Behaviour of a Tunnel Face Reinforced by Bolts : Influence of an Deviated Installation

摘要

In recent years, there have been numerous studies into the behaviour of tunnel face reinforced withrnbolt, but most of study was suppose the parallel installation of bolts. Although in generally, therninstallation of bolt was parallel to the excavation directions, but many cases when be conducted thernboring in the fields, boring hole was bended according to geological conditions and operationrntechniques.rnThis paper presents the results of laboratory investigation on the deformation behaviour of tunnelrnface reinforced with bolts. Although the reinforcing effect is significantly influenced by thernconstruction conditions, in specially we focused on an installation angel of bolt. The laboratory testrnwas constructed on the difference installation angle and compared with the parallel installation. Thernresults of this experiment suggest that it is important to keep boring precise to prevent bolt therndeviation of installation and, if installation deviation is inevitable, it is necessary to add extra bolts