Seismic‐while‐drilling by using tunnel boring machine noise

Geophysics ◽  
2002 ◽  
Vol 67 (6) ◽  
pp. 1798-1809 ◽  
Author(s):  
Lorenzo Petronio ◽  
Flavio Poletto
Keyword(s):  
Large Diameter ◽  
Tunnel Boring Machine ◽  
High Amplitude ◽  
Direct Access ◽  
S Wave ◽  
Tunnel Excavation ◽  
Tunnel Boring ◽  
Cutting Head ◽  
Geothermal Wells ◽  
Radial Dimension

The tunnel boring machine (TBM) is used extensively to mechanically excavate tunnels. To optimize the mechanical drilling and work safely, an estimate of the geology to be drilled is necessary. We consider using the elastic waves produced by the TBM cutting wheel to obtain seismic‐while‐drilling (SWD) information for predicting the geology ahead of the drilling front. This method uses accelerometers mounted on the TBM together with geophones located along and outside the tunnel, similar to the technique successfully used to drill oil and geothermal wells. Study of noise and the resolution of the signal produced by the large‐diameter cutting head shows that nonstationary noise separation can be achieved by locating sensors at the front and rear ends of the tunnel. The (higher) resolution in front of the TBM is limited by pilot delays, while the (lower) lateral resolution is limited by the radial dimension of the TBM. Analysis of seismic data acquired in a field test shows that P‐ and S‐wave arrivals have a wide frequency band and high amplitude in seismic traces measured 700 m away from the drilling front. In comparison with SWD applications in wells, tunnel SWD technology has the advantage of allowing direct access to the tunnel front, which makes it easy to connect the TBM reference sensors for while‐drilling monitoring. This method can be successfully applied without interfering with drilling activity to monitor tunnel excavation continuously, reduce risks, and optimize drilling.

The TBM and Space-Curved Belt Conveyor in Jinping-II

2013 ◽  
Vol 790 ◽  
pp. 269-272
Author(s):  
Wang Yuan ◽  
Dong Ming Zhang
Keyword(s):  
Large Diameter ◽  
Tunnel Boring Machine ◽  
Advanced Technology ◽  
Belt Conveyer ◽  
Long Distance ◽  
Diversion Tunnel ◽  
Tunnel Excavation ◽  
Tunnel Boring ◽  
Jinping Ii Hydropower Station ◽  
Rock Tunnel

This paper is mainly about the hard rock tunnel boring machine (TBM) and the space-curved belt conveyer used in flow-diversion tunnel at Jinping-II hydropower station, This kind of rock excavation and transportation mode by TBM and the space-curved belt conveyer not only represents the advanced technology in the process of tunnel excavation and transportation, but also resolve the ventilation problem in excavation and transportation of the large diameter tunnel with long distance. This application also brings better working conditions and increases the safety in the case of low input.

scholarly journals Rayleigh-to-shear wave conversion at the tunnel face — From 3D-FD modeling to ahead-of-drill exploration

Geophysics ◽  
2007 ◽  
Vol 72 (6) ◽  
pp. T67-T79 ◽  
Author(s):  
Thomas Bohlen ◽  
Ulrich Lorang ◽  
Wolfgang Rabbel ◽  
Christof Müller ◽  
Rüdiger Giese ◽  
...  
Keyword(s):  
Rayleigh Waves ◽  
Damage Zone ◽  
Tunnel Boring Machine ◽  
High Amplitude ◽  
Body Waves ◽  
Front Face ◽  
S Wave ◽  
Tunnel Face ◽  
S Waves ◽  
Cutter Head

For safe tunnel excavation, it is important to predict lithologic and structural heterogeneities ahead of construction. Conventional tunnel seismic prediction systems utilize body waves (P- and S-waves) that are directly generated at the tunnel walls or near the cutter head of the tunnel boring machine (TBM). We propose a new prediction strategy that has been discovered by 3D elastic finite-difference (FD) modeling: Rayleigh waves arriving at the front face of the tunnel are converted into high-amplitude S-waves propagating further ahead. Reflected or backscattered S-waves are converted back into Rayleigh waves which can be recorded along the sidewalls. We name these waves RSSR waves. In our approach, the front face acts as an S-wave transceiver. One technical advantage is that both the sources and the receivers may be placed behind the cutter head of the TBM. The modeling reveals that the RSSR waves exhibit significantly higher amplitudes than the directly reflected body waves. The excavation damage zone causes dispersion of the RSSR wave leading to multimodal reflection response. For the detection of geologic interfaces ahead, RSSR waves recorded along the sidewalls are corrected for dispersion and stacked. From the arrival times, the distance to the S-S reflection point can be estimated. A recurrent application, while the tunnel approaches the interface, allows one to quantify the orientation of the reflecting interfaces as well. Our approach has been verified successfully in a field experiment at the Piora adit of the Gotthard base tunnel. The distance to the Piora fault zone estimated from stacked RSSR events agrees well with the information obtained by geologic surveying and exploratory drilling.

