A study on the application of the distributed optical fiber sensing monitoring technology in the process of dismantling
- PDF / 1,716,575 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 71 Downloads / 172 Views
ORIGINAL PAPER
A study on the application of the distributed optical fiber sensing monitoring technology in the process of dismantling temporary tunnel shoring Zi-Xiang Li 1 & Gong-Yu Hou 1,2 & Tao Hu 1 & Tian-Ci Zhou 1 & Hai-Lin Xiao 1 Received: 12 May 2020 / Accepted: 23 September 2020 / Published online: 29 September 2020 # Saudi Society for Geosciences 2020
Abstract Temporary shorings are necessary for the stabilization of the tunnels with large cross-sections that are excavated using the New Austrian tunnelling method. The dismantling of the temporary shoring during the process of secondary lining construction would be a very serious threat to the safety of the tunnel. Therefore, in this work, a field observation was made based on distributed optical fiber sensing monitoring technology in order to determine the deformation behavior of the tunnel and to identify the most influential steps of dismantlement. The study is carried out during the tunnel’s temporary shoring dismantling stage. The performance of the tunnel during every dismantling stage was analyzed based on the monitoring results using the finite element numerical simulation method. Based on the analysis results, the settlement of the tunnel was estimated through the strain curve that was obtained by using optical fiber. Furthermore, the study results showed that the continuous removal at the bottom of the shoring of the tunnel weakens the vertical support force at the bottom of the tunnel and thereby resulting in large settlement variation in all the dismantling steps. The highest value of the settlement variation obtained during the analysis is 5.7 mm, and the corresponding tensile strain variation of the crown is 50 με. Furthermore, the results showed that it is feasible to use the optical fiber to estimate the settlement of the tunnel. The max deviation obtained was 0.9 mm and the results were compared with the results of a total station. The study results of this research are applicable to the tunnels that were excavated using the New Austrian tunnelling method and have temporary shorings. Keywords Distributed optical fiber . Monitoring technology . Deformation monitoring . Back analysis for deformation . Temporary shoring dismantling
Introduction Temporary shorings are necessary during the construction of composite lining tunnels with large cross-sections using the New Austrian tunnelling method (Golser 1976). During the process of construction of the lining tunnels, the most Responsible Editor: Zeynal Abiddin Erguler * Zi-Xiang Li [email protected] 1
School of Mechanics and Civil Engineering, China University of Mining and Technology, Ding No.11 Xueyuan Road, Haidian District, Beijing, China
2
School of Mining and Geological Engineering, Xinjiang Institute of Engineering, 1350 Edinghu Road, Toutunhe District, Urumqi Economic and Technological Development Zone, Xinjian, China
dangerous process is the removal of the temporary shoring of the initial lining in order to construct the second lining (Tao et al. 2014; Jian-guo et al. 2009). Th
Data Loading...
