Abstract
Underground construction projects such as tunnel construction are at high risk of water-induced disasters. Because this type of disaster poses a serious threat to worker safety and productivity, instruments and methods that can accurately detect the water source are critical. In this study, a water detection instrument that combines Magnetic Resonance Sounding (MRS) and Time-domain Electromagnetic Method (TEM) techniques to yield a joint MRS-TEM interpretation method was developed for narrow underground spaces such as tunnels. Joint modules including a transmitter and receiver were developed based on a dual-purpose and modular design concept to minimize the size and weight of the instrument and consequently facilitate transportation and measurement. Additionally, wireless control and communication technology was implemented to enable inter-module cooperation and simplify instrument wiring, and wireless synchronization was accomplished by implementing a Global Positioning System (GPS)-based timing scheme. The effectiveness and reliability of the instrument were verified via indoor laboratory tests and field measurement signal tests. Furthermore, the practicability of the combined instrument and its interpretation method was verified via a field case performed in a tunnel in Hubei, China.
Highlights
With rapid socio-economic development and changes in the global climate, the world is facing the reality of increasingly urgent water resource problems
This paper describes the basic principles of the time-domain electromagnetic method (TEM) and Magnetic Resonance Sounding (MRS) method and their joint inversion process, with emphases on descriptions of key technologies, including the structure of the combined MRS-TEM instrument, wireless control transmission, Global Positioning System (GPS)
Further analysis of the MRS-TEM joint inversion measurements revealed the distribution of areas with a relatively large water content at 2–20 m beyond the tunnel face
Summary
With rapid socio-economic development and changes in the global climate, the world is facing the reality of increasingly urgent water resource problems. The most commonly-employed commercial TEM instruments available for underground measurements are the EM-47 (Geonics Limited, Mississauga, ON, Canada) and V8 (Phoenix Geophysics, Scarborough, ON, Canada); these instruments have the same problem in terms of size and weight, but they have limited functionality.Considering this, [16] developed a combined MRS-TEM instrument based on the similarities between MRS and TEM instruments; test results demonstrated that their proposed instrument could effectively perform groundwater detection. Field tests that were conducted in a tunnel near Qiyue Mountain in Hubei Province, China, to verify the effectiveness of the proposed instrument are described, and the MRS-TEM combined advanced detection results are presented and discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
