Joint induced anisotropic deformation and supporting effects of rockbolts for tunnels excavated in regularly jointed rock masses
Journal
Rock Characterisation, Modelling and Engineering Design Methods
ISBN
9781315884929
Date Issued
2013-05-17
Author(s)
Abstract
Based on a three-dimensional non-linear constitutive model, this study investigates the anisotropic deformation of a tunnel excavated in jointed rock masses and associate supporting effects of rockbolts. Using a numerical model capable of describing the influence of mechanical behavior of intact rock, the spatial configuration of joint sets, and mechanical behavior of the joint plane on the non-linear behavior of a rock mass, this manuscript reveals the joint-induced anisotropy in failure zone and deformation surrounding a tunnel. The support effects of a rockbolt are generally limited. However, when the rockbolt is pre-stressed and acts perpendicular to a joint plane, the shear displacement and associated dilation of the plane is constrained. And the joint sliding failure caused by tunnel excavation can be reduced. The rockbolt provides a beaming effect. Such an effect is significant in locations where the joint planes parallel to tunnel wall and influenced by the numbers of joint sets and joint strength.
Type
book part