Advantages of tunnel monitoring using distributed fibre optic sensing

2021 ◽  
Vol 15 (1) ◽  
pp. 1-12
Author(s):  
Fabian Buchmayer ◽  
Christoph Martin Monsberger ◽  
Werner Lienhart

AbstractPredictive maintenance and safety assessment during the construction and operational phase are becoming more and more important in modern tunnelling. However, traditional measurement methods are often time-consuming, expensive and partially require an interruption of the tunnel traffic. In this article, we present a tunnel monitoring approach based on distributed fibre optic sensing (DFOS), which delivers hundreds of strain and temperature sensing points inside the structure and gives completely new information about the behaviour of the tunnel lining. Measurements can be performed automatically without the need of access to the tunnel and hence, monitoring can be made without disturbing the tunnel construction or operation. The developed system was installed within the shotcrete tunnel lining of a railway tunnel under construction in Austria. In addition to the critical installation process, this article discusses the main monitoring results and compares them to conventional measurements.

2011 ◽  
Vol 105-107 ◽  
pp. 1203-1210 ◽  
Author(s):  
Da Li ◽  
Zhan Fu Luo ◽  
Yong Sheng Li

The tunnel which excavated through the fault fracture zone is still one of the difficulties in the current tunnel construction. Guanjiao tunnel is the longest high-altitude tunnel in the world, and also the longest railway tunnel which is under construction in China. The 9# shaft which located in Erlang fault fracture zone with several faults, complicated geological conditions is difficult to excavate. In the representative section of F3 fault and its influence zone, F22 fault fracture zone, the monitoring tests on contact pressure between surrounding rock and primary support and stress of steel arch is conducted. According to the above monitoring results,the project recommendations are proposed to ensure the smooth construction of tunnel.


2012 ◽  
Vol 268-270 ◽  
pp. 664-672
Author(s):  
Ya Ting Sun ◽  
Zhi Rong Mei ◽  
Jun Wei Zhang

The conventional mucking system of tunnel construction in China has a series of deficiencies and stubborn problems. Tunnel mucking technologies matched with different tunnel construction methods have been analyzed systematically and the continuous belt mucking methodology which is appropriated with drilling-blasting method was presented. The continuous belt mucking technology includes mucking scheme design and mucking equipment configuration. Compared with the conventional mucking methods, the comprehensive benefit can be fully demonstrated by the new continuous belt mucking system. On the other hand, the predominance on environmental protection of the continuous belt mucking technoloty matches up with the conservation policy. The technology would be widely applied in long tunnels and tunnels embedded in frozen ground and located in bitter cold plateau. The economic benifis and contribution to society of continuous belt mucking technology would be remarkable.


2013 ◽  
Vol 303-306 ◽  
pp. 811-814 ◽  
Author(s):  
Ning Suo ◽  
Hui Lin Wang

This paper puts forward the railway tunnel construction based on GIS for deformation monitoring data analysis as the foundation of railway tunnel construction safety monitoring and risk early warning system. Practice shows that the system in engineering information acquisition, construction deformation data analysis, early warning and monitoring data has obvious advantages. And it is still in help users to make decisions and plays an important role to ensure the safety of tunnel construction.


2012 ◽  
Vol 238 ◽  
pp. 808-813
Author(s):  
Fei Zhou ◽  
Yong Li Xie ◽  
Jin Xing Lai

Combined with highway tunnel monitoring measurement work of Bijia Mountain, the contents and methods of site monitoring and the analyzing methods for collected data of highway tunnel construction were studied. A comparative way was used to analyze the different curves of displacement with time on the two typical segments of ground settlement convergence and vault crown settlement. The result shows that the site monitoring curves of displacement with time can be divided into normal type and abnormal one. This article puts forward some feasible suggestions about how to guide the safe construction through the two types of curve. The aim of this article is to explore the changing of the abnormal curve before the dangerous accident occur, and give the causes of the reasonable analysis after collapse happened.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Teemu Myllylä ◽  
Vesa Korhonen ◽  
Erkki Vihriälä ◽  
Hannu Sorvoja ◽  
Tuija Hiltunen ◽  
...  

This paper presents experimental measurements conducted using two noninvasive fibre optic methods for detecting heart pulse waves in the human body. Both methods can be used in conjunction with magnetic resonance imaging (MRI). For comparison, the paper also performs an MRI-compatible electrocardiogram (ECG) measurement. By the simultaneous use of different measurement methods, the propagation of pressure waves generated by each heart pulse can be sensed extensively in different areas of the human body and at different depths, for example, on the chest and forehead and at the fingertip. An accurate determination of a pulse wave allows calculating the pulse transit time (PTT) of a particular heart pulse in different parts of the human body. This result can then be used to estimate the pulse wave velocity of blood flow in different places. Both measurement methods are realized using magnetic resonance-compatible fibres, which makes the methods applicable to the MRI environment. One of the developed sensors is an extraordinary accelerometer sensor, while the other one is a more common sensor based on photoplethysmography. All measurements, involving several test patients, were performed both inside and outside an MRI room. Measurements inside the MRI room were conducted using a 3-Tesla strength closed MRI scanner in the Department of Diagnostic Radiology at the Oulu University Hospital.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Haibin Huang ◽  
Peng Li ◽  
Chuang Wang ◽  
Bingxiang Yuan ◽  
Minjie Chen ◽  
...  

In order to study the vibration influence of tunnel drilling and blasting method on the built tunnel with small clear distance, taking the intersection of Zhuhai Dahengqinshan No. 1 tunnel and Zhuji urban rail tunnel as the engineering background, we used ABAQUS finite element software to conduct numerical simulation analysis on the influence of different blasting loads on existing tunnels with small clear distance in Zhuji tunnel construction. The following conclusions were drawn: the blasting construction of the tunnel under construction had the greatest impact on the vault of the existing tunnel; when the peak load was reduced by half, the stress value, vertical displacement, and resultant velocity of Mises were also reduced by half, which indicates that reducing the peak value of blasting load appropriately can ensure the safety of tunnel construction. When the peak load is 2.7 MPa, the measured and simulated values were less than the resultant velocity limit required by the specification. In addition, the relative error between the measured value and the simulated value was less than 5%, indicating the accuracy of the numerical simulation.


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