In 2012 the 36,5 km long section of the expressway S7 between the Polish villages Paslek and Milomlyn was completed. The road alignment partially crossed up to 11 m thick organic soil formations showing a consistency in the range of plastic to soft plastic. Therefore subsoil improvement measures such as unreinforced full displacement concrete piles and a geotextile reinforced embankment were designed by the owner. Despite the executed soil improvement measures only seven months after the release for traffic settlements up to 70 cm occurred along a 35 m long section of the expressway. Utilizing 2D Finite Element Method as well as comparative calculations using conventional methods a failure back analysis was conducted by Zentrale Technik - Technical Office Vienna. The article at hand focusses on the executed assessment of damage as well as on the results of the performed failure analyses and furthermore the elaborated restoring concepts and the restoring measure executed on site are presented.