32 Damage to concrete structures
the pendulum pillars failed, leading to a load increase in the other pendulums, which in their turn failed. Due to the failure of the tensile pendulum
pillars, a moment redistribution occurred in the main span of the bridge,
leading to values higher than the design value. As a consequence, the main
span also failed, ending in the complete collapse of the Melle Bridge.
In summary, a design detail (the hinges) indirectly caused the collapse
of the bridge. Unfortunately, the bridge seemed not very robust. Although
the bridge was hyperstatic (statically indeterminate), failure of the pendulums immediately provoked failure in the main span, giving a nice but
Figure 2.3 Picture of the tensile pendulum pillars (after failure).
Figure 2.2 Schematic view of the Melle Bridge, and some details (tensile pendulum pillar
and hinge).