| 摘要 |
In the driving of a tubular, underground cavity (1) at a great depth by means of a driving unit (3) which has tools for excavating the rock at the heading face (5) in the front area of a shield casing (4) absorbing the rock pressure, a pasty material (15) with a low internal coefficient of friction is injected into the annular space (16), limited to the inside by the shield casing (4) and to the outside by the wall (13) of the driven cavity (1) and closed off towards the heading face (5) and to the rear, and is held in the annular space (16) in a pressure state selected as a function of the rock pressure. This material, conveniently a mixture of a clay material, such as, for example, montmorillonite and water, behaves like a solid in the annular space and is thus able to transmit the rock pressure to the shield casing (4) but has a very small angle of internal friction so that the driving forces exerted by the driving jacks (9) are largely independent of the rock pressure. During the driving, a sliding surface (17) forms in this material so that seizing of the driving unit (3) is prevented even after prolonged stoppage. <IMAGE>
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