that the use of slag backfill is not allowed, which avoids the hidden dangers that may be caused by the use of unqualified materials and further improves the quality of the project.

[0041] Step seven: After the arch profile has been corrected, use the arch acceptance tool to check the profile again to ensure that all deviations are within the allowable range. This completes the construction.

[0042] In this embodiment, the inverted arch acceptance plate 1 and the shaping rod 4 are connected by bolts; a diagonal brace is also provided on the inner side of the inverted arch acceptance plate 1; the diagonal brace is connected between the bottom plate and the side wall of the inverted arch acceptance plate 1. The inverted arch acceptance plate 1 is made of steel plate or aluminum alloy plate, which has good durability and stability; the diagonal brace of the inverted arch acceptance plate 1 is processed by Φ22 threaded steel. The shaping rod 4 is made of section steel.

[0043] In this embodiment, the rolling support device includes a connecting plate 7 and a rolling sleeve 8; the connecting plate 7 is arranged at the bottom of the arch acceptance plate 1 and on both sides of the tunnel centerline, and the connecting plates 7 on both sides of the central axis are arranged laterally correspondingly; a positioning shaft 9 is detachably connected between the laterally corresponding connecting plates 7; the rolling sleeve 8 is sleeved on the positioning shaft 9 and can roll on the positioning shaft 9, and the rolling sleeve 8 adopts a 2cm galvanized steel pipe.

[0044] In this embodiment, the cross-section of the chute 2 is in the shape of a horizontally placed U, and clamping edges 10 are respectively arranged at both side ends of the chute 2; the vertical section of the sliding end 6 is arc-shaped, the lower end of the sliding end 6 is connected to the top of the shaping rod 4, an enlarged end is arranged at the upper end of the sliding end 6, and the enlarged end is clamped in the chute 2; the shaping rod 4 is formed by splicing section steel rod segments, and adjacent section steel rod segments are connected by welding or bolt connection.

[0045] In this embodiment, when setting the tunnel center line in step two, first set the center line points, the distance between longitudinally adjacent center line points is not greater than 3 m. After the setting is completed, connect the front and rear center line points, and use self-spray paint to draw the tunnel center line; then set the elevation control points on the side walls on both sides respectively, the distance between longitudinally adjacent elevation control points is not greater than 3 m, and connect the elevation control points on the side walls on both sides with self-spray paint lines; ensure it is accurate and eye-catching for facilitating the determination of the position of the full-size tooling.

[0046] In this embodiment, in step three, after the invert acceptance tooling is installed, use measuring tools (such as total station, level, etc.) to position and calibrate the invert acceptance plate 1 to ensure that the position and size of the invert acceptance plate 1 are consistent with the geometric position and size of the design drawing.

[0047] In this embodiment, in step four, the sensor collects the vertical distances between the invert and the invert acceptance plate 1 at different positions, so as to obtain the three-dimensional coordinate information of the corresponding points of the invert, and calculate the invert profile parameters through multiple measurement points; the invert profile parameters in step five include the width, curvature and height of the corresponding cross-section of the invert.

[0048] In this embodiment, in step six, the process of correcting the invert profile is specifically as follows:

[0049] If under-excavation occurs locally in the invert profile, it is processed by supplementary blasting or chiseling with a breaker.

[0050] If over-excavation occurs locally in the invert profile, it is filled with primary support concrete, and it is strictly prohibited to backfill with tunnel muck.

[0051] In this embodiment, after the acceptance in step seven is completed, an acceptance report is generated according to the acceptance process. The acceptance report includes measurement data, deviation analysis, correction measures and final acceptance conclusion, and the acceptance report serves as an important basis for quality control and project management.

[0052] In this embodiment, the side of the invert acceptance plate 1 close to the tunnel wall is the outer side, and the side of the invert acceptance plate 1 away from the tunnel wall is the inner side.

[0053] In this embodiment, a perforation is provided on the connecting plate 7; threads are respectively arranged at both ends of the positioning shaft 9, and the ends of the positioning shaft 9 are correspondingly passed through the perforation and fixed by double nuts.

[0054] In this embodiment, a laser is provided at the central axis of the surface of the invert acceptance plate 1. During the movement of the invert acceptance plate 1, the laser emitted by the laser is kept in the same vertical plane as the central axis of the tunnel, so as to verify and ensure the position of the invert acceptance plate 1 in real time.

[0055] The above embodiments are not an exhaustive list of specific implementation manners, and there may be other embodiments. The purpose of the above embodiments is to illustrate the present invention, rather than limiting the protection scope of the present invention. All applications obtained by simple changes of the present invention fall within the protection scope of the present invention.

