Vol. 5 No. 2 (2021)
Articles

The relationship between the radius of plastic zone of the shotcrete in a combination preservative system of weak rock mass

Published 2021-09-01

Abstract

Since the most important factor in constructing tunnels underground is secure drilling and tapping and in the meantime the preservative system to meet the second objective, namely to reduce the cost and time plays an important role. On the other hand, drilling in weak rock mass requires preservative system at the time of drilling, that amount of deformation caused by the weight of the rock mass around the tunnel as well as loads caused by high tunnel structures will be reduced dramatically. A common method to create a preservative system in the tunnel excavation, the use of rock bolts With appropriate diameters and also shotcrete with a thickness depends on the type of geometry of the tunnel and the surrounding rock mass of tunnels in rock mass resistance. in this paper, the relationship between the length of the rock bolt and the thickness of concrete (shotcrete) with a radius of plastic zone around the area excavated in the rock mass in weak rock mass is invesigated using Plaxis 2D software and this relationship is offered.