A study on risks and countermeasures of shallow biogas in the construction of metro shield tunnels
Shallow biogas is an engineering geological hazard in the process of urban metro construction, affecting the safety and quality of tunnel construction. The existence of shallow biogas not only poses a threat to the safety of the investigation, but also affects the normal construction of the metro buildings and structures. Therefore, the shallow biogas problem with a maximum pressure of 0.43 MPa is a serious hazard in the construction of Hangzhou Metro Line 6. This paper firstly presents the hazard generation mechanism of shallow biogas in shield tunnel construction and discusses the biogas source and risk identification process in geological exploration. Then, by analyzing the relationships among the tunnel excavation speed, the amount of excavated soil and the biogas in the formation, the formula for determining the biogas level is established. The characteristics of different construction stages of Hangzhou metro project, the practical engineering experience and the results of indoor test and monitoring are taken into account. At the same time, this paper proposes a risk identification and control system for shield tunnelling through biogas formation. The hidden dangers of shallow biogas in metro shield tunnel construction can be minimized using this system. The example of Hangzhou Metro Line 6 shows that this system can effectively identify and control the risk of shallow biogas, and help to improve the technological plans, which provides an important reference for other similar biogas formation in the construction of metro tunnels.
- Record URL:
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Supplemental Notes:
- This paper was sponsored by TRB committee AKB60 Standing Committee on Tunnels and Underground Structures.
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Corporate Authors:
Transportation Research Board
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Authors:
- Jiang, Xi
- Bai, Yun
- Zhang, Zhuanzhuan
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Conference:
- Transportation Research Board 100th Annual Meeting
- Location: Washington DC, United States
- Date: 2021-1-5 to 2021-1-29
- Date: 2021
Language
- English
Media Info
- Media Type: Digital/other
- Features: Figures; Maps; Photos; References; Tables;
- Pagination: 12p
Subject/Index Terms
- TRT Terms: Biomass fuels; Depth; Hazards; Rapid transit; Risk; Risk analysis; Shields (Tunnels); Soils; Tunneling
- Identifier Terms: Hangzhou Metro (China)
- Subject Areas: Bridges and other structures; Construction; Public Transportation; Safety and Human Factors;
Filing Info
- Accession Number: 01763770
- Record Type: Publication
- Report/Paper Numbers: TRBAM-21-01631
- Files: TRIS, TRB, ATRI
- Created Date: Feb 4 2021 10:57AM