60 Ground improvement by deep vibratory methods
For overconsolidated sand, the same researchers recommend as a rough
guideline:
M
q
q
M
q
= ⋅
=
5
5 0
250
50
c
c
c
for below
MPa
MPa for below
MPa
(3.5)
When SPT results are considered or specified in a project, Table 3.4 provides a useful guideline for the translation of N-values into equivalent q c
values of the CPT (see also Figure 3.28).
φ′ = 48°
46°
44°
42°
40°
38°
36°
34°
32°
30°
20
30
40
50
10
0
300
350
400
200
250
150
100
50
0
Cone resistance q c (MPa)
Vertical effective stress σ′
vo (kPa)
Figure 3.19 Relationship between σ′ vo , q c , and φ′. (Redrawn from Lunne, T. et al., Cone
Penetration Testing in Geotechnical Practice, Blackie Academic & Professional,
Glasgow, Scotland, 1997; after Robertson, P.K. and Campanella, R.G., Can.
Geotech. J., 20(4), 718, 1983.)
For overconsolidated sand, the same researchers recommend as a rough
guideline:
M
q
q
M
q
= ⋅
=
5
5 0
250
50
c
c
c
for below
MPa
MPa for below
MPa
(3.5)
When SPT results are considered or specified in a project, Table 3.4 provides a useful guideline for the translation of N-values into equivalent q c
values of the CPT (see also Figure 3.28).
φ′ = 48°
46°
44°
42°
40°
38°
36°
34°
32°
30°
20
30
40
50
10
0
300
350
400
200
250
150
100
50
0
Cone resistance q c (MPa)
Vertical effective stress σ′
vo (kPa)
Figure 3.19 Relationship between σ′ vo , q c , and φ′. (Redrawn from Lunne, T. et al., Cone
Penetration Testing in Geotechnical Practice, Blackie Academic & Professional,
Glasgow, Scotland, 1997; after Robertson, P.K. and Campanella, R.G., Can.
Geotech. J., 20(4), 718, 1983.)