70 Ground improvement by deep vibratory methods
Soil behavior type index I c
CPT grain characteristic correction
factor K
c
2.0
3.0
4.0
1.0
0
3
2
1
5
4
2.6
2.6
Gravelly
sands
Sand
mixtures
Silt
mixtures
Clay
Sands
Figure 3.25 Grain-characteristic correction factor for determination of clean-sand
equivalent CPT resistance. (Redrawn from NCEER, in Youd, T.L. and Idriss, I.M.
(eds.), Proceedings of the NCEER Workshop on Evaluation of Liquefaction Resistance,
Technical Report NCEER-97-0022, 1997.)
5.0
4
3
2
1
0
6.0
Earthquake magnitude M
Magnitude scaling factor MSF
NCEER recommended
range of MSF
7.0
8.0
9.0
Figure 3.26 Magnitude scaling factor. (Redrawn from NCEER, in Youd, T.L. and Idriss, I.M.
(eds.), Proceedings of the NCEER Workshop on Evaluation of Liquefaction
Resistance, Technical Report NCEER-97-0022, 1997.)