A method for adjusting a tunnel overrun error
By locking the tunnel's internal conductor control network and the line design software, the problem of excessive tunnel breakthrough error was solved, enabling rapid and accurate tunnel error adjustment and reducing rework and costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA RAILWAY NO 5 ENGINEERING GROUP CO LTD
- Filing Date
- 2026-01-28
- Publication Date
- 2026-05-29
Smart Images
Figure CN122108072A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of tunnel engineering and surveying engineering technology, and in particular to a method for adjusting the excessive breakthrough error of a tunnel. Background Technology
[0002] With rapid economic development and the ever-changing science and technology, the scale of engineering construction is becoming increasingly larger. Some key highway, railway and water conservancy projects often use extra-long tunnels to connect the lines. The control network inside the tunnel is generally carried out by using total station traverse surveying in combination with gyroscopes for tunnel measurement and control. The external network is generally controlled by GNSS plane. The breakthrough accuracy is affected by a combination of factors such as external and internal tunnel measurements and inter-phase measurements. There may be situations where insufficient technical level leads to inadequate control or poor site conditions and lack of management attention, often resulting in breakthrough errors exceeding the limit.
[0003] For situations where tunnel breakthrough errors exceed limits, existing technologies employ expert review combined with rework, or structural reinforcement using offset lining. Both of these adjustment methods require extensive work and involve uncontrollable costs. Therefore, this proposal suggests a method for adjusting tunnel breakthrough errors exceeding limits to address the aforementioned issues. Summary of the Invention
[0004] The purpose of this invention is to provide a method for adjusting the tunnel breakthrough error to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for adjusting tunnel breakthrough error exceeding the limit, which, based on the breakthrough error measurement value confirmed by re-measurement and the breakthrough control measurement results, adjusts the tunnel with breakthrough error exceeding the limit by locking the tunnel's internal conductor control network and designing a conforming alignment using line design software. The adjustment method includes the following operational steps: Step 1: Determine the tunnel breakthrough error. After the tunnel is completed, unidirectional independent traverse measurements are taken to the breakthrough surface for both large and small mileage sections, and the lateral breakthrough error value is calculated. Step 2: Conduct cross-sectional measurements of the already lined section of the tunnel, using independent traverse survey results to measure the existing lining cross-section; Step 3: Conduct tunnel breakthrough control surveys. After verifying the measurement and determining the lateral breakthrough error value, for tunnels that are determined to have large errors and urgently need adjustment, conduct breakthrough adjustment and shaping, and select two methods according to the source of error. The first method is to directly adjust the results inside and outside the tunnel at both ends, using the control points outside the tunnel to directly adjust the results inside the tunnel, and then complete all the work in the subsequent alignment adjustment. The second method is to use control points at both ends of the tunnel and forced constraint points inside the tunnel to determine the locations of batch over- or under-excavation. Under the premise that the control network adjustment can meet the accuracy requirements, it ensures that the completed secondary lining of the tunnel is not under-excavated to the greatest extent possible, and completes the control network adjustment work. Step 4: Re-measure the cross-section of the lined section. Use the results of the traverse wire mesh to re-measure the completed lining section and evaluate whether it meets the requirements. If not, repeat step 3. Step 5: Perform alignment calculation for the tunnel breakthrough section, draw a breakthrough diagram based on the re-measurement data that meets the requirements, and use the route design software to fine-tune the alignment of the tunnel breakthrough section. Step six: Carry out the construction of the tunnel breakthrough section, using the breakthrough control survey results and the fine-tuned breakthrough section alignment for the construction of the breakthrough section.
[0006] Preferably, the calculation of the lateral penetration error value is expressed as follows: (1); (2); (3); in, This represents the difference between the ordinates of two points. This represents the difference between the ordinates of two points. The azimuth of the tunnel centerline at the breakthrough face is represented by (X1, Y1) and (X2, Y2), which represent the coordinates of the same point measured by the traverse at different mileages.
[0007] Preferably, the independent traverse represents the results of separate adjustments of measurements at different mileages, serving as a benchmark for measuring the lining already constructed before the breakthrough.
