In tunnel construction, it often takes long time to
build temporary support structure, and the teporary structure cannot be reused
easily after demolition. A design and construction scheme of reuseable precast
temporary invert arch is put forward, and application tests are carried out in
loess tunnel with threebench sevenstep
method. By comparing the field data of fiber Bragg grating sensors and
numerical simulation results, the implementation effect of precast temporary
inverted arch is studied. The results show that: (1) Precast temporary inverted
arch is simple, and reuseable and can be assembled fast, which helps to quickly form temporary inverted
arch and close primary support structure after middle bench excavation in largesection tunnel construction with threebench
seven steps method. (2) Compared with traditional threebench sevenstep excavation construction
scheme, the "threebench sevenstep excavation + precast temporary inverted arch" method
proposed can effectively decrease the stress and deformation of primary support
structure, in which the maximum principal strain of the primary support is
reduced by 72%, and the vault settlement is reduced by 78%. (3) With precast
temporary inverted arch, middle bench can be sealed quickly, which improve the
interaction between primary structure and surrounding rock, effectively reduce
the plastic deformation range of the surrounding rock after tunnel excavation,
and ensure the safety of tunnel construction.
XIA Hai, XU Guangyang, FU Jinyang, XIAO Ouhui, ZHANG Yuehui, ZHAO Ningning, YANG Junsheng
. Study on Technology of Precast Temporary Inverted Arch
in Loess Tunnel with ThreeBench Method and Its
Application[J]. Tunnel Construction, 2021
, 41(S1)
: 431
.
DOI: 10.3973/j.issn.2096-4498.2021.S1.057
