Tunnel back-break detection method based on laser-point cloud

Abstract

The invention discloses a tunnel back-break detection method. The method includes the following steps that S1, according to center line data of a tunnel line, the thickness value and width value of a section are set, and tunnel section point cloud automatic partitioning is carried out; S2, the partitioned section point cloud is projected to the XOY plane, and a convex hull extraction method is adopted for carrying out automatic extraction of a section point cloud contour lines to obtain a measured section line; and S3, the tunnel design section is utilized, the distances between feature points of the tunnel design section and the measured section line and the locations of the feature points are calculated, and back-break automatic detection is carried out. Tunnel back-break detection is carried out by utilizing three-dimensional laser-point cloud data, and rapid partitioning of the section point cloud is achieved by adopting radius searching and a rectangular partitioning algorithm; on the basis of back-break area statistics of a polygonal intersection algorithm, the method is suitable for back-break detection of various types of tunnels; and compared with a traditional total-station section measurement mode, the detection efficiency is high, results are comprehensive and full and accurate, and the measurement precision meets the back-break detection requirement.

Description

technical field [0001] The invention relates to the field of tunnel overbreak and undercut detection, in particular to a method for tunnel overbreak and underbreak detection using a three-dimensional laser scanner and a laser point cloud processing algorithm thereof. Background technique [0002] The tunnel structures of highways, railways and urban rail transit projects have different cross-sectional design shapes. Tunnel construction methods include mining method, shield method, open-cut method, underground method, etc., and their construction techniques are also quite different. Regardless of the structure type and construction method of the tunnel, due to errors in the measurement and construction process, there will be inconsistencies in the shape and position of the measured tunnel section and the designed section. For tunnels using mining method, open cut method or underground excavation method, it is necessary to conduct over- and under-excavation detection during t...

AI Technical Summary

Problems solved by technology

Only the edge line after the projection of the circular tunnel has a symmetrical structure, so this method is not suitable for non-circular tunnels;

[0006] (2) This method extracts the section points according to the set angle interval, and cannot extract the characteristic section points of the tunnel

This type of method cannot calculate the overbreak and underbreak of feature points of rectangular, horseshoe-shaped and other tunnel types, and the calculation of overbreak and underbreak of these feature points is very important

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