Paper contribution

Mobilisation of a fully grouted passive rock bolt along its length

Elise Le Guidec; Coffi Gbewade; Yannick Fargier; Marion Bost

Proceedings
EUROCK 2026
Pages
775-780
Submitted
28 January 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

The ageing of hydraulic structures and the reassessment of flood parameters in light of regulatory, technical, and climatic changes are increasing the need for rehabilitation. When the theoretical stability of a structure can no longer be assured, particularly in extreme flood events, one of the reinforcement techniques considered is the use of fully grouted passive rock bolts. Groups of bolts with varying inclination angles could be set in order to withstand the two load directions causing the dam to fail by sliding or tilting. The group effect therefore must be studied through the comparison of the contribution of an isolated bolt with that of a group of bolts, and through the definition of the bolt configurations inducing this effect. This contribution depends on the mobilisation of the rebar and the surrounding environment. It appears relevant to isolate the rebar and analyse its mobilisation in order to subsequently study different configurations. The aim of this study is therefore to characterise the mobilisation of the rebar along its length. To achieve this, a large-scale direct shear test is carried out under constant normal stress. The mobilisation all along the rebar is monitored by optical fibre during the test. A finite element model is developed so that rebar mobilisation can be compared considering both numerical and experimental results. The validated numerical model will enable the group effect to be later studied.

Contributors

Authors

  1. Elise Le Guidec Univ Gustave Eiffel, Univ Lyon, GERS-RRO, France
  2. Coffi Gbewade CEREMA, France ORCID 0009-0003-3240-8844
  3. Yannick Fargier Univ Gustave Eiffel, Univ Lyon, GERS-RRO, France ORCID 0000-0003-1139-6461
  4. Marion Bost Univ Gustave Eiffel, Univ Lyon, GERS-RRO, France; CEREMA, France ORCID 0000-0003-0452-5931

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References

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