ABSTRACT
The bridge structure was monitored since 1993, annual increment of midspan deflection was about 8 mm. Total differences between the theoretical road level and the result of measurement immediately before start of remediation were about 140 mm. Some probable reasons of this phenomenon can be summarized below:
– lower value of Young’s modulus of concrete – the shear effects (incl. the shear lag) on deflection
in the design stage were ignored – wrong function for time prediction of creep – unexpected higher influence of relaxation of pre-
stressing steel
During remediation, the stiffness of the structure was increased and an additional upward directed relieving loading were provided by additional external prestressing tendons-Fig. 2.
