3D-FEM ANALYSIS OF SHIELD TUNNEL CONSTRUCTION WITH GROUND-SPRING MODEL

Abstract

The shield tunneling has been extensively implemented for construction of underground
transportation systems in urban areas. Reports on tunnel segment damage during tunnel construction become
increasing. The jack thrust force is the essential cause of damage to the segment. The objective of this article
is to present the model which analyzes the behavior of tunnel lining during construction. The model consists
of five rings and ten segments for each ring connected together with the shear springs which represent the
segment joints and ring joints. The zero thickness interface elements are used to model the segment interface
behavior and soil stiffness is represented by mean of ground springs. All relevant construction loads are taken
into account in the analysis. The ground spring model is implemented into FEM program ABAQUS to analyze
the behavior of segmental lining during construction along straight and curve alignments. The analysis results
agree with the measurement data and confirm that the stresses of tunnel segments are governed by jack thrust
force. The ground-spring model has been proven to be appropriate for analysis of behavior of the tunnel
segments.