Displacement mapping of point clouds: application of retaining structures composed of sheet piles

Zhao, Yang, Seo, Hyungjoon and Chen, Cheng (2021) Displacement mapping of point clouds: application of retaining structures composed of sheet piles. Journal of Civil Structural Health Monitoring, 11 (4). pp. 915-930.

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Abstract

<jats:title>Abstract</jats:title><jats:p>The measurement of displacement is an important factor to evaluate the stability of a retaining structure. In this paper, a large-scale retaining structure with a width of 70 m and a height of 6 m was monitored using 3-D laser scanning. Displacement mapping was proposed to globally monitor the entire retaining structure. The point cloud obtained immediately after the excavation was converted into the mesh, and the point clouds obtained on the second and seventh days after excavation were compared to the mesh using the Cloud to Mesh (C2M) comparison method. Since the C2M displacement can be underestimated in the inclined section of the sheet pile, after filtering using the azimuth and element angles automatically, only the flat sections of the sheet pile can be segmented from original point clouds collectively and consistently. The displacement mapping results identify not only the local behavior of the sheet pile, such as the bending point and the maximum displacement position, but also the global behavior, such as the expansion of the maximum displacement in the retaining structure. The results of the displacement mapping were confirmed through site investigation as well. In the displacement mapping result, the maximum displacement was found around rows 2 and 3 of the 37th sheet pile, and the analyzed result of the load cell installed on the anchor indicated that the anchor constructed in the 37th sheet pile shows the plastic behavior. It was established that other sheet piles are affected by the damage to the local anchor through the H-beam and the maximum displacement in the displacement mapping is expanded horizontally in a positive parabola shape. Therefore, it was confirmed that displacement mapping using laser scanning can complement existing monitoring techniques and can contribute to evaluating the behavior of a large-scale retaining structure during excavation.</jats:p>

Item Type:	Article
Uncontrolled Keywords:	Displacement mapping, Laser scanning, Point cloud, Retaining structure, Sheet pile, Anchor
Divisions:	Faculty of Science and Engineering > School of Engineering
Depositing User:	Symplectic Admin
Date Deposited:	17 Sep 2021 08:35
Last Modified:	18 Jan 2023 21:28
DOI:	10.1007/s13349-021-00491-y
Open Access URL:	https://doi.org/10.1007/s13349-021-00491-y
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3137362

Available Versions of this Item

• Displacement mapping of point clouds: application of retaining structures composed of sheet piles. (deposited 25 May 2021 10:45)
  • Displacement mapping of point clouds: application of retaining structures composed of sheet piles. (deposited 17 Sep 2021 08:35) [Currently Displayed]