Abstract
In mine roadway support operations, floor bolting not only played a role in floor heave control, but also in reinforcing roof and its two sides. Correspondingly, bolting of roof and two sides also played a part in floor heave control. To quantify the effect of such bolting, based on roadway support in extremely weak rock, three physical models were produced and tested in laboratory. Through comparison of their displacements in three physical simulation experiments, the reinforcing effect of bolting in extremely weak rock roadways was quantified. Reinforcing coefficients was defined as displacement ratio between original support and new support regime. Results indicated that the reinforcing coefficients, for bolting of roof and its two sides, on floor, two sides, and roof reached 2.18, 3.56, and 1.81 respectively. The reinforcing coefficients for floor bolting on floor, two sides, and roof reached 3.06, 2.34, and 1.39 respectively. So in this extremely weak rock, the surrounding rock should be considered as an integral structure in any support operation: this allows for better local strength improvement, and provided future design guidance.
Highlights
Roadway control in soft rock is a problem in many mines (Bilir 2011; Ghiasi et al 2012; Serafeimidis and Anagnostou 2013; Thomas et al 2013)
In mine, based on rock mass strength (RMS), content of mudstone, features of joint planes, and the mechanism of plastic deformation, weak rock was classified into four types (He et al 2002): extremely weak rock, high-stress soft rock, jointed soft rock and mixed soft rock
Under different support regimes, the roadway underwent different amounts of deformation so the efficacy of each set of supporting conditions could be quantified on the basis of their relative displacements
Summary
Roadway control in soft rock is a problem in many mines (Bilir 2011; Ghiasi et al 2012; Serafeimidis and Anagnostou 2013; Thomas et al 2013). Under this mining induced stress, roadways in soft rock undergo large, continuous deformation as they are excavated. Three rock mass classification systems, the rock mass rating (RMR), the rock mass strength (RMS), and the slope mass rating (SMR) have been widely applied to areas of hard rock and weak rock in civil engineering. Brook and Hutchinson (2008) indicated that the relative weightings of the different parameters within the RMR, RMS, and SMR classification schemes would need modifying for weak rock masses, but the precise details of this were difficult to determine. In mine, based on RMS, content of mudstone, features of joint planes, and the mechanism of plastic deformation, weak rock was classified into four types (He et al 2002): extremely weak rock (swelling soft rock), high-stress soft rock, jointed soft rock and mixed soft rock
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
