Civil Engineering September 2021 | Vol 29 No 8

Civil Engineering September 2021 29 Each of the defects listed in the 2016 visual bridge inspection was investigated on the point cloud model. The following section shows an image of one of the defects on each of the bridges as an example and includes a discussion on the other defects. Railway Bridge defects Identified defect: interlocking blocks missing The missing interlocking blocks are clearly visible on the abutment as seen in Figure 6. Other defects: Illumination underneath the bridge was limited and the images captured were too dark to identify the abutment-seating crack below the bearing. It appears as if herbicide has been applied to the abut- ment protection works since 2016, as only slight vegetation growth is visible. River Bridge defects Identified defect: pier spall Spalling at the top of the pier is clearly visible as seen in Figure 7. Other defects: The illumination underneath the bridge was limited and the images captured were too dark to identify the crack in the abutment wall. The debris and vegetation in the waterway were clearly visible and this prevented the drone pilot from capturing images underneath the bridge. It was clear that the scuppers need to be extended and the handrails repainted. Vegetation on the road surface along with the hidden guardrail were also visible. Figure 6 Identified defect: interlocking blocks missing (Railway Bridge) Figure 7 Identified defect: pier spall (River Bridge)