米字型靠尺遍历离散点云检测隧道初支平整度

The Detection Method of the Flatness of Tunnel Initial Support by Traversing Discrete Point Cloud with a Ruler of Eight-direction Radiation

研究目的:为便捷、快速地开展隧道初支平整度检测,基于三维激光扫描的离散点云数据,提出运用米字型靠尺模拟人工检测的初支平整度全局检测方法,并对主要实现过程中的隧道设计轮廓嵌入、点云数据展开、米字型靠尺遍历、测站平整度计算、网格平整度评价等技术进行说明。研究结论:(1)本文方法直接基于离散点云进行模拟人工检测,不需要构建拟合曲面,能保持特征点云的位置不失真;(2)基于投影展开后的点云成果数据,可以从纵、横、斜向同步进行平整度检测,相比人工只能从纵向检测,该方法检测覆盖更全面,更贴近工程实际;(3)在桑园隧道应用本文方法进行初支平整度检测,检测结果的精度可以媲美人工检测,验证了本文方法的有效性,可为铁路隧道施工中的初支平整度质量检测提供实践参考。

Research purposes:To meet the need of convenient and rapid initial support flatness detection of tunnels,based on the discrete point cloud data of 3D laser scanning,a global detection method of initial support flatness using the vertical,horizontal and oblique directions ruler to simulate manual detection is proposed,and the techniques of tunnel design contour embedding,point cloud data expansion,ruler traversal,station flatness calculation and grid flatness evaluation are also described.Research conclusions:(1)This method is directly based on discrete point clouds to simulate artificial detection,without building a fitting surface,and can maintain the position of the feature point cloud without distortion.(2)Based on the point cloud result data after projection expansion,the flatness detection can be carried out synchronously from vertical,horizontal and oblique directions.Compared with manual detection only from the vertical direction,the detection coverage of this method is more comprehensive and closer to the engineering reality.(3)The accuracy of the detection results can be comparable to manual detection,which verifies the effectiveness of this method.It can provide practical reference for the quality inspection of initial support flatness in railway tunnel construction.