Structural damage from overload
Increasing the spacing between adjacent supports creates longer cantilevered sections. Under static loads, the sudden increase in bending moment in the middle section can lead to sagging and deformation. Long-term use can cause cracking in the bridge welds and loosening of bolts. Dynamic seismic loads can exacerbate the swaying of the cantilevered sections, exceeding the material fatigue limit and ultimately causing the bridge to fracture and the supports to fall off.
Failure of seismic performance
With fewer support points, earthquake impact forces are directly transmitted to the connections between the bridge and the building structure (such as embedded components in walls and floor slabs), potentially causing pullout and damage to embedded components, leading to overall bridge displacement and collapse. This can also damage other mechanical and electrical equipment, causing secondary hazards such as electric shock and fire.
Failure of acceptance and rework
The spacing between seismic supports is a key factor in project acceptance. If the actual spacing exceeds the design and the requirements of the "Code for Seismic Design of Building Mechanical and Electrical Engineering," the project will be deemed unqualified and require dismantling the existing supports and re-adjusting them, increasing material and labor costs and delaying the overall construction schedule.
Hidden dangers in later operation and maintenance
Deformation of the bridge causes uneven stress on the internal cables, which may damage the cable insulation layer and cause signal transmission failures in the weak current bridge. In addition, it is difficult to carry out routine inspections and maintenance on the deformed bridge, which greatly increases the probability of equipment failure.
