Christopher Orcutt ; William D. Cook ; and Denis Mitchell, M.ASCE
Abstracts:Four variable-depth pier cap beams were constructed and tested. These specimens were designed to have reinforcement details that had similar features to two different types of pier cap beams used in the Champlain Bridge in Montréal, Canada. The objectives were to examine the behavior of variable-depth cap beams at service loading and at failure to analyze the effectiveness of crack control reinforcement and inclined reinforcement, as well as to investigate the influence of added external horizontal post-tensioning. The observed cap beam responses were compared with two prediction models: sectional analyses and nonlinear finite-element analyses. The amount of crack control reinforcement was important in controlling crack widths at the service load level. The inclined shear reinforcement was found to be effective in resisting shear. Horizontal post-tensioning was effective in reducing crack widths and increasing the overall stiffness of the cap beams but did not lead to significant increases in shear strength. Failure shears predicted by the sectional analyses were conservative. Nonlinear finite element analyses gave good predictions of the complete behavior and strength of the cap beams.
Shi-Zhi Chen ; Gang Wu ; De-Cheng Feng, A.M.ASCE ; Zhun Wang ; and Xu-Yang Cao
Abstracts:Highway bridges are vital infrastructure engineering whose safety severely influences the safety and stability of society. Damage identification, as the core part of structural health monitoring, plays an essential role in highway-bridge maintenance to help detect potential damage. There have been many studies conducted, with various damage identification methods proposed. However, there are still several problems with the durability of sensors and the reliability of methods, such as the issue of false alarm. Under this background, this paper proposed a multi-cross-reference method for highway-bridge damage identification method utilizing long-gauge fiber Bragg-grating (FBG) sensors. Through several numerical simulations and on-site testing, its feasibility under various conditions was verified. The results demonstrated that through this method the location of damage can be accurately identified with error of less than 5% in identified damage extent.