Shield
launching is a key link in shield tunneling, and also a highrisk
link. Based on the shield launching project of Shengjinta StationLiuyanjing Station of Nanchang Rail Transit Line 3, a statistical analysis on the main tunneling
parameters of the shield launching along a smallradius
curve in the waterrich sandy stratum is conducted, and
the advantage interval of related parameters are determined. Finally, based on
the shield attitude control parameters and surface subsidence, the driving
parameters control effect is evaluated. The results show the following. (1) In
the horizontal direction, there is a significant difference between the two
groups of cylinder thrust changes in the curved section and the straight
section. The smaller the radius of the line horizontal curve, the greater the
difference. The thrust differences of the two groups of cylinders in the
horizontal direction of the left and right line in curved and straight section
are 87.2% and 75.8% respectively. (2) The smaller the horizontal curve radius,
the greater the total thrust and cutterhead torque, while the tunneling speed
is slightly reduced. The average total thrusts of the left line and the right
line are 1 397.6 t and 1 671.7 t, the average cutterhead torques are 3 101.1 kN·m and 3 723.9 kN·m, and the average
tunneling speed is 38.8 mm/min and 35.1 mm/min, respectively. (3) As the
stratum of the excavation section of the initial section is relatively uniform,
the pressure of the soil chamber increases linearly with the buried depth of
the tunnel, and due to the smaller radius of the curve on the right line, the
dispersion degree of the soil chamber pressure is relatively high. (4) The
grouting amounts of shield tail on the left and right lines vary little, and
the dominant interval is 3~6 m3, with an average of
about 4 m3. (5) The horizontal shield posture overrun
rates of the initial section in the left and right line are only 2% and 4%
respectively, and the maximum accumulated surface settlement is only 6.25 mm,
which indicates that the control effect of driving parameters in the launching
section in smallradius curve in this project is good,
and the driving parameters have good adaptability to stratum conditions and
line type.
AN Bin
,
LIU Xueba
,
YANG Chunbo
,
WANG Zuxian
. Study on Tunneling Parameters Control for EPB Shield
Launching along a Smallradius Curve in Waterrich Sandy Stratum[J]. Tunnel Construction, 2020
, 40(S2)
: 289
-296
.
DOI: 10.3973/j.issn.2096-4498.2020.S2.037
