The water inrush risk encountered in Qingdao Metro
tunnel crossing submarine slightlyweathered tuff with 30~60 m burial depth and F5 fault and
fracture zone with 500 m width should be solved. The doublemode TBM is adopted, the open mode of TBM is adopted for submarine
hard rock section, and the soilpressure balance mode
of TBM is adopted for F5 fault and fracture zone based on comprehensive
comparison and selection on construction period, geology and groundwater.
According to the hydrogeological environment under special working conditions,
selection and optimization of TBM are carried out as follows: (1) The shield
tail brushes are added to improve the equipment′s antiseepage ability; the shield plate at the tail of the shield is
installed to ensure the grouting effect. (2) The advanced geological drilling
rig and double grout grouting equipment are equipped to achieve advanced
drilling and grouting reinforcement. (3) The heavy alloy cutters are adopted to
reduce the frequency of tool replacement and the size of excavation face is
increased to reduce the risk of TBM jamming due to complex geology. (4) The
steel grille at the opening position of the cutter is added to prevent large
amount of hole slag from damaging the cutter. (5) The holes on the pressure
separator are added to realize nopressure mode front
drilling and grouting reinforcement. When crossing fault and fracture zone, the
belt conveyor and related equipment are removed, the holes in the pressure
separator is sealed, the screw conveyor and foam system is installed to change
the open mode to the earthpressure balance mode, so as
to improve the safety of the double mode TBM. Through the research of
optimization of equipment, process test, mode conversion of TBM and soil
pressure balance, the construction of auxiliary guide tunnel for Dayang StationNorth Qingdao Station of Line 8 crossing complex hydrogeology of sea
area is successfully completed.
LIU Ze
,
WANG Yong
,
LI Xiaofeng
,
WU Zhihao
. Key Technologies for Type Selection and Application of
Doublemode TBM in Complex Geology of Sea Area[J]. Tunnel Construction, 2020
, 40(6)
: 868
-872
.
DOI: 10.3973/j.issn.2096-4498.2020.06.012
