Assessment of loading characteristics of resin grouted rock bolts under different confinement pressure through laboratory and numerical modelling studies

0557563 - ÚGN 2023 IN eng C - Conference Paper (international conference)
Rajashekhar, K. - Ram, S. - Kumar, A. - Waclawik, Petr - Naresh, M.
Assessment of loading characteristics of resin grouted rock bolts under different confinement pressure through laboratory and numerical modelling studies.
Proceedings of the 9th Asian Mining Congress. Kolkata: The Mining, Geological & Metallurgical Institute of India (MGMI), 2022, s. 311-319.
[Asian Mining Congress and International Mining Exhibition (9.). Kolkata (IN), 04.04.2022-07.04.2022]
Institutional support: RVO:68145535
Keywords : rock bolts * numerical modelling * rock-resin
OECD category: Environmental and geological engineering, geotechnics

Rock bolts have become primary means of support system in Indian underground coal mines. Resin grouted, stiff and high capacity rock bolts support are being used in mechanised working. Application of resin grouted rock bolts is gradually increasing in Indian coalfields due excellent bonding between the interfaces of this reinforcement system of support. Confinement in immediate roof and side of pillar develops redistribution of in-situ horizontal stress and vertical stress respectively which leads to deformation with time. There are numbers of factors for the deformation but the level of induced stress driven deformation/spalling/fracturing depends on depth of cover and nature of overlying strata. Further, the load transfer to the bolt is dependent on the shear stress capable of being generated on the interfaces of the rock-resin and the bolt-resin through mechanical interlocking. Considering the abovementioned facts, investigations on efficacy of the rock bolt by varying the confining pressure at depth of cover 100-1000m is carried out on numerical models. Finite difference based numerical modelling using elastic constitutive model is considered for this study to evaluate the loading characteristics at varying depth of cover. Tension in the rock bolt found to be decreased with the depth of cover due to the influence of considerable inherent of confinement pressure. On the basis of observed loading characteristics of rock bolt in the models, an indigenous design for Short Encapsulation Pull-Out Tests (SEPTs) is also developed for detailed investigations in laboratory. Further, the numerical modelling provided significant information about roof sag, distribution of horizontal stress and its impact over rock bolt support.
Permanent Link: https://hdl.handle.net/11104/0336023