Method for analyzing and evaluating influence of shield tunnel underpass on deformation of existing overpass
By acquiring the analysis area of the bridge body and conducting oblique core sampling and tensile strength analysis, combined with the relative position of the shield tunnel direction and the directly stressed area of the bridge body, the accuracy problem of the deformation impact analysis of shield tunnels passing under existing overpasses in the existing technology has been solved, and a more accurate assessment of bridge deformation and confirmation of hidden dangers has been achieved.
Patent Information
- Application Number
- CN202511634402.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-10
- Publication Date
- 2026-02-10
AI Technical Summary
Existing methods for analyzing the deformation impact of shield tunnels passing under existing overpasses cannot effectively combine the relative position of the shield tunnel's orientation and the directly stressed area of the bridge structure, resulting in inaccurate core drilling angles and an inability to accurately assess potential deformation hazards in the bridge structure.
By acquiring the analysis area of the bridge body, oblique rock core collection and tensile strength analysis are carried out. Combined with the relative position of the shield tunnel direction and the directly stressed area of the bridge body, the core drilling angle is determined, the longitudinal distribution of lithology is compared, and the types of directly stressed areas are classified.
It improved the accuracy of bridge deformation analysis, ensured the comprehensiveness of the bridge analysis area and the accurate identification of deformation hazards, and reduced the safety risks of shield tunneling to existing overpasses.
Smart Images
Figure CN121502877A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of tunnel construction and involves data analysis technology. Specifically, it is a method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation. Background Technology
[0002] The existing methods for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation have the following shortcomings:
[0003] 1. Existing methods for analyzing the impact of overpass deformation usually only analyze the impact of shield tunnels on the space actually covered by the existing overpass. They cannot effectively combine the shield tunnel direction with the area covered by the existing overpass for geometric correlation analysis, nor can they combine the actual shield depth to determine the analysis area of the bridge body. Therefore, it is difficult to accurately assess the actual impact of shield construction on overpasses.
[0004] 2. Existing methods for analyzing the deformation impact of overpasses only involve longitudinal core drilling of the directly stressed areas of the bridge structure. They fail to consider the relative position of the shield tunnel and the directly stressed areas of the bridge structure to determine the core drilling angle for oblique core drilling. Consequently, they cannot identify potential deformation hazards in the directly stressed areas of the bridge structure by comparing the tensile strength and lithology of the oblique core samples. This results in a lack of accuracy in the bridge deformation analysis and evaluation methods.
[0005] Therefore, we propose an analytical evaluation method for the impact of shield tunnels passing under existing overpasses on deformation. Summary of the Invention
[0006] In view of the shortcomings of existing technologies, the purpose of this invention is to provide an analysis and evaluation method for the impact of shield tunnels passing under existing overpasses on deformation, and to improve the accuracy of the analysis and evaluation method for the deformation impact of existing overpasses.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: a method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, comprising the following steps:
[0008] Step S1: Obtain the bridge body analysis area and screen the directly stressed areas of the bridge body within the bridge body analysis area to obtain bridge body area screening data;
[0009] Step S2: Based on the bridge area screening data, oblique rock cores are collected from the directly stressed areas of the bridge body, and tensile strength analysis and lithological longitudinal distribution consistency ratio analysis are performed on the oblique rock cores. Based on the analysis results, the directly stressed areas of the bridge body are classified into types to obtain the directly stressed area classification data.
[0010] Step S3: Deformation assessment of the existing overpass is performed based on the data of the direct stress zone division and the data of the bridge body zone screening.
[0011] Furthermore, in step S1, the specific steps are as follows:
[0012] Step S11: Obtain planar images of the geographical areas where the existing overpasses and shield tunnels are located to obtain planar images of the bridge and tunnel areas. Mark the spatial area covered by the existing overpasses in the planar images of the bridge and tunnel areas as the existing overpass area. Obtain the shield tunnel construction line and mark the spatial area covered by the shield tunnel construction line in the planar images of the bridge and tunnel areas as the tunnel construction area.
[0013] Step S12: Perform a relative position analysis between the tunnel construction area and the existing overpass area, and obtain the bridge analysis area based on the analysis results;
[0014] Step S13: Select the areas of the existing overpass that are in direct contact with the bridge body analysis area as the direct stress area of the bridge body, and obtain the bridge body area screening data.
[0015] Furthermore, in step S12, the specific steps are as follows:
[0016] Step S121: Obtain the center axis corresponding to the tunnel construction area to obtain the center axis of the shield tunnel;
[0017] Step S122: Set a sliding traversal point in the central axis of the shield tunnel, and obtain the real-time position of the sliding traversal point on the central axis of the shield tunnel to obtain the real-time axis feature center point;
[0018] Step S123: Perform geometric distance analysis between the real-time axis feature center point and the existing overpass area, and obtain the edge distance of the bridge and tunnel area corresponding to the real-time axis feature center point based on the analysis results;
[0019] Step S124: Use the sliding traversal points to traverse the central axis of the shield tunnel, obtain the edge distance of the bridge and tunnel area when the sliding traversal points are in different positions, and obtain multiple edge distances of the bridge and tunnel area.
[0020] Step S125: Set a preset range for the distance between the edges of the bridge and tunnel areas. If the distance between the edges of the bridge and tunnel areas is within the preset range, set the position of the shield tunnel center axis where the sliding traversal point is located as a first type axis point. If the distance between the edges of the bridge and tunnel areas is not within the preset range, set the position of the shield tunnel center axis where the sliding traversal point is located as a second type axis point.
[0021] Step S126: Obtain the connection between the first type of axis points and the corresponding real-time edge pixels to obtain multiple point pixel connections;
[0022] Step S127: Obtain the closed area enclosed by each pixel connection, the existing overpass area, and the central axis of the shield tunnel to obtain multiple connection analysis areas. Then, take the union of the multiple connection analysis areas to obtain the bridge body analysis area.
