Abstract: The interaction mechanics among the endsuspended pile, rock shoulder and footlock anchor should be studied. Hence, the calculation methods of preloaded axial force of the footlock anchor are proposed based on the positions of endsuspended pile at the bottom of potential sliding surface of rock slope. When the endsuspended pile is located below the potential sliding surface, the preloaded axial force of footlock anchor is equal to the passive zone combined force minus rock shoulder reaction force when the rock foundation pit is not excavated. When the endsuspended pile is above the potential sliding surface, the preloading axial force of footlock anchor is equal to the passive zone combined force plus the thrust of endsuspended pile when the rock foundation pit is not excavated. And the calculation formulas of the preloaded axial force of footlock anchor under two conditions are given. Finally, the results are verified by the finite element method. The results show that the calculation results of the preloaded axial force of footlock anchor according to the calculation methods are basically rational.

Key words: endsuspended pile, footlock anchor, preloaded axial force, dualistic foundation pit