Use of dynamic cone penetrometer versus other field and lab tests for subsurface characterization.

摘要

The purpose of this research was to correlate the results of the Dynamic Cone Penetrometer (DCP) used in surface characterization with presently trusted methods of testing such as the Nuclear Density Gauge (NDG), sand cone, Standard Penetration Test (SPT) and the relatively new Refraction Microtremor (ReMi). For this purpose, each of the previously mentioned methods were tested in the field. The DCP was corrected against the sand cone and NDG in the lab. The results obtained in the testing indicated that the DCP is a reliable method of evaluating the SPT blow count N60 values, which is used in numerous geotechnical correlations for soil property evaluation. When the DCP tests results were compared to the SPT results, it was determined that the DCP is more sensitive to changes in the soil with depth than the SPT. Given the economy of performing the DCP test versus the traditional SPT, some effort was made to investigate the possible use of Soil Conservation Service (SCS) soil survey data to offset the advantage of using SPT representative samples to obtain additional data. Unfortunately, the site chosen did not clearly fall in a single SCS soil unit and such data did not substitute for the lab assessed SPT sample information. NDG results were altered by the chemical properties of the soil. Therefore, NDG test results were discarded in favor of sand cone test results (mostly moisture) in an attempt to find a correlation between the moisture-density state of the soil and the DCP blows. The limited ReMi data did not allow for creation of a reliable DCP and ReMi comparison.