Seawall Survey Asbuilt

Accurately surveying seawalls has often been a challenging exercise, especially where the coastal environment is hazardous. With the advent of UAVs (drones) we can now safely survey great detail, both the physical shape and dimensions of the wall and rocks but also gather high resolution imagery. Both of these sources of information give planners and engineers extremely valuable data to enable all types of remediation and strengthening design.

If the seawall is exposed and the capture can be completed at low tide then photometric mapping, that's mapping via triangulation using many overlapping photos. However, in situations whereby there is grass, scrub or overhanging trees covering the seawall then LiDAR is a more suitable approach. LiDAR uses active light pulses to penetrate through the vegetation and more accurately map the surface below.

The data is post-processed and triangulated for import into 3D software, or CAD such as 12D or Civil3D. From here, analysts can generate accurate cross-sections, calculate volumes or add supplementary information such as marine or geotechnical survey data of the subsurface or land abutting the seawall.

3D GIS and visualisation software is also very beneficial in establishing how the seawall interacts with the surrounding geography, structures such as coastal roads and railways, while also allowing the generation of view sheds and videos for demonstrating issues and proposed resolutions.