[0023] Furthermore, in step S123, the specific steps are as follows:
[0024] Edge extraction is performed on the existing overpass area, and the extracted overpass area edges are divided into several edge pixels;
[0025] Draw a line connecting each edge pixel to the center point of the real-time axis feature and extend it to obtain multiple edge pixel feature lines. If an edge pixel feature line intersects only one edge pixel, then this edge pixel is set as a valid edge pixel. If an edge pixel feature line intersects multiple edge pixels, calculate the straight-line distance between each intersecting edge pixel and the center point of the real-time axis feature. Compare the values of the multiple straight-line distances obtained and set the intersecting edge pixel with the smallest value as a valid edge pixel.
[0026] Obtain the straight-line distance between each valid edge pixel and the center point of the real-time axis feature, compare the values of the multiple obtained straight-line distances, set the valid edge pixel with the largest value as the real-time edge feature pixel, and set the physical distance between the real-time edge pixel and the center point of the real-time axis feature as the planar feature distance.
[0027] The shield depth of the shield tunnel at the center point of the real-time axis feature is obtained, and the shield depth at the center point is obtained.
[0028] The distance to the edge of the bridge and tunnel area corresponding to the real-time axis feature center point is obtained by calculating the planar feature distance and the shield depth at the center point.
[0029] Furthermore, in step S2, the specific steps are as follows:
[0030] Step S21: Obtain bridge area screening data, obtain the direct stress area of the bridge body based on the bridge area screening data, and arbitrarily select a sample stress area from the obtained direct stress area of the bridge body.
[0031] Step S22: Perform core geological analysis on the stress area of the sample, and divide the stress area of the sample into a potential stress area and a reasonable stress area based on the analysis results;
[0032] Step S23: Divide each directly stressed area of the bridge body into different types to obtain the directly stressed area division data;
[0033] In step S22, the specific steps are as follows:
[0034] Step S221: Create a three-dimensional model of the bridge body analysis area to obtain a three-dimensional model of the bridge body area. Mark the sample stress area in the three-dimensional model of the bridge body area to obtain the sample stress model area. Mark the shield tunnel center axis in the three-dimensional model of the bridge body area to obtain the tunnel model center axis.
[0035] Step S222: In the 3D model of the bridge area, obtain the geometric center point corresponding to the sample stress model area and set it as the sample geometric center point. Obtain the distance between the sample geometric center point and each axis position in the central axis of the tunnel model to obtain multiple axis geometric center distances. Set the axis position corresponding to the smallest axis geometric center distance as the nearest shield point in the area.
[0036] Step S223: Extract the edge contour of the sample stress area in the sample stress model area to obtain the edge contour of the stress area. Randomly select several contour feature points from the edge contour of the stress area and draw a line connecting each contour feature point to the nearest shield point in the area to obtain multiple contour shield connection lines.
[0037] Step S224: Obtain the ground area in the 3D model of the bridge area, obtain the projection line of each contour shield connection line in the ground area of the model, obtain multiple contour shield ground projection lines, and arbitrarily select a sample ground projection line from the multiple obtained contour shield ground projection lines.
[0038] Furthermore, in step S22, the specific steps are as follows:
[0039] Step S225: Oblique core drilling is performed on the spatial area where the sample ground projection line is located, and hardness analysis is performed on the drilled oblique core. The comprehensive tensile strength of the core corresponding to the sample ground projection line is obtained based on the analysis.
[0040] Step S226: Obtain the comprehensive tensile strength of the rock core corresponding to each contour shield ground projection line, and calculate the average of the obtained comprehensive tensile strength of the rock core to obtain the average value of the rock core tensile strength in the region, and set a benchmark value for the rock core tensile strength;
[0041] Step S227: If the average tensile strength of the rock core in the region is less than the benchmark value of the tensile strength of the rock core, then the stress area of the sample is directly classified as the stress area of the hidden danger.
[0042] Step S228: If the average tensile strength of the core sample is greater than or equal to the benchmark tensile strength of the core sample, then the longitudinal distribution analysis of the lithology of the stressed area of the sample is carried out, and the stress potential of the stressed area of the sample is further assessed based on the analysis results.
[0043] Furthermore, in step S225, the specific steps are as follows:
[0044] The contour feature points corresponding to the sample ground projection line are set as sample contour feature points, and the contour shield connection line corresponding to the sample ground projection line is set as sample contour shield connection line. The angle between the sample ground projection line and the sample contour shield connection line at the sample contour feature points is obtained to obtain the core drilling angle.
[0045] In the bridge analysis area, the feature points of the sample contour are used as the starting point for core drilling. Core drilling is carried out along the shield tunnel connection line of the sample contour until the center axis of the shield tunnel is reached to obtain the sample core.
[0046] The drilled rock cores were divided into rock cores of the first combination to rock cores of the a combination according to the rock core type. The tensile strength values of the rock cores of the first combination to rock cores of the a combination were obtained respectively.
[0047] The length of the rock core covered by the first rock core to the a-th rock core in the sample drilled rock core is obtained, and the length of the first rock core covered to the a-th rock core covered is obtained. The ratio of the length of the first rock core covered to the a-th rock core covered to the length of the sample drilled rock core is calculated, and the length of the first rock core covered to the a-th rock core covered is obtained.
[0048] The comprehensive tensile strength of the core corresponding to the ground projection line of the sample is obtained by calculating the proportion of the length of the first core to the proportion of the length of the a-th core and the tensile strength of the first core to the tensile strength of the a-th core.
[0049] Furthermore, in step S228, the specific steps are as follows:
[0050] Cores drilled within the stress zone of the sample were obtained, resulting in multiple inclined cores. Characteristic inclined cores and comparison inclined cores were randomly selected from the multiple inclined cores obtained.
[0051] The first core traversal point is set in the characteristic oblique core, and the second core traversal point is set in the comparison oblique core;
[0052] Mark the distance between the real-time position of the first core traversal point in the characteristic oblique core and the core drilling starting point as A1, and mark the core drilling angle corresponding to the characteristic oblique core as A2. Calculate A1×cosA2 to obtain the converted longitudinal distance of the first core traversal point.
