Method for evaluating construction quality of tunnel drilling and blasting based on three-dimensional laser scanning

[0038] Example

[0039] like figure 1 shown, figure 1 This is a schematic diagram of the work flow of the method for evaluating the construction quality of tunnel drilling and blasting based on three-dimensional laser scanning according to the present invention.

[0040]A method for evaluating the construction quality of tunnel drilling and blasting based on three-dimensional laser scanning, the method includes the following steps: firstly, a tunnel data acquisition module is used to collect data, then a tunnel data preprocessing module is used to process the collected data, and a tunnel is constructed according to the processing results. The three-dimensional model building module adopts the post-processing module of the tunnel three-dimensional model for post-processing, and finally uses the tunnel drilling and blasting quality evaluation module to evaluate the results.

[0041] The specific implementation method of each module is as follows:

[0042] 1. Tunnel data acquisition module

[0043] like figure 2 shown, figure 2 This is a working flow chart of the method for evaluating the construction quality of tunnel drilling and blasting based on three-dimensional laser scanning under the tunnel data acquisition module.

[0044] The realization method of the tunnel data acquisition module is as follows: (1) Use the three-dimensional laser scanner and the total station to collect the tunnel data respectively. The three-dimensional laser scanner and the total station must perform error checking before data acquisition to ensure the scanning accuracy and Large-scale scanning; (2) 3D laser scanner obtains tunnel point cloud data and tunnel image data, and total station obtains tunnel point cloud reference data, providing data sources for tunnel multi-view point cloud data splicing; (3) Layout at the tunnel site The 3D laser scanner completes tunnel station layout, backsight point coordinate scanning, station coordinate scanning, rough scanning of tunnel scenes, and fine scanning of tunnel scenes; (4) On the basis of the above, tunnel point cloud data and tunnel image data are obtained.

[0045] Considering that there are many suspended particles in the drilling and blasting tunnel, the noise is large, and the ground vibration is obvious, the distance between each scanning station should not be too long, and at the same time, it is necessary to ensure that the overlap between two adjacent scanning stations is greater than 40%, in order to obtain a more complete picture. Drilling and blasting tunnel hole type data.

[0046] The control target used for point cloud data splicing adopts spherical target, and no less than 4 control targets are set between each station, following the principle of approximate triangle, to obtain the overall coordinate registration accuracy of the measurement area, and at the same time pay attention to The target should not be too far away from the scanner, otherwise the recognition accuracy of the target center will be reduced.

[0047] 2. Tunnel data preprocessing module

[0048] like image 3 shown, image 3 This is a working flow chart of the method for evaluating the construction quality of tunnel drilling and blasting based on three-dimensional laser scanning in the tunnel data preprocessing module.

[0049] The implementation method of the tunnel data preprocessing module is as follows: (1) Import the collected tunnel point cloud data and tunnel image data into the tunnel data preprocessing module, and preprocess the data, including coordinate transformation, data removal redundancy, data removal noise, and data processing. Simplified; (2) Based on Visual C++6.0 and Matlab7.0, identify the reflector logo. When there is no reflector logo, the feature is collected immediately, and when there is a reflector logo, the reflector logo is collected; (3 ) Perform sequence splicing and overall matching on the collected data to achieve data fusion and check whether it is the last scanned data graph. If so, the tunnel multi-view cloud data splicing is completed. If not, the tunnel multi-view must be re-aligned. The cloud data is spliced ​​and matched until it meets the requirements.

[0050] The coordinate transformation method mainly uses the Taylor series expansion method to linearize the model, and then solves the three rotation parameters X of the coordinate transformation. 0 , Y 0 ,Z 0 , the three translation parameters ε x , ε y , ε z , a scale parameter δ u , realize the coordinate conversion of 3D laser scanning technology.

[0051] Data de-redundancy mainly refers to the overlapping of the multi-station scan data of the registered tunnel, and the redundancy of the scan data caused by it must be removed.

[0052] Data removal noise is mainly aimed at jitter caused by lidar rotation during data acquisition, interference from moving objects, stray light and background light during scanning, signal-to-noise ratio of received signal, laser beam width, laser divergence, laser wavelength, receiver response, The noise generated by the accuracy of the electronic clock and the positioning and orientation accuracy of the platform is removed mainly by manual deletion and automatic judgment by the system.

[0053] Based on Visual C++ 6.0 and Matlab 7.0, the identification of the reflector is identified, and the point cloud data under different stations are converted to the same station. The main method used is to call the Matlab 7.0 function in Visual C++ 6.0. library, and then use various matrix operations of Matlab 7.0 to solve the coordinate transformation matrix according to the known coordinate data contained in the target of the same name selected for scanning, and finally realize tunnel point cloud data splicing.

[0054] 3. Tunnel 3D model building block

[0055] like Figure 4 shown, Figure 4 This is a working flow chart of the method for evaluating the construction quality of tunnel drilling and blasting based on three-dimensional laser scanning under the tunnel three-dimensional model building module.

[0056] The realization method of tunnel 3D model building module is: (1) Based on tunnel multi-view point cloud data splicing, the tunnel geometry fitting mainly includes point fitting, curve fitting, surface fitting, cylinder fitting, cone fitting and vector line (2) Based on the above work, complete the construction of the three-dimensional model of the tunnel.

[0057] 4. Tunnel 3D model post-processing module

[0058] like Figure 5 shown, Figure 5 This is a working flow chart of the method for evaluating the construction quality of tunnel drilling and blasting based on three-dimensional laser scanning in the tunnel three-dimensional model post-processing module.

[0059] The realization method of the post-processing module of the 3D tunnel model is as follows: (1) Build a model based on the 3D tunnel, and perform post-processing on the 3D model of the tunnel, including texture mapping, topology analysis, vulnerability repair, shadow removal, and model simplification; (2) The geometry of the tunnel Measurement, including distance measurement, angle measurement, area measurement, volume measurement.

[0060] 5. Tunnel drilling and blasting quality evaluation module

[0061] like Image 6 shown, Image 6 This is a working flow chart of the method for evaluating the construction quality of tunnel drilling and blasting based on three-dimensional laser scanning in the tunnel drilling and blasting quality evaluation module.

[0062] The implementation method of the tunnel drilling and blasting quality evaluation module is: (1) Calculation of various evaluation factors, mainly including blasting surface flatness calculation, blasting contour smoothness calculation, blasting surface half-porosity calculation, blasting surface blast hole utilization calculation, Calculation of vector value of blasting over and under excavation, calculation of blasting over and under excavation area, calculation of measured area of ​​blasting, and calculation of theoretical blasting area; (2) 3D model output of tunnel, including output of tunnel section diagram and tunnel monitoring data; (3) 3D model of tunnel Display, including model zoom, model rotation, model translation; (4) Tunnel 3D model format conversion, the main formats include DWG, IGES, STL.

[0063] The tunnel drilling and blasting quality evaluation module mainly uses the visual programming language DelPhi to evaluate the three-dimensional model of the tunnel. Before the tunnel drilling and blasting construction, a laser scan is performed on the excavation surface area to obtain a three-dimensional image of the tunnel hole shape. After the excavation is completed, perform another scan or supplementary scan for the difficult area to scan, and superimpose the point cloud data results obtained by successive scans for comparative analysis, so as to realize the difference between the scanning points of each section of the tunnel relative to the design cross-section over-under-excavation value. Calculation, calculation of the measured area of ​​the entire cross-section of the tunnel and the calculation of the over-under-excavation area, as well as the calculation of the flatness of the blasting surface, the smoothness of the blasting contour line, and the half-porosity of the blasting surface.