The transition zone at
Amposta between a 20-m-high embankment and a viaduct structure over
the Ebro River is stiffened through grouting from the side, without interference
with the railway traffic. This includes high speed trains passing at
200 km/h.
Figure 1 illustrates the layout of the treatment grouting tubes and
Figure 2 shows the installation of the grouting sleeve tubes working
from an auxiliary embankment, which is built alongside of the
existing embankment. During the grouting operation, the sleeper
movements are continuously monitored by leveling millimeteric scales
(Figure 3).
At the beginning and at
the end of each working day, additional control of the rails is made
by levelling (Fig. 3). The initial condition of the embankment, in terms of
its shear wave velocity, is established by means of PS-logging and
cross-hole testing. The dynamic response during traffic passage is
also measured before the grouting treatment. After the grouting is
completed, cross-hole technique is used at the treatment level and
below the treatment zone (Figure 4). The dynamic response of the
track after the grouting process is also measured.
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