Civil Engineering Reference
In-Depth Information
time of the design earthquake, calculate the liquefaction-induced settlement of the tank.
Answer:
Since the tank is in the middle of a liquefied soil layer, it is expected that the empty
tank will not settle, but rather will float to the ground surface.
Liquefaction-Induced Ground Damage
7.18
A soil deposit has a 6-m-thick surface layer of unliquefiable soil underlain by a
4-m-thick layer that is expected to liquefy during the design earthquake. The design earth-
quake has a peak ground acceleration
a
max
equal to 0.40
g.
Will there be liquefaction-
induced ground damage for this site?
Answer:
Based on Fig. 7.6, liquefaction-induced
ground damage is expected for this site.
7.19
Use the data from Prob. 6.12 and Fig. 6.13. Assume that the groundwater table
is unlikely to rise above its present level. Using a peak ground acceleration
a
max
equal to
0.20
g
and the standard penetration test data, will there be liquefaction-induced ground
damage for this site?
Answer:
Based on Fig. 7.6, liquefaction-induced ground damage is
expected for this site.
7.20
Use the data from Prob. 7.13 and Fig. 7.12. Assume that the groundwater table
is unlikely to rise above its present level. Using a peak ground acceleration
a
max
equal to
0.20
g
and the standard penetration test data, determine the minimum thickness of a fill
layer that must be placed at the site in order to prevent liquefaction-induced ground dam-
age for this site.
Answer:
Based on Fig. 7.6, minimum thickness of fill layer
2.2 m.
7.21
Use the data from Prob. 7.14 and Fig. 7.13. Assume that the groundwater table
is unlikely to rise above its present level. Using a peak ground acceleration
a
max
equal to
0.20
g
and the standard penetration test data, will there be liquefaction-induced ground
damage for this site?
Answer:
The solution depends on the zone of assumed liquefaction
(see App. E).
Volumetric Compression
7.22
Solve the example problem in Sec. 7.4.4, using the Tokimatsu and Seed (1987)
method and assuming that the 50-ft-thick deposit of sand has (
N
1
)
60
5.
Answer:
11 in.
(28 cm).
7.23
Solve the example problem in Sec. 7.4.4, using the Tokimatsu and Seed (1987)
method and the chart shown in Fig. 7.7, assuming that the 50-ft-thick deposit of sand has
(
N
1
)
60
15.
Answer:
Using the Tokimatsu and Seed (1987) method, settlement
1.3 in.
(3.3 cm). Using the chart shown in Fig. 7.7, settlement
0.9 in. (2 cm).
7.24
Solve the example problem in Sec. 7.4.4, using the Tokimatsu and Seed (1987)
method and the chart shown in Fig. 7.7, assuming that the 50-ft-thick deposit of sand will
be subjected to a peak ground acceleration of 0.20
g
and the earthquake magnitude
7.5.
Answer:
Using the Tokimatsu and Seed (1987) method, settlement
0.9 in. (2.3 cm). Using
the chart shown in Fig. 7.7, settlement
0.6 in. (1.5 cm).
7.25
Solve the example problem in Sec. 7.4.4, using the Tokimatsu and Seed (1987)
method and assuming that the 50-ft-thick deposit of sand has (
N
1
)
60
5, a peak ground accel-
eration of 0.20
g,
and the earthquake magnitude
7.5.
Answer:
Settlement
2 in. (5 cm).
