Three-Dimensional Finite Simulation Analysis of Forepoling Bolt Pre-Supporting at Tunnel Entrance
ZHANG Jian-guo
WEN Shu-lian
Abstract：In order to ensure the construction safety of tunnel entrance under the complicated geological condition , the surrounding rock should be pre-supported .The forepoling bolt pre-supporting is adopted and the three-dimensional finite numerical simulation is used to analyze its effect .The calculation results show that when the vault displacement is less than 50 mm and the displacement of side wall is no more than 45 mm, the final safety factor of primary support is about 5.0, so the forepoling bolt pre-supporting can ensure the safety of supporting structure at tunnel entrance .Meanwhile , when the maximum axial force of the forepoling bolt is slightly higher than 13 kN and has a ladder-like distribution , the maximum is located in middle of the forepoling bolt and decreases to two ends gradually , and the axial force of the forepoling bolt in the vault is larger than that of the side walls .
Keywords：tunnel entranceforepoling boltpre-supportingfinite numerical simulationcomplicated geological condition
Publication Date：2014-01-01
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：5( 51-54,70 )