A method for intelligent control of tunnel over-excavation and under-excavation

Abstract

This invention relates to the field of blasting construction technology, specifically disclosing an intelligent control method for tunnel over- and under-excavation, comprising the following steps: S1, scanning the tunnel face to be blasted to generate high-precision point cloud data; S2, constructing a BIM model of the tunnel face based on the high-precision point cloud data and performing spatial coordinate registration; determining whether it is the first blast; if not, displaying the blast holes from the previous blast on the tunnel face BIM model; S3, receiving the input of the spatial coordinate data of the blast holes for the current blast, and creating the blast holes for the current blast on the tunnel face BIM model according to the blast hole spatial coordinates; S4, installing an intelligent laser projector inside the tunnel; S5, setting reference control points at the tunnel arch, calculating projection parameters, and projecting the blast holes for the current blast on the tunnel face BIM model onto the actual tunnel face; S6, drilling according to the projection, installing explosives, and blasting. The technical solution of this invention can accurately locate changes in the blast hole layout and improve blasting accuracy.

Description

Technical Field

[0001] This invention relates to the field of blasting construction technology, and in particular to an intelligent control method for tunnel over-excavation and under-excavation. Background Technology

[0002] Over- or under-excavation in tunnels negatively impacts the stability of the surrounding rock. Over- or under-excavation results in an uneven, non-smooth tunnel profile, increasing the risk of quality problems and excessive material consumption. Some over-excavation is caused by excessive explosive charges; in this case, the impact of blasting may loosen the surrounding rock, compromising its original bearing capacity. When over-excavation occurs, ensuring backfill quality during construction is difficult. Particularly at the tunnel arch and waist, compaction is challenging due to construction constraints, resulting in poor contact between the support and the surrounding rock, creating gaps and even large cavities. These gaps and cavities create point contact between the rock and the support, hindering the rock's ability to resist deformation and potentially leading to excessive deformation or even collapse.

[0003] To control the accuracy of the tunnel outline, traditional methods typically involve using a total station to measure the borehole layout, manually marking the blast hole positions on the tunnel face (e.g., by spraying red paint), and then drilling. However, this method relies on manual operation, has limited accuracy, and makes it difficult to fully reuse and compare the results of previous blasting operations. If there were over- or under-excavation issues in the previous blasting, the optimization and adjustment of the blast hole positions in the next round lacks data support, and the adjustment effect depends on experience-based judgment, resulting in significant uncertainty.

[0004] Therefore, there is a need for an intelligent tunnel blasting control method that can intuitively display changes in blast hole layout, improve blasting accuracy, and effectively control over- and under-excavation, so as to achieve dynamic optimization of excavation accuracy and real-time monitoring of over- and under-excavation. Summary of the Invention

[0005] This invention provides an intelligent control method for tunnel over- and under-excavation, which can intuitively display changes in blast hole layout and improve blasting accuracy.

[0006] To solve the above-mentioned technical problems, this application provides the following technical solution:

[0007] A method for intelligent control of tunnel over-excavation and under-excavation includes the following steps:

[0008] S1. A 3D laser scanner is used to scan the tunnel face to be blasted to generate high-precision point cloud data.

[0009] S2. Construct a tunnel face BIM model based on high-precision point cloud data and perform spatial coordinate registration; determine whether it is the first blast; if it is not the first blast, display the blast holes of the previous blast on the tunnel face BIM model.

[0010] S3. Receive the input of the spatial coordinate data of the blast holes for this blasting, and create the blast holes for this blasting on the BIM model of the working face according to the spatial coordinates of the blast holes.

[0011] S4. Install intelligent laser projectors inside the tunnel;

[0012] S5. Set up benchmark control points at the tunnel arch, calculate projection parameters, generate a dynamic light spot array, and project the blast holes of this blasting on the BIM model of the tunnel face onto the actual tunnel face.

[0013] S6. Drill holes according to the projection, install explosives, and carry out blasting.

