To improve the effective use of rock bolt support system for practical and economic considerations in support system. A generic rock bolt design procedure usually starts with the identification of the rock mass strength, which is a process to minimize the deformation induced by the dead weight of loosened rock. It also control the stress redistributions in the rock next to the excavated areas. There has been a growing interest for application of numerical modelling to bolt/resin/rock integration with an aim of understand load transfer mechanisms. In this regard, parametric study was carried out to predict the displacement of fully grouted rock bolts intersected by single rock joint. Main characteristics of the analytical model considered in the bolt profile, joint movement under pull test condition anchorage capacity of fully grouted bolts have been studied. The performance of the proposed analytical model was validated by experimental methods and compared with numerical modeling. The short encapsulation pullout tests of crown bolt capacity were successfully modelled and directly compared with the in-situ pullout tests. The result showed that the proposed rock bolt models can credibly predict the bonding forces and axial loading along the length of rock bolt.
Rock bolt is the most extensively used support element in support systems in underground construction. Rock bolting design is indeed mainly based on experience and it appears that rock bolting design is simply a business of selection of rock bolt types and the determination of bolt length and spacing, but, one essentially uses, either explicitly or implicitly, a methodology in a specific rock bolting design (Li, 2017). In case of jointed rockmass, the rock joints sometimes are open, which is an indication that the in situ rock stresses are low in the rock mass. The task of rock support in low stress rock masses is to prevent rock blocks from falling. To do so, the maximum load exerted on the support elements, such as rock bolts, is the deadweight of the potentially falling block. But as the depth increases geological discontinuities in the rock mass became less and the discontinuities were less open. Rock burst is an instability issue in overstressed hard and strong rock. The goal of rock support in such conditions is to absorb the kinetic energy of the ejected rock. Energy-absorbing rock bolts should be used in burst-prone rock masses.
