To improve the structural design theory of the
secondary lining trolley, numerical simulations and field measuring are
conducted to analyze the structural stress and formwork deformation of the
secondary lining trolley under various concrete pouring conditions, and the
stress distribution and variation patterns of the trolley are summarized by
taking the Fangshan tunnel of the Linyi-Tengzhou expressway as a
example. Results show that: (1) The trolley stress primarily concentrates on
arch springing jacks, portal frames, and load-bearing
columns, with a maximum reaching 585.8 MPa. The maximum formwork deformation occurs at the crown when
asymmetrically concreting at sidewalls, reaching 10.97 mm. (2) The end columns
tensioned and the central one compressed along the walking direction of the
trolley when concreting sidewalls, whereas the end columns compressed and the
central one tensioned after crown concreting. When the outer columns are
concreted to the crossbeam with a height difference, the stress difference
reaches an extreme. The left column′s tensile stress
reaches 12.2 MPa and the
right column′s compressive stress reaches 23.6 MPa. (3) When there is a concreting
height difference, the left compressed and the right tensioned. After crown
concreting, the compressive stress on the crossbeam decreases from both ends to
the center. Taking the front end section of trolley waking direction as an
example, the stress changes little when sidewalls have not yet been concreted
to the crossbeam height; when concreting to the crossbeam height, the stress on
both sides changes from tensile to compressive, with the left and right
reaching 19.2 MPa and 4.4 MPa, respectively.
KONG Qiang
,
SONG Renjie
,
DING Weicheng
,
WU Yimin
,
CHI Zuoqiang
. Stress Distribution and Variation Patterns of
Secondary Lining Trolley Structure During Concrete Pouring
Process[J]. Tunnel Construction, 2025
, 45(S1)
: 340
-350
.
DOI: 10.3973/j.issn.2096-4498.2025.S1.033