[0053] Mark the distance between the real-time position of the second core traversal point in the comparison oblique core and the core drilling starting point as B1, mark the core drilling angle corresponding to the comparison oblique core as B2, calculate B1×cosB2 to obtain the converted longitudinal distance of the second core traversal point.
[0054] If the converted longitudinal distance between the first core traversal point and the second core traversal point is equal, and the first core traversal point and the second core traversal point are of the same core type, then the first core traversal point in the characteristic oblique core is set as the core consistency point.
[0055] If the converted longitudinal distance between the first core traversal point and the second core traversal point is not equal, or if the first core traversal point and the second core traversal point are not in the same core type, then the first core traversal point in the characteristic oblique core is set as a core inconsistency point.
[0056] Furthermore, in step S228, the specific steps are as follows:
[0057] The first and second core traversal points were used to traverse the characteristic oblique core and the comparison oblique core, respectively. The ratio of the number of consistent points in the core to the number of points traversed in the characteristic oblique core was calculated to obtain the lithological consistency ratio corresponding to the comparison oblique core.
[0058] Replace each oblique drilled core except for the characteristic oblique core with a comparison oblique core, and obtain the lithological consistency ratio corresponding to each comparison oblique core. Calculate the average of the obtained consistency ratios of multiple cores to obtain the comprehensive lithological consistency ratio corresponding to the characteristic oblique core.
[0059] Replace each inclined core with a characteristic inclined core, obtain the lithological consistency ratio corresponding to each characteristic inclined core, and calculate the average of the multiple lithological consistency ratios to obtain the regional lithological longitudinal distribution consistency ratio.
[0060] A baseline range for the vertical distribution consistency ratio of lithology is set. If the vertical distribution consistency ratio of lithology in a region is within the baseline range, the stress area of the sample is classified as a reasonable stress area. If the vertical distribution consistency ratio of lithology in a region is not within the baseline range, the stress area of the sample is classified as a potential stress area.
[0061] Furthermore, in step S3, the specific steps are as follows:
[0062] Obtain bridge area filtering data, and then obtain the bridge analysis area based on the bridge area filtering data. Obtain bridge area filtering data, and then obtain the hidden stress area and the reasonable stress area respectively based on the bridge area filtering data.
[0063] If there are potential stress areas within the bridge analysis area, it is determined that the existing overpass has potential deformation risks, and a strain risk warning is issued.
[0064] If there are no potential stress areas within the bridge analysis area, it is determined that the existing overpass does not have any potential deformation risks, and there is no need to issue a strain risk warning.
[0065] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:
[0066] 1. This invention analyzes the geometric correlation between the shield tunnel alignment and the coverage area of existing overpasses, and effectively combines the actual shield tunneling depth to determine the bridge analysis area, thus ensuring the comprehensiveness of the bridge analysis area.
[0067] 2. This invention determines the core drilling angle by combining the direction of the shield tunnel with the relative position of the directly stressed area of the bridge body, and performs oblique core drilling. By comparing the tensile strength and lithological consistency of the oblique core, the deformation potential of the directly stressed area of the bridge body is confirmed, thereby improving the accuracy of the bridge deformation analysis and evaluation method. Attached Figure Description
[0068] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.
[0069] Figure 1 This is a diagram illustrating the implementation steps of the present invention;
[0070] Figure 2 This is a schematic diagram of the effective edge pixels of the present invention;
[0071] Figure 3 This is a schematic diagram of the connection analysis area in this invention. Detailed Implementation
[0072] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0073] Please see Figure 1 This invention provides a technical solution: a method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, comprising the following specific steps:
[0074] Step S1: Obtain the bridge body analysis area and screen the directly stressed areas of the bridge body within the bridge body analysis area to obtain bridge body area screening data;
[0075] In step S1, the specific steps are as follows:
[0076] Planar images of the geographical areas where existing overpasses and shield tunnels are located are obtained to obtain planar images of the bridge and tunnel areas. The spatial area covered by the existing overpasses in the planar images of the bridge and tunnel areas is marked as the existing overpass area. The shield tunnel construction line is obtained and the spatial area covered by the shield tunnel construction line in the planar images of the bridge and tunnel areas is marked as the tunnel construction area.
[0077] It should be noted here that:
[0078] In this application, the shield tunnel referred to herein is a shield tunnel that has not yet been constructed, and the shield construction route referred to herein is the construction route pre-planned by the factory design team before construction.
[0079] The relative location of the tunnel construction area and the existing overpass area is analyzed, and the analysis area of the bridge body is obtained based on the analysis results.
[0080] Specifically as follows:
[0081] Obtain the center axis corresponding to the tunnel construction area to obtain the center axis of the shield tunnel;
[0082] It should be noted here that:
[0083] In this application, the central axis of the shield tunnel is specifically the line connecting the geometric center points of each tunnel cross-section within the tunnel construction area. The central axis of the shield tunnel is parallel to the shield tunneling direction.
[0084] A sliding traversal point is set in the central axis of the shield tunnel, and the real-time position of the sliding traversal point on the central axis of the shield tunnel is obtained to obtain the real-time axis feature center point.
[0085] Geometric distance analysis is performed between the real-time axis feature center point and the existing overpass area, and the edge distance of the bridge and tunnel area corresponding to the real-time axis feature center point is obtained based on the analysis results.
[0086] Specifically as follows:
[0087] Edge extraction is performed on the existing overpass area, and the extracted overpass area edges are divided into several edge pixels;
[0088] Please see Figure 2Draw a line connecting each edge pixel to the center point of the real-time axis feature and extend it to obtain multiple edge pixel feature lines. If an edge pixel feature line intersects only one edge pixel, then this edge pixel is set as a valid edge pixel. If an edge pixel feature line intersects multiple edge pixels, calculate the straight-line distance between each intersecting edge pixel and the center point of the real-time axis feature. Compare the values of the multiple straight-line distances obtained and set the intersecting edge pixel with the smallest value as a valid edge pixel.