Multi-Objective Inversion Design of Cutting Head by Hard Rock Boring Machine Based on Fuzzy Theory and Genetic Algorithms

2011 ◽  
Vol 199-200 ◽  
pp. 1331-1334 ◽  
Author(s):  
Qiang Zhang ◽  
Qiu Shuang Song ◽  
Shou Ju Li ◽  
Ying Tian
Keyword(s):  
Tool Wear ◽  
Hard Rock ◽  
Design Method ◽  
Fuzzy Theory ◽  
Tunnel Boring Machine ◽  
Multi Objective ◽  
Tunnel Boring ◽  
Cutting Head ◽  
Lower Tool ◽  
Rock Tunnel

Along with the shearer's developed in the mining process, especially the rock tunnel boring roadway driving has become a major factor restricting the efficiency of coal, development of a suitable rock tunnel boring machine is very important, this paper use of rock excavation and after the release of stress concentration broken rock rolling theory, inverse problem approach using indirect parameters of the cutting head of, on the cutting head of the energy efficiency and the lowest maximum, minimum tool wear characteristics of multi-objective, were normalized, transformed into single objective problem, a genetic algorithm. The results showed that: the inversion of multi-objective design method is feasible to design a new type of driving hard rock cutting efficiency of institutions to provide 9%, compared with 20% reduction in energy consumption, lower tool wear 55.2% for the rock tunnel excavation needs.

Interface prediction ahead of the excavation front by the tunnel-seismic-while-drilling (TSWD) method

Geophysics ◽  
2007 ◽  
Vol 72 (4) ◽  
pp. G39-G44 ◽  
Author(s):  
Lorenzo Petronio ◽  
Flavio Poletto ◽  
Andrea Schleifer
Keyword(s):  
Seismic Data ◽  
Reference Signal ◽  
Tunnel Boring Machine ◽  
S Wave ◽  
Tunnel Boring ◽  
Vertical Seismic Profiling ◽  
Mechanical Excavation ◽  
Seismic Sensors ◽  
Interface Prediction ◽  
Interval Velocities

Predicting geologic interfaces ahead of a tunnel front is of major importance when boring tunnels. Unexpected variations in ground properties can cause problems for tunnel-boring advance and risk for human safety. The tunnel-seismic-while-drilling (TSWD) method utilizes noise produced during mechanical excavation to obtain interpretable seismic data. This passive method uses accelerometers mounted on the advancing tunnel-boring machine (reference signals) together with seismic sensors located along and outside the tunnel. Data recorded by fixed sensors are crosscorrelated with the reference signal and sorted by offset. Similar to reverse vertical seismic profiling, crosscorrelated TSWD data are processed to extract the reflected wavefield. During mechanical excavation of a [Formula: see text] tunnel through upper Triassic dolomite, a survey was performed to predict geologic interfaces. Faults intersecting the tunnel were observed on seismic TSWD data and later were confirmed by geostructural inspection. P- and S-wave interval velocities obtained by TSWD data along the bored tunnel were used to compute dynamic rock moduli to support tunnel completion.

The Process Hypothesis and Feasibility Study on Drilling-Blasting Machine Method in Tunnel Excavation

2012 ◽  
Vol 256-259 ◽  
pp. 1316-1319
Author(s):  
Feng Shan Hao ◽  
Gui Zhong Tian ◽  
Tu Long Wang
Keyword(s):  
New Technologies ◽  
Tunnel Boring Machine ◽  
Action Mechanism ◽  
Tunnel Face ◽  
Machine Method ◽  
Tunnel Excavation ◽  
Tunnel Boring ◽  
Geological Conditions ◽  
Economic Technology ◽  
Blasting Method

This paper was based on many pre-existing or being successful tunnel projects for study. Through in-depth investigation and analysis of the action mechanism on rock and the construction control under complex geological conditions, the author synthesized the technical advantages of the drilling-blasting method and tunnel boring machine technology into integration as a new drilling-blasting machine method applied in tunnel (lane) excavation. If this method intended by conventional process, it’s difficult to realize mechanized continuous excavating. In this problem, the author put forward two new technologies named helicoid tunnel face and shallow blasthole close blasting to improve. Respectively from the theory, economic, technology and safety, the paper demonstrates the feasibility of drilling-blasting machine method.

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