Yokota, Y, Zhao, Z, Nie, W, Date, K, Iwano, K, Koizumi, Y & Okada, Y 2019, 'Development of a new deformation-controlled rockbolt: numerical modelling and laboratory verification', in J Hadjigeorgiou & M Hudyma (eds), Ground Support 2019: Proceedings of the Ninth International Symposium on Ground Support in Mining and Underground Construction, Australian Centre for Geomechanics, Perth, pp. 545-556, https://doi.org/10.36487/ACG_rep/1925_39_Yokota
(https://papers.acg.uwa.edu.au/p/1925_39_Yokota/)
Abstract: To prevent large tunnel deformations caused by rock bursts or squeezing ground conditions, rockbolts need to satisfy both strength capacity and the required deformability. Currently, energy-absorbing rockbolts, such as the cone bolt and the D-bolt, have been successfully used in deep mining to avoid sudden tunnel collapses. This paper proposes a new energy-absorbing rockbolt, referred to as a deformation-controlled rockbolt (DC-bolt). The performance of the proposed DC-bolt was verified by numerical simulations using discontinuous deformation analysis (DDA) and by prototype laboratory tests. As a result, it is concluded that the DC-bolt possesses both high loading capacity and deformation capacity. Additionally, the DC-bolt can limit rock surface movement when it reaches a certain displacement. Thus, it can be a useful tunnel support for tunnels that are to be excavated in squeezing ground conditions.

Keywords: energy-absorbing rockbolt, deformation-controlled rockbolt, pull-out test, DDA