SHAFT EXCAVATION CONSTRUCTION METHOD

PURPOSE:To provide the collapse of a shaft sidewall by excavating a plurality of inclined shafts extending along the excavation direction at a prescribed angle from the inside of an excavated shaft, and by filling reinforcing materials into the inclined shafts, so that the stresses caused by the earth pressure of surrounding natural ground can be borne. CONSTITUTION:For the surrounding natural ground A of a shaft 1b to be excavated, a plurality of inclined shafts 2 extending along the excavating direction at a prescribed angle are excavated from the inside of an excavated shaft 1a. Then, reinforcing materials 4 such as a steel bar 4a, concrete 4b and the like are filled in the inside of respective inclined shafts 2, and while reinforcing the surrounding natural ground A in the excavating direction of the shaft 1b to be excavated, excavation is advanced forward. While successively repeating the above procedure, a shaft B is excavated up to a desired depth. Thus, the stress caused by the earth pressure of the surrounding natural ground A can be borne by the reinforcing materials 4, so that the collapse of the sidewall of the shaft B can be prevented.