DBPapers
DOI: 10.5593/SGEM2016/B13/S05.070

NEW TYPE OF FRICTION ROCK BOLT: DESIGN AND TEST RESULTS

T.Akhvlediani, N. Chikhradze, E. Mataradze, N. Bochorishvili
Tuesday 6 September 2016 by Libadmin2016

References: 16th International Multidisciplinary Scientific GeoConference SGEM 2016, www.sgem.org, SGEM2016 Conference Proceedings, ISBN 978-619-7105-57-5 / ISSN 1314-2704, June 28 - July 6, 2016, Book1 Vol. 3, 553-558 pp

ABSTRACT
The growing use of friction rock bolts has raised theimportance of their design improvement, which, among other results, can result in ensuringtheir safer application in tunnels. At present, studies are underway at various scientific centers to increase the efficiency of rock bolts focusing on the properties of rock bolt performance in connection with elasticity and deformational characteristics of rocks, as well as perfection of rock bolt designs and methods of improving their working capacity, prevention of corrosion, etc
A proposed new design of a friction rock bolt consists of a metal tube and a bearing plate. A steel tube has a 3-4mm groove along the whole length. Before being placed into a borehole, a tube is filled with special expandable solution. During the hardening and expansion of solution, pressure (50-70MPa) develops on tube walls. Under pressure a tube opens around a groove allowing a close contact between tube and borehole surfaces, which leads to the operation of a rock bolt.
This paper describes results of computer modeling of stress condition of rocks around a rock bolt and tests conducted to establish the rock bolt capacity in different geological and technical conditions.

Keywords: Rock bolt, Expandable solution, Tunnel, Clampingforce