Consideration of the mechanical behaviour and the influence on ground of vertical pre-reinforcement

Abstract

The vertical pre-reinforcement bolt method is used to stabilize the ground at the top of tunnels with shallow overburden to prevent ground surface settlement and to stabilize slopes. However, the design of this method is mainly empirical, based on similar construction cases, and a quantitative design method has not been established. Model tests simulating the vertical pre-reinforcement bolt method and its numerical analysis were conducted to establish a rational design concept for the vertical pre-reinforcement bolt method. The results of the model test showed that the vertical pre-reinforcement bolt method can improve the continuity of the ground regardless of overburden and slope angle. It was found from numerical analysis that the spacing, width and properties of the bolts were related to the reinforcement effect.