| 摘要 |
<p>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.</p> |
