Design and analyse prestressed concrete: pretensioned and post-tensioned beams, precast girder bridges with a composite deck, prestressed columns, square precast piles and spun hollow-core PHC piles. Lay out the strands, choose the tendon profile, and see the losses, the stresses at every stage, an interactive stress build-up and Magnel diagram, ultimate strength, shear, camber and traffic deflection — with drawings, a 3D model, the stressing and erection sequence, quantities and a design Excel workbook.
Scope & limitations
Preliminary design for feasibility and education. Use the strand and anchorage manufacturer's data, a time-dependent analysis, the full traffic models and a grillage for bridges, and wave-equation analysis with PDA for driven piles; have the design checked by a qualified engineer.
What the prestressing studio does
Pick the element — a pretensioned or post-tensioned beam, a multi-bay, multi-storey post-tensioned frame, a precast girder bridge with a composite deck, a prestressed column, a square precast pile or a spun hollow-core PHC pile. Sections are built from real shapes (I-girders, tees, boxes, troughs, rectangles, hollow circles) with strands laid out row by row; the tendon follows a straight, harped, debonded or parabolic profile.
The studio works out the losses (elastic shortening, friction and draw-in, relaxation, shrinkage and creep), the fibre stresses at transfer, deck pour and service along the span against the adopted limits, the number of strands needed, an interactive stress build-up with sliders and a Magnel diagram you can click, ultimate strength by strain compatibility, shear, camber and traffic deflection. Bridges get a design vehicle and lane load with Courbon distribution; columns and piles get N–M interaction with the prestrain, and piles get handling and driving checks. Everything flows into an A3 drawing set, a 3D model, the casting, stressing and erection sequence with hold points, quantities, programme and a design Excel workbook with drawings and buttons.
The post-tensioned frame element designs a multi-bay, multi-storey frame of post-tensioned T-beams on reinforced concrete columns. The tendon runs continuously through every span on a parabolic profile; friction, wobble and draw-in are traced along its length and elastic shortening, shrinkage, creep and relaxation give the transfer and long-term force in each span. The tendon is replaced by its equivalent loads and the whole frame is solved by the stiffness method, which gives the total prestress moment, the secondary (hyperstatic) moments and the precompression lost into the columns. Dead and patterned live load are added for the stress checks at transfer and service, strength with the secondary moments included, shear with the vertical tendon component, long-term deflection and column N–M strength. Output: frame elevation with tendons, moment and stress diagrams, beam sections, tendon force and set-out table, column interaction, a 3D model, the floor-cycle sequence, quantities and the design workbook.
Beams, girder bridges, columns, square and PHC piles
Losses, stages, interactive Magnel diagram, ultimate and shear