[0089] Obtain the straight-line distance between each valid edge pixel and the center point of the real-time axis feature, compare the values of the multiple obtained straight-line distances, set the valid edge pixel with the largest value as the real-time edge feature pixel, and set the physical distance between the real-time edge pixel and the center point of the real-time axis feature as the planar feature distance.
[0090] It should be noted here that:
[0091] In this application, the physical distance of the connection involved here is specifically the real physical distance between the real-time edge pixel and the real-time axis feature center point, not the distance on the image.
[0092] The shield depth of the shield tunnel at the center point of the real-time axis feature is obtained, and the shield depth at the center point is obtained.
[0093] The distance between the plane feature distance and the shield depth at the center point is calculated to obtain the distance between the edge of the bridge and tunnel area corresponding to the center point of the real-time axis feature.
[0094] The distance to the edge of the bridge and tunnel area corresponding to the real-time axis feature center point is calculated using the following formula:
[0095]
[0096] Where Qsb is the distance to the edge of the bridge and tunnel area corresponding to the center point of the real-time axis feature, Jby is the planar feature distance, and Dgs is the shield depth at the center point;
[0097] The sliding traversal points are used to traverse the central axis of the shield tunnel to obtain the edge distance of the bridge and tunnel area when the sliding traversal points are in different positions, thus obtaining multiple edge distances of the bridge and tunnel area.
[0098] Set a preset range for the distance between the edges of the bridge and tunnel areas. If the distance between the edges of the bridge and tunnel areas is within the preset range, set the position of the shield tunnel center axis where the sliding traversal point is located as a first type axis point. If the distance between the edges of the bridge and tunnel areas is not within the preset range, set the position of the shield tunnel center axis where the sliding traversal point is located as a second type axis point.
[0099] It should be noted here that:
[0100] In this application, the lower limit of the preset interval for the bridge and tunnel area edge distance is the minimum shield thickness of the shield tunnel's central axis. For historical shield tunnel projects that have completed shield tunneling operations, the minimum bridge and tunnel area edge distance corresponding to each historical shield tunnel project is obtained. The difference between the mean and standard deviation of the multiple minimum bridge and tunnel area edge distances is calculated to obtain the upper limit of the preset interval for the bridge and tunnel area edge distance.
[0101] The connection between the first type of axis point and the corresponding real-time edge pixel point is obtained to obtain multiple point pixel connection lines;
[0102] Please see Figure 3 The closed area enclosed by each pixel connection, the existing overpass area, and the central axis of the shield tunnel is obtained to get multiple connection analysis areas. The union of the multiple connection analysis areas is then taken to obtain the bridge body analysis area.
[0103] The areas where existing overpasses are in direct contact with the bridge body analysis area are selected as the direct stress areas of the bridge body, thus obtaining bridge body area screening data;
[0104] It should be noted here that:
[0105] In step S1 above, the geometric correlation analysis between the tunnel alignment and the coverage area of the existing overpass, combined with the actual tunneling depth, is used to determine the analysis area of the bridge structure. This method significantly improves the comprehensiveness of the analysis of the impact of bridge deformation. Traditional analysis methods are often limited to the actual coverage area of the bridge structure, ignoring the complex spatial relationship between the tunnel and the bridge. Step S1, through geometric analysis, can accurately identify the potential impact paths of tunneling on different areas of the bridge structure, especially those key parts that may experience significant deformation due to the intersection of the tunnel alignment and the bridge structure.
[0106] Furthermore, by combining the actual tunneling depth, the analysis area can be further refined to ensure that the deformation impact from the surface to deep underground layers is taken into account. This comprehensive analysis not only helps to more accurately predict the range of bridge deformation but also provides a more reliable basis for subsequent risk assessment and response measures, thereby effectively reducing the safety risks of tunneling construction to existing overpasses.
[0107] Step S2: Based on the bridge area screening data, oblique rock cores are collected from the directly stressed areas of the bridge body, and tensile strength analysis and lithological longitudinal distribution consistency ratio analysis are performed on the oblique rock cores. Based on the analysis results, the directly stressed areas of the bridge body are classified into types to obtain the directly stressed area classification data.
[0108] In step S2, the specific steps are as follows:
[0109] Obtain bridge area screening data, acquire the direct stress area of the bridge body based on the bridge area screening data, and arbitrarily select a sample stress area from the acquired direct stress area of the bridge body, and screen the sample stress area into soil geological area and rock geological area.
[0110] If the stress area of the sample is a soil geological area, then soil moisture analysis is performed on the stress area of the sample, and the stress area of the sample is divided into a potential stress area and a reasonable stress area based on the analysis results.
[0111] Specifically as follows:
[0112] Mark a soil moisture monitoring area around the stress area of the sample to obtain the soil moisture area of the sample. Set up several moisture collection points within the soil moisture area of the sample.
[0113] The process of analyzing soil moisture in the sample soil moisture area involves setting several soil sample collection depths, and naming the multiple soil sample collection depths in ascending order of their numerical values from R1 sample collection depth to Rj sample collection depth.
[0114] It should be noted here that:
[0115] In this application, R1, R2, R3...Rj in the sample collection depth from R1 to Rj are the numbers corresponding to the soil sample collection depths, and j is an integer greater than 0;
[0116] In this application, the numerical interval between any two adjacent sample collection depths is equal. If the depth interval between sample collection depth R1 and sample collection depth R2 is 5m, then the depth interval between sample collection depth R2 and sample collection depth R3, ..., the depth interval between sample collection depth Rj-1 and sample collection depth Rj is also 5m.
[0117] Multiple soil samples were obtained from the soil samples collected at the R1 sampling depth at the humidity sampling point. The soil density of the R1 soil samples in their original sampling state was obtained, resulting in multiple R1 soil wet densities. The average of the multiple R1 soil wet densities was calculated to obtain the R1 soil mean wet density.
[0118] Repeat the process of obtaining the mean wet density of soil R1, and obtain the mean wet density of soil corresponding to the sampling depth of sample R2 to sample Rj respectively, to obtain the mean wet density of soil R2 to mean wet density of soil Rj.
