NATURAL GROUND SITUATION PREDICTION METHOD

PROBLEM TO BE SOLVED: To provide a natural ground situation prediction method and a tunnel boring method, capable of boring a tunnel while easily predicting the situations of natural ground in front of a face as daily construction management.SOLUTION: The natural ground situation prediction method includes: a first step of performing a work of setting a face side measurement point on a first measurement cross section and setting a pit mouth side measurement point separated from the face side measurement point to the pit mouth side by a distance a, a work of measuring an initial value which is the positional relation between the face side measurement point and the pit mouth side measurement point, a work of measuring a measurement value which is the positional relation between the face side measurement point and the pit mouth side measurement point at a stage that a face K reaches a position separated from the measurement cross section by a distance b, and a work of calculating relative displacement which is a difference between the initial value and the measurement value; and a second step of calculating the relative displacement similarly to the first step after the face K passes through a second measurement cross section. On the basis of comparison between the relative displacement calculated in the first step and the relative displacement calculated in the second step, the natural ground situation in front of the face K is predicted.