Handbook for Bridge Inspections - TSP2

9.2 CONCRETE ELEMENTS
202 Movement of Concrete Element
Description
The movement of bridge elements away from their original position, e.g. horizontal disp lacement
or rotation of abutment , piers or parts of the superstructure. Evidence of movement can o ften be
seen in bearings and joint gaps.
Cause of Damage
... Design fau lts - overestimation of the ground's carrying capacity; earth pressure underestimated .
... Materia l defects - incorrect materials for the infill.
... Construction fau lts - foundations not constructed as designed .
... Loads impact from traffic.
• Inadequate day-ta-day operation/maintenance - absence of cleaning measures for joints .
... Accident impact, e.g. flooding or traffic impacts.
Current Measurements
'" Measuring th e movements.
Degree of Damage/Consequences
The degree of damage should be fixed based on the size and probable development of the movement.
Please note that movement is more cri tical for inclined than straight bridges because of the
sideways di splacement of the superstructure.
Extreme movements can affect the carrying capacity, but nonnally it is the maintenance costs
which are influenced. Protruding edges along the kerb may affect traffic safety.
Conditions which trigger Maintenance
These should be assessed for each particular case and wi ll often depend on the relationship between
the move ments whi ch have come to light and the capacity of the bearings and possibl y of the joint
constructions. Furthermore the situation may depend on whether protruding edges represent a
danger to trafiic.
Actions
• Cleaning joints
• Jacking up and adjusting bearings and possibly also building them up
• Replacement of infillmaterial with lighter ones in order to reduce the pressure onthe ground.
148 Handbook for Bridge Inspections