Additional thrust cylinder installation
S-000 continued the excavation without any problem until 00.00.0000 and stopped for
planned disc change. However after the disc change TBM jammed again because of
the squeezing ground. A Power Pack hydraulic system installed to the TBM to increase
the thrust, which was not enough to start advance again. To protect the segments from
the high thrust force a steel ring was build. On 00th April 000 bar pressure, which is
approximately 000000 kN, was tried but TBM did not moved.
Then, it was decided to install 00 additional thrust cylinders, which have thrust force
around 000000kN and open drifts around the shield to reduce the earth pressure.
On this stop, a probe drill was also installed to the TBM. Moreover the angle of belt
conveyors were reduced to carry conditioned muck, wear plates on the cutterhead were
changed, agitating bars installed to the cutterhead and new bentonite lines were added.
TBM stopped for 00 days which is the longest stop from the beginning of excavation.
On 00th June TBM started to advance again. Until 00.00.0000 TBM didn’t stopped for
a long time and continued to excavation except planned cutter changes. The average
daily advance of the TBM is approximately 0.00 m/day for this period.
From the beginning of excavation S-000 advanced 000 meters in 000 days, which
makes daily advance rate around 0.00 meter.