LiDAR Survey for Geotechnical Assessment

High resolution Drone LiDAR survey of Illawarra Escarpment for geotechnical assessment and road stabilisation design

PROJECT OVERVIEW

One of the main arterial roads that descends the Illawarra escarpment includes several known geotechnical risk sites including rockfalls, shallow landslides and embankment failures. Drone LiDAR survey of the road corridor and adjacent slopes was required to inform geotechnical assessment and stabilisation design. The steep and heavily vegetated nature of the site precluded access for conventional survey methods, beyond the extent of the immediate road corridor, and additional information was required by engineers and geologists working on the project.

PROJECT SCOPE
Drone LiDAR
Drone LiDAR
Geotechnical Assessment
Geotechnical Assessment
Digital Terrain Modelling
Digital Terrain Modelling
DIODRONE SOLUTION

Diodrone developed a survey solution which utilised drone LiDAR to develop a high-fidelity digital terrain model (DTM). The temperate rainforest, typical of the Illawarra Escarpment, had a very dense vegetation canopy and so drone LiDAR capture was carefully planned to maximise ground returns and point cloud density.

Diodrone’s LiDAR capture achieved an average point density of 500 points/m2 and provided sufficient ground information for terrain modelling, even in areas of the extremely dense vegetation. When assessed against a network of control points established throughout the road corridor, Diodrone’s deliverables achieved an accuracy of better than 50mm RMSE and included high resolution topographic detail of slopes which are otherwise inaccessible and unknown.

Despite a dense vegetation, Diodrone was able to achieve high resolution topographic detail at better than 50mm accuracy.

High resolution drone LiDAR was able to penetrated heavily vegetated terrain to develop a detailed point cloud and digital terrain model
High resolution LiDAR was able to penetrate even the thickest area of rainforest canopy, which after a detailed point cloud classification, was used to develop a digital terrain model of the survey area.
 
LiDAR derived digital terrain model combined with conventional survey
The LiDAR derived digital terrain model was combined with a conventional road corridor survey to provide designers with the most accurate and reliable surface model of the road corridor and adjacent slopes.