[0014] Furthermore, it also includes:

[0015] S7. Scan the contour surface after the blast to generate point cloud data of the contour surface after the blast;

[0016] S8. Generate a BIM model of the blasted contour surface based on the point cloud data of the blasted contour surface, determine whether there are over-excavated areas and under-excavated areas, and mark the over-excavated areas and under-excavated areas if they exist.

[0017] Furthermore, step S2 specifically includes: preprocessing the point cloud data and converting the preprocessed point cloud data into a coordinate system consistent with the tunnel design drawings;

[0018] Import the point cloud into the BIM modeling software, use the point cloud surface extraction tool to generate the tunnel face surface; use control points to align the point cloud coordinates with the tunnel design coordinates;

[0019] The system retrieves the previous blast hole location information from the pre-created blast hole database. If no information is found, it is determined to be the first blast. If information is found, it is determined to be a non-first blast. The system then retrieves the previous blast hole location information from the blast hole database and overlays its coordinates onto the current BIM face model in different colors.

[0020] Furthermore, in step S3, the input methods include manual input and automatic input; the manually input borehole parameters include: number, spatial coordinates, borehole diameter, borehole depth, and angle; the input borehole parameters are stored in the borehole database;

[0021] The input boreholes are mapped to their spatial locations in the BIM model of the working face; and a three-dimensional borehole solid model is generated on the BIM model.

[0022] Furthermore, step S5 specifically includes: setting up no fewer than three reference control points in the tunnel; after the control points are installed, measuring their spatial positions using a total station and performing coordinate registration;

[0023] Based on the spatial coordinates of the blast holes, the positions of the control points, and the coordinates of the projector in the BIM model, a three-dimensional geometric inversion calculation is performed to determine the projection parameters, including the projector's projection angle, position and orientation; projection range and scaling ratio; and the corresponding projection point of each blast hole on the actual working face.

[0024] The projection parameters are input into the laser projector to generate and project a dynamic light spot array, projecting the blast holes of this blast onto the actual working face.

[0025] Furthermore, S8 specifically includes: importing the design excavation outline surface and constructing a BIM model of the design excavation outline surface; preprocessing the point cloud data after blasting and performing spatial coordinate registration so that the point cloud and the excavation outline surface BIM model are accurately aligned in the same coordinate system.

[0026] For each point P in the post-blast point cloud, calculate its nearest vertical distance d to the designed excavation profile surface:

[0027] If d > +Δ, it is determined to be an over-dig point;

[0028] If d < –Δ, it is determined to be an under-dug point;

[0029] If –Δ≤d≤+Δ, it is determined to be a qualified point;

[0030] Where Δ is the error tolerance;

[0031] Spatial clustering algorithms are used to cluster all over-dig and under-dig points to form over-dig and under-dig regions.

[0032] Furthermore, in step S3, when it is not the first blast, the currently input blast hole is automatically associated with the blast hole of the previous blast, and it is determined whether the distance between the associated blast holes exceeds a threshold. If it exceeds the threshold, an early warning is issued.

[0033] This solution generates high-precision point cloud data using laser scanning and constructs a BIM model to realistically recreate the actual terrain of the tunnel face. It can also overlay and display information from previous blasting boreholes, providing a data foundation and comparison basis for the current blasting plan, thus improving the convenience and accuracy of borehole adjustments for users. By dynamically projecting the locations of the current blasting boreholes onto the actual tunnel face using a laser projector, the intuitiveness and accuracy of drilling operations are improved, avoiding errors from manual marking and controlling over- and under-excavation issues at the source. Furthermore, by scanning and comparing the tunnel face after blasting, over- and under-excavation areas are identified and marked, providing a basis for correction in subsequent blasting operations, which helps to dynamically optimize the blasting plan and continuously improve construction accuracy. Attached Figure Description

[0034] Figure 1 This is a flowchart of an embodiment of an intelligent control method for tunnel over-excavation and under-excavation. Detailed Implementation

[0035] The following detailed description illustrates the specific implementation method:

[0036] Example 1

[0037] like Figure 1 As shown in the figure, an intelligent control method for tunnel over-excavation and under-excavation in this embodiment includes the following steps:

[0038] S1. A 3D laser scanner is used to scan the tunnel face to be blasted to generate high-precision point cloud data.

