Abstract:

The technological and uplift tests of underreamed anchors are carried out based on the development of mechanical underreamed devices of anchorage. The results show that the mechanical underreamed device has good adaptability for geology conditions; the bearing capacity of underreamed anchor increases by 20 %-30 % on an average than that of the normal anchor, and the maximum bearing capacity increases by 66 %; the phenomena of axial strain steep dropping for underreamed anchor show the end-bearing effect of underreamed anchors obviously.

Key words: geotechnical anchorage, mechanical underreamed device, underreamed anchor, uplift resistance, anchor end effect of bearing capacity