To smoothly connect the precast internal structure and
the shield segments of an electric power tunnel, a novel fully-precast
internal diaphragm structural design draft based on the grouting rubber capsule
is proposed. This structure can eliminate the problems in the existing plans.
The construction site Beijing is located at the region with seismic
precautionary intensity of eight degree, the seismic safety is a critical
factor for selecting structural design drafts. Thus, it is necessary to examine
the seismic responses of the novel structure and their differences with
alternative structural plans. Herein, a three-dimensional
nonlinear site-tunnel-internal
structure finite element model is constructed based on the proposed novel
design draft, the postgrouting mortar and the castinplace design drafts. The seismic analyses
are conducted using the integrated response displacement method. The structural
deformation, connection region deformation, and internal force responses are
compared. Results reveal the followings: (1) The deformation of the internal
diaphragm structure is small under infrequent seismic. The stable structure can
normally transfer the internal force. Moreover, the flexible rubber capsules
arranged between the precast bottom diaphragms and the segments deform under
the seismic effect in both radial and circumferential directions of the tunnel,
drastically reducing the axial and shear force of the internal structure. (2)
For the post-grouting mortar design draft, the contact
shear stress concentrates at regions near the circumferential seam. (3) The
seismic safety of the novel structural design draft outperforms the two
traditional design drafts. In addition, the grouting capsules are dry
connections with rapid construction features, the applicable potential of the
proposed novel design draft is great.
JIANG Zhiwei
,
HUANG Yesheng
,
WU Chenggang
,
LIN Fang
,
PENG Zhiyong
,
FAN Qi
,
LIU Ying
. Novel Precast Internal Structure of an Electric Power
Tunnel and Its Seismic Response Analysis[J]. Tunnel Construction, 2025
, 45(S1)
: 208
-216
.
DOI: 10.3973/j.issn.2096-4498.2025.S1.021
