Structural analysis of cracked concrete piers and proposed rehabilitation using CFRP rods.

摘要

All the concrete piers on 8th Avenue Viaduct, Denver, CO have shown an extensive amount of cracking, both vertically and diagonally. A pier by pier inspection performed in 2015 revealed that the cracks were expanding. Two bi-axial tilt-meters were installed on the fixed pier (Pier 11) to measure the rotation in both directions. A 3d model using ANSYS Mechanical APDL 16.0 software of the viaduct was built and calibrated using the field measurements. A separate fine model of pier 18, where cracks were expanding the most, was also constructed using the same software, which included the reinforcement detailing and the non-linear properties of the material. Dead, live and temperature loads were all applied on the general model under Strength I limit state and the resulting forces transferred to pier 18 were obtained and then applied onto the fine model of the pier, in order to perform non-linear finite element analysis. As expected, the model showed extensive cracking similar to the actual condition of the pier. A rehabilitation system of CFRP rods was proposed and tested on the model, showing very favorable results. The author of this thesis recommends this repair be used for all the piers on 8th Avenue Viaduct.