Quality Deviation Evaluation of Shield-segment Assembly Based on 3D Point-cloud
Quality defects in segment assembly,such as misalignment and ellipse deformation,often occur during shield-tunneling excavation.Construction quality defects threaten tunnel stability and safety.To ensure the safe construction and service of shield tunnels,a quality assessment of the shield segment assembly is necessary during construction.Limited by manual detection methods,traditional site-quality assessment is challenged by low efficiency,limited accuracy,and missing data.Three dimensional laser scanning was introduced to collect point-cloud data during the assembly of the shield-segment lining.The ellipticity and misalignment values of the shield segments were calculated by the long and short-axis algorithms and the improved slope segmentation algorithms.Based on the theory of center-point extraction of ring-seam data,a method for extracting 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 assembly quality of shield-construction segments.
urban rail transitshield segmentassembly quality3D point clouddeviation detectioninter-ring misalignment
万方数据
维普
