Abstract
The descriptions of soil or rock classification in drilling-log were converted into numerical values, then the quantificated log data were transformed into the spectral intensity of Walsh rectangular waveform function. Analysis were performed on 142 of drilling log data of 12m depth from ground surface obtained in the eastern area of Muroran City, Hokkaido, Japan.
The results obtained here are as follows;
(1) The spectrum of each number of zero crossing shows the characteristics of variation in soil classification under the ground surface.
(2) The spectral intensity of 0 time of zero-crossing have a considerable information on the variation of soil classification. Consequent low number of zero-crossing spectra, such as from 1 to 7 times of zero-crossing, are more informable than the other higher number of ones.
(3) Almost of spectra of one time of zero-crossing were negative in the whole area of eastern Muroran. The finding indicates that the quantificated value in the lower half part of underground of 12m depth from ground surface is larger than the upper half. In this way, the spectral contour maps of each number of zero-crossing should be interpreted according each waveform.
(4) From topographical view point, the drilling points higher than 5 times of superior number of zero-crossing are found in the area of old river mouth or talus in the eastern part of the City.
(5) The selection of drilling-logs by means of cluster analysis makes it easy to interpret the spectral contour maps.
