摘要: |
In 2003, there were 38 metal truss bridges 50 years of age or older remaining on the State of Texas highway system. Of these 38 bridges, 33 are listed in the National Register of Historic Places. Many of these bridges do not meet current design criteria for rehabilitation due to narrow deck widths, low vertical clearance, and substandard load capacity. In addition, the existing bridge railing systems on these bridges have not been shown to meet the current requirements for safety and strength. This project addressed the design and performance of acceptable traffic railings for existing and new truss bridges in Texas. Specific objectives were to: (1) design/develop a retrofit railing for low- speed applications on the Roy B. Inks Bridge in Llano, Texas; (2) design/develop a retrofit railing for high-speed applications on the U.S. 281 bridge over the Brazos River in Palo Pinto County, Texas; (3) identify criteria which can serve as a basis for design exceptions; and (4) design/develop a traffic railing for new truss bridges. |