Limits...
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

Raw TLS intensity data (a) and digital image; (b) obtained at tunnel Tempi T1 face immediately after blasting and excavation material removal; Laser intensity data of the same section, as seen from behind the tunnel face (c).
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f7-sensors-12-11249: Raw TLS intensity data (a) and digital image; (b) obtained at tunnel Tempi T1 face immediately after blasting and excavation material removal; Laser intensity data of the same section, as seen from behind the tunnel face (c).

Mentions: Figure 7 shows the raw laser intensity data (Figure 7(a)), and the corresponding digital image (Figure 7(b)) obtained at the tunnel face immediately after blasting. The limits of the excavation area and signs of rock perturbation due to the last advancement are clearly visible in the unsupported rock laser scanning image. Also, the intensity data from the laser scans, in many cases, can record efficiently the geological features of the excavation area–such as in Figure 7(c), where the change of rock type is evident. As stated already, laser scanning data can substantially enhance the geological/geotechnical documentation of the rock surface. However, this topic is not elaborated thereinafter in study and the interested reader is referred to consult Decker and Dove [26] and Fekete et al. [27].


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

Gikas V - Sensors (Basel) (2012)

Raw TLS intensity data (a) and digital image; (b) obtained at tunnel Tempi T1 face immediately after blasting and excavation material removal; Laser intensity data of the same section, as seen from behind the tunnel face (c).
© Copyright Policy
Related In: Results  -  Collection

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

f7-sensors-12-11249: Raw TLS intensity data (a) and digital image; (b) obtained at tunnel Tempi T1 face immediately after blasting and excavation material removal; Laser intensity data of the same section, as seen from behind the tunnel face (c).
Mentions: Figure 7 shows the raw laser intensity data (Figure 7(a)), and the corresponding digital image (Figure 7(b)) obtained at the tunnel face immediately after blasting. The limits of the excavation area and signs of rock perturbation due to the last advancement are clearly visible in the unsupported rock laser scanning image. Also, the intensity data from the laser scans, in many cases, can record efficiently the geological features of the excavation area–such as in Figure 7(c), where the change of rock type is evident. As stated already, laser scanning data can substantially enhance the geological/geotechnical documentation of the rock surface. However, this topic is not elaborated thereinafter in study and the interested reader is referred to consult Decker and Dove [26] and Fekete et al. [27].

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