[0008] Preferably, the measurement of independent traverse results includes the following steps: A1, GPS external horizontal control survey, to establish horizontal control points in the tunnel construction area; A2, Traverse surveying inside the tunnel: Establishing a traverse inside the tunnel and measuring angles and sides to complete the traverse surveying work; A3, Correction of traverse distance in tunnel: Correction of the measured traverse distance; A4, In-situ adjustment data processing for the tunnel traverse, involves organizing and analyzing the measurement data.
[0009] Preferably, the implementation of full-tunnel constrained adjustment is to use COSACODAPS or SYADJ software to first adjust the observation data and then evaluate the accuracy. The adjustment requires that the traverse line meets the minimum requirements of each index.
[0010] Preferably, the evaluation criteria in step four are based on the existing traverse results and centerline, measuring the over-excavation and under-excavation alignment of the tunnel cross-section, and determining whether the requirements of the acceptance criteria are met after adjustment.
[0011] Preferably, if it is a railway tunnel, the accuracy requirements of establishing a CPIII track control network can be considered on the basis of the original traverse network, and the accuracy standard can be appropriately improved as needed.
[0012] Preferably, the alignment fine-tuning of the tunnel breakthrough section adjusts differentiated parameters according to the breakthrough error value and smoothness requirements of different tunnels, and only the lining of the breakthrough section is adjusted.
[0013] Preferably, the operation of fine-tuning the alignment of the tunnel breakthrough section first determines the total adjustment amount based on the breakthrough error measurement results, then determines the preliminary alignment direction after adjustment through the alignment of the breakthrough section, then selects the line adjustment parameters, enters the compiled parameters into the line design software, performs fine-tuning of the line, and finally generates the alignment fine-tuning scheme.
[0014] Preferably, the parameter adjustment process includes adjusting the horizontal curves according to the route, determining the adjustment length based on the length of the reserved through section, determining the radius, and determining the length of the transition curve.
[0015] The technical effects and advantages of this invention are as follows: This method ensures the safety of the lined sections to the greatest extent possible, eliminating the need for rework on the lined sections. By using road design software in the alignment adjustment process, it can maximize the adjustment of tunnel breakthrough errors exceeding limits. It can calculate quickly and accurately, eliminating the need for rework on the completed parts, and enabling rapid construction and closure. Furthermore, it adopts tunnel breakthrough control measurements at both the front and rear ends, meets the full center error requirements of traverse surveying, and complies with smoothness control requirements. Attached Figure Description
[0016] Figure 1 This is a flowchart illustrating the implementation of the operation method of the present invention.
[0017] Figure 2 This is a schematic diagram illustrating the operation of the present invention.
[0018] Figure 3 This is a design diagram of the RBCCE circuit design software of the present invention.
[0019] Figure 4 This is an example diagram of the weakest side of the conductor and its accuracy in this invention.
[0020] Figure 5 This is a diagram showing the calculation results of the plane closure error of an example conductor according to the present invention.
[0021] Figure 6 This invention uses RBCCE circuit design software to perform local adjustments to the line type in the line element diagram. Detailed Implementation
[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0023] This invention provides, for example Figure 1 and Figure 2 The method shown is for adjusting tunnel breakthrough errors exceeding the limit. Based on the breakthrough error measurement values confirmed by re-measurement and the breakthrough control measurement results, the method adjusts tunnels with breakthrough errors exceeding the limit by locking the tunnel's internal traverse control network and designing a suitable alignment using route design software. The adjustment method includes the following steps: Step 1: Determine the tunnel breakthrough error. After the tunnel is completed, unidirectional independent traverse measurements are taken to the breakthrough surface for both large and small mileage sections, and the lateral breakthrough error value is calculated. Specifically, the calculation of the lateral continuity error value is expressed as follows: (1); (2); (3); in, This represents the difference between the ordinates of two points. This represents the difference between the ordinates of two points. The azimuth of the tunnel centerline at the breakthrough face is represented by (X1, Y1) and (X2, Y2), which represent the coordinates of the same point measured by the traverse at different mileages.
