曲线梁桥预应力钢筋合力重心线计算方法

A Method of Calculating the Center Line of Gravity of Prestressing Force of Steel in Plane Curved Girder Bridges

The Transformation theorem of the center line of gravity of the prestressing force of steel (i. e., the c.g.s.-line) with preserving the compressive line (i.e, the C-line) is extended and used in the design of plane curved girder bridges with multi-main girders and variable prestressing force. For a plane curved girder bridge with a known bending moment envelope, if a resonable curve in the limiting zone of C-line is selected as a predetermined C-line, a corresponding c.g.s.-line can be uniquely obtained by the method. This c.g.s.-line produces a C-line which is close to the one selected before in the meaning of least square. So the method ensures that there will be no tensile stress or only a tensile stress smaller than the alowable one in concrete.