Statistical Evaluation of CPT and DMT Measurements at the Heber Road Site

A series of field tests were conducted at several sites in the Imperial Valley, South California from 1983 to 1985. The field testing program included cone penetration, dilatometer, standard penetration, piezocone, seismic piezocone, and screw plate tests. The data base collected at these sites is extensive and available to the interested reader as raw or reduced data on diskettes (Reyna, 1990). Included in this data base are mechanical cone data obtained at the same sites by the U.S.G.S. following the 1979 Imperial Valley earthquake. This paper discusses only a subset of the data base, concentrating on cone and dilatometer measurements, with emphasis on a comparison of their effectiveness and levels of variability. Attention is also given to the differences in penetration resistance values obtained using mechanical and electrical cones. In addition, the influence of the rate of penetration on dilatometer parameters is evaluated by comparing tests conducted at normal rates of penetration and extension to tests at slower rates.