ABSTRACT
This paper describes research conducted to investigate the statistical fluctuation and interpret the density profiles obtained by a nuclear-density cone penetrometer (ND-CP). The laboratory results show that the amount of fluctuations present in the ND-CP measurements can be approximated by Normal or Gaussian distribution. The coefficient of variation for RI count and BG count data’s is 2.4% and 15.1% respectively. The moving-average technique has been employed for the measured raw data at different time intervals in order to reduce the statistical fluctuation. It was found that the error due to the statistical fluctuation in ND-CP measurement is less than 1% if an averaging span of 10 cm is used. The raw data obtained from the field results when averaged over 10cm depth shows that the cone profile count distribution trend is not distorted or deformed compared to the original raw data, which means the loss of information about the density through the filtering is negligible. This averaging is necessary to smooth the measured wet density profile. Therefore, the ND-CP measurements are averaged over a span of 10cm depth to minimize the statistical fluctuations.
