| Summary: | 碩士 === 國立中央大學 === 土木工程研究所 === 83 === Ground settlement induced by the deep excavation may cause the
inclination of neighboring underground tunnels, which may
endanger the safety of trains. Most of the previous studies
dealing with the deep excavation focused on the deep excavation
itself or the interaction of the deep excavation and
neighboring structures. Therefore the purpose of this research
is to investigate the interaction of the deep excavation and
underground tunnels in the vicinity of the excavated zone. The
deformation and pore pressure induced by the deep excavation
are time-dependent. In this study assuming plane strain
condition, a nonlinear two dimensional finite element effective
stress model based on the Biot consolidation theory is
developed to investigate the nonlinear time-dependent behavior
of deep excavation.The nonlinear behavior of soil is assumed to
follow the modified cam clay model. From the parametric
studies, it was found that (1) It is acceptable to design the
diaphragm wall regardless of the effect of tunnels around the
excavated zone. (2) The ground settlement induced by the deep
excavation is more affected by the distance of tunnels from
the excavated zone than the embedment depth of the tunnel.(3)In
the analysis of deep excavation with tunnel on one side only,
the ground settlement and the retaining wall deformation on the
side without the tunnel can be approximated by the result
obtained considering the symmetric case without tunnel present,
while those of the side with tunnel present can be simulated by
the case with tunnel on both sides. (4)The longer the
excavation time, or the shorter of the distance from ground
surface or diaphragm wall to tunnels is, the more seriously the
tunnel inclines.(5) The larger the width of excavation zone is,
the larger deformation of the wall and the higher the degree of
inclination of the tunnel are. As a result, it must be careful
in explaining the result of one dimensional model which can''t
take the effect of excavation width into
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