Pre-stressed Concrete

The SOFiSTiK program system enables to analyze and design pre-stressed concrete bridges in one continuous process, starting with the planning stage up to the final check analysis. For the analysis model one can choose between a frame system as well as a finite element system. During this analysis of the pre-stressed cable geometries, for the 3D routes of pre-stressed cables, the pre-stressed forces are also calculated with the consideration of the stressing procedure and the friction losses. An eccentric position of the pre-stressed cable in the conduit can be considered. The effect of the pre-stress for truss structures is determined as a statically designated pre-stress due to curvature loads and it is stored as a load of a load case.  For folded and slab structures, the program analyzes the pre-stress of a penetrated element and stores it strand for strand as an element stiffness. In the finite element method, the pre-stress stiffness is realized by means of a special pre-stressed element. The element mesh is not imposed to additional restrictions. The geometry of the tension strand within a QUAD element is a 3D cubic parabola between the penetration points of the side surfaces of the elements. Here, construction stages such as creeping and shrinking can be considered, even within a cross section.