Document Type

Conference Paper

Publication Date

2018

Publication Details

Edward Pullan, Danqi Li and Paul C Hagan, Comparison of the Performance of Resin and Cementitious Grouting Media for Cable Bolts, Proceedings of the 18th Coal Operators' Conference, Mining Engineering, University of Wollongong, 363-372.

Abstract

Cable bolting systems are an integral part of ground support designed to improve the stability of underground excavations. As geotechnical conditions vary, each component in the cable bolt system must be optimized to maximise the efficiency of the system. This study examined the performance of cable bolts with two different types of grouting agent – a standard cementitious material and a resin-based grout; in two strengths of confining material; and, in two different borehole diameters. Performance was quantified in terms of peak load, residual load and stiffness. The UNSW modified Laboratory Short Encapsulation Pull-out Test (LSEPT) facility was employed where an axial load was applied to a high capacity modified cable bolt. Results of the study indicated significant differences in the performance of the cable bolt between being grouted in strong and weak materials with the former resulting in the highest average peak loads of 406 kN and 397 kN respectively for the cement and resin grouts respectively indicating both grouts were just as effective in load transfer. The average peak load in the weak material was about 24% less at around 315 kN and in one case 207 kN with cement grout in the standard borehole diameter. In general, peak load was slightly higher when grouted in the standard borehole diameter in strong material but this trend was reversed in the weak material. Interestingly in terms of residual load, or the load bearing capacity after 90 mm displacement, the reduction from the peak load was much less at just 35% in the weak material to 203 kN whereas the reduction in the strong material was 63% to 145 kN. Little difference was observed in the stiffness between all test scenarios.

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