To explore the difference between the excavation of
curved and straight tunnels on the surrounding soil and tunnel structure, 3D
numerical models for straight and curved tunnels′ excavation are established respectively to analyze the physicomechanical parameters of the strata and shield structure and the
construction load parameters such as shield jacking force are examined. Then,
the numerical simulation results are compared with the monitored data of the
project to validate the feasibility of the models and analyze the difference of
strata displacement and segment strain between the two models. Finally, the
influence of unbalanced jacking force on soil displacement and segment strain
during curved tunnel excavation is analyzed under conditions with various
jacking force ratios and deflection angles. The results show the following: (1)
Compared with the straight tunnel, the excavation of the curved tunnel results
in an increase in soil settlement above the crown, range of settlement, and
segment strain. (2) With the increasing jacking force difference and deflection
angle of shield, the uneven surface settlement increases, the asymmetry of
horizontal displacement of inner and outer soil increases, and the increment of
radial and axial strain of segment increases. (3) The distribution of radial
strain of segment varies due to different jacking force directions (inner side
and outer side), and when the jacking force direction is outer side, the
segment is prone to crack in the range of 75°~135° and 180°~285°. (4)
When the unbalance degree of jacking force is over large, the radial strain of
the entire segment varies sharply, bringing adverse affect to the structure.
CHEN Yinji, ZHANG Zhiguo, MU Linlong, CHEN Jie, LU Zheng, CHEN Zhongkan
.
Numerical Simulation Analysis of Influence of Curved
Tunneling on Deformation of
Adjacent Strata and Segments
[J]. Tunnel Construction, 2023
, 43(S1)
: 271
-282
.
DOI: 10.3973/j.issn.2096-4498.2023.S1.031
