Method for excavating rock cavities

Abstract

In a method for excavating rock cavities in the form of substantially cylindrical, vertical or low placed rock cavities for the storage of gas, fluid, solid products or for another purpose, one first, from a transport tunnel (2), excavates an upper circular room (3). From this circular room (3), one excavates the roof shape of the rock cavity (1) to be; and then, from a second transport tunnel (7) excavates a second annular tunnel (5) from a middle level in the rock cavity (1) to be. From the second transport tunnel (7), one also excavates a lower circular room (8) situated on a level which is substantially at the level where the lowest level of the rock cavity (1) to be, is. At this lowest level one excavates a third annular tunnel (13); between the circular room (8) and the third annular tunnel (13) provides tap holes (9). From the second annular tunnel (5), stopping is carried out in a substantially annular vertical or inclined zone from the middle level to the lowest level and removes blasted rock mass through the tap holes (9). One then separates a substantially conical roof volume (10) above the annular room (8) whereafter, finally, a remaining, central, substantially cylindrical rock pillar (14), substantially placed above the annular room (8), is blasted completely or partly at one or more events and rock mass obtained is removed via the tap holes (9).

Dependencies are inferred from the claim text.