[0039] Specifically, a standing laser scanning method is adopted, and a 3D laser scanner is set up in an unobstructed location within 10-15 meters of the working face; if there are shadowed areas on the working face (such as equipment obstruction), multiple 3D laser scanner positions are set up to ensure coverage of all surfaces;

[0040] After the 3D laser scanner is set up, record the relative position of the 3D laser scanner and the working face. In subsequent setup processes, this relative position should be used in principle (the position can be adjusted if there are new shaded areas).

[0041] The 3D laser scanner is started and horizontal calibration is performed. After calibration, the tunnel face and the circumferential support of the tunnel face are scanned. In this embodiment, the scanning resolution is 1cm dot pitch.

[0042] After scanning is complete, export the raw point cloud data. If multiple 3D laser scanners are used, the point clouds from each scanner need to be stitched and registered to obtain the final point cloud data.

[0043] S2. Construct a tunnel face BIM model based on high-precision point cloud data and perform spatial coordinate registration; determine whether it is the first blast; if it is not the first blast, display the blast holes of the previous blast on the tunnel face BIM model.

[0044] Specifically, the point cloud data is preprocessed, including noise removal and smoothing; the preprocessed point cloud data is then converted into a coordinate system consistent with the tunnel design drawings to facilitate positioning.

[0045] Import the point cloud into BIM modeling software and use the point cloud surface extraction tool to generate the tunnel face surface; use control points to align the point cloud coordinates with the tunnel design coordinates; control points include tunnel axis control points, reflection target points, etc.

[0046] The system retrieves the location information of the previous blast hole from a pre-created blast hole database. If no information is found, it's considered the first blast; otherwise, it's considered a subsequent blast. The system then retrieves the previous blast hole location information from the database and overlays its coordinates onto the current BIM face model using a different color (e.g., blue). In this embodiment, the blast hole location information includes spatial coordinates, diameter, depth, and angle. Displaying the blast holes from the previous blast facilitates analysis of the previous blast results by construction personnel, providing a reference for optimizing the blast hole layout for the current blast.

[0047] If it is not the first blast, in other embodiments, depending on user needs, the blast holes of multiple blasts can also be set to display different colors.

[0048] S3. Receive the input of the spatial coordinate data of the blast holes for this blasting, and create the blast holes for this blasting on the BIM model of the working face according to the spatial coordinates of the blast holes.

[0049] Specifically, input methods include manual input and automatic input;

[0050] Manual input includes single input and batch import; single input: input the borehole parameters one by one in the system interface, including: number, spatial coordinates (X,Y,Z), borehole diameter (mm), borehole depth (m), angle (angle with the normal of the working face), explosive charge (kg), and blasting rounds; batch import supports importing the borehole parameter list of this blasting design from Excel or CSV format files;

[0051] When inputting automatically: The system automatically generates the current borehole layout plan based on the previous borehole location information. Users can select and drag the plan to adjust it. The corresponding parameters are displayed in real time while dragging. Users can also adjust the parameters to simplify the input process.

[0052] The system automatically maps the input borehole coordinates to their spatial location in the BIM model of the tunnel face; and generates a 3D borehole solid model on the BIM model. Each borehole is displayed as a cylindrical structure with attributes including: spatial coordinates, direction, vector length (hole depth), radius (hole diameter), and auxiliary information (number, charge parameters, blasting rounds, etc.). Users can click on any borehole to display its attributes.

[0053] The input borehole parameters are stored in the borehole database;

[0054] In this embodiment, the currently input blast holes are displayed in red to distinguish them from historical blast holes. If there were over- or under-digging issues in the previous blasting, this allows the user to easily compare with historical blast holes and adjust the current blast holes accordingly.

[0055] S4. Install a laser projector inside the tunnel;

[0056] Specifically, select an unobstructed, geologically stable area 10-15 meters in front of the tunnel face for the installation of the laser projector. Fix the laser projector on a tripod to ensure that the projection range covers the entire tunnel face. In practical applications, depending on the size of the tunnel cross-section excavation, one or more laser projectors can be used in collaboration.

