881
Technical Committee 104 /
Comité technique 104
situated in central Switzerland (Alpnach) and the other one in
the northern part of Switzerland (Merenschwand). Two
foundations of a supporting girder (4 storey-building) were
controlled in Alpnach. In Merenschwand two foundations of an
easured.
geodetic
measurement provided information of the settlements. One of
the pressure pad used in Alpnach is shown in figure 7.
Figure 7: Pressure pad embedded in a layer of fine sand (Arnold and
igure 8. The darker shaded areas in the
mbers 3, 7, 8, 9
at the center part of the rafts and 1, 2, 5, 6 on the foundation edges
measurement points (Arnold 2012).
Th
dle field by
1 and 3 show even tension at lower rates of loads.
(Arnold, 2012).
mns
The arrangement and the dimensions of the campaign in
t Nr. 1 and 7 & 13 at Raft Nr. 2: Pressure pads to
me
loads are distributed near the columns (Pads 7 and 17) while
earth-fill supporting roof were m
3.1
Measurement equipment
The measurement equipment consisted of pressure pads which
are able to measure the pressure at a reduced area, of strain gage
devices and of displacement transducers to measure the
deformation of the load bringing columns. Additional
Laue 2010).
4 MEASURING CAMPAIGN IN ALPNACH
The arrangement of the measurement system at the location in
Alpnach is given in f
middle of the foundation indicate the columns (cross-section
are : 1.0 m · 0.30 m).
a
Figure 8: Sketch of the measurement systems in Alpnach: D1 – D4 are
strain gages to measure the deformations of the columns. Numbers 4, 5,
10, 14 correlates to the pressure pads under the rafts. Nu
indicate geodetic
4.1
Results
e measurements of the pressure pads in Alpnach are given in
figure 9.
The measurements in Alpnach show the high dependency of
the static system on the development of pressures under a
foundation. Higher stresses are measured with the pressure pads
4 and 5, which are positioned at locations towards the inward
field between the two foundations while values measured with
the other two pads remain smaller. This can be explained using
the measured the strains on both sides of the column (Figure
10). Both columns show bending towards the mid
higher compression on strain gauges 2 and 4 while strain gauges
Figure 9: Measurements of the pressure pads 4, 5, 10 and 14 at Alpnach
Figure 10: Measurements of the strains in the two investigated colu
at Alpnach (Arnold, 2012).
5 MEASURING CAMPAIGN IN MERENSCHWAND
Merenschwand are given in Figure 11 while results of the
measurements with the pressure pads are shown in Figure 12.
Figure 11: Sketch of the measurement systems in Merenschwand: D1 –
D4: Displacement transducers to measure the deformations of the
col mns; 6 & 17 at Raf
u
asure the pressure between foundation and soil; 1 – 4 at Raft Nr. 1
and 5 – 8 (7 at foundation edge) at Raft Nr. 2: geodetic measurement
points (Arnold 2012).
Higher loads are introduced into the ground under raft 2 than
under raft 1. Even though the strain measurements in the
column showed small bending of the columns, the stress
distributions anticipates a more expected behaviour here. Higher
Raft Nr. 1
Raft Nr. 2
Raft Nr. 1
Raft Nr. 2
