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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

Example of cross-section extraction for the N. Ikonio tunnel based on the TLS (a) and total station (b) survey data. Note the lack of point information in the top left corner of plot (b) due to the ventilation duct system.
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f13-sensors-12-11249: Example of cross-section extraction for the N. Ikonio tunnel based on the TLS (a) and total station (b) survey data. Note the lack of point information in the top left corner of plot (b) due to the ventilation duct system.

Mentions: Analysis of the tunnel surface measurements obtained for the N. Ikonio case study leads into similar conclusions. A total number of 50 cross-sections were surveyed at a space interval 1.5 m and every 0.5 m on each section using the 5601DR total station. Also, the same portion was surveyed using the Callidus CP-3200 TLS unit. The sensor horizontal and vertical angular resolution was set to dHz = 0.25° and dV = 0.125°, which allowed the extraction of cross-sections containing 6,000 to 9,000 apex points. Figure 13 shows typical results of the analyses. From these plots the high resolution associated with the TLS method is immediately evident (Figure 13(a)). In contrast, for the case of the total station survey, the same cross-section contains only 32 points (Figure 13(b)). In fact, in these plots, the lack of information is more evident in the top left corner of the cross-section due to the ventilation duct system. Nevertheless, the differences observed in the over-break (over-cut) volume computations between the two methods are in the order of 5% and in agreement with the findings of the Tempi T1 case study.


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

Gikas V - Sensors (Basel) (2012)

Example of cross-section extraction for the N. Ikonio tunnel based on the TLS (a) and total station (b) survey data. Note the lack of point information in the top left corner of plot (b) due to the ventilation duct system.
© Copyright Policy
Related In: Results  -  Collection

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

f13-sensors-12-11249: Example of cross-section extraction for the N. Ikonio tunnel based on the TLS (a) and total station (b) survey data. Note the lack of point information in the top left corner of plot (b) due to the ventilation duct system.
Mentions: Analysis of the tunnel surface measurements obtained for the N. Ikonio case study leads into similar conclusions. A total number of 50 cross-sections were surveyed at a space interval 1.5 m and every 0.5 m on each section using the 5601DR total station. Also, the same portion was surveyed using the Callidus CP-3200 TLS unit. The sensor horizontal and vertical angular resolution was set to dHz = 0.25° and dV = 0.125°, which allowed the extraction of cross-sections containing 6,000 to 9,000 apex points. Figure 13 shows typical results of the analyses. From these plots the high resolution associated with the TLS method is immediately evident (Figure 13(a)). In contrast, for the case of the total station survey, the same cross-section contains only 32 points (Figure 13(b)). In fact, in these plots, the lack of information is more evident in the top left corner of the cross-section due to the ventilation duct system. Nevertheless, the differences observed in the over-break (over-cut) volume computations between the two methods are in the order of 5% and in agreement with the findings of the Tempi T1 case study.

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