PROJECT VELACS - CONTROL TEST-RESULTS

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.