To construct metro stations in core urban areas, superlarge
crosssection quasirectangular
steel pipe jacking is adopted to construct Jing′an
Temple station of Shanghai metro line 14. However, because research on the
construction technology and stress characteristics of the new structure is
still at the initial stage, and the design key points and stress weak points
are unclear, the field experimental research is conducted in this study. Water
and soil pressure sensors and steel structure strain gauges are arranged to
collect the magnitude and variation law of external load and steel structure
strain during pipe jacking, and the mechanical performance of the pipe jacking
structure under various construction conditions is studied. The results reveal
the following: (1) Under the operation condition, the total pressure
distribution is uniform and symmetrical, the total pressure at the top is
slightly larger than that at the bottom, and the pressure in the lower half
ring is roughly reversed Ushaped. (2) Under the
condition of synchronous grouting, the slurry sleeve quickly transfers the
grouting pressure to the pipeline. (3) Under the secondary grouting condition,
the entire ring grouting pressure is approximately 330 kPa, which is 1.56 times
higher than that under the operation condition, and the structure is the most
unfavorable. (4) The circumferential stress mechanism of the pipe joint is
similar to that of the entire ring rectangular frame structure, and the top and
bottom of the structure are the most unfavorable stress sections. (5) The
longitudinal stress of the pipe joint is small; therefore, it is necessary to
note the retreat amount of the pipe jacking tunnel, increase the backstepping
reaction force, and implement waterproof measures for the ring joint.
PAN Weiqiang
,
JIAO Bochang
,
LIU Xian
.
Mechanical Behaviors of QuasiRectangular
Steel Pipe Jacking Structure with Large CrossSection:
a Case Study of Jing′an Temple Pipe Jacking
Station on Shanghai Metro Line 14
[J]. Tunnel Construction, 2022
, 42(6)
: 975
-983
.
DOI: 10.3973/j.issn.2096-4498.2022.06.005
