Final answer:
Engineers add dampers, cable-stays, and other design features to prevent torsion in suspension bridges. Engineers prevent torsion in suspension bridges by using stiffening trusses or box girders, carefully anchoring cables, and incorporating wind-resisting elements.
Step-by-step explanation:
Engineers add various components to suspension bridges to prevent torsion from happening. One important addition is the use of dampers, which are devices that absorb energy and reduce vibrations caused by wind or other external forces. These dampers help to stabilize the bridge and prevent torsional movements.
Another addition is the inclusion of cable-stays in the bridge design. Cable-stays are cables that connect the bridge deck to the towers and help to distribute the weight of the bridge evenly. This reduces the risk of torsion and ensures the stability of the bridge.
Additionally, engineers may incorporate design features such as aerodynamic shapes and wind deflectors to minimize the impact of wind on the bridge, further reducing the chances of torsional movements.
Engineers prevent torsion in suspension bridges by using stiffening trusses or box girders, carefully anchoring cables, and incorporating wind-resisting elements. Thermal stress is also managed by accounting for expansion and contraction in material design.
To prevent torsion and ensure the stability of suspension bridges, engineers incorporate several design features. One significant addition aimed at mitigating torsion is the use of deep and stiff truss structures or box girders along the roadway, which help distribute the forces evenly, reduce twisting, and increase the overall rigidity of the bridge deck. Additionally, the strategic placement and anchoring of the main cables, along with the use of wind-resisting elements like aerodynamic bridge decking, help prevent the bridge from undergoing resonant oscillations, which contributed to the historical collapse of the Tacoma Narrows Bridge in 1940.
Engineers also consider the effects of thermal expansion in their designs. When constructing large infrastructure like highways or bridges, space is often left between components, or the materials are selected based on their similar thermal expansion coefficients, allowing for free expansion and contraction without accumulating thermal stress that can cause cracks or distortions.
The tragic examples of the Tacoma Narrows Bridge and the Silver Bridge underscore the critical importance of comprehensive design processes that incorporate advanced mathematical and scientific analysis to ensure long-term structural integrity and safety.