基于三维点云的盾构管片拼装质量偏差评价方法

盾构机在掘进过程中，由于盾构姿态控制不当等因素，管片拼装时常发生错台值、椭圆度失准等工程质量问题，这些施工质量问题往往会对隧道的稳定性及安全性造成影响，为保证盾构隧道的安全施工与健康服役，在施工过程中对盾构管片拼装质量进行动态评估尤为重要。针对传统盾构管片拼装检测效率低，精度有限及检测数据全面性差等问题，应用三维激光扫描技术采集盾构管片拼装成型后的点云数据，通过长短轴法和改进的按斜率分割法分别对盾构管片的椭圆度和错台值进行测算；同时提出环段数据拟合提取隧道中轴线及中心点的方法，实现盾构管片拼装质量高精度、高效率、自动化检测。结合实际盾构隧道工程案例分析，验证基于三维点云的盾构管片拼装质量偏差检测方法的可行性。

Quality Deviation Evaluation of Shield-segment Assembly Basedon 3D Point-cloud

Quality defects in segment assembly, such as misalignment and ellipse deformation, often occur during shieldtunneling excavation. Construction quality defects threaten tunnel stability and safety. To ensure the safe construction and serviceof shield tunnels, a quality assessment of the shield segment assembly is necessary during construction. Limited by manualdetection methods, traditional site-quality assessment is challenged by low efficiency, limited accuracy, and missing data. Threedimensional laser scanning was introduced to collect point-cloud data during the assembly of the shield-segment lining. Theellipticity and misalignment values of the shield segments were calculated by the long and short-axis algorithms and theimproved slope segmentation algorithms. Based on the theory of center-point extraction of ring-seam data, a method forextracting the central axis and center point of a tunnel through ring- segment data fitting was proposed for high precision,efficiency, and automation to detect shield-segment assembly quality. A shield-tunnel project was conducted to demonstrate and validate the proposed method. The results show that the proposed method can efficiently and automatically assess the assemblyquality of shield-construction segments.