Abstract: Aiming at the bearing capacity of rock anchorages for West River Bridge construction on Guangzhou bank slope, the engineering geological investigation, indoor and in-situ rock mechanical tests, borehole camera, sound wave tests, etc. are carried out to gain the rock mass geomechanical characteristics and the slope’s geomechanical model. Then anchorage tests are carried out to confirm the reliability of prestressed cables in-situ. The three dimensional numerical simulation is used to research the stability of the wall rock around anchorages when group cables prestressed and bearing load, as well as the distribution rule of prestressed cables’ resistance arranged at different positions in an anchorage. The results indicate that the rock anchorage system is stable when the West River bridge constructed and the displacements of the slope’s surface keep mm level; the prestressed cables’ anchoring force turn out uneven distribution and mainly concentrate in 2 m scope on the front of anchoring section; in the prestressed cable group of one rock anchorage, the concentration degree of cable resistance is first the angle cable, next the side cable, last the middle cable which from a large to small in turn. The overload experiments show that the rock anchorage system's ultimate anti-pullout capacity is not smaller than 8 times of the designed pulling load. Prestressed cables’ monitoring indicates that the axial force of cable is just stable during the whole period when the construction load increasing; and the middle cable’s axial force is less than the angle cable’s one. The research methods and results can be for reference in similar bridge constructions and anti- pullout projects.

Key words: rock slope, anchorage, prestressed cable, anchoring force, numerical simulation