[0119] Multiple R1 soil samples were dried, and the soil density of the dried R1 soil samples was obtained to obtain multiple R1 soil dry densities. The average of the multiple R1 soil dry densities was calculated to obtain the R1 soil mean dry density.
[0120] Repeat the process of obtaining the mean dry density of soil in R1, and obtain the mean dry density of soil corresponding to the sampling depth of sample R2 to sample Rj respectively, to obtain the mean dry density of soil in R2 to Rj.
[0121] The soil dry and wet density deviations corresponding to the stress area of the sample are obtained by calculating the ratio of the mean dry density of soil R1 to the mean dry density of soil Rj and the ratio of the mean wet density of soil R1 to the mean wet density of soil Rj.
[0122] The deviation of soil dry and wet density corresponding to the stress area of the sample is calculated using the following formula:
[0123]
[0124] Where Tgs is the soil dry and wet density deviation corresponding to the sample stress area, Tsdi is the mean dry density of soil Ri, Ssdi is the mean wet density of soil Ri, and j is the quantity value corresponding to the soil sample collection depth.
[0125] It should be noted here that:
[0126] In this application, the average dry density of soil Ri is any one of the average dry densities of soil R1 to Rj, and the average wet density of soil Ri is any one of the average wet density of soil R1 to Rj.
[0127] Set a soil dry-wet density deviation range. If the soil dry-wet density deviation is within the soil dry-wet density deviation range, then the sample stress area will be directly divided into a reasonable stress area. If the soil dry-wet density deviation is not within the soil dry-wet density deviation range, then the sample stress area will be directly divided into a hidden stress area.
[0128] It should be noted here that:
[0129] In this application, the reasonable stress area referred to herein includes the case where the soil dry-wet density deviation is at the boundary of the soil dry-wet density deviation range.
[0130] Multiple historical sample areas that have been divided into reasonable stress zones are obtained, and the soil dry-wet density deviation corresponding to each historical sample area is obtained. The obtained soil dry-wet density deviations are compared numerically, and the soil dry-wet density deviation with the largest value is set as the upper limit of the soil dry-wet density deviation interval, and the soil dry-wet density deviation with the smallest value is set as the lower limit of the soil dry-wet density deviation interval.
[0131] If the stress area of the sample is a rock geological area, core geological analysis is performed on the stress area of the sample, and the stress area of the sample is divided into a potential stress area and a reasonable stress area based on the analysis results.
[0132] Specifically as follows:
[0133] A three-dimensional model is created for the bridge analysis area to obtain the three-dimensional model of the bridge area. The sample stress area is marked in the three-dimensional model of the bridge area to obtain the sample stress model area. The shield tunnel center axis is marked in the three-dimensional model of the bridge area to obtain the tunnel model center axis.
[0134] In the 3D model of the bridge area, the geometric center point corresponding to the sample stress model area is obtained and set as the sample geometric center point. The distance between the sample geometric center point and each axis position in the central axis of the tunnel model is obtained to obtain multiple axis geometric center distances. The axis position corresponding to the smallest axis geometric center distance is set as the nearest shield point in the area.
[0135] It should be noted here that:
[0136] In this application, the distance of the connection referred to herein is specifically the actual distance in a real-world scenario.
[0137] The edge contour lines of the sample stress area in the sample stress model area are extracted to obtain the edge contour lines of the stress area. Several contour feature points are randomly selected from the edge contour lines of the stress area, and a line is drawn connecting each contour feature point to the nearest shield point in the area to obtain multiple contour shield connection lines.
[0138] It should be noted here that:
[0139] In this application, the contour shield tunnel connecting lines, the stress area edge contour lines, and the contour feature points involved are all in one-to-one correspondence. That is, for any contour shield tunnel connecting line, there is a unique stress area edge contour line and contour feature point corresponding to it, and the same applies to the stress area edge contour line and contour feature points.
[0140] The ground area in the 3D model of the bridge area is acquired, and the projection line of each contour shield connection line is obtained in the ground area of the model. Multiple contour shield ground projection lines are obtained, and a sample ground projection line is randomly selected from the multiple contour shield ground projection lines.
[0141] Oblique core drilling was carried out in the spatial area where the sample ground projection line was located, and the hardness analysis of the drilled oblique core was performed. Based on the analysis, the comprehensive tensile strength of the core corresponding to the sample ground projection line was obtained.
[0142] Specifically as follows:
[0143] The contour feature points corresponding to the sample ground projection line are set as sample contour feature points, and the contour shield connection line corresponding to the sample ground projection line is set as sample contour shield connection line. The angle between the sample ground projection line and the sample contour shield connection line at the sample contour feature points is obtained to obtain the core drilling angle.
[0144] In the bridge analysis area, the feature points of the sample contour are used as the starting point for core drilling. Core drilling is carried out along the shield tunnel connection line of the sample contour until the center axis of the shield tunnel is reached to obtain the sample core.
[0145] The drilled rock cores were divided into rock cores of the first combination to rock cores of the a combination according to the rock core type. The tensile strength values of the rock cores of the first combination to rock cores of the a combination were obtained respectively.
[0146] It should be noted here that:
[0147] In this application, 'a' in the first to the a-th core combination is the number of core types included in the sample drilled core, and 'a' is an integer greater than 0.
[0148] In this application, the core tensile strength referred to herein is specifically obtained through existing rock mass tensile tests;
[0149] The types of rock cores involved here include, but are not limited to, sandstone, shale, and slate.
[0150] The length of the rock core covered by the first rock core to the a-th rock core in the sample drilled rock core is obtained, and the length of the first rock core covered to the a-th rock core covered is obtained. The ratio of the length of the first rock core covered to the a-th rock core covered to the length of the sample drilled rock core is calculated, and the length of the first rock core covered to the a-th rock core covered is obtained.
[0151] The comprehensive tensile strength of the rock core corresponding to the ground projection line of the sample is obtained by calculating the length ratio of the first rock core to the length ratio of the a-th rock core and the tensile strength of the first rock core to the tensile strength of the a-th rock core.
