886
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
n curves of reinforced
odels shift to left side of strain axis and consequently
obtained shear strain is reduced.
Also, increasing content ratio of tire chips in mixture
causes shear modulus degradatio
m
Figure 6. Damping ratio of Reinforced and Unreinforced model
with TC
r
=40%.
Damping ratio curve of reinforced and un-reinforced
model with TC
r
=40% are presented in Fig. 6. At all
models, the scattering of damping ratio values is high.
As a general result, value of damping ratio is reduced by
increasing strain amplitude. This process is similar to
conclusions of Brennan (2004), which explained
mentioned phenomena happens when the soil particles
lose contact each other due to increase of pore water
pressure and consequently cause frictional energy of soil
skeleton reduced and since damping ratio is the ratio of
dissipated energy to absorbed energy therefore damping
alue of the
10
-2
, is
cr
atio of Reinforced Models
build-up of excess
-up of
mixture due to
decreasing excess pore water generation.
increased with increasing tire
chips mixture
5
Ghi
s
o
Baha
Uch
Tow
ab
halandarzadeh, A., Fakher, A. 2009.
Experimental study on seismic deformation modes of
reinforced-soil walls. j. Geotextiles and Geomembranes.,
27(9), 121-136.
3) Maximum shear modulus of reinforced soil increased
with increasing tire chips content in
4) Mean damping ratio is
chips content in sand-tire
REFERENCES
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sand reinforced with carpet waste fibers under triaxial
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Zheng-Yi, F. and Sutter, G. Dynamic Properties of Granulated
Rubber/Sand Mixtures, Geotechnical Testing Journal,
GTJODJ, Vol. 23, No. 3, September 2000, pp.338-344.
Hyodo, M., Yamada, S., Okamoto, M. 2007, Undrained cyclic
hear properties of Tire chips–sand mixture, Int. workshop
n scrap Tire derived geomaterials, Yokosuka, Japan.
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liquefaction”, 6
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imura, M. ,Chi, N.A. ,Nirmalan ,S. ,Sato ,T. ,Mediani , M.,
Towhata , I. 2007. Shaking table test on the effect of tire
chips and sand mixture in increasing liquefaction
resistance and mitigation uplift of pipe, International
workshop on scrap tire derived geomaterials, Yokosuka,
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Zeghal, M. and Elgamal, A.W. 1994. Analysis of site
ratio is reduced.
liquefaction using earthquake records. J. Geotech. Eng.,
120(6), 996–1017.
hata, I. 2008. Geotechnical earthquake engineering,
3.3.1.
Mean damping ratio
Due to observing relatively irregular and non-uniform
trends of damping ratios versus shear strain that has
occurred because of various reasons such as high shear
strain amplitude and sudden increase in pore water
pressure, a new parameter is defined as the mean value
of damping ratio by Sabermahani et al. (2009) to
compare the values of damping ratio of reinforced
models with each other. The values of mean damping
ratio versus tire chips content ratio of reinforced model
tests are plotted in Fig. 7. Results show that v
Springer First Edition.
Brennan, A. J. 2004. Vertical drains as a countermeasure to
earthquake-induced soil liquefaction. PhD thesis, Univ. of
Cambridge, Cambridge, U.K.
ermahani, M., G
S
mean damping ratio at the shear strain range of
eased with increase in tire chips content.
in
Fig.7 .Mean damping r
4
CONCLUSIONS
1) It seems tire chips can control the
pore water pressure of the mixture during earthquake
and increase liquefaction resistance.
2) Although unreinforced sand shows reducing in
stiffness during earthquake due to rapid build
excess pore water pressure, no sign of losing in stiffness
was observed in reinforced sand with tire chips.
