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Laboratory Test of EPB Shield Tunneling in Mixed-Face Conditions.
- Source :
-
International Journal of Geomechanics . Sep2021, Vol. 21 Issue 9, p1-15. 15p. - Publication Year :
- 2021
-
Abstract
- Field measurements and laboratory tests were carried out to study the mechanical behaviors of soil in response to earth pressure balance (EPB) shield tunneling in mixed-face conditions, i.e., layers of granite and sand. Specifically, an experimental investigation was carried out using a laboratory-scale model to replicate the EPB tunneling operations in such ground conditions. The effects of the ratio of rock/sand at the tunnel face (Tr/Ts) and the cover-to-diameter ratio (C/D) on the soil pressure in the chamber, ground displacement, and volume loss were examined. The results show that the soil's response to the mixed-face conditions differs significantly from that in the homogenous ground and highly depends on the ratio of rock/sand, especially for relatively shallow tunnels. As the ratio of rock/sand at the tunnel face increased, the pressure gradient in the chamber became more inconsistent. The translated cumulative curve does not always provide a good fit in the mixed-face conditions, particularly in cases when the rock/sand ratios are high. A smaller width of settlement trough has been observed for cases with a large rock/sand ratio compared to that in clay and cohesionless soil. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 15323641
- Volume :
- 21
- Issue :
- 9
- Database :
- Academic Search Index
- Journal :
- International Journal of Geomechanics
- Publication Type :
- Academic Journal
- Accession number :
- 151717496
- Full Text :
- https://doi.org/10.1061/(ASCE)GM.1943-5622.0002098