[0152] The comprehensive tensile strength of the rock core corresponding to the ground projection line of the sample is calculated using the following formula:
[0153]
[0154] Where Zkl is the comprehensive tensile strength of the rock core corresponding to the ground projection line of the sample, Xcbi is the length ratio of the i-th rock core, Qkli is the tensile strength of the i-th rock core, and a is the number of rock core types included in the sample drilled rock core.
[0155] It should be noted here that:
[0156] In this application, the i-th core length percentage can be any one of the core length percentages from the first core length percentage to the a-th core length percentage, and the i-th core tensile strength can be any one of the core tensile strengths from the first core tensile strength to the a-th core tensile strength.
[0157] Repeat the process of obtaining the comprehensive tensile strength of the rock core corresponding to the ground projection line of the sample, obtain the comprehensive tensile strength of the rock core corresponding to the ground projection line of each contour shield, and calculate the average value of the obtained comprehensive tensile strength of the rock core to obtain the average value of the rock core tensile strength of the region, and set a benchmark value of rock core tensile strength.
[0158] It should be noted here that:
[0159] The direct stress area of the existing overpass bridge body that has completed shield tunnel construction is obtained, and the average tensile strength of the rock core corresponding to the direct stress area of the existing overpass bridge body is obtained. The average tensile strength of the rock core with the smallest value is set as the reference value of the rock core tensile strength.
[0160] The completed shield tunnel construction mentioned here has the same specifications as the shield tunnel construction in the tunnel construction area.
[0161] If the average tensile strength of the rock core in the region is less than the benchmark value of the tensile strength of the rock core, then the stress area of the sample will be directly classified as the stress area with potential hazards.
[0162] If the average tensile strength of the core sample is greater than or equal to the benchmark value of the tensile strength of the core sample, then the longitudinal distribution analysis of the lithology of the stressed area of the sample will be carried out, and the stress potential of the stressed area of the sample will be further assessed based on the analysis results.
[0163] Specifically as follows:
[0164] Cores drilled within the stress zone of the sample were obtained, resulting in multiple inclined cores. Characteristic inclined cores and comparison inclined cores were randomly selected from the multiple inclined cores obtained.
[0165] It should be noted here that:
[0166] In this application, the characteristic oblique core and the compared oblique core involved herein cannot be the same core;
[0167] The first core traversal point is set in the characteristic oblique core, and the second core traversal point is set in the comparison oblique core;
[0168] Mark the distance between the real-time position of the first core traversal point in the characteristic oblique core and the core drilling starting point as A1, and mark the core drilling angle corresponding to the characteristic oblique core as A2. Calculate A1×cosA2 to obtain the converted longitudinal distance of the first core traversal point.
[0169] Mark the distance between the real-time position of the second core traversal point in the comparison oblique core and the core drilling starting point as B1, mark the core drilling angle corresponding to the comparison oblique core as B2, calculate B1×cosB2 to obtain the converted longitudinal distance of the second core traversal point.
[0170] If the converted longitudinal distance between the first core traversal point and the second core traversal point is equal, and the first core traversal point and the second core traversal point are of the same core type, then the first core traversal point in the characteristic oblique core is set as the core consistency point.
[0171] If the converted longitudinal distance between the first core traversal point and the second core traversal point is not equal, or if the first core traversal point and the second core traversal point are not in the same core type, then the first core traversal point in the characteristic oblique core is set as a core inconsistency point.
[0172] The first and second core traversal points were used to traverse the characteristic oblique core and the comparison oblique core, respectively. The ratio of the number of consistent points in the core to the number of points traversed in the characteristic oblique core was calculated to obtain the lithological consistency ratio corresponding to the comparison oblique core.
[0173] Replace each oblique drilled core except for the characteristic oblique core with a comparison oblique core, and obtain the lithological consistency ratio corresponding to each comparison oblique core. Calculate the average of the obtained consistency ratios of multiple cores to obtain the comprehensive lithological consistency ratio corresponding to the characteristic oblique core.
[0174] Replace each inclined core with a characteristic inclined core, obtain the lithological consistency ratio corresponding to each characteristic inclined core, and calculate the average of the multiple lithological consistency ratios to obtain the regional lithological longitudinal distribution consistency ratio.
[0175] Set a benchmark interval for the vertical distribution consistency ratio of lithology. If the vertical distribution consistency ratio of lithology in a region is within the benchmark interval, the stress area of the sample is classified as a reasonable stress area. If the vertical distribution consistency ratio of lithology in a region is not within the benchmark interval, the stress area of the sample is classified as a potential stress area.
[0176] It should be noted here that:
[0177] In this application, the upper limit of the benchmark interval for the longitudinal distribution consistency ratio of lithology is 100%, meaning that the lithology distribution of any two inclined rock cores is consistent. The direct stress area of the existing overpass body that has completed shield tunnel construction is obtained, and the regional longitudinal distribution consistency ratio of the lithology corresponding to the direct stress area of the existing overpass body is obtained. The regional longitudinal distribution consistency ratio with the smallest value is set as the lower limit of the benchmark interval for the longitudinal distribution consistency ratio of lithology.
[0178] Repeat the process of dividing the sample stress area into different types, and divide each bridge body directly stress area into different types to obtain the direct stress area division data.
[0179] It should be noted here that:
[0180] Step S2 determines the core drilling angle by combining the relative position of the shield tunnel alignment and the directly stressed area of the bridge structure, and then drills the core at an angle. The tensile strength and lithological consistency of the angled core are then compared to identify potential deformation hazards in the directly stressed area of the bridge structure. This method significantly improves the accuracy of bridge deformation analysis and evaluation. Traditional methods often rely on vertically drilled core samples, which are difficult to fully reflect the true lithological characteristics and tensile properties of the directly stressed area of the bridge structure under complex stress states. Step S2, through angled drilling, can more realistically simulate the oblique stress generated by shield tunneling on the bridge structure, thus more accurately assessing the tensile strength and deformation characteristics of the core under oblique stress conditions. By comparing the core samples with the lithological consistency of the directly stressed area of the bridge structure, potential deformation hazards can be identified in a timely manner, providing more accurate data support for the safety assessment of the bridge structure. This analytical method not only enhances the specificity of deformation analysis but also improves the reliability of the evaluation results, helping to more effectively ensure the structural safety of the bridge structure during shield tunneling.
