Recovery and Structural Repair
The product of a collision in the Nantoco bridge, located in Region III 777 Km, was commissioned urgently for analysis.
The bridge is composed of prestressed beams which suffered several cutting cables.
Within the repair alternatives were:
- External post-tensioning. In this case the solution is to restore the tension of the cables cut through a mechanism of external post-tensioning.
- Generate symmetric beam by further cutting of cables. This solution does not restore the original strength of the beam, but eliminates probable deformation of the beam in its secondary. This solution has already been ruled out for reasons of calculation where the beam was determined that 18.5 requires cables to withstand design loads.
- Ability to recover lost wiring cut bending of the beam by carbon fiber sheets. In addition, a bracing system between beams is proposed, as a security measure against possible movement of the beam in its secondary.
These solutions are related to the capacity and structural stability. For our engineers, the third option is the most optimal from a structural point of view and repair, and to solve the problems of strength and stability of the beams, and shortens repair them.
Finally, it was necessary to include repair concrete damaged by the stroke, mainly the beam edge, which further shear reinforcement with carbon fiber is placed to ensure that contribute to cutting temper resistance, which could eventually lose some of their strength capacity.
Project proposal repair and structural recovery.
Overall, it was proposed to restore the lost capacity by cutting flex cables, with using carbon fiber sheets, Adcos Carbostrip.
In addition, it was proposed to run between damaged bracing beams, thus eliminating the chance of warping of beam.
Finally, we must make concrete repair, filling with concrete or other high strength mortar. In addition, a confinement with carbon fiber blankets Adcos Carbotex in the repaired area was conducted, to ensure the monolithic area and some possible loss of shear strength of the section.