Claims

1. An acceptance method for the invert of a tunnel, characterized in that, The steps are as follows: Step 1, design the acceptance tooling: According to the design drawings and the requirements of the invert structure of the tunnel, design the invert acceptance tooling; The invert acceptance tooling includes an invert acceptance plate (1), a chute (2) and a sensor (3); the cross-section of the invert acceptance plate (1) is adapted to the cross-sectional shape of the designed invert; the invert acceptance plate (1) is installed at the invert at the bottom of the tunnel, and the midline of the invert acceptance plate (1) corresponds to the tunnel midline; fixed rods (4) are installed at intervals along the longitudinal direction on the inner side of the invert acceptance plate (1); the shape of the fixed rod (4) is adapted to the cross-sectional shape of the invert acceptance plate (1), and both ends of the fixed rod (4) extend beyond the top edges on both sides of the invert acceptance plate (1); limiting plates (5) are respectively arranged along the longitudinal direction and continuously on the side walls on both sides of the tunnel at the top positions at both ends of the invert acceptance plate (1); a chute (2) is arranged along the longitudinal direction and continuously on the plate surface of the limiting plate (5); sliding ends (6) are respectively arranged at both ends of the fixed rod (4); the sliding ends (6) are inserted into the chute (2) and slide along the chute (2); a rolling support device is arranged at the bottom of the invert acceptance plate (1); the sensors (3) are arranged at intervals on the invert acceptance plate (1) for real-time measurement of the geometry of the tunnel invert; the rolling support device includes a connecting plate (7) and a rolling sleeve (8); the connecting plate (7) is arranged at the bottom of the invert acceptance plate (1) on both sides of the tunnel midline, and the connecting plates (7) on both sides of the central axis are arranged transversely corresponding to each other; a positioning shaft (9) is detachably connected between the transversely corresponding connecting plates (7); the rolling sleeve (8) is sleeved on the positioning shaft (9) and can roll on the positioning shaft (9); the cross-section of the chute (2) is in the shape of a lying U, and clamping edges (10) are respectively arranged at both side ends of the chute (2); the vertical section of the sliding end (6) is arc-shaped, the lower end of the sliding end (6) is connected to the top of the fixed rod (4), the upper end of the sliding end (6) is provided with an enlarged end, and the enlarged end is clamped in the chute (2); Step 2, measurement and lofting: First, release the tunnel midline, and release the elevation control lines on the side walls on both sides of the tunnel corresponding to the upper ends on both sides of the invert acceptance plate (1); when releasing the tunnel midline, first loft the midline points, the distance between longitudinally adjacent midline points is not greater than 3m, after completion of lofting, connect the front and rear midline points, and draw the tunnel midline with self-spray paint; then loft the elevation control points on the side walls on both sides respectively, the distance between longitudinally adjacent elevation control points is not greater than 3m, and connect the elevation control points on the side walls on both sides with self-spray paint lines; Step 3, installation and positioning of the inverted arch acceptance tooling: the designed inverted arch acceptance plate (1) is installed at the inverted arch at the bottom of the tunnel, and the limit plates (5) are installed on the side walls on both sides of the tunnel; then the two ends of the inverted arch acceptance plate (1) are respectively inserted into the slide grooves of the limit plates (5) to ensure the stability and accuracy of the inverted arch acceptance tooling during the installation process; after the inverted arch acceptance tooling is installed, the inverted arch acceptance plate (1) is positioned and calibrated by a measuring tool to ensure that the position and size of the inverted arch acceptance plate (1) are consistent with the geometric position and size of the design drawing; Step 4: measuring the profile of the inverted arch: after the inverted arch acceptance tool is positioned, three auxiliary workers slowly move it forward and backward through the rolling support device, and use the sensor (3) to collect the profile data of the inverted arch; the centerline position and the elevations of the two ends of the inverted arch acceptance plate (1) are accurately controlled during the movement process; Step 5, deviation detection and analysis: Process the data collected from the invert profile to obtain relevant invert profile parameters, compare the invert profile parameters with the design requirements, and record the deviation values; Step 6, deviation correction and adjustment: For the part of the inverted arch profile parameters that do not meet the design requirements, the construction personnel will adjust the inverted arch according to the deviation report to ensure that the inverted arch profile meets the design standards; Step seven: After the invert arch profile has been corrected, use the invert arch acceptance tool to check the profile again to ensure that all deviations are within the allowable range. This completes the construction.

2. The acceptance method of the tunnel invert according to claim 1, characterized in that: The inverted arch acceptance plate (1) and the shaping rod (4) are connected by bolts; an inclined brace is also provided on the inner side of the inverted arch acceptance plate (1); and the inclined brace is connected between the bottom plate and the side wall of the inverted arch acceptance plate (1).

3. The acceptance method of the invert of a tunnel according to claim 1, characterized in that: In step 4, the sensor collects the vertical distances between the inverted arch and the inverted arch acceptance plate (1) at different positions, thereby obtaining the three-dimensional coordinate information of the corresponding points of the inverted arch, and calculating the inverted arch profile parameters through multiple measurement points; the inverted arch profile parameters in step 5 include the width, curvature and height of the corresponding section of the inverted arch.

4. The acceptance method of the tunnel invert according to claim 1, characterized in that: In step 6, the process of correcting the invert profile is as follows: If the invert arch profile is partially under-excavated, it should be treated by supplementary blasting or chipping with a breaker hammer; If over-excavation occurs locally in the invert profile, primary support concrete shall be used to fill the gap.

5. The acceptance method of the tunnel invert according to claim 1, characterized in that: After the acceptance is completed in step seven, an acceptance report is generated according to the acceptance process. The acceptance report includes measurement data, deviation analysis, corrective measures and final acceptance conclusion. The acceptance report serves as an important basis for quality control and project management.

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