1795
Technical Committee 204 /
Comité technique 204
Figure 3. Stages of construction
3.3 Analyses results
In the first models, factor of safety for stability of the reinforced
slop, before any excavations, was analyzed. According to
analysis, the safety factor of 1.44 is obtained.
Right drift clusters are removed by two steps after removing
left side clusters. Numerical analyses resulted vertical
settlements up to about 44 millimetres obtained.
Figure 4 presents final vertical deformations, for after
construction conditions, considering 4 steps for removing the
soil clusters according to the construction. As it shown, the
maximum settlements is about 44 [mm] and it accured under the
foundation of the 6-storey bulding, while the factor of safety
after construction is 1.39.
Figure 4. After construction settlements
The construction has performed and the settlements were
monitored parallel to the tunnel construction from several
settlement points on the 6-storey building and some
convergence station in the initial lining of the tunnel. Figure 5
presents location of settlements monitoring point around the
6-storey building.
Figure 5. Settlements monitoring points
Figure 6 shows the monitored settlements during and after
construction together with the 3D model results.
Figure 5. Settlements from monitoring and modeling
According to analysis for after construction condition, the
maximum vertical deformations of foundation of 6-storey
building are about 44mm.
The maximum in-situ monitored settlement on the 6-storey
building was less than 27 [mm] just after construction
completion which smaller than models results.
As shown in Figure 5, the maximum settlements from
modeling results are greater than the monitoring results. The
settlements obtained from numerical modeling are greater for all
construction stages after full balancing of out-of-balance forces
for each stage.
4 CONCLUSIONS
The numerical analyses have performed by using 3D finite
element software to control performance and stability of the
tunnel. Regarding 6-story building and the reinforced slop upon
the tunnel, settlement of ground surface, was considered the
main concern of ground performance.
Monitoring results shows that the maximum settlement of
the building’s foundation was about 27 [mm] just after
construction completion which is smaller than the numerical
results.
