In order to measure and analyze the tunnel 3D deformation accurately, effectively and conveniently, we use the 3D point clouds instead of Total station data. A 63.6 m long tunnel was scanned twice by using a Leica C10 laser scanner (max scanning range is 300 m), for each of the scans, to obtain the accurate data and to avoid to having tunnel bending part, we divide the tunnel into five sections for the measurements, and for each measurement, the data is scanned in one station. Since the original data includes some noise, to remove noise in the point clouds, we study a new Fractional calculus template for data smoothing. After that, we propose a new method to extract the tunnel central axis based on the 3D invariant moments, and then the tunnel posture is rotated to make the central axis parallel to the reference direction, which is rotational invariant and repeatable. Based on the central axis in each section, the cross-sections are detected, and the elliptic features of a cross-section are calculated for analyzing the tunnel convergence. To make cross-section measurement rotational invariant, we apply the zeroth, the first and the second moments to obtain major and minor axes through the cross-section center. The experiment results demonstrate that this method can meet the accuracy requirements, and it can be with an accuracy of 2 mm for cross-section measurement. It is useful for tunnel engineering applications both in the tunnel 3D point cloud analysis and 3D information extraction.

为了准确，有效，方便地测量和分析隧道的3D变形，我们使用3D点云代替了全站仪数据。使用Leica C10激光扫描仪（最大扫描范围为300 m）对一条63.6 m长的隧道进行了两次扫描，对于每次扫描，为了获得准确的数据并避免出现隧道弯曲的部分，我们将隧道分为五个部分测量部分，对于每次测量，都在一个站中扫描数据。由于原始数据包含一些噪声，因此为了消除点云中的噪声，我们研究了一种新的分数阶微积分模板，用于数据平滑。之后，我们提出了一种基于3D不变矩提取隧道中心轴的新方法，然后旋转隧道姿态以使中心轴与参考方向平行，这是旋转不变且可重复的。基于每个截面的中心轴，检测截面，并计算截面的椭圆特征，以分析隧道的收敛性。为了使横截面测量旋转不变，我们应用零矩，第一矩和第二矩来获得穿过横截面中心的长轴和短轴。实验结果表明，该方法可以满足精度要求，断面测量精度可以达到2mm。这对于隧道3D点云分析和3D信息提取中的隧道工程应用程序都非常有用。计算横截面的椭圆形特征，以分析隧道的收敛性。为了使横截面测量旋转不变，我们应用零矩，第一矩和第二矩来获得穿过横截面中心的长轴和短轴。实验结果表明，该方法可以满足精度要求，截面测量精度可以达到2 mm。这对于隧道3D点云分析和3D信息提取中的隧道工程应用程序都非常有用。计算横截面的椭圆形特征，以分析隧道的收敛性。为了使横截面测量旋转不变，我们应用零矩，第一矩和第二矩来获得穿过横截面中心的长轴和短轴。实验结果表明，该方法可以满足精度要求，截面测量精度可以达到2 mm。这对于隧道3D点云分析和3D信息提取中的隧道工程应用程序都非常有用。横截面测量的精度为2 mm。这对于隧道3D点云分析和3D信息提取中的隧道工程应用程序都非常有用。横截面测量的精度为2 mm。这对于隧道3D点云分析和3D信息提取中的隧道工程应用程序都非常有用。