Details

Autor(en) / Beteiligte

• Singh, Prasoon
• (Sam) Spearing, A.J.S.
• Jessu, K.V.
• Caroline Pinazzi da Silva Ribeiro, Pâmmela

Titel

Establishing the need to model the actual state of stress along rock bolts

Ist Teil von

• International journal of mining science and technology, 2020-05, Vol.30 (3), p.279-286

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2020

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• Proper design of rock bolt support in underground mines is critical to avoid incidents, accidents and loss of production. The traditional design approach only considers the axial (tensile) capacity and this is clearly not the situation in situ, where a rock bolt is subjected to both axial and shear/bending loads which determines its overall performance and failure behaviour. To demonstrate and analyse the shear displacement in bedded roof, scaled physical models of underground excavation were created. From the models it was found that the shear displacement between the layers depends on the vertical roof deformation and thickness of beds. To analyse the effect of combined loading on rock bolt design for suspension and beam building models, analytical methods were used to calculate the required spacing of rock bolt for a given safety factor. Numerical models were then created using Rocscience RS2 software to establish the stresses on the rock bolt. The results show a significant reduction in safety factor for suspension as demonstrated in an example (reduced from 3.5 to 2.0) and beam building (2.0 to 1.36) when the rock bolt capacities are calculated considering the effect of combined loading as opposed to just the axial or shear loads.