Doubly prestressed roof-ceiling construction wiht grid flat-soffit for extremely large spans

摘要

The doubly prestressed roof-ceiling construction with grid flat soffit for extremely large-span is prefabricated element intended for assembling roofs of extremely large-span buildings with flat soffit. The construction comprises the grid soffit construction (1) and the upper concrete girder (2) of a modified "T" shaped or of an inverse "V"-shaped cross section, interconnected by slender steel pipe-rods (3) that stabilize the upper girder (2) against lateral buckling. The empty openings within elements of the horizontal grid (1) are fulfilled with plates (6) wherewith a flat soffit is achieved. The construction is prestressed by the double prestressing. The grid-soffit (1) is prestressed centrically and the upper girder (2) is prestressed by the wedge (5) at the midspan.