Evaluation method of collapse risk of unstable rock mass

摘要

PROBLEM TO BE SOLVED: To provide an evaluation method of collapse risk of unstable rocks capable of preparing a nomograph related to the relation between a falling safety ratio of rocks on a slope and vibration characteristics and evaluating stability of each rock on the slope more in detail.SOLUTION: In the evaluation method of the collapse risk of unstable rocks, vibrations of the unstable rocks on the slope are measured on site, a rock sample of the unstable rocks or peripheral rocks of the same rock kind is acquired, rock physical properties (tensile strength, elastic coefficient) of the unstable rocks are recognized by an indoor test of the rock sample, collation is performed with a nomograph indicating the relation between a dominant frequency and the falling safety ratio for the respective rock physical properties (tensile strength, elastic coefficient), the falling safety ratio of the unstable rocks is obtained, and thus, the collapse risk of the unstable rocks is evaluated.