The particularity of sandypebble
strata in Chengdu, China introduces problems to shield tunnels, such as
cutterhead jamming, center mud cake, excessive wear of cutterhead, and broken
screw conveyor shaft. Therefore, the discreteelement
theory and analysis method are adopted to simulate the shieldtunneling process in sandypebble strata,
and the law of soil movement and force characteristics of the shield are
studied. It is concluded that (1) the moving speed of soil particles around the
tunneling face of the cutterhead is higher than that of the center; (2) the
soil moving speeds in the center of the soil chamber and at both sides of the
screw shaft extending into the soil chamber are slow; and (3) the compressive
force distribution of soil on tunneling face and soil chamber is related to the
rotation direction of the cutterhead. Finite element analysis is conducted on
the cutterhead and screw conveyor using EDEMANSYS
coupling, and the results show that: (1) The maximum stress on the cutterhead
is 123.27 MPa during shield tunneling, which is located at the junction of the
cloud leg and the flange; the maximum deformation is 1.69 mm, which is located
on the outermost ring beam of the cutterhead. (2) The maximum stress on the
screw conveyor is 59.01 MPa, which is located at the connection between the
rear partition of the soil chamber and the screw barrel, and the maximum
deformation is 0.49 mm, which is located between the outer ring of the spiral
blade near the junction of the soil chamber and the screw barrel.
ZHAO Weixing
,
GUAN Huisheng
,
LIAO Jiang
. Discrete Element Simulation and Interaction Analysis
of Shield Tunneling Process[J]. Tunnel Construction, 2021
, 41(7)
: 1132
-1140
.
DOI: 10.3973/j.issn.2096-4498.2021.07.006
