Method and apparatus for supporting the wall of an upwardly excavated shaft

摘要

There is provided a method and apparatus for supporting the wall of an upwardly excavated shaft. Cylindrical support frames which are successively thrust up through the shaft are respectively composed of several arcuate members and one or more disjointing members. A plurality of top supporting plates are provided on the top of the series of the cylindrical frames and are designed to fall inwardly toward the center of the shaft after the excavation of the shaft is terminated, thus constructing an umbrella like device for supporting the roof of the shaft.