OBSERVATIONAL PROCEDURE FOR TUNNEL CONSTRUCTIONS IN LANDSLIDE AREA BY USING FACE BOLTS AND INVERT STRUTS

Abstract

  When tunnels are constructed around landslide area, the ground tends to be instable due to excavations. It is a crucial issue to design the support system for controlling the ground behavior to be stabilized. This paper proposes an observational procedure for the tunnel construction in landslide area. It is a method to install long-length face bolts and invert struts to resist the ground movement. The size of the support and the time of the installation were decided by using field measurement results. The method was applied to a highway tunnel where a few landslide blocks were existed around the tunnel portals. In this paper the detail procedure is described, and the applicability of the method is discussed on the basis of field measurement results.