基于数字化图像的引水隧洞超欠挖检测及其应用技术研究

Over⁃under⁃excavation Detection Based on Digital Image of Water Diversion Tunnels and Its Application

为有效减少小断面引水隧洞围岩开挖超欠挖量,依托犬木塘水库大山岭隧洞工程,采用一种基于图像处理技术的超欠挖检测方法,使用数码相机采集隧洞图像数据,并进行点云数据处理、三维曲面重建、图像拼接展开等步骤来实现隧洞超欠挖检测,并对所提方法应用于引水隧洞工程的有效性进行验证。应用结果表明:通过三维曲面重建的实际轮廓与设计开挖轮廓对比分析可计算引水隧洞超欠挖值、超欠挖面积及超欠挖体积量等参数,通过图像拼接矫正构建隧洞地质展开图,能直观展示节理素描等围岩信息。该研究实现了对小断面引水隧洞超欠挖的精准快速检测,具有广泛的应用前景,可为后续施工设计提供依据。

In order to effectively reduce the amount of over⁃under⁃excavation in the perimeter rock excavation of small cross⁃section diversion tunnels,an over⁃under⁃excavation detection method based on image processing technology is adopted based on the Dashanling Tunnel Project of Quanmutang Reservoir.A digital camera is used to collect image da⁃ta of tunnels,and point cloud data processing,three⁃dimensional surface reconstruction,and image splicing and unfol⁃ding are performed to realize the detection of over⁃under⁃excavation of the tunnels and verify the validity of the proposed method when it is applied to diversion tunnel projects.The effectiveness of the proposed method in the water diversion tunnel project is verified.The application results show that:by comparing and analyzing the actual contour of the 3D surface reconstruction and the designed excavation contour,we can calculate the value of over⁃under⁃excavation,the area of over⁃under⁃excavation and the volume of over⁃under⁃excavation of the diversion tunnel,and construct the geological unfolding map of the tunnel through the image splicing and rectification,which can visualize the peripheral information of the rock such as nodal sketches,and provide a basis for the subsequent adjustments in the design and construction of the tunnel.