| 摘要 |
<P>PROBLEM TO BE SOLVED: To appropriately perform quantitative evaluation of stability for a rock lump in a columnar shape, which is held by a rock bed at the upper end part and has a joint. <P>SOLUTION: A weathering degree of a rock lump having a columnar shape is set by a joint (step S1), and on the basis of the relation of the weathering degree of the rock lump and a lowering degree of tensile strength of the rock lump, the lowering degree of the tensile strength of the rock lump is derived (step S2). The tensile strength of a sample which is similar to the rock lump and is not weathered is measured. The density of the sample is measured and the density of the sample is defined as the density of the rock lump (step S3). By using the following equation (1), a length in the axial direction of the rock lump falling from a rock bed is calculated (step S5). Le=k×Sp/(ρg×sinθ)...(1), provided that Le: the length in the axial direction of the rock lump falling from the rock bed, k: the lowering degree of the tensile strength of the rock lump, Sp: the tensile strength of the sample, ρ: the density of the rock lump, g: gravity acceleration, and θ: an inclination angle in the axial direction of the rock lump relative to the horizontal direction. <P>COPYRIGHT: (C)2013,JPO&INPIT |
