Environmental Engineering Reference
In-Depth Information
Fig. 10.10
Urgent countermeasures construction to respond to sediment-related disasters. Paper
shredder residue mixed with soft soil; the rapid stabilization helps speed up the restoration work
local soft sediment so it could be used to make a temporary works area, and then in
building a detour route while the reconstruction of highway 291 took place (Taka-
hashi et al.
2006
). This demonstrated that this approach can also be used at disaster
recovery sites (Fig.
10.10
).
10.2.6.4
Sunaoshi River Channel Excavation Works (Sendai Miyagi
Prefecture Civil Engineering Office River Erosion Control
Third Section)
In the March 11, 2011 Great East Japan earthquake, depending on location the tsu-
nami height exceeded 10 m. Sediment carried by this huge tsunami deposited in the
Sunaoshi river channel in Tagajo city blocking the channel. These tsunami deposits
carried sediments from the bottom of the sea, and using these in the construction
of the new river embankment was difficult. However, after using the fiber-solid-
ification technique, the sediment could be improved to the level required for use
in the river levee embankments. The soil liquefaction resistance rate (FL) of the
improved sediment was 1.5-13 times that of general fill material (sandy soil) of
FL 0.12, so is much more resistant to liquefaction. In addition, an increased shear
resistance increases the stability of the soil, river levees and road embankment, and
