| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of predicting and determining working face stability capable of precisely predicting and determining by quantitatively estimating the stability of the tunnel face before breakdown.SOLUTION: A preceding boring hole 1 is formed by drilling an upper surface of a tunnel T in a drilling direction from a face T1. Displacement measuring means is set in the preceding boring hole 1 to measure an underground displacement over the face. Measured values measured by the displacement measuring means are compared with preset control limits based on prepared three dimensional analysis results, to predict and determine the stability of the face (not-drilled area). |
