Bridges
- Publication no: ABC2017-134-17
- Published: 26 April 2017
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The change in title of the 2004 Australian Standard AS 5100 Part 7 Rating to the revised AS 5100 Part 7 Bridge Assessment is symbolic of the change of focus of this part of the standard. The 2004 version of the standard had an objective “to calculate the load rating factor of a bridge for a nominated rating vehicle”. The new revision provides a means of assessing all vehicle types. This changes is in response to the need to manage heavier vehicles using existing bridges, a diverse range of vehicles and ageing infrastructure in a fiscally constrained environment.
It is critical to understand that the method of assessing the capacity of existing bridges is different to designing a new bridge. This revision of the standard clarifies the difference between bridge design and bridge assessment. The new AS 5100 Part 7 has clearly defined the load cases that are to be included in bridge assessment. There is a flowchart to explain the procedures. For the first time, Part 7 discusses vehicles such as cranes and Heavy Load Platforms (HLP). Note, only trucks were discussed in the 2004 version. Load factors have also been customised to a range of actual vehicles. The difference between actual vehicles and the design loads in standards is clarified.
To assist the designer, there is a summary of material properties from past standards for materials that have been historically used. This is to reduce the considerable effort required to search for this information. For materials such as cast iron and wrought iron, some actual test results, as well as, methods for assessing materials are provided.
The revision to this standard are needed by both the engineering profession and freight industry to assess the structural capacity of bridges for a wide and diverse range of conditions. It provides engineering rigor and consistency.