The Delft Sand, Clay & Rock Cutting Model, 2019a

Clay Cutting.
7.3.6. Abelev & Valent (2010).
Abelev & Valent (2010) investigated the strain rate dependency of the strength of soft marine deposits of the Gulf
of Mexico. They used a precision rheometer with rotational rates from 0.25 up to 1000 1/min and water contents
of 55% to 95%. They describe several models like an inverse hyperbolic sine:
y 0 arcsin
(7-28)
0
A logarithmic law and a power law:
y 0
log 10
y
and 0 0
(7-29)
3.0
2.8
2.6
2.4
Strengthening Factor λ c vs. Relative Strain Rate
55%
65%
Strengthening Factor λ c (-)
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
0.1 1.0 10.0 100.0 1000.0 10000.0
Relative strain rate (-)
75%
85%
95%
Theory
Lower Limit
Theory
Upper Limit
© S.A.M.
Figure 7-16: Abelev & Valent (2010) data.
The data of Abelev & Valent (2010) are shown in Figure 7-16, together with a lower limit and an upper limit based
on the equation derived in this chapter. Based on their experiments they suggest a modified power law:
y 0
(7-30)
0
The use of the equation derived in this chapter however gives even better results.
y 0
ln1
(7-31)
0
One can see some dependency of the strengthening effect on the water content. It seems that the higher the water
content, the larger the strengthening effect.
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