本文介绍了一种基于高密度三维激光扫描仪的高精度快速全断面变形检测新方法——Tunnelscan隧道扫描测量系统, 该系统采用扫描仪绝对定位法进行点云配准和隧道控制坐标系坐标传递，使用与断面点距离最小的最小二乘法进行隧道实测断面中心点计算和基于与参考断面的断面差环状过滤器进行隧道点云切片杂点过滤，通过多次过滤、拟合迭代后获得去噪后的真圆管环实测断面。该系统还通过参考断面轮廓线投影法将三维点云投影成激光雷达隧道正射影像，为实现隧道结构安全“全面检测”提供了一种全新用户成果类型，用于全面分析隧道断面变形、结构侵界和裂缝渗水等隧道病害。采用该方法在昆明地铁3号线马眠区间做了一段竣工测量实地测试，经过总体分析后，再按图索骥去找断面变形量较大里程的断面图可谓是事半功倍，非常适合地铁隧道变形检测大数据量的批量化分析，而且成果查看比直接在三维点云或者三维模型上分析更加直观，没有视角遮挡问题。

A new, fast, accurate and fullface deformation detection method based on highdensity 3D laser scanning technology, tunnel scanning and measuring system Tunnelscan, is introduced. The absolute positioning method （APM） of point cloud is used to register multiple scans and transfer the tunnel control coordinate system to them. The least square method based on minimum distance from crosssection points is used to calculate the center point of crosssection. A ringshape point cloud filter based on the distance difference from the measured crosssection and the referenced crosssection is applied to remove the noisy points that are actually not on the tunnel wall. The multiple loops of this ringshape filtering and center point calculation will be executed to get the refined center points and crosssection points of proper circular tunnel constructed by TBM method. It can also offer a new type of user report based on orthophoto of tunnel by laser intensity direction and ranging （LIDAR） of overall tunnel wall, which can provide a quick and big picture of tunnel diseases, such as crosssection deformation, structure clearance alarm, cracks or leakages, etc, using referenced crosssection contour projection method. A real 3D scanning asbuilt survey test in Majie StationMianshan Station section on Kunming Metro Line No.3 is carried out. With the abovementioned colorful overall tunnel map on the crosssection deformation analysis, much effort can be saved to find out those crosssection charts with large deformation. Apart from that, the analysis with orthophoto of tunnel is much more visual than that directly with 3D tunnel point cloud or that with 3D model for the shelter of visual angle.