[0024] Step 2: Conduct cross-sectional measurements of the already lined sections of the tunnel. Use independent traverse results to measure the existing lining cross-sections. Independent traverses represent the results of separate adjustments of measurements at different mileages, serving as a benchmark for measuring the completed lining before tunnel breakthrough. Specifically, the measurement of independent traverse results includes the following steps: A1. GPS external plane control survey: Establish plane control points in the tunnel construction area to provide reliable benchmark references. Use high-precision GPS equipment to measure and record the coordinates (latitude, longitude, and elevation) of the control points to ensure that these points remain stable throughout the survey process. Perform necessary data calculations and coordinate transformations to adapt to the needs of subsequent tunnel surveys. A2, Traverse Field Surveying Inside the Tunnel: Establishing a traverse line inside the tunnel, measuring angles and sides to complete the traverse field survey. Based on the established horizontal control, using total station-type surveying instruments to conduct traverse surveying, measuring the direction, distance, and height of the traverse line, recording specific data at each measurement point, and ensuring the horizontal and vertical status of the instruments during the surveying process to improve measurement accuracy; A3, Correction of traverse distance in tunnel: Correct the measured traverse distance to eliminate the influence of measurement system errors. Based on the measurement results, perform adjustment calculations, analyze possible errors in the measurement process (instrument errors, environmental factors), and make corresponding corrections. When necessary, use standard correction formulas to ensure that the actual traverse distance accurately reflects the true situation of the lining. A4, In-tunnel traverse adjustment data processing: Organize and analyze measurement data to ensure the accuracy of the final results. Input measurement data into adjustment software or use manual calculation to adjust the traverse, calculate measurement errors, analyze the rationality of the results, and generate the final measurement report, including measurement data, adjustment results, error analysis, and construction recommendations.
[0025] Step 3: Conduct tunnel breakthrough control survey (locking net). After verifying the measurement and determining the lateral breakthrough error value, for tunnels that are determined to have large exceedances and urgently need adjustment, conduct breakthrough adjustment and shaping. Use the control points inside the tunnel to lock the net. After the results are fixed, the control points can be protected by PVC pipes during subsequent construction. They can continue to be used after the bottom slab is completed to maintain the consistency of the system. There are differences in the standards of various professions. Two methods are selected according to the source of error. The first method is to directly adjust the results inside and outside the tunnel at both ends, using the control points outside the tunnel to directly adjust the results inside the tunnel, and then complete all the work in the subsequent alignment adjustment. The second method involves using control points at both ends of the tunnel and forced constraint points inside the tunnel to determine the locations of over- or under-excavation in batches. Under the premise that the control network adjustment meets the accuracy requirements, this ensures that the completed secondary lining of the tunnel is not under-excavated to the maximum extent possible. The control network adjustment work is completed, as shown in Tables 1 and 2 below. Table 1 is the limit table for the breakthrough error of highway tunnels, and Table 2 is the limit table for the breakthrough error of railway tunnels. The error for highways needs to be calculated as twice the mean error as the limit. For example, the limit for highway errors below 3 km is 15 cm, and for railway errors below 4 km is 10 cm. Railway standards are stricter than highway standards, and the requirements for curve radius and smoothness are also higher. Any values exceeding the limits in the table need to be adjusted. The implementation of the full-tunnel constraint adjustment uses COSACODAPS or SYADJ software to first adjust the observation data and then evaluate the accuracy. The adjustment requires the connecting survey traverse to meet the minimum requirements of each indicator.
[0026] Table 1 Limits of Highway Tunnel Breakthrough Error
[0027] Table 2 Limits of Railway Tunnel Breakthrough Error
[0028] It should be noted that full-tunnel constrained adjustment is a measurement data processing method used in tunnel engineering, primarily for precise adjustment of observation data within the tunnel. This method effectively improves the accuracy and reliability of measurement results, ensuring the quality of tunnel construction and monitoring, including the use of COSACODAPS or SYADJ software for adjustment processing and accuracy assessment. The steps of full tunnel constraint adjustment include: Data preparation involves collecting and organizing observational data obtained during the measurement process, including traverse surveys, GPS measurements, horizontal angles, vertical angles, and distances, ensuring data integrity, and removing outliers and erroneous measurement data. Choose adjustment software based on your specific needs, including COSACODAPS or SYADJ. These software programs have powerful adjustment functions and data processing capabilities, which can meet the requirements of tunnel surveying. Install and configure the software to ensure it functions properly. Import the observation data. Import the organized observation data into the selected adjustment software. The software provides a data import template. Ensure that the data format meets the requirements. Check the accuracy of the imported data to ensure that there are no omissions or errors. Set up the adjustment model in the software, including selecting constraints, observation types and error models, determining the control points and traverses that need to be constrained, and setting constraints during the adjustment process. To perform adjustment processing, start the adjustment calculation. The software will perform adjustment processing based on the set model and imported data. The software will automatically calculate the adjustment results for each observation, including coordinates, direction and distance. Accuracy assessment: After the adjustment is completed, the software will generate an accuracy assessment report, including the accuracy indicators of the adjustment results (standard deviation, error ellipse and reliability). The adjustment results are analyzed to check whether they meet the design and construction requirements and to evaluate whether the measurement accuracy meets the engineering standards. The output results generate a detailed measurement report based on the adjustment results. The report should include information such as the measurement process, adjustment results, accuracy assessment, and error analysis. The output results can be used for subsequent engineering decisions, construction monitoring, and maintenance work.
