Method of predicting ground mountain condition

摘要

PROBLEM TO BE SOLVED: To provide a prediction method for a natural ground situation that accurately identifies not only tunnel subsidence but also displacement of a horizontal inner space, thereby allowing accurate prediction on a natural ground situation in front of a pit face.SOLUTION: A prediction method for a natural ground situation is for predicting a natural ground situation in front of a pit face as a tunnel T is excavated, the tunnel having a cross-section that includes at least a semi-circular part Ta. In the method, a plurality of inclinometers 1, 2, 3 are installed at a tunnel arch section along an axial direction of the tunnel T at intervals, for acquiring measurement data from the inclinometers 1, 2, 3 and calculating an amount of change in an inclination angle from the measurement data of adjacent inclinometers, thus predicting the natural ground situation in front of the pit face, based on the calculation result. The inclinometers 1, 2, 3 are installed in a range between 55 and 65 degrees from a spring line SL in a horizontal direction, around an intersection O between the spring line SL and a center line CL in a vertical direction.SELECTED DRAWING: Figure 2