It’s my opinion that third party structures surveys for years have been let’s say Tick Box!!!!!
Failure of contracting quality of work comes to mind!
In-house surveys have the same problem.
I worked on tunnel assessments for the underground back in the 2000s. Inspections were carried out by inspectors in full accordance with LU inspection standards with the same routine applied year after year. But it didn't really get any engineering input. Two examples stand out:
1. The tunnel lining segments were inspected, even the number of missing bolts connecting the tunnel lining segments were counted and recorded, but structural beams supporting cross-passage openings were not looked at. We found a beam which had crushed at the ends by 40mm, bolts in the segments above sheared off, web bent and sheared. Thankfully the cross-passage wasn't needed so it was propped and then filled in with concrete.
2. Odd spalling patterns found on some concrete linings. Were being recorded and could have been construction defects, but we thought it was worth looking into. Turned out after some investigation, analysis and specialist testing that the whole lining was failing in service. "Do we need to shut the Jubilee line?" asked the Tubelines safety board. We managed to avoid that but the whole stretch of lining got replaced.