Abstract:

The anchoring mechanisms of screw bolts in sandy soil ground are analyzed. The anchoring section of the original screw bolts are optimized in consideration of the resistance of the anchoring blades and the friction resistance of the sandy soils. The concept of highdensity compression friction anchoring is used to design the new bolts, which are installed by means of selfscrewing. New screw bolts are designed after the bolts have been trialled in 5 typical sandy soil job sites in Xi'an. The newlydesigned bolts are used in the reinforcement of the foundation pit of TJSG4 bid section of line 2 of Xi'an Metro, which demonstrates that the bolts are reliable both in theory and practice.

Key words: screw bolt, Metro, soil nail, soil bolt, foundations pit reinforcement, recoverable bolt