[0181] Step S3: Evaluate the deformation of the existing overpass based on the data of the direct stress zone division and the data of the bridge body area screening;
[0182] The specific steps in step S3 are as follows:
[0183] Obtain bridge area filtering data, and then obtain the bridge analysis area based on the bridge area filtering data. Obtain bridge area filtering data, and then obtain the hidden stress area and the reasonable stress area respectively based on the bridge area filtering data.
[0184] If there are potential stress areas within the bridge analysis area, it is determined that the existing overpass has potential deformation risks, and a strain risk warning is issued.
[0185] If there are no potential stress areas within the bridge analysis area, it is determined that the existing overpass does not have any potential deformation risks, and there is no need to issue a strain risk warning.
[0186] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, characterized in that, Includes the following steps: Step S1: Obtain the bridge body analysis area, and screen the directly stressed areas of the bridge body in the bridge body analysis area to obtain bridge body area screening data; Step S2: Based on the bridge area screening data, the sample stress area is screened into soil geological area and rock geological area. If the sample stress area is a soil geological area, soil moisture analysis is performed on the sample stress area, and the sample stress area is classified according to the analysis results. If the sample stress area is a rock geological area, oblique rock cores are collected from the direct stress area of the bridge body, and tensile strength analysis and lithological longitudinal distribution consistency ratio analysis are performed on the oblique rock cores. The direct stress area of the bridge body is classified according to the analysis results, and the direct stress area classification data is obtained. Step S3: Deformation assessment of the existing overpass is performed based on the data of the direct stress zone division and the data of the bridge body zone screening.
2. The method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, as described in claim 1, is characterized in that... In step S1, the specific steps are as follows: Step S11: Obtain planar images of the geographical areas where the existing overpasses and shield tunnels are located, and obtain planar images of the bridge and tunnel areas. Mark the spatial area covered by the existing overpasses in the planar images of the bridge and tunnel areas as the existing overpass area, and mark the spatial area covered by the shield tunnel construction line in the planar images of the bridge and tunnel areas as the tunnel construction area. Step S12: Perform a relative position analysis between the tunnel construction area and the existing overpass area, and obtain the bridge analysis area based on the analysis results; Step S13: Select the areas of the existing overpass that are in direct contact with the bridge body analysis area as the direct stress area of the bridge body, and obtain the bridge body area screening data.
3. The method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, as described in claim 2, is characterized in that... In step S12, the specific steps are as follows: Step S121: Obtain the center axis corresponding to the tunnel construction area to obtain the center axis of the shield tunnel; Step S122: Set a sliding traversal point in the central axis of the shield tunnel, and obtain the real-time position of the sliding traversal point on the central axis of the shield tunnel to obtain the real-time axis feature center point. Step S123: Perform geometric distance analysis between the real-time axis feature center point and the existing overpass area, and obtain the edge distance of the bridge and tunnel area corresponding to the real-time axis feature center point based on the analysis results; Step S124: Use the sliding traversal points to traverse the central axis of the shield tunnel, obtain the edge distance of the bridge and tunnel area when the sliding traversal points are in different positions, and obtain multiple edge distances of the bridge and tunnel area. Step S125: Set a preset range for the distance between the edges of the bridge and tunnel areas. If the distance between the edges of the bridge and tunnel areas is within the preset range, set the position of the shield tunnel center axis where the sliding traversal point is located as a first type axis point. If the distance between the edges of the bridge and tunnel areas is not within the preset range, set the position of the shield tunnel center axis where the sliding traversal point is located as a second type axis point. Step S126: Obtain the connection between the first type of axis points and the corresponding real-time edge pixels to obtain multiple point pixel connections; Step S127: Obtain the closed area enclosed by each pixel connection, the existing overpass area, and the central axis of the shield tunnel to obtain multiple connection analysis areas. Take the union of the multiple connection analysis areas to obtain the bridge body analysis area.
4. The method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, as described in claim 3, is characterized in that... In step S123, the specific steps are as follows: Edge extraction is performed on the existing overpass area, and the extracted overpass area edges are divided into several edge pixels; Draw a line connecting each edge pixel to the center point of the real-time axis feature and extend it to obtain multiple edge pixel feature lines. If an edge pixel feature line intersects only one edge pixel, then this edge pixel is set as a valid edge pixel. If an edge pixel feature line intersects multiple edge pixels, calculate the straight-line distance between each intersecting edge pixel and the center point of the real-time axis feature, and set the intersecting edge pixel with the smallest distance value as a valid edge pixel. Obtain the straight-line distance between each valid edge pixel and the center point of the real-time axis feature. Set the valid edge pixel with the largest value as the real-time edge feature pixel. Set the physical distance between the real-time edge pixel and the center point of the real-time axis feature as the planar feature distance. Obtain the shield depth of the shield tunnel at the center point of the real-time axis feature to obtain the center point shield depth. Calculate the edge distance of the bridge and tunnel area using the planar feature distance and the center point shield depth.
5. The method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, as described in claim 1, is characterized in that... In step S2, the specific steps are as follows: Step S21: Obtain bridge area screening data. Based on the bridge area screening data, arbitrarily select a sample stress area in the direct stress area of the bridge body. If the sample stress area is a soil geological area, perform soil moisture analysis on the sample stress area. Based on the analysis results, divide the sample stress area into hidden stress areas and reasonable stress areas. Step S22: If the stress area of the sample is a rock geological area, then the stress area of the sample is used as the sample, and oblique core analysis is performed on each direct stress area of the bridge body. Based on the analysis results, the stress area of the sample is divided into the hidden stress area and the reasonable stress area. The specific steps are as follows: Step S221: Obtain the three-dimensional model of the bridge body area, mark the sample stress area as the sample stress model area in the three-dimensional model of the bridge body area, and mark the shield tunnel center axis as the tunnel model center axis in the three-dimensional model of the bridge body area. Step S222: Obtain the geometric center point corresponding to the sample stress model area, and set the point closest to the central axis of the tunnel model as the nearest shield point in the area; Step S223: Obtain the edge contour line of the stress area, randomly select several contour feature points from the edge contour line of the stress area, and draw a line connecting each contour feature point to the nearest shield tunnel point in the area to obtain multiple contour shield tunnel connection lines. Step S224: Obtain the ground area in the 3D model of the bridge body area, obtain the projection line of each contour shield connection line in the ground area of the model, obtain multiple contour shield ground projection lines, and arbitrarily select a sample ground projection line.
