The paper presents the results of a reevaluation of the Mixed Company site profile and constitutive properties using both field and laboratory data. Revisions to the subsurface profile were based primarily on the water contents determined in the soil overburden at shot time. An extensive reanalysis of the seismic velocity data was conducted. New constitutive property recommendations for the overburden soil were developed based on laboratory tests conducted on specimens taken in the field just a few days after the event. The properties of the Kayenta Formation were revised to consider the effect of loading rate on the initial portion of the uniaxial strain (UX) test stress-strain curves, the effects of anisotropy on the observed triaxial shear (TX) and UX test behaviors, and the correlation observed between shear strength obtained from laboratory tests and strength obtained from an in situ test.

Results of an in situ investigation of the shear moduli at the Mixed Company site near Grand Junction, Colorado, are presented. Shear moduli were determined from crosshole S-wave velocity and Menard pressuremeter tests in the sandstones of the Kayenta and Wingate Formations at the site. In addition to the data from these tests, rock quality designation data and electrical, caliper, neutron, and gamma logs for three borings at the site are presented. (Author).