[0057] S5. Set up benchmark control points at the tunnel arch, calculate projection parameters, generate a dynamic light spot array, and project the blast holes of this blasting on the BIM model of the tunnel face onto the actual tunnel face.

[0058] Specifically, no fewer than three high-precision reflective reference control points are set up on the tunnel arch or sidewall. The control points must be consistent with the coordinates set in the BIM model to form a three-dimensional coordinate reference of "control point-actual space-model". After the control points are installed, their spatial positions are measured by a total station and input into the system for coordinate registration.

[0059] Based on the spatial coordinates of the blast holes, the positions of the control points, and the coordinates of the projector in the BIM model, a three-dimensional geometric inversion calculation is performed to determine the projection parameters, including the projector's projection angle, position and orientation; projection range and scaling ratio; and the corresponding projection point of each blast hole on the actual working face.

[0060] The projection parameters are input into the laser projector for automatic calibration. After automatic calibration, a dynamic light spot array is generated and projected to project the blast holes of this blast onto the actual working face.

[0061] S6. Workers drill holes according to the projection, install explosives, and carry out blasting;

[0062] S7. Scan the contour surface after blasting to generate point cloud data of the contour surface after blasting; refer to step S1. The contour surface is the surface formed by the designed excavation line, which defines the ideal shape and size that the tunnel should be excavated into.

[0063] S8. Generate a BIM model of the blasted contour surface based on the point cloud data of the blasted contour surface, determine whether there are over-excavated areas and under-excavated areas, and mark the over-excavated areas and under-excavated areas if they exist.

[0064] Specifically, import the design excavation outline and construct a BIM model of the design excavation outline.

[0065] After preprocessing the point cloud data following blasting, spatial coordinate registration is performed to ensure accurate alignment of the point cloud with the BIM model of the excavation outline in the same coordinate system.

[0066] For each point P in the post-blast point cloud, calculate its nearest vertical distance d to the designed excavation profile surface:

[0067] If d > +Δ, then it is determined to be an over-dig point;

[0068] If d < –Δ, then it is determined to be an under-dug point;

[0069] If –Δ≤d≤+Δ, then it is a qualified point.

[0070] Here, Δ represents the error tolerance, which is set according to relevant construction specifications or project requirements.

[0071] Spatial clustering algorithms are used to cluster all over-excavation and under-excavation points, forming over-excavation and under-excavation areas. In this embodiment, over-excavation areas are displayed as overlaid red semi-transparent blocks in the BIM model, while under-excavation areas are displayed as overlaid blue semi-transparent blocks. When the mouse hovers over an over-excavation or under-excavation area, parameter information is displayed, including maximum deviation value, area, volume, etc.

[0072] This embodiment utilizes laser projection technology to visualize the designed blast hole locations on the actual tunnel face, simplifying the worker's workflow and enhancing the feasibility and intuitiveness of hole placement. After blasting, 3D scanning technology is used to collect the post-blast morphology of the tunnel face, and the point cloud data is compared and analyzed with the designed excavation contour to automatically identify over-excavation and under-excavation areas. This allows construction personnel to intuitively grasp the deviation of the blasting results, providing quantitative basis for the next round of blast hole optimization and forming a positive feedback loop mechanism. By establishing a closed-loop control system, this solution enables each round of blasting to continuously optimize based on the data from the previous round, achieving dynamic precision control of the tunnel excavation process. This iterative feedback-adjustment-re-execution approach helps improve the accuracy of blasting and reduce over-excavation and under-excavation areas.

[0073] Example 2

[0074] The difference between this embodiment and Embodiment 1 is that in step S3 of this embodiment, during non-first blasting, the currently input blast hole is automatically associated with the blast hole of the previous blast, and it is determined whether the distance between the associated blast holes exceeds a threshold. If it exceeds the threshold, an early warning is issued. During association, all current blast holes are traversed and spatially matched with the blast holes in the previous blasting record; for each current blast hole, its nearest blast hole from the previous blast is searched; it is determined whether there is a unique mapping relationship in the spatial position; if the condition is met, the association relationship is established. The threshold can be set according to the actual situation. This embodiment, by judging whether the distance between two consecutive blast holes is too large, can remind designers to check whether the hole placement is reasonable.

