1335
Technical Committee 202 /
Comité technique 202
Figure 2. Layout of the trial embankment (Constructed and tested in Ibaraki, Japan, 2011)
-2
0
2
4
6
- 600
- 500
- 400
- 300
- 200
- 100
0
Distance
（
m
）
Road height
（
mm
）
25
50
100
150
Settlement (mm)
200
250
300
350
400
450
500
550
Settlement of 250mm
○ ：
Before Great East
Japan Earthquake
(9
th
March 2011)
● ：
After Great East
Japan Earthquake
(16
th
March 2011)
Photographs 5. Deformation performance of Confined–Reinforced
Earth (550mm differential settlement
, tested in
Ibaraki, Japan, 2011).
4.2 Deformation performance
Trial embankment after testing looks as shown in Photographs 5.
It is clearly observed that the central part of road is artificially
lowered by 550mm. Experimental results indicate that use of
the newly developed high rigidity confined-reinforced earth
(CRE) can maintain the minimum road usability for vehicles
even when the amount of differential settlement reaches
approximately 600 mm.
Although the asphalt pavement settles together with the
embankment, there is no crack or sharp gap in the CRE
pavement shown in Photograph 5 (2). Instead, the CRE asphalt
pavement settled in a gentle curve as shown in Figure 3.
Conversely, in the case of conventional asphalt pavement, the
asphalt pavement splits resulting in a step-like gap that started
to appear when the forced settlement reached approximately
200 mm. The gap at the stage of differential settlement of 550
mm is shown in Photograph 5 (3).
Figure 3. Surface deformation profile of asphalt concrete pavement
reinforced by Confined-Reinforced Earth.
4.3 Seismic performance
On 11th March, 2011, the Great East Japan Earthquake of
Magnitude 9 occurred during the test when the settlement was
250mm. About 200gal of seismic power acted on the trial
embankment. Deformation of CRE being compared with
conventional pavement before and after the earthquake is shown
in Photographs 6. Figure 3 also shows that excessive
deformation of CRE did not occur after the earthquake.
There was no additional crack or gap in the CRE pavement
after the earthquake as seen in Photographs 6. Conversely, in
the case of conventional asphalt pavement, the cracks of asphalt
pavement further opened after the earthquake.
Photograph 7 shows the perfect soundness of CRE as seen in
the structure of the asphalt pavement after the earthquake. Only
small amount of additional deformation of the CRE structure
was observed after the severe earthquake as shown in Figure 3.
4.4 Traficability
Photographs 8 show the trafficability tests of asphalt concrete
pavement reinforced by CRE after 550mm differential
settlement. The longitudinal curve of CRE is gentle enough for
all types of vehicles to drive at low speed. Conversely, in the
case of conventional asphalt pavement, it is obviously
impossible for vehicles to drive in such conditions.
The authors consider that the high rigidity subgrade using the
confined-reinforced earth can contribute to the construction of
