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DEVELOPMENT OF CROSS SECTION MANAGEMENT SYSTEM IN TUNNEL USING 
TERRESTRIAL LASER SCANNING TECHNIQUE 
Seo, Dong-Ju a ' , Lee, Jong Chool b , Lee, Young-Do c , Lee, Yong-Hee d , Mun, Du-Yeoul e 
a Dept, of Civil Engineering, Pukyong National University, Pusan, Korea(Ref) - dpsdj@mail.pknu.ac.kr. 
Dept, of Civil and Constrution Engineering, Pukyong National University, Pusan, Korea(Ref) - jclee@pknu.ac.kr. 
Dept, of Civil, Dongeui Technical High School, Pusan, Korea(Ref) - leeydl976 @hanmail.net. 
d Dept of City Delevoepment, Kaya University, Gimhae , Kyungnam , Korea(Ref) - yhlee0515@korea.com. 
Dept, of Civil Engineering, Dongeui University, Pusan, Korea(Ref) - dymun@deu.ac.kr. 
WG V/3 Terrestrial Laser Scanning. 
KEY WORDS: Terrestrial Laser Scanning Technique, Cross Section Management System in Tunnel, Overbreak, Underbreak, 
Economic Analysis 
ABSTRACT 
Laser scanning technology with high positional accuracy and high density will be widely applied in vast range of fields including 
geomatics. Especially, the development of laser scanning technology enabling long range information extraction is increasing its full 
use in civil engineering. This study taps into the strengths of a terrestrial laser scanning technique to develop a tunnel cross-section 
management system that can be practically employed for determining the cross-section of tunnels more promptly and 
accurately.First, high-density three-dimensional data was obtained in a prompt and accurate manner using a terrestrial laser scanner. 
Data processing was then conducted to promptly determine arbitrary cross-sections at 0.1-, 0.5-, and 1-meter intervals.A laser 
scanning technique was also used to quickly and accurately calculate the overbreak and underbreak of each cross-section and from 
the entire tunnel length. As the developed system utilizes vast amounts of data, it was possible to promptly determine the shape of 
arbitrary cross-sections and to calculate the overbreak and underbreak more accurately with higher area precision.A economic 
analysis of various techniques for determining the tunnel cross-section revealed that this measurement system is also outstanding 
from an economical perspective. It is expected, therefore, that the system will not only enable more efficient and cost-effective 
tunnel drilling management and monitoring but also will provide a basis for future construction and management of tunnel cross- 
sections. 
1. INTRODUCTION 
Although many capitals are invested for the development of 
tunnel and underground space due to the geographical condition 
that over 70 % of national land is formed by the mountains and 
the congested district of city is the majority in our nation, the 
efficiency of measuring works is practically decreased as 
obtaining the location information with the existing traditional 
measurements from the works before starting construction. 
Recently many studies on the determination of tunnel internal 
cross section using the Digital Photogrammetry, the Non Prism 
Totalstation, etc are being tried. But, in case of the Digital 
Photogrammetry, there are many cases that it is difficult to 
discriminate the subjects for photography because of the 
restricted sources of light from the poor measuring 
environments and working conditions in the tunnel and it is 
very difficult to abstract the characteristic from the character of 
irregular tunnel internal cross section. And the 
Non Prism Totalstation using the noncontact-type measuring 
method can efficiently obtain the 3-dimensional location 
information of the cross section as compared with the existing 
measuring method but requires many times for calculating the 
determination of exact cross section and the outbreak quantity, 
etc. 
But, if the 3-dimensional laser scanner making it possible to 
obtain high-accuracy data and high location precision even 
under those disadvantageous conditions is used, the huge 
quantities of data about tunnel internal cross section can be 
obtained and more exact outbreak quantity and underbreak 
quantity can be calculated. 
Regarding to the laser scanning technology, the scope of the 
utilization was further varied by the spread of the high- 
precision 3-dimensional laser scanners for the middle and long 
distance in the early 2000’s and the study on this technology is 
continuously performed in the areas of engineering works, the 
road and the cultural properties, etc also (Lee et al., 2003; Son 
et al.,2003; Lee, 2005; Yunet al., 2006; Jang et al., 2006; kim et 
al., 2006; Kim, 2007). 
Non Prism Totalstation using the noncontact-type measuring 
method can efficiently obtain the 3-dimensional location 
information of the cross section as compared with the existing 
measuring method but requires many times for calculating the 
determination of exact cross section and the outbreak quantity, 
etc (Collins and Sitar, 2005). 
But, if the 3-dimensional laser scanner making it possible to 
obtain high-accuracy data and high location precision even 
under those disadvantageous conditions is used (Alba et al., 
2005), the huge quantities of data about tunnel internal cross 
section can be obtained and more exact outbreak quantity and 
underbreak quantity can be calculated (Hashash et al., 2005). 
* Corresponding author.