[0075] The above are merely embodiments of the present invention. The invention is not limited to the fields covered by these embodiments. Commonly known structures and characteristics in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are able to access all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for intelligent control of tunnel over-excavation and under-excavation, characterized in that, Includes the following steps: S1. A 3D laser scanner is used to scan the tunnel face to be blasted to generate high-precision point cloud data. S2. Construct a tunnel face BIM model based on high-precision point cloud data and perform spatial coordinate registration; determine whether it is the first blast; if it is not the first blast, display the blast holes of the previous blast on the tunnel face BIM model. S3. Receive the input of the spatial coordinate data of the blast holes for this blasting, and create the blast holes for this blasting on the BIM model of the working face according to the spatial coordinates of the blast holes. S4. Install intelligent laser projectors inside the tunnel; S5. Set up benchmark control points at the tunnel arch, calculate projection parameters, generate a dynamic light spot array, and project the blast holes of this blasting on the BIM model of the tunnel face onto the actual tunnel face. S6. Drill holes according to the projection, install explosives, and carry out blasting; S7. Scan the contour surface after the blast to generate point cloud data of the contour surface after the blast; S8. Generate a BIM model of the blasted contour surface based on the point cloud data of the blasted contour surface, determine whether there are over-excavation areas and under-excavation areas, and mark the over-excavation areas and under-excavation areas if they exist. Step S2 specifically includes: preprocessing the point cloud data and converting the preprocessed point cloud data into a coordinate system consistent with the tunnel design drawings; Import the point cloud into the BIM modeling software, use the point cloud surface extraction tool to generate the tunnel face surface; use control points to align the point cloud coordinates with the tunnel design coordinates; From the pre-created borehole database, search for the location information of the previous borehole. If not, it is determined to be the first blast. If it is, it is determined to be a non-first blast. Retrieve the location information of the previous borehole from the borehole database and overlay its borehole coordinates onto the current BIM face model in different colors. In step S3, the input methods include manual input and automatic input; the manually input borehole parameters include: number, spatial coordinates, borehole diameter, borehole depth, and angle; the input borehole parameters are stored in the borehole database. Map the input blast holes to their spatial locations in the BIM model of the working face; and generate a 3D solid model of the blast holes on the BIM model; Step S5 specifically includes: setting up no fewer than three reference control points in the tunnel; after the control points are installed, measuring their spatial positions using a total station and performing coordinate registration. Based on the spatial coordinates of the blast holes, the positions of the control points, and the coordinates of the projector in the BIM model, a three-dimensional geometric inversion calculation is performed to determine the projection parameters, including the projector's projection angle, position and orientation; projection range and scaling ratio; and the corresponding projection point of each blast hole on the actual working face. The projection parameters are input into the laser projector to generate and project a dynamic light spot array, projecting the blast holes of this blast onto the actual working face; S8 specifically includes: importing the design excavation outline surface and constructing a BIM model of the design excavation outline surface; preprocessing the point cloud data after blasting and performing spatial coordinate registration so that the point cloud and the excavation outline surface BIM model are accurately aligned in the same coordinate system. For each point P in the post-blast point cloud, calculate its nearest vertical distance d to the designed excavation profile surface: If d > +Δ, it is determined to be an over-dig point; If d < –Δ, it is determined to be an under-dug point; If –Δ ≤ d ≤ +Δ, it is considered a qualified point; Where Δ is the error tolerance; Spatial clustering algorithms are used to cluster all over-dig and under-dig points to form over-dig and under-dig regions.

2. The intelligent control method for tunnel over-excavation and under-excavation according to claim 1, characterized in that: In step S3, when it is not the first blast, the currently input blast hole is automatically associated with the blast hole of the previous blast, and it is determined whether the distance between the associated blast holes exceeds the threshold. If it exceeds the threshold, an early warning is issued.

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