抄録
Generally, rippability which indicates the difficulty of the rock excavation is assessed on the basis of the measurement of the elastic wave velocity on rock mass. Usually, the engineers estimate from the measured two-dimensional profile of the velocity to the three-dimensional one of the rippability on the basis of their experiential informations. But the result is not necessarily consistent with the real conditions.
Then we have made an attempt to utilize the Quantification 1 of a statistical method on a personal computer as to the assessment of the three-dimensional rippability in an investigated area. To sum up, we have adopted the depth of the velocity layer which can be excavated only by the ripping machine as an outside valiable, and landform type, altitude and rock type as items. And we have classified three categories of ridge, valley, and slope type in landform type, and some categories at ten meter intervals in altitude, and three categories of sandstone, mudstone and green rock in rock type. The analysis has been put into practice with respect to original 150 data on the seismic prospecting lines.
By the result in this investigated area, the depth of the velocity layer is largely related to landform type and altitude. Namely the depth has a tendency to become deeper in ridge parts and shollower in valley parts, and also to become deeper as the altitude becomes higher.
