摘要
针对因工业应用成本限制,中、小盾构隧道成型质量无损检测技术迁移至大直径盾构隧道时精度、速度折损严重的问题,以巡检车为载体,集成二维激光扫描仪、编码器和计算机等设备,研制了大盾构隧道成型质量巡检车,并提出一种基于数字图像的盾构质量非对称巡检方法.分析大直径盾构的施工环境,滤除地面、车体点云,并采用邻域向量法提取中轴线,建立隧道中心坐标系.偏心布置巡检路线,按照点云密度将采样点云分为稠密侧和稀疏侧点云,通过不同方法实现对管片接缝特征的拾取:将稠密侧点云绕中轴线展开为二维灰度图像,并通过缩放、归一化、梯度阈值分割等方法实现接缝图像分割;基于直线方程对接缝进行分类,结合管片结构、布置点位,推导出稀疏侧接缝与稠密侧接缝的线性分布公式,间接拾取稀疏侧接缝.根据接缝特征点计算两侧管片边缘点云簇,计算管片错台量;剔除接缝点云簇,使用最小二乘法拟合隧道点云,计算隧道椭圆度.最后在某大直径盾构隧道进行巡检试验,试验结果表明:成型质量巡检车在十四米盾构隧道中巡检速度为3 km·h-1,与传统方法的错台量检测偏差小于2 mm,椭圆度检测偏差小于0.1%,可以满足大直径盾构隧道成型质量巡检的高速度、高精度、低成本需求.
With the development of tunnel construction,the detection,control,and treatment of all kinds of tunnel lining diseases have received increased attention.Therefore,tunnel nondestructive testing technology is widely used as an intelligent emerging technology.Due to the cost limitations of industrial applications,nondestructive testing technology of medium-and small-shield tunnels experiences serious losses in accuracy and speed when transferred to large-diameter shield tunnels.A large shield tunnel forming quality inspection vehicle is developed by integrating a two-dimensional(2D) laser scanner with a wheel shaft encoder and an industrial computer.Based on this equipment,an asymmetric shield quality inspection method based on digital images is proposed.By analyzing the construction environment of a large-diameter shield tunnel,the ground and vehicle body point clouds are filtered,the central axis is extracted using the neighborhood vector method,and the central coordinate system of the tunnel is established.The inspection route is arranged eccentrically,and the sampling point clouds are divided into dense and sparse side point clouds according to their tunnel density.Moreover,different methods are used to pick up the joint features of the segment.The dense side point cloud is expanded around the central axis into a 2D gray image,and the joint image is segmented by scaling,normalization,and gradient threshold segmentation.According to the classification of joints based on the linear equation,the linear distribution formula of sparse and dense side joints is deduced by combining the segment structure and the point placement,with the sparse side joints picked up indirectly.According to the joint characteristic points,the edge point clusters on both sides of the segment and the segment misalignment are calculated.The least square method is used to fit the tunnel point cloud and calculate tunnel ellipticity.Tests are conducted in a largediameter shield tunnel to verify the effectiveness of the inspection method,and the following conclusions are made from the test results:The inspection speed of the molding quality inspection vehicle in the 14-meter shield tunnel is 3 km·h-1;compared with traditional detection methods,the average deviation of segment dislocation detection is less than 2 mm;the average deviation of tunnel contour maximum deformation detection is less than 2 mm,and the average deviation of ovality detection is less than 0.1%.This meets the highspeed,high-precision,and low-cost requirements of large-diameter shield tunnel molding quality inspections.
作者
赵先琼
邓凯
张亚洲
马英博
夏毅敏
ZHAO Xianqiong;DENG Kai;ZHANG Yazhou;MA Yingbo;XIA Yimin(The College of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China;China Railway 14th Bureau Group Shield Engineering Co.,Ltd.,Nanjing 211899,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2024年第2期365-375,共11页
Chinese Journal of Engineering
基金
湖南省创新型省份建设专项(2019GK1010)
中南大学研究生创新基金资助项目(2022ZZTS0732)。
关键词
大直径盾构隧道
激光扫描
阈值分割
错台检测
变形检测
large-diameter shield tunnel
laser scanning
threshold segmentation
dislocation detection
deformation detection
