Assessment and rehabilitation of a deteriorated heat pipeline overpass

A deteriorated heat pipeline overpass was subjected to assessment and rehabilitation. Lack of technical documentation, increased loading, and changing design codes had to be taken into consideration. The numerous damages and their origin were identified. Special attention was paid to corrosion at the connection zones, being the result of inadequate paint coating, aggressive environment, and leakages for technological installations. The structure was originally designed according to the design code PN-62/B-03200 from the 1960’s using the permissible stress method. After rehabilitation it was supposed to fulfil current requirements of Eurocodes. Static strength analyses were performed for both codes and the differences between them were noted. The methods for rehabilitation were limited by the requirement of limited intervention and maintaining the structure under service. The applied solution for the strengthening in form of the steel profiles welded to the existing structure is described.