1786
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
Table1 The test scheme
Test
number
T-B
（
Deep
groove section
）
T-C
（
Thick soft
subsoil section
）
T-E(Waterway
excavation
section)
Mileage
stake
K9+200
～
K9+300
K9+500
～
K9+600
K10+400
～
K10+700
Test
conditions
Consolidation-
Excavation of
the foundation
trench-
Backfilling-
Back silting
Consolidation-
Excavation of
the foundation
trench-
Backfilling-
Back silting
Consolidation-
Excavation of the
foundation
trench-
Backfilling-
Back silting-
Waterway
excavation
Table2 Physical properties of various soil on natural foundation
The name of soil
layer
μ
C
（
kPa
）
φ （°
）
Buoyant density
（
kg/m
3
）
Silt
0.43
6.0
2.0
680
Clay and silt clay 0.39
22.0
22.0
940
Clay coarse
0.30
22.0
25.0
900
Coarse sand
0.30
18.0
32.0
1100
Fine sand
0.35
21.0
33.0
1000
Medium sand
0.32
20.0
34.0
1030
＜ 3
＜ 6
＜ 32
Figure1. Test point distribution
2.2 Rearch results analysis
The stress path figure of GDS stress path simulation test about
different layers of soil stess path at different depths from GDS
stress path simulation tests is shown in Figures 2 to 4.
Based on the compression modulus, modulus of resilience,
recompression modulus and re-springback modulus (waterway
excavation) from test, numerical analysis ground deformation
characteristics of a typical cross-section. The test results is
shown in Figures 5 to 8, where the displacement deformation
values are relative displacement values.
From Figures 5 and 6, in the deep channel section of the
natural foundation, the rebound curve of the bottom of the
foundation trench has an arch-shaped distribution after
excavation ; the rebound of foundation trench center is larger ;
the recompression curve has a saddle-shaped distribution. The
entire tube foundation cross-sectional displacement in the
process of excavation and backfill is relatively small.
0
50000
100000
150000
200000
250000
300000
0 50000 100000 150000 200000 250000 300000
q/ Pa
p/ Pa
a1
a2
a3
b1
b2
b3
c1
c2
c3
Figure2. Stress path of B sectional test points
0
50000
100000
150000
200000
250000
300000
350000
0
100000
200000
300000
4000
q/ Pa
p/ Pa
a1
a2
a3
b1
b2
b3
c1
c2
Figure3. Stress path of C sectional test points
0
50000
100000
150000
200000
250000
300000
0
100000
200000
300000
400000
q/ kPa
p/ kPa
a1
a2
a3
b1
b2
b3
c1
c2
c3
Figure4. Stress path of E sectional test points
0. 0720
0. 0730
0. 0740
0. 0750
0. 0760
0
10
20
30
40
Rel at i ve
di spl acement / m
The di st ance f r om Lef t sl ope f oot / m
Figure5. Springback displacement of the bottom of B section foundation
trench after excavation
From Figures 7 and 8, in the main channel excavation
section, the recompression and re-springback curve of tube
foundation soil in E section has a saddle-shaped distribution.
And the cross-sectional displacement in the process of backfill
and re-excavation is relatively small. The re-excavation of
channel has limited impact on the uneven settlement
deformation.
0 0930
- 0. 0925
- 0. 0920
- 0. 0915
- 0. 0910
- 0. 0905
- 0. 0900
0
10
20
30
40
Rel at i ve
di spl acement / m
The di st ance f r om l ef t sl ope f oot / m
Figure6. Recompression displacement of the bottom of B section
foundation trench after backfilling
- 0. 0485
- 0. 048
- 0. 0475
- 0. 047
- 0. 0465
0
10
20
30
40
50
Rel at i ve
di spl acement / m
The di st ance f r oml ef t sl ope f oot / m
Figure7. Recompression displacement of the bottom of E section
foundation trench after backfilling
