Supporting tunnel face by Fiber glass pipes technology is an effective method to
maintain the stability of tunnel face, thus reducing surface settlements, face deformation
and maintaining the safety of the workers and the mechanisms used in tunneli
ng.
This paper presents the results of finite-difference numerical analyses (FLAC3D program)
on the behavior of a shallow tunnel face reinforced by longitudinal fiber glass pipes. A 3D
numerical model has been calibrated and used to demonstrate the effectiveness of this
technique, and perform a parametric study to determine the critical reinforcements
parameters (the density (number of pipes)(A) and length (L)). The results indicate that the
face reinforcement technique using longitudinal fiber glass pipes can significantly reduce
the movements (face displacement and surface settlements), and thus improving the face
stability. These movements decrease by increasing the length of the pipes and increasing
the density of the pipes until reaching the critical density, and when we reach the critical
length, the pipes must be renewed to maintain the stability of the tunneling process.
