The laboratory characterization of a reconstituted offshore silty-clay and the calibration of a constitutive model to the laboratory test results are described. The laboratory tests included one-dimensional consolidation tests, undrained monotonic direct simple shear tests, and shear wave velocity measurements on reconstituted block specimens. Duplicate tests were performed in two different laboratories. The test data were used to calibrate the MIT-S1 anisotropic constitutive model. Simulated responses, using the finite-difference code, FLAC, are compared to the experimental data. Parametric studies of various constitutive model parameters are presented and discussed. The results show that a reasonable calibration of the model for various behaviors of this silty soil was attained from only a few standard laboratory tests.