Abstract
The compressional wave velocity, apparent density and uniaxial compressive strength of rock specimens are measured in the laboratory. Numbers of the specimens are about 170, half of them are sandstone and the others sandy shale, tuff, crystalline limestone, granite, andesite, ASO lava etc. When rearranging our experimental results we can take out the following interresting conclusions.
In order to evaluate compressive strength from compressional wave velocity, we have need to take off some particular groups of rocks such as crystalline limestone, conglomerate, breccia and spherulitic holohyaline ASO lava. Then, compressional wave velocity V and compressive strength of rock specimens are closely combine each other by following empirical formula.
σc=43V2.23 (1±0.4)
The above equation does not be applicable for rock specimens which are weathered and have cracks or anisotropy in surface observation.
