Abstract
To evaluate stability of rock blocks on slope, professional engineers now carry out the qualitative investigations, such as topography reading, field study. Therefore, quantitative evaluation technique which field engineers can execute is needed. Hammering test is one of qualitative evaluating methods about the stability of rock blocks on slope. We investigated quantitative evaluating method of rock blocks stability using hammering test by experiments and field measurements. The results of experiments and the field measurements show that we can evaluate rock blocks stability by the amplitude and frequency of the sound pressure spectrum obtained from hammering test. As the bonded zone area between rock block and bedrock become small, the maximum amplitude of the sound pressure spectrum become large and the dominant frequency of the spectrum become lower. The frequencies of the sound pressure spectrum peaks distributed under 0.5kHz harmonize with the maximum peak of velocity spectrum measured by vibration measurement. These results are recognized in both of the experiments and the field measurements. If the spectrum amplitude and the dominant frequency of the sound pressure spectrum from the rock blocks are normalized by those of the bedrocks, we can evaluate the rock blocks stability regardless of rock type variation. Based on the above-mentioned results, we proposed an evaluation procedure of the rock blocks stability on slopes.
