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Three-dimensional laser scanning for geometry documentation and construction management of highway tunnels during excavation.

Gikas V - Sensors (Basel) (2012)

Bottom Line: This paper discusses the use and explores the potential of laser scanning technology to accurately track excavation and construction activities of highway tunnels.Also, it discusses the planning, execution, data processing and analysis phases of laser scanning activities, with emphasis given on geo-referencing, mesh model generation and cross-section extraction.Specific case studies are considered based on two construction sites in Greece.

View Article: PubMed Central - PubMed

Affiliation: School of Rural and Surveying Engineering, National Technical University of Athens, 9 I Polytechniou Str., Zographou, Athens 15780, Greece. vgikas@central.ntua.gr

ABSTRACT
Driven by progress in sensor technology, computer software and data processing capabilities, terrestrial laser scanning has recently proved a revolutionary technique for high accuracy, 3D mapping and documentation of physical scenarios and man-made structures. Particularly, this is of great importance in the underground space and tunnel construction environment as surveying engineering operations have a great impact on both technical and economic aspects of a project. This paper discusses the use and explores the potential of laser scanning technology to accurately track excavation and construction activities of highway tunnels. It provides a detailed overview of the static laser scanning method, its principles of operation and applications for tunnel construction operations. Also, it discusses the planning, execution, data processing and analysis phases of laser scanning activities, with emphasis given on geo-referencing, mesh model generation and cross-section extraction. Specific case studies are considered based on two construction sites in Greece. Particularly, the potential of the method is examined for checking the tunnel profile, producing volume computations and validating the smoothness/thickness of shotcrete layers at an excavation stage and during the completion of excavation support and primary lining. An additional example of the use of the method in the geometric documentation of the concrete lining formwork is examined and comparisons against dimensional tolerances are examined. Experimental comparisons and analyses of the laser scanning method against conventional surveying techniques are also considered.

No MeSH data available.


Related in: MedlinePlus

TLS spherical targets used for geo-referencing the point cloud.
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f4-sensors-12-11249: TLS spherical targets used for geo-referencing the point cloud.

Mentions: Absolute positioning (geo-referencing) of the unified point cloud can be achieved if the coordinates of the feature points used to register adjacent point clouds are known in the global coordinate system employed for construction. This can be accomplished using special targets, the location of which is computed in the global coordinate system using a total station (see Figure 4). A simpler and faster, albeit less accurate technique resides on geo-referencing every point cloud acquired from a single scan shot independently from its neighboring point clouds. This technique works in two steps. Firstly, the point cloud data are shifted in regard to the global coordinate system by working out the location occupied by the scanner. Secondly, orientation of the scan data is accomplished using a known direction from the laser scanner position to a topographic prism that is visible in the point cloud. Dead reckoning of the laser scanner and prism locations is achieved by means of a total station.


Three-dimensional laser scanning for geometry documentation and construction management of highway tunnels during excavation.

Gikas V - Sensors (Basel) (2012)

TLS spherical targets used for geo-referencing the point cloud.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472883&req=5

f4-sensors-12-11249: TLS spherical targets used for geo-referencing the point cloud.
Mentions: Absolute positioning (geo-referencing) of the unified point cloud can be achieved if the coordinates of the feature points used to register adjacent point clouds are known in the global coordinate system employed for construction. This can be accomplished using special targets, the location of which is computed in the global coordinate system using a total station (see Figure 4). A simpler and faster, albeit less accurate technique resides on geo-referencing every point cloud acquired from a single scan shot independently from its neighboring point clouds. This technique works in two steps. Firstly, the point cloud data are shifted in regard to the global coordinate system by working out the location occupied by the scanner. Secondly, orientation of the scan data is accomplished using a known direction from the laser scanner position to a topographic prism that is visible in the point cloud. Dead reckoning of the laser scanner and prism locations is achieved by means of a total station.

Bottom Line: This paper discusses the use and explores the potential of laser scanning technology to accurately track excavation and construction activities of highway tunnels.Also, it discusses the planning, execution, data processing and analysis phases of laser scanning activities, with emphasis given on geo-referencing, mesh model generation and cross-section extraction.Specific case studies are considered based on two construction sites in Greece.

View Article: PubMed Central - PubMed

Affiliation: School of Rural and Surveying Engineering, National Technical University of Athens, 9 I Polytechniou Str., Zographou, Athens 15780, Greece. vgikas@central.ntua.gr

ABSTRACT
Driven by progress in sensor technology, computer software and data processing capabilities, terrestrial laser scanning has recently proved a revolutionary technique for high accuracy, 3D mapping and documentation of physical scenarios and man-made structures. Particularly, this is of great importance in the underground space and tunnel construction environment as surveying engineering operations have a great impact on both technical and economic aspects of a project. This paper discusses the use and explores the potential of laser scanning technology to accurately track excavation and construction activities of highway tunnels. It provides a detailed overview of the static laser scanning method, its principles of operation and applications for tunnel construction operations. Also, it discusses the planning, execution, data processing and analysis phases of laser scanning activities, with emphasis given on geo-referencing, mesh model generation and cross-section extraction. Specific case studies are considered based on two construction sites in Greece. Particularly, the potential of the method is examined for checking the tunnel profile, producing volume computations and validating the smoothness/thickness of shotcrete layers at an excavation stage and during the completion of excavation support and primary lining. An additional example of the use of the method in the geometric documentation of the concrete lining formwork is examined and comparisons against dimensional tolerances are examined. Experimental comparisons and analyses of the laser scanning method against conventional surveying techniques are also considered.

No MeSH data available.


Related in: MedlinePlus