Geoscience Reference
In-Depth Information
Fig. 15.49. Portable equipment forpercussion penetration of screen pipe
0.8
G.L-5.0m
0.6
0.4
: Case 1
: Case 2
: Case 3
: Case 4
0.2
0.0
0
200
400
600
800
1000
Maximum input acceleration (Gal)
Fig. 15.50. Excess prewater pressure which was mitigated by screen pipes
(Harada et al.,2006)
Figure15.50 indicates the development of excess pore water pressure. The shorter the
pipe spacing, the lower the excess pore water pressure. Moreover, the temperature of
ground water whichwasejected due toliquefaction wasmeasured tobe16
◦
C. Thistem-
perature was identical with the ground water temperature prior to shaking. Hence, there
seemstobenoheatingeffectsinsubsoilliquefaction.Aftertesting,thescreenpipeswere
excavated(Figure15.51)tomakesurethatsignificantcloggingdidnotoccurinthescreen
of pipes and that thedrainage effects would beefficient during future earthquakes.