[0029] COSACODAPS's functions include: multi-data processing, supporting adjustment of different types of observation data, including total station surveying, GPS surveying, and leveling; constrained adjustment, capable of full-tunnel constrained adjustment, suitable for tunnels and large-scale engineering projects, ensuring the accuracy of measurement results; accuracy assessment, providing detailed accuracy analysis and assessment reports, including standard deviation and error ellipse indices, to help users evaluate the reliability of measurement results; visualization functions, supporting data visualization, facilitating users to check measurement results and analyze potential problems; and a user-friendly interface, with an intuitive operating interface and rich help documentation, reducing the learning curve for users.
[0030] SYADJ's functions include: flexible adjustment processing, supporting various types of observation data input and enabling adjustment processing using different measurement methods; global and local adjustment, providing global and local adjustment functions, allowing users to choose the processing method according to actual needs; error analysis, enabling detailed error analysis of adjustment results and generating relevant reports to help users make scientific decisions; data management, supporting data management and import / export, facilitating data integration and analysis; and graphical output, supporting the generation of graphical output of measurement results, including charts and maps of adjustment results for easy visualization. This adjustment method takes the synergy between measured data support and technical means as its core logic, explicitly using the re-measured and confirmed continuity error measurement value and continuity control measurement results as the sole basis for adjustment, avoiding the subjective defects of traditional methods that rely on experience-based judgment.
[0031] Step 4: Re-measure (determine) the cross-section of the lined section. Use the results of the traverse wire mesh to re-measure the completed lining section and evaluate whether it meets the requirements. If not, repeat step 3. Specifically, the evaluation criteria in step four are based on the existing traverse results and centerline, measuring the over-excavation and under-excavation alignment of the tunnel cross-section, and determining whether the acceptance criteria are met after adjustment. If the tunnel is a railway tunnel, the accuracy requirements for establishing a CPIII track control network need to be considered on the basis of the original traverse network.
[0032] Step 5: Perform alignment calculation for the tunnel breakthrough section, draw a breakthrough diagram based on the re-measurement data that meets the requirements, and use the line design software to fine-tune the alignment of the tunnel breakthrough section. The alignment fine-tuning of the tunnel breakthrough section adjusts the differentiated parameters according to the breakthrough error value and smoothness requirements of different tunnels, and only the lining of the breakthrough section is adjusted. Specifically, the operation of fine-tuning the alignment of the tunnel breakthrough section first determines the total adjustment amount based on the breakthrough error measurement results. Then, the preliminary alignment direction after adjustment is determined through the alignment of the breakthrough section. After that, the alignment adjustment parameters are selected, the compiled parameters are entered into the alignment design software, the alignment is finely adjusted, and finally the alignment fine-tuning plan is generated. The alignment content of parameter adjustment includes adjusting the horizontal curves according to the alignment direction, determining the adjustment length according to the reserved breakthrough section length, determining the radius, and determining the length of the transition curve.
