Abstract: Fixing devices for connecting components, particularly prefabricated concrete members and tubbing stones, consist of pluglike anchors adapted to be forced with elastic deformation into anchor holes, which are formed in the components and are open to the joint between the components. As a result, the anchors are frictionally held in and/or positively locked in the anchor holes. The anchors are substantially stiff and have a peripheral surface which at least in portions intended for a retaining engagement with the inside surface of the anchor hole is designed to be elastically deformable at least in an approximately radial direction. The surface consists at least in these portions of a plastic material which has entropy elasticity.

Abstract: In the provision of elongate underground cavities having a large volume are to be provided, particularly in the construction of underground railroad stations having at least two stories, it is desired to avoid a need for excavating an open pit and to minimize the handling of material. This is accomplished in that the cavity is excavated and lined in a two consecutive stages. In the first stage, two laterally spaced apart galleries are driven in the longitudinal direction of the cavity by a mining technique in the region of a top segment of the desired cavity and are formed each with an outer side face, which constitutes a portion of a side face of said top segment. Only one of said galleries is driven at any given time in any given cross-section of said top segment. Each of said galleries is provided on said outer side face with a supporting permanent first lining. The ground between said two galleries is removed to complete the excavation of said top segment.