Design of pretensioned soil nailing systems in excavations

Abstract

In the present study, analytical design procedures are proposed to evaluate the maximum pretension forces and to estimate stability of the pretension soil nailing system. In addition, modified bearing plate system is proposed and reliability analysis focusing on probability of a failure against the punching shear is carried out. The predicted results are compared with data obtained from the actual excavation site in which construction is made using the pretension soil nailing system. Based on the proposed procedures, effects of both a radius of the influence circle and the dilatancy angle on the thickness of shotcret facing and the bonded length are also analyzed. Further, efficiencies of the pretension soil nailing system in terms of a reduction both in deformations and nail lengths are examined in detail throughout illustrative examples and the FLAC(2D) program analysis.