Ce. Fear et Ec. Mcroberts, RECONSIDERATION OF INITIATION OF LIQUEFACTION IN SANDY SOILS, Journal of geotechnical engineering, 121(3), 1995, pp. 249-261
The Berkeley trigger criterion for evaluating the potential for earthq
uake-induced phenomena in sandy soils is reviewed in this paper. The h
istorical database comprising the criterion is reconsidered using a co
nsistent ''weakest-link-in-the-chain'' approach. Revised plots of aver
age cyclic stress ratio (CSR) versus (N-l)(60) are presented using the
new minimum values of (N-1)(60). Lower-bound state lines, in terms of
(N-l)(60), are applied to the nonliquefied data and upper-bound state
lines are applied to the liquefied data. It is found that these lines
do not coincide, forming a single trigger line in either clean sand o
r sand with fines; instead, they define a zone in which liquefaction m
ay or may not occur. An additional zone is defined in which earthquake
-induced phenomena are likely to consist of only sand boils. This supp
orts the necessity of site-specific investigations to determine liquef
action potential. The results of this study demonstrate the effect of
fines content on liquefaction potential, but not to the same extent as
found in original interpretations of the field data.