6. The method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, as described in claim 5, is characterized in that... Step S22 further includes: Step S225: Oblique core drilling is performed on the spatial area where the sample ground projection line is located, and hardness analysis is performed on the drilled oblique core. The comprehensive tensile strength of the core corresponding to the sample ground projection line is obtained based on the analysis. Step S226: Obtain the comprehensive tensile strength of the rock core corresponding to each contour shield ground projection line, and calculate the average of the obtained comprehensive tensile strength of the rock core to obtain the average value of the rock core tensile strength in the region, and set a benchmark value for the rock core tensile strength; Step S227: If the average tensile strength of the rock core in the region is less than the benchmark value of the tensile strength of the rock core, then the stress area of the sample is directly classified as the stress area of the hidden danger. Step S228: If the average tensile strength of the core sample is greater than or equal to the benchmark tensile strength of the core sample, then the longitudinal distribution analysis of the lithology of the stressed area of the sample is carried out, and the stress potential of the stressed area of the sample is further assessed based on the analysis results.
7. The method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, as described in claim 6, is characterized in that... In step S225, the specific steps are as follows: The contour feature points corresponding to the sample ground projection line are set as sample contour feature points, and the contour shield connection line corresponding to the sample ground projection line is set as sample contour shield connection line. The angle between the sample ground projection line and the sample contour shield connection line at the sample contour feature points is obtained to obtain the core drilling angle. In the bridge analysis area, the feature points of the sample contour are used as the starting point for core drilling. Core drilling is carried out along the shield tunnel connection line of the sample contour until the center axis of the shield tunnel is reached to obtain the sample core. The drilled rock cores were divided into rock cores of the first combination to the a combination according to the rock core type, and the tensile strength values were obtained to obtain the tensile strength of the first rock core to the a combination. The length of the rock core covered by the first rock core to the a-th rock core in the sample drilled rock core is obtained, and the length of the first rock core covered to the a-th rock core covered is obtained. The ratio of the length of the first rock core covered to the a-th rock core covered to the length of the sample drilled rock core is calculated, and the length of the first rock core covered to the a-th rock core covered is obtained. The comprehensive tensile strength of the core corresponding to the ground projection line of the sample is obtained by calculating the proportion of the length of the first core to the proportion of the length of the a-th core and the tensile strength of the first core to the tensile strength of the a-th core.
8. The method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, as described in claim 6, is characterized in that... In step S228, the specific steps are as follows: Core samples were obtained from the stress-bearing area of the sample, resulting in multiple inclined core samples. Featured inclined core samples and comparative inclined core samples were randomly selected. The first core traversal point is set in the characteristic oblique core, and the second core traversal point is set in the comparison oblique core; Mark the distance between the real-time location of the first core traversal point and the core drilling starting point in the characteristic oblique core as A1, mark the core drilling angle corresponding to the characteristic oblique core as A2, and calculate the converted longitudinal distance of the first core traversal point. Mark the distance between the real-time location of the second core traversal point and the core drilling starting point in the comparison oblique core as B1, mark the core drilling angle corresponding to the comparison oblique core as B2, and calculate the converted longitudinal distance of the second core traversal point. If the converted longitudinal distance between the first core traversal point and the second core traversal point is equal, and the first core traversal point and the second core traversal point are of the same core type, then the first core traversal point in the characteristic oblique core is set as the core consistency point. If the converted longitudinal distance between the first core traversal point and the second core traversal point is not equal, or if the first core traversal point and the second core traversal point are not in the same core type, then the first core traversal point in the characteristic oblique core is set as a core inconsistency point.
9. The method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, as described in claim 8, is characterized in that... In step S228, the specific steps are as follows: The first and second core traversal points were used to traverse the characteristic oblique core and the comparison oblique core, respectively. The ratio of the number of consistent points in the core to the number of points traversed in the characteristic oblique core was calculated to obtain the lithological consistency ratio corresponding to the comparison oblique core. Replace each oblique drilled core except for the characteristic oblique core with a comparison oblique core, and obtain the lithological consistency ratio corresponding to each comparison oblique core. Calculate the average of the obtained consistency ratios of multiple cores to obtain the comprehensive lithological consistency ratio corresponding to the characteristic oblique core. Replace each inclined core with a characteristic inclined core, obtain the lithological consistency ratio corresponding to each characteristic inclined core, and calculate the average of the multiple lithological consistency ratios to obtain the regional lithological longitudinal distribution consistency ratio. Set a benchmark range for the vertical distribution consistency ratio of lithology. If the vertical distribution consistency ratio of lithology in a region is within the benchmark range, the stress area of the sample is classified as a reasonable stress area. If it is not, the stress area of the sample is classified as a potential stress area.
10. The method for analyzing and evaluating the impact of shield tunnels passing under existing overpasses on deformation, as described in claim 1, is characterized in that... In step S3, the specific steps are as follows: Obtain bridge area filtering data, and then obtain the bridge analysis area based on the bridge area filtering data. Obtain bridge area filtering data, and then obtain the hidden stress area and the reasonable stress area respectively based on the bridge area filtering data. If there are potential stress areas within the bridge analysis area, it is determined that the existing overpass has potential deformation risks, and a strain risk warning is issued. If there are no potential stress areas within the bridge analysis area, it is determined that the existing overpass does not have any potential deformation risks, and there is no need to issue a strain risk warning.