Bridge Failure
Bridge Failures:
Donan Engineering’s team of professional forensic engineers is experienced at performing studies of bridge failures. Bridges are generally large, complex structures that provide a sufficient means to pass over a roadway, waterway, railway, or other structure. As engineering design evolves, the materials and techniques are sharpened to produce bridges with longer spans and smaller sections.
After the failure or collapse of a bridge, a bridge study is necessary to determine the cause and origin of the failed component. The nature of bridge failures varies widely because of the various types and uses of bridges that are constructed. Although it is not possible to describe here all of the potential failures in bridges, some of the common areas of investigation are:
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Overload
A driveway bridge collapsed when a 10-ton dump truck was hauling debris off of a construction site. The wood decking and telephone pole timber beams could not support the weight of the truck. Load limits are usually posted before highway and federal bridges that may be found insufficient for heavier vehicles. Usually special permits and routes are required for vehicles that may carry abnormally heavy loads. |
Collision
This highway bridge was obstructed by equipment that was being transported by a truck. The structural damage was mostly sustained to this fascia (edge) pre-stressed concrete girder. The pre-stressed strands, stirrups, and other steel reinforcement were exposed when the concrete was knocked loose. Some of the pre-stressed strands can be seen unraveled in the photograph. Elevations of the beams were checked and determined suitable for predated values. Repairs were recommended, and the bid provided by a bridge contractor was reviewed for cost-analysis. |
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Construction
This wood truss bridge collapsed during erection. The bridge was designed as a closed bridge with a roof and siding on the exterior. Once completed, the roof and siding would act as diaphragm and provide lateral stability for the structure. During erection, no lateral bracing was installed to prevent the buckling of the top chord truss; thus, the bridge collapsed because it was not adequately braced during erection. |
These are just a few examples of bridges that Donan Engineering’s professionals have inspected. It is sometimes difficult to determine the mode of failure or collapse of any bridge, let alone such large, complex structures. Donan Engineering has professionals with the skills and expertise to get to the bottom of these complex investigations.