Abstract: This paper presents the numerical analysis results of the grouted hollow anchors in the Gangtoushan Tunnel excavation support.The mechanism of the grouted hollow anchors is briefly introduced and the commercial software FLAC 3D is used.The displacement at the top of tunnel, plastic zones within the tunnel liner and the shear stress field during the construction are compared between the grouted hollow anchors and the conventional cement mortar grouted anchors. The results suggest that,compared with the conventional anchors, the grouted hollow anchors has a better performance in terms of pressure grouting since the grouting slurry can penetrating the fissures and cracks, results in a higher anchorage force and improved rock mass.

Key words: Grouted Hollow Anchors, Tunnel Excavation Support, Numerical Simulations, Anchorage Effect