A Probabilistic Assessment of Marginal Lithotypes in the Mercia Mudstone Group Formation for Tunnelling Risk Management on the North Bristol Relief Sewer Project
Publication: Geo-Risk 2023
ABSTRACT
The North Bristol Relief Sewer tunnel project involves a 6.5 km tunnel constructed primarily in the complex Mercia Mudstone Group formation. Early in the project, unexpected challenges with cutter tool wear and groundwater control were encountered, raising the need for further evaluation of the ground investigation data and a detailed assessment of the ground risks. This paper summarizes the geostatistical modelling approach used to characterize the lithology and geotechnical parameters within the Mercia Mudstone Group formation, and the added value of this approach to quantify uncertainties and risks. The developed geological model is validated by muck observations recorded during construction. In addition, discussion on recommendations for improved classification of the Mercia Mudstone as it pertains to tunnelling risks is presented.
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REFERENCES
Armstrong, M., Galli, A., and Beucher, H. (2011). Plurigaussian Simulations in Geosciences. Springer-Verlag Berlin Heidelberg.
Chandler, R. J., and Forster, A. Engineering in Mercia Mudstone by RJ Chandler and A. Foster. CIRIA, 2001.
Gangrade, R. (2021). Quantifying Spatial Geotechnical Uncertainty to Advance the Practice of Risk Assessment and Decision-Making in Tunnel Projects. PhD Thesis, Colorado School of Mines.
Green, G. W. (1992). British regional geology: Bristol and Gloucester region. Bernan Press (PA).
Hobbs, P., et al. (2002). Engineering geology of British rocks and soils: mudstones of the Mercia Mudstone Group. British Geological Survey.
Madani, N., and Emery, X. (2017). Plurigaussian modeling of geological domains based on the truncation of non-stationary Gaussian random fields. Stoch Environ Res Risk Assess 31:893–913. https://doi.org/10.1007/s00477-016-1365-9.
Madani, N., and Emery, X. (2015). Simulation of geo-domains accounting for chronology and contact relationships: application to the Río Blanco copper deposit. Stoch Environ Res Risk Assess 29:2173–2191. https://doi.org/10.1007/s00477-014-0997-x.
Madani, N., Maleki, M., and Emery, X. (2019). Nonparametric Geostatistical Simulation of Subsurface Lithotypes: Tools for Validating the Reproduction of, and Uncertainty in, Lithotypes Geometry. Nat Resour Res 28:1163–1182. https://doi.org/10.1007/s11053-018-9444-x.
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Geo-Risk 2023
Pages: 66 - 74
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Published online: Jul 20, 2023
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