Handbook for Bridge Inspections - TSP2

load Bearing Cables
• Broken strands. A cable is most subject to broken strands around
the clamps, saddles and anchorage caps. Broken strands can be
identified by longitudinal cracks in the painted surface along the
edges of the broken strands. New brea ks should be marked on
the sketch by specifying the cable number and the approximate
distance from the tower, suspension rods or similar parts.
• Corrosion. Cables should be checked fo r external corrosion and
signs of internal corrosion. This is especially the case with
unprotected cabl es. One indication of internal corrosion can be
an increase in cable diameter.
• Wear and tear/chaffing. Cables are often subj ected to wear and
tear or chaffing around the suspension rod clamps if the suspen
sian rods are hanging out of line.
• Check whether any of the spinning material has begun to leak
out of the inner cable.
• The condition of the surface treatment should be evaluated.
• Check whether there has been any slipping between cables and
their saddles.
• Packing around the saddl es. Ensure that the cables are compl e
tely surrounded by packing material if this has been used and
that the fasteners are in good condition. The packing material
should be soft and elastic and bear no signs of cracks or other
damage.
Figllre 6. 5- /: Broken Strands of a Cable
Saddles/ Bearings of
Main Cables
Anchorage Caps
• Loose/missing bolts, nuts or clamp plates
• Movement
• Cracks
• Corrosion damage
• Condit ion of the surface treatment
• Birds' nests or other forms of surface soiling
• Check that the anchorage caps arc correctly seated on their stays
and that the tangents of the cabl es fonn the correct angles.
• Check whether the cement grouting in the joints betwcen cables
and cable heads is still intact. The grouting should be removed
from a couple of the cable heads of each anchorage. If corrosion
Handbook for Bridge Inspections 75