The extralarge diameter (over 14 m)
slurry shield would be subjected to alternating loads when tunneling in soft
and hard strata, which would lead to difficult tunneling parameters selection,
frequent tool replacement, overload failure, and the loosening of the tool
holder bolt, as well as seriously affect the tunneling safety. To achieve realtime load monitoring of tool replacement devices and guide the
construction through sensing the load data, a suite of realtime load monitoring systems based on fiber Bragg grating technology
are proposed based on the Su′ai tunnel in Shantou,
China. The monitoring system measures the bolt load in a muddywater environment with smart bolts, then transmits the signal via
wireless communication technology, and finally stores and analyzes the load
data based on data acquisition software. The results show the following: (1)
The electromagnetic environment has no harm on the system in a muddywater environment and the system can monitor the load stably and
reliably. (2) When shield tunneling in soft and hard strata, the axial load of
bolts changes periodically and varies greatly due to the different installation
positions. The rock intrusion height can be estimated to guide the tool
configuration according to the difference of the axial load of bolts in soft
and hard strata. (3) By monitoring the bolt axial force, the phenomena of bolt
loosening and pretightening force attenuation can be identified, which is
conducive to timely conduct countermeasures for reducing the construction risk.
The system can be used for realtime load monitoring,
boltloosening identification, and rock intrusion
height estimation of shield tunneling, as well as for providing guidance.
WANG Chaofeng
,
WANG Guo′an
,
WANG Kai
. Design and Application of Real-time
Monitoring System for Load of Cutter Replacement
Device under Atmospheric Pressure of Extra-Large Diameter Slurry Shield[J]. Tunnel Construction, 2021
, 41(8)
: 1404
.
DOI: 10.3973/j.issn.2096-4498.2021.08.018
