A largediameter
(15 m) highway shield tunnel for drainage and storage with superdeep cover depth (10 m) requires high joint bearing capacity under
high internal water pressure. Thus, a new circumferential fast connector is
developed. The fast connector assembly time is short and does not require
manual tightening, the roundness of the tunnel is high after assembly, the
segment dislocation and opening are small, and waterproof performance is good.
In this paper, to investigate the structural form, material properties, the connection
between the connector and anchor bar, and the force transmission between the
connection and concrete segment, a case study is conducted on a 650 mm thick
segment, a tensile physical test of the joint is implemented, and a numerical
simulation method is employed to compare experimental and calculated values.
The main conclusions are summarized as follows: (1) The tested cast iron
connection load capacity is 512 kN, which satisfies design requirements. The
bearing capacity during the elastic phase is 400 kN, and the ultimate bearing
capacity is 645 kN, which can guide shield tunnel design. (2) The experiments
conclude with connector failure; thus, the design of the connection between the
anchor bar and connector is reasonable and reliable. When the test is
suspended, the maximum stress of the four anchor bars is 348 MPa, reaching 87%
of the tensile yield strength of HRB400 anchor bars, which is close to the
design value of 360 MPa. (3) Under axial tensile force, the stress of the
connector body and anchor is uneven; thus, the unevenness should be considered
in the connection design, and a reasonable optimization design should be
realized.
GUAN Linxing
,
SUN Wei
,
ZHANG Mengxi
,
FANG Tao
,
ZHANG Guiyang
. Mechanical Performance and Experimental Research on Circumferential Fast Connector of Shield Tunnel[J]. Tunnel Construction, 2022
, 42(6)
: 967
-974
.
DOI: 10.3973/j.issn.2096-4498.2022.06.004
