Results presented in this paper represent the first part of research p
roduced by the Verification of Liquefaction Analysis by Centrifuge Stu
dies (VELACS), a cooperative research effort involving eight universit
ies. Ultimately, the objective of the project is to perform a series o
f dynamic centrifuge model tests on a variety of different soil models
to study the mechanisms of liquefaction-induced failure and to use th
e results of these tests to verify various numerical procedures used i
n the analysis of liquefaction problems. However, prior to completing
this final part of the project, a series of model tests was run by eac
h of the eight universities to evaluate the dependence of centrifuge t
est results on the testing apparatus and test team; these results are
presented here. Each university performed one model test using a stand
ard model box; soil- and test-preparation technique; soil configuratio
n: and input earthquake motion. Model accelerations, pore-water pressu
res, and surface settlements were measured during the eight tests and
are compared in this paper. The test results help to define a general
mechanism of liquefaction and show that similar results can be obtaine
d when testing standard models at different centrifuge facilities. Alt
hough some scatter was observed, the results are sufficiently close to
endorse their use in analysis validation exercises.