Stud Welds Secure Bridges in Transportation Infrastructure
For eons, man has built bridges over waterways and canyons to get to the other side. The earliest bridges were simple support beams such as tree trunks or rock slabs pushed out to cross a narrow stream bed. Over time, early bridge “engineers” extended the length of the bridge span by creating rope bridges and suspending them across the gap between two support structures. “Clapper” bridges were built by piling a stack of stones into a pier shape and dragging a wood or stone deck over it to create the crossing. The Romans perfected the art of arch bridges, stringing a series of stone arches from one end of the span to the other and laying the deck over the top of them all. Many Roman bridges are still in use throughout Europe, centuries after their construction.
Modern bridge building is based on the principles of compression and tension that are evident in all bridges, but modern materials and designs allow for longer spans and beautiful profiles. Today’s bridges are built with steel, which was introduced in the 1800s. Early welding techniques were developed to connect steel pieces to each other and were used extensively in building the bridges of the 19th- and early-20th centuries. The introduction of stud welding in the 1930s created the opportunity to build even longer, stronger bridges, and most of the bridges built since the mid-20th century are stronger and sturdier because of the stud welds that connect their separate elements together.
Bridges marry forces
Inside every bridge are individual elements working together to manage the dueling forces of tension and compression that are created by the bridging structure. Ensuring that all the separate elements are securely connected to each other reduces the possibility that too much tension or compression in any aspect of the bridge will cause it to fail.
Stud welds are essential elements in many of the components that make up today’s modern bridge designs. At each end of the bridge, stud welded headed anchors are used to ensure the bridge is securely attached to and within the stone or concrete piers that connect the bridge to the land. Stud welded deformed bars are used in place of headed anchors when the bridge anchor application requires a more complex configuration. Across the deck of the bridge, studs welded to steel I and U beams provide fasteners for the concrete slab, and marry the two materials – steel and concrete – into the composite structure that carries the bridge load. Threaded studs can be welded onto any metal surface in, on, and around the bridge to provide the foundation for windows, columns or other design components.
All Studs used in bridges are buried in concrete. The strength created by embedding stud welds into today’s bridges offers long-term stability and reliability to these integral aspects of today’s complex transportation infrastructure.