[0033] It should be noted that route design software includes professional road design software such as RBCCE. RBCCE's functions include: alignment design tools, providing convenient tools for designing horizontal and vertical alignments, automatically calculating parameters such as curve radius and tangent length, supporting multiple road design standards and specifications, allowing users to select the applicable design standard according to their needs; automated calculations, where the software can automatically perform relevant calculations, including road sight distance, gravity lines, and superelevation, reducing manual calculation workload and providing instant feedback, allowing users to view the impact of design changes on road performance in real time; visualization effects, powerful visualization functions that can generate 3D views to help designers intuitively understand the design effects, supporting the generation of design drawings and reports, facilitating the sharing of design information with other engineers and stakeholders; data integration, supporting data integration with other engineering software (CAD software), facilitating collaboration between different disciplines, and importing terrain data and other relevant information for more refined design; and optimization functions, including optimization algorithms that help users select the best solution from multiple design options.
[0034] Step six: Carry out the construction of the tunnel breakthrough section, using the breakthrough control survey results and the fine-tuned breakthrough section alignment for the construction of the breakthrough section.
[0035] This adjustment method mainly consists of two parts: tunnel control network locking and alignment adjustment. The first part is control network locking. In the construction of extra-long tunnels, the mileage sections are excavated separately, and the secondary lining usually follows the bottom slab with safety step distance requirements. Therefore, to ensure the stability of the completed sections, two measures are usually adopted: increasing the allowance for deformation and locking the control network. The allowance for deformation increases according to the tunnel length. In the construction of long tunnels, the allowance for tunnel breakthrough is no less than 5cm. This part is considered in excavation, initial support, and secondary lining, and needs to be reserved for application in the adjustment method as the core redundancy space for error adjustment, without additional cost. Control network locking is to ensure the stability of the completed sections before and after, and to minimize or eliminate the influence of the control network after breakthrough error adjustment. Its primary principle is to meet the minimum total length relative closure error requirement of the tunnel control network application level. The adjustment method adopted is to lock points at the mileage sections. The coordinate values of the points are the results of single-ended adjustment and can conform to the existing lining at that end as much as possible. The second part is line type adjustment, which uses RBCCE for line type simulation (reference). Figure 3 (As shown in the figure) or other line design software, different parameters are used for different tunnel breakthrough error values and smoothness requirements (refer to Table 3 below). After calculation using different parameters, only 300m of lining in the breakthrough section needs to be adjusted to meet railway standards at the highest standard. Therefore, the adjustability of highway and water conservancy tunnels is even greater. The detailed process is as follows: First, the total adjustment amount is determined based on the breakthrough error measurement results. The preliminary direction of the adjusted line shape is determined by the alignment of the breakthrough section, i.e., how the curves on both sides will grow. Then, reasonable line adjustment parameters are selected (specifically, the horizontal curve is adjusted according to the line direction, the adjustment length is determined according to the reserved breakthrough section length, the radius is determined, and the transition curve length is determined). The preliminary parameters are entered into the RBCCE line design software for fine-tuning of the line, and finally, the fine-tuning scheme of the simulated alignment of the straight section is determined.
[0036] Table 3 RBCCE Simulation Adjustment Curve Data Table
[0037] Implementation Case 1: Adjustment of the Through Section of a Curved Tunnel This invention is described in detail using a complete case of a highway tunnel. The curve of a highway tunnel starts at K35+020 and ends at K38+060, with a tunnel length of 3.04km. The tunnel breakthrough point is located at K36+480. The curve elements (coordinates after X-2930000, Y-495000) of the line are shown in Table 4 below. It can be inferred that the breakthrough point is located on the third segment of the circular curve.
[0038] Table 4 Adjustment of Line Element Parameters for Straight Highway Sections
[0039] After the tunnel was completed, a traverse observation point was set at K36+480 on the breakthrough face. Measurements were taken at both the small and large mileages. The coordinates of the point at the small mileage were (2598.291, 2964.053, 1107.342), and the coordinates at the large mileage were (2598.308, 2964.299, 1107.198). The tangent azimuth of the line obtained by calculation at this mileage is 0°15′02.2″.
[0040] Based on the measured data, the difference between the two points can be calculated as (0.017, 0.246, -0.025). According to the formula mentioned earlier, f... x =0.246*cos0°15′2.2″-0.017*sin0°15′2.2″=0.246m, f y =0.33sin0°15′2.2″+0.051*cos0°15′2.2″=0.018m, f h =0.025m. Therefore, the transverse breakthrough error of the tunnel is 0.246m, the longitudinal breakthrough error is 0.018m, and the elevation breakthrough error is 0.025m. Then, according to the requirements of the Highway Tunnel Construction Technical Specifications in Table 1, the elevation breakthrough error f... h = 0.025m0.025<f h Limit 0.025 * 2 = 0.05m; Lateral penetration error f x = 0.246m>f x Limit = 0.100 * 2 = 0.2m.
[0041] If so, it can be determined that the lateral penetration error exceeds the limit and technical processing is required.
[0042] First, we re-measured the lining of the entire tunnel based on the layout of the tunnel guide, and confirmed that the reserved breakthrough amount near the breakthrough face is sufficient, and adjustments can be made to the excess area, as shown in Table 5 below. Table 5 Statistical Table of Tunnel Cross-Section Measurement
[0043] Then, the control network was re-measured, and the control network layout is shown in Table 6 below (all double traverse single row).
[0044] Table 6 Control Network Layout Table
[0045] After reviewing the entire network of observation data and conducting a second re-survey (organizing GPS static plane control and traverse tunnel control measurements), the problem was identified as stemming from the failure to strictly adhere to the re-survey frequency for control points CKGPS1, CKGPS2, JKGPS1, and JKGPS2 during construction. The initial network data had been used for the past two years. CKGPS1, located below a coal mine, was offset by approximately 4cm towards the inside of the mountain. The inner side of the gully oriented approximately to the transverse direction of the tunnel, resulting in a 4cm offset in the initial direction of the entire network. The side length of CKGPS1~CKGPS2 is 306m, and the traverse extends 1803m perpendicular to the tunnel face. The calculated tunneling error due to this offset is 1803 / 306*0.04=0.24m, which is the main factor causing the tunneling error to exceed the limit of 24.6cm.
[0046] Due to the safety margin requirements for Class IV surrounding rock, the lining had already advanced to approximately 100m from the breakthrough face before the breakthrough. If conventional methods were used for adjustment, partial removal of the existing lining would be necessary. Therefore, this method was adopted for adjustment. Then, based on the existing control results and the fact that the secondary lining section met the adjustment requirements, the first step was to lock the control network. Since the determined cause of the deviation was a point error, not a significant difference due to accidental error, the correct point coordinates were used for adjustment, as shown in Table 7 below. Table 7 Control Point Adjustment Process Table
[0047] The difference in control point data, fed back to the field, represents the theoretical offset of the design cross-section centerline, and is the basis for adjustments. In this case, the route runs roughly north-south, so the ΔY error is very close to the lateral continuity error. After the entire network is adjusted, the accuracy indicators are referenced... Figure 4 and Figure 5 As shown: Once the control point results and differences are determined, the proposed adjustment amount can be determined.
[0048] Once the desired adjustment amount was determined, the RBCCE line design software was used to make local adjustments to the line type. The adjusted line element reference... Figure 6 As shown: The adjustment is based on the highway route design specifications. When the design speed is greater than or equal to 80 km / h and the ratio of the radius of the great circle (R) to the radius of the small circle (R2) is less than 1.5, a spiral curve is not required and superelevation changes are not considered.
[0049] The adjustment range of the line type is small, and the line types before and after can be connected smoothly. It has no impact on other lines. The statistics of the simulated line type of the adjusted curve are shown in Table 8 below. Table 8 Curve Adjustment Table
[0050] After the control network is locked and the alignment is adjusted, the tunnel cross-section is re-measured based on the control network results and alignment adjustment results to confirm that the over-excavation and under-excavation of each cross-section can meet the design requirements.
[0051] Then, the construction of the connecting section is carried out to complete the adjustment of the connection error.
[0052] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for adjusting tunnel breakthrough error exceeding limits, characterized in that, Based on the confirmed breakthrough error measurement values and breakthrough control measurement results, tunnels with breakthrough errors exceeding the limit will be adjusted by locking the tunnel's internal traverse control network and designing a suitable alignment using route design software. The adjustment method includes the following steps: Step 1: Determine the tunnel breakthrough error. After the tunnel is completed, unidirectional independent traverse measurements are taken to the breakthrough surface for both large and small mileage sections, and the lateral breakthrough error value is calculated. Step 2: Conduct cross-sectional measurements of the already lined section of the tunnel, using independent traverse survey results to measure the existing lining cross-section; Step 3: Conduct tunnel breakthrough control surveys. After verifying the measurement and determining the lateral breakthrough error value, for tunnels that are determined to have large errors and urgently need adjustment, conduct breakthrough adjustment and shaping, and select two methods according to the source of error. The first method is to directly adjust the results inside and outside the tunnel at both ends, using the control points outside the tunnel to directly adjust the results inside the tunnel, and then complete all the work in the subsequent alignment adjustment. The second method is to use control points at both ends of the tunnel and forced constraint points inside the tunnel to determine the locations of batch over- or under-excavation. Under the premise that the control network adjustment can meet the accuracy requirements, it ensures that the completed secondary lining of the tunnel is not under-excavated to the greatest extent possible, and completes the control network adjustment work. Step 4: Re-measure the cross-section of the lined section. Use the results of the traverse wire mesh to re-measure the completed lining section and evaluate whether it meets the requirements. If not, repeat step 3. Step 5: Perform alignment calculation for the tunnel breakthrough section, draw a breakthrough diagram based on the re-measurement data that meets the requirements, and use the route design software to fine-tune the alignment of the tunnel breakthrough section. Step six: Carry out the construction of the tunnel breakthrough section, using the breakthrough control survey results and the fine-tuned breakthrough section alignment for the construction of the breakthrough section.
2. The method for adjusting tunnel breakthrough error according to claim 1, characterized in that, The calculation of the lateral penetration error value is expressed as follows: （1）； （2）； （3）； in, This represents the difference between the ordinates of two points. This represents the difference between the ordinates of two points. The azimuth of the tunnel centerline at the breakthrough face is represented by (X1, Y1) and (X2, Y2), which represent the coordinates of the same point measured by the traverse at different mileages.
3. The method for adjusting tunnel breakthrough error according to claim 1, characterized in that, The independent traverse lines represent the results of separate adjustments for each mileage, serving as a benchmark for measuring the lining already constructed before the breakthrough.
4. The method for adjusting tunnel breakthrough error according to claim 3, characterized in that, The measurement of the independent traverse results includes the following steps: A1, GPS external horizontal control survey, to establish horizontal control points in the tunnel construction area; A2, Traverse surveying inside the tunnel: Establishing a traverse inside the tunnel and measuring angles and sides to complete the traverse surveying work; A3, Correction of traverse distance in tunnel: Correction of the measured traverse distance; A4, In-situ adjustment data processing for the tunnel traverse, involves organizing and analyzing the measurement data.
5. The method for adjusting tunnel breakthrough error according to claim 1, characterized in that, The implementation of the full tunnel constraint adjustment is carried out using COSACODAPS or SYADJ software. The observation data is first adjusted and then the accuracy is evaluated. The adjustment requires that the traverse line meets the minimum requirements of each index.
6. The method for adjusting tunnel breakthrough error according to claim 1, characterized in that, The evaluation criteria in step four are based on the existing traverse results and centerline, measuring the over-excavation and under-excavation alignment of the tunnel cross-section, and determining whether the acceptance criteria are met after adjustment.
7. The method for adjusting tunnel breakthrough error according to claim 6, characterized in that, If the tunnel for the over- or under-excavation measurement of the aforementioned line type is a railway tunnel, then the accuracy requirements for establishing a CPIII track control network must be met based on the original traverse network.
8. The method for adjusting tunnel breakthrough error according to claim 1, characterized in that, The tunnel alignment fine-tuning adjusts differentiated parameters based on the tunnel's breakthrough error value and smoothness requirements, and only adjusts the lining of the breakthrough section.
9. The method for adjusting tunnel breakthrough error according to claim 8, characterized in that, The process of fine-tuning the alignment of the tunnel breakthrough section first determines the total adjustment amount based on the breakthrough error measurement results. Then, the preliminary alignment direction after adjustment is determined by the alignment of the breakthrough section. After that, the alignment adjustment parameters are selected, the compiled parameters are entered into the alignment design software, the alignment is finely adjusted, and finally, the alignment fine-tuning scheme is generated.
10. The method for adjusting tunnel breakthrough error according to claim 9, characterized in that, The parameter adjustment process includes adjusting horizontal curves according to the route, determining the adjustment length based on the length of the reserved through section, determining the radius, and determining the length of the transition curve.