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8
ENGINEERING GEOLOGY OF THE ROCKS AND SOIL
74. Earthquake, Lateral force, V=ZIKCSW
Where, Z = zone factor,
I=intensity=1, 1.5 for Hospital
K=0.67, Space Frame K=0.80, Frame / shear wall K=1,
Shear wall Box K=1.33
C=1/(15√T), T=0.1N, No. of floor
S=1 or 1.5 for Rock foundation
W= Total Building dead load plus 25% floor live load.
ENGINEERING SUBSURFACE INVESTIGATION
Field Vane Shear Test
75. Torque, T=px= ∏C
u
(d
2
h/2)+(d
3
/6)
Cu= 1.7- 0.54 (PI) where C Correction factor, PI Plasticity index of the soil.
Standard Penetration test,
76. Corrected N-value, N
1
(60)= N x C
e
x C
l
x C
s
x C
d
x C
N
C
N
= √ (p / σ
v
)
where P 100 kPa or 2.0 ksf or 1 tsf, or 1 kg/cm 2
where (N1 )60 =Normalized SPT blow count, for 60% rod-energy ratio
and 100
kPa (1 kg/cm 2 ; 1 tsf, 2 ksf)
N= Field SPT blow count, from 6 to 18 inches
C
e
= Correction for hammer release system energy
C
l
= Correction for rod length
C
s
=Correction for sampler type
C
d
=Correction for bore hole diameter
C
N
=Correction for effective overburden pressure
Static-Cone Penetration Test
A rod, having an enlarged cone-shaped tip of 1.4 inches diameter, is pushed
into theground at the rate of 2 to 4 feet per minute of the soils encountered.
An empirical relationship between normalized cone resistance, normalized
friction ratio, and soil identification is.
77. q
c1e
= q
c
/( σ
v
' )
c
78. ƒ
c1e
= ƒs/ (σ
v
')
s
79. R
ƒ
=100 (ƒs/q
c
)
where σ
v
'= Vertical effective stress (1 atm, 1 tsf, or 100 kPa)
qc1e =Normalized cone resistance
qc =Measured cone resistance (1 atm, 